Functional characterization of reductive dehalogenases by using blue native polyacrylamide gel electrophoresis

Dehalococcoides mccartyi strains are obligate organohalide-respiring bacteria harboring multiple distinct reductive dehalogenase (RDase) genes within their genomes. A major challenge is to identify substrates for the enzymes encoded by these RDase genes. We demonstrate an approach that involves blue native polyacrylamide gel electrophoresis (BN-PAGE) followed by enzyme activity assays with gel slices and subsequent identification of proteins in gel slices using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). RDase expression was investigated in cultures of Dehalococcoides mccartyi strain BAV1 and in the KB-1 consortium growing on chlorinated ethenes and 1,2-dichloroethane. In cultures of strain BAV1, BvcA was the only RDase detected, revealing that this enzyme catalyzes the dechlorination not only of vinyl chloride, but also of all dichloroethene isomers and 1,2-dichloroethane. In cultures of consortium KB-1, five distinct Dehalococcoides RDases and one Geobacter RDase were expressed under the conditions tested. Three of the five RDases included orthologs to the previously identified chlorinated ethene-dechlorinating enzymes VcrA, BvcA, and TceA. This study revealed substrate promiscuity for these three enzymes and provides a path forward to further explore the largely unknown RDase protein family.

Electron donor availability for microbial reductive processes following thermal treatment

Thermal treatment is capable of removing significant free-phase chlorinated solvent mass while potentially enhancing bioremediation effectiveness by establishing temperature gradients in the perimeter of the source zone and by increasing electron donor availability. The objectives of this study were to determine the potential for enhanced reductive dechlorination activity at the intermediate temperatures that establish in the perimeter of the heated source zone, and to evaluate the effect of electron donor competition on the performance of the microbial reductive dechlorination process. Microcosms, constructed with tetrachloroethene- (PCE-) and trichloroethene- (TCE-) impacted soils from the Great Lakes, IL, and Ft. Lewis, WA, sites were incubated at temperatures of 24, 35, 50, 70, and 95 °C for 4 months. Reductive dechlorination did not occur in microcosms incubated at temperatures above 24 °C even though mesophilic PCE-to-cis-1,2-dichloroethene dechlorinators were present in Ft. Lewis soil suggesting electron donor limitations. Five days after cooling the microcosms to 24 °C and bioaugmentation with the methanogenic, PCE-to-ethene-dechlorinating consortium OW, at least 85% of the initial PCE and TCE were dechlorinated, but dechlorination ceased prior to complete conversion to ethene. Subsequent biostimulation with hydrogen gas mitigated the dechlorination stall, and conversion to ethene resumed. The results of this study demonstrated that temperatures >35 °C inhibit reductive dechlorination activity at the Great Lakes and Ft. Lewis sites, and that the majority of reducing equivalents released from the soil matrix during heat treatment are consumed in methanogenesis rather than reductive dechlorination. These observations suggest that bioaugmenting thermal treatment sites with cultures that do not contain methanogens may allow practitioners to realize enhanced dechlorination activity, a potential benefit of coupling thermal treatment with bioremediation.

Solution and microbial controls on the formation of reduced U(IV) species

Reduction of U(VI) to U(IV) as the result of direct or indirect microbial activity is currently being explored for in situ remediation of subsurface U plumes, under the assumption that U(IV) solubility is controlled by the low-solubility mineral uraninite (U(IV)-dioxide). However, recent characterizations of U in sediments from biostimulated field sites, as well as laboratory U(VI) bioreduction studies, report on the formation of U(IV) species that lack the U═O(2)═U coordination of uraninite, suggesting that phases other than uraninite may be controlling U(IV) solubility in environments with complexing surfaces and ligands. To determine the controls on the formation of such nonuraninite U(IV) species, the current work studied the reduction of carbonate-complexed U(VI) by (1) five Gram-positive Desulfitobacterium strains, (2) the Gram-negative bacteria Anaeromyxobacter dehalogenans 2CP-C and Shewanella putrefaciens CN32, and (3) chemically reduced 9,10-anthrahydroquinone-2,6-disulfonate (AH(2)QDS, a soluble reductant). Further, the effects of 0.3 mM dissolved phosphate on U(IV) species formation were explored. Extended X-ray absorption fine structure (EXAFS) spectroscopy analysis demonstrated that the addition of phosphate causes the formation of a nonuraninite, phosphate-complexed U(IV) species, independent of the biological or abiotic mode of U(VI) reduction. In phosphate-free medium, U(VI) reduction by Desulfitobacterium spp. and by AH(2)QDS resulted in nonuraninite, carbonate-complexed U(IV) species, whereas reduction by Anaeromyxobacter or Shewanella yielded nanoparticulate uraninite. These findings suggest that the Gram-positive Desulfitobacterium strains and the Gram-negative Anaeromyxobacter and Shewanella species use distinct mechanisms to reduce U(VI).

Stable carbon isotope enrichment factors for cis-1,2-dichloroethene and vinyl chloride reductive dechlorination by Dehalococcoides

Compound-specific stable isotope analysis (CSIA) is a promising tool for monitoring in situ microbial activity, and enrichment factors (ε values) determined using CSIA can be employed to estimate compound transformation. Although ε values for some dechlorination reactions catalyzed by Dehalococcoides (Dhc) have been reported, reproducibility between independent experiments, variability between different Dhc strains, and congruency between pure and mixed cultures are unknown. In experiments conducted with pure cultures of Dhc sp. strain BAV1, ε values for 1,1-DCE, cis-DCE, trans-DCE, and VC were -5.1, -14.9, -20.8, and -23.2‰, respectively. The ε value for 1,1-DCE dechlorination was 48.9% higher than the value reported in a previous study, but ε values for other chlorinated ethenes were equal between independent experiments. For the dechlorination of cis-DCE and VC by Dhc strains BAV1, FL2, GT, and VS, average ε values were -18.4 and -23.2‰, respectively. cis-DCE and VC ε values determined in pure Dhc cultures with different reductive dehalogenase genes (e.g., vcrA vs bvcA) varied by less than 36.8 and 8.3%, respectively. In the BDI consortium, ε values for cis-DCE and VC dechlorination were -25.3‰ and -19.9‰, 31.6% higher and 15.3% lower, respectively, compared to the average ε value for Dhc pure cultures. As cis-DCE and VC ε values are all within the same order-of-magnitude and fractionation is always measured during Dhc dechlorination, CSIA may be a valuable approach for monitoring in situ cis-DCE and VC reductive dechlorination.

Effects of elevated temperature on Dehalococcoides dechlorination performance and DNA and RNA biomarker abundance

Coupling thermal treatment with microbial reductive dechlorination is a promising remedy for tetrachloroethene (PCE) and trichloroethene (TCE) contaminated source zones. Laboratory experiments evaluated Dehalococcoides (Dhc) dechlorination performance, viability, and biomarker gene (DNA) and transcript (mRNA) abundances during exposure to elevated temperatures. The PCE-dechlorinating consortia BDI and OW produced ethene when incubated at temperatures of 30 °C, but vinyl chloride (VC) accumulated when cultures were incubated at 35 or 40 °C. Cultures incubated at 40 °C for less than 49 days resumed VC dechlorination following cooling; however, incubation at 45 °C resulted in complete loss of dechlorination activity. Dhc 16S rRNA, bvcA, and vcrA gene abundances in cultures showing complete dechlorination to ethene at 30 °C exceeded those measured in cultures incubated at higher temperatures, consistent with observed dechlorination activities. Conversely, biomarker gene transcript abundances per cell in cultures incubated at 35 and 40 °C were generally at least one order-of-magnitude greater than those measured in ethene-producing cultures incubated at 30 °C. Even in cultures accumulating VC, transcription of the vcrA gene, which is implicated in VC-to-ethene dechlorination, was up-regulated. Temperature stress caused the up-regulation of Dhc reductive dehalogenase gene expression indicating that Dhc gene expression measurements should be interpreted cautiously as Dhc biomarker gene transcript abundances may not correlate with dechlorination activity.

U(VI) reduction to mononuclear U(IV) by Desulfitobacterium species

The bioreduction of U(VI) to U(IV) affects uranium mobility and fate in contaminated subsurface environments and is best understood in Gram-negative model organisms such as Geobacter and Shewanella spp. This study demonstrates that U(VI) reduction is a common trait of Gram-positive Desulfitobacterium spp. Five different Desulfitobacterium isolates reduced 100 microM U(VI) to U(IV) in <10 days, whereas U(VI) remained soluble in abiotic and heat-killed controls. U(VI) reduction in live cultures was confirmed using X-ray absorption near-edge structure (XANES) analysis. Interestingly, although bioreduction of U(VI) is almost always reported to yield the uraninite mineral (UO(2)), extended X-ray absorption fine structure (EXAFS) analysis demonstrated that the U(IV) produced in the Desulfitobacterium cultures was not UO(2). The EXAFS data indicated that the U(IV) product was a phase or mineral composed of mononuclear U(IV) atoms closely surrounded by light element shells. This atomic arrangement likely results from inner-sphere bonds between U(IV) and C/N/O- or P/S-containing ligands, such as carbonate or phosphate. The formation of a distinct U(IV) phase warrants further study because the characteristics of the reduced material affect uranium stability and fate in the contaminated subsurface.

Stable carbon isotope fractionation of 1,2-dichloropropane during dichloroelimination by Dehalococcoides populations

The isotope fractionation of 1,2-dichloropropane (1,2-D) during dichloroelimination to propene by Dehalococcoides populations was explored in laboratory experiments in order to provide data for the characterization of the fate of 1,2-D in heterogeneous subsurface systems. Compound specific stable carbon isotope analysis (CSIA) was used to determine the bulk enrichment factors (epsilonbulk), reactive position specific enrichment factors (epsilonreactive), and apparent kinetic isotope effect (AKIE) values for 1,2-D dichloroelimination in two distinct Dehalococcoides-containing cultures. The epsilonbulk factors calculated in the two cultures were statistically identical, -10.8 +/- 0.9 and -11.3 +/- 0.8 per thousand, even though the cultures were derived from geographically distinct locations. AKIE values for 1,2-D dichloroelimination assuming stepwise and concerted reaction mechanisms were approximately 1.033 and 1.017, respectively. These values are within the range of previously reported values for dichloroelimination reactions and were equivalent to values reported for biotic 1,2-dichloroethane and abiotic 1,1,2,2,-tetrachloroethane and pentachloroethane dichloroelimination reactions.

Fate of TCE in heated Fort Lewis soil

This study explores the transformation of trichloroethene (TCE) caused by heating contaminated soil and groundwater samples obtained from the East Gate Disposal Yard (EGDY) located in Fort Lewis, WA. After field samples transferring into glass ampules and introducing 1.5 micromol of TCE, the sealed ampules were incubated at temperatures of 25, 50, and 95 degrees C for periods of up to 95.5 days. Although TCE was completely transformed into cis-1,2-dichloroethene (cis-DCE) after 42 days at 25 degrees C by microbial activity, this transformation was not observed at 50 or 95 degrees C. Chloride levels increased after 42 days at 25 degrees C corresponding to the mass of TCE transformed to cis-DCE, were constant at 50 degrees C, and increased at 95 degrees C yielding a TCE degradation half-life of 1.6-1.9 years. These findings indicate that indigenous microbes contribute to the partial dechlorination of TCE to cis-DCE at temperatures of less than 50 degrees C, whereas interphase mass transfer and physical recovery of TCE will predominate over in situ degradation processes at temperatures of greater than 50 degrees C during thermal treatment at the EGDY site.

Detection and quantification of Geobacter lovleyi strain SZ: implications for bioremediation at tetrachloroethene- and uranium-impacted sites

Geobacter lovleyi strain SZ reduces hexavalent uranium, U(VI), to U(IV) and is the first member of the metal-reducing Geobacter group capable of using tetrachloroethene (PCE) as a growth-supporting electron acceptor. Direct and nested PCR with specific 16S rRNA gene-targeted primer pairs distinguished strain SZ from other known chlorinated ethene-dechlorinating bacteria and closely related Geobacter isolates, including its closest cultured relative, G. thiogenes. Detection limits for direct and nested PCR were approximately 1 x 10(6) and 1 x 10(4) 16S rRNA gene copies per mul of template DNA, respectively. A quantitative real-time PCR (qPCR) approach increased the sensitivity to as few as 30 16S rRNA gene copies per mul of template DNA but was less specific. Melting curve analysis and comparison of the shapes of amplification plots identified false-positive signals and distinguished strain SZ from G. thiogenes when analyzed separately. These indicators were less reliable when target (strain SZ) DNA and nontarget (G. thiogenes) DNA with high sequence similarity were mixed, indicating that the development of qPCR protocols should not only evaluate specificity but also explore the effects of nontarget DNA on the accuracy of quantification. Application of specific tools detected strain SZ-like amplicons in PCE-dechlorinating consortia, including the bioaugmentation consortium KB-1, and two chlorinated ethene-impacted groundwater samples. Strain SZ-like amplicons were also detected in 13 of 22 groundwater samples following biostimulation at the uranium- and chlorinated solvent-contaminated Integrated Field-Scale Subsurface Research Challenge (IFC) site in Oak Ridge, TN. The numbers of strain SZ-like cells increased from below detection to 2.3 x 10(7) +/- 0.1 x 10(7) per liter groundwater, suggesting that strain SZ-like organisms contribute to contaminant transformation. The G. lovleyi strain SZ-specific tools will be useful for monitoring bioremediation efforts at uranium- and/or chlorinated solvent-impacted sites such as the Oak Ridge IFC site.

Geobacter lovleyi sp. nov. strain SZ, a novel metal-reducing and tetrachloroethene-dechlorinating bacterium

A bacterial isolate, designated strain SZ, was obtained from noncontaminated creek sediment microcosms based on its ability to derive energy from acetate oxidation coupled to tetrachloroethene (PCE)-to-cis-1,2-dichloroethene (cis-DCE) dechlorination (i.e., chlororespiration). Hydrogen and pyruvate served as alternate electron donors for strain SZ, and the range of electron acceptors included (reduced products are given in brackets) PCE and trichloroethene [cis-DCE], nitrate [ammonium], fumarate [succinate], Fe(III) [Fe(II)], malate [succinate], Mn(IV) [Mn(II)], U(VI) [U(IV)], and elemental sulfur [sulfide]. PCE and soluble Fe(III) (as ferric citrate) were reduced at rates of 56.5 and 164 nmol min(-1) mg of protein(-1), respectively, with acetate as the electron donor. Alternate electron acceptors, such as U(VI) and nitrate, did not inhibit PCE dechlorination and were consumed concomitantly. With PCE, Fe(III) (as ferric citrate), and nitrate as electron acceptors, H(2) was consumed to threshold concentrations of 0.08 +/- 0.03 nM, 0.16 +/- 0.07 nM, and 0.5 +/- 0.06 nM, respectively, and acetate was consumed to 3.0 +/- 2.1 nM, 1.2 +/- 0.5 nM, and 3.6 +/- 0.25 nM, respectively. Apparently, electron acceptor-specific acetate consumption threshold concentrations exist, suggesting that similar to the hydrogen threshold model, the measurement of acetate threshold concentrations offers an additional diagnostic tool to delineate terminal electron-accepting processes in anaerobic subsurface environments. Genetic and phenotypic analyses classify strain SZ as the type strain of the new species, Geobacter lovleyi sp. nov., with Geobacter (formerly Trichlorobacter) thiogenes as the closest relative. Furthermore, the analysis of 16S rRNA gene sequences recovered from PCE-dechlorinating consortia and chloroethene-contaminated subsurface environments suggests that Geobacter lovleyi belongs to a distinct, dechlorinating clade within the metal-reducing Geobacter group. Substrate versatility, consumption of electron donors to low threshold concentrations, and simultaneous reduction of electron acceptors suggest that strain SZ-type organisms have desirable characteristics for bioremediation applications.

Neuroleptic-related dyskinesias in children and adolescents

BACKGROUND

Few studies have investigated the comparative risk of neuroleptic-related dyskinesias in children and adolescents receiving typical versus newer, atypical antipsychotics. This prospective study was completed to test whether clinical use of atypical antipsychotics is associated with less risk for developing neuroleptic-related dyskinesias than clinical use of typical neuroleptics in an unselected heterogeneous population of seriously emotionally disturbed youths admitted to acute residential treatment. We also tested a novel model of predictive risk for neuroleptic-related dyskinesias in children and adolescents.

METHOD

102 children and adolescents receiving typical neuroleptics, atypical antipsychotics, or the combination were studied. Youths developing neuroleptic-related dyskinesias were compared with youths free of dyskinesias over a 3-month study period on demographic, diagnostic, and treatment variables. Logistic regression was utilized to develop a novel model of predictive risk.

RESULTS

Of neuroleptic-treated youths, 5.9% had probable tardive dyskinesia, a rate less than the prevalence of tardive dyskinesia in chronic neuroleptic-treated adults. Use of typical neuroleptics was significantly (p = .03) associated with dyskinesia compared with use of atypical antipsychotics. Four variables including IQ, initial Abnormal Involuntary Movement Scale score, type of antipsychotic, and cumulative number of risk factors accounted for 35.8% of the variance when predicting dyskinetic status.

CONCLUSION

Use of atypical antipsychotics appears to be associated with less dyskinesia risk than typical neuroleptics in an unselected group of seriously emotionally disturbed children and adolescents. Results support a cumulative risk model of neuroleptic-related dyskinesia in youths.

Massachusetts Youth Screening Instrument for mental health needs of juvenile justice youths

OBJECTIVE

This report describes the development of the Massachusetts Youth Screening Instrument-Second Version (MAYSI-2), a brief screening measure to identify youths with potential mental, emotional, or behavioral problems at entry points in the juvenile justice system.

METHOD

This 52-item self-report measure, with content relevant to common mental health problems in delinquent populations, was administered to 1,279 male and female youths, aged 12 to 17, in Massachusetts juvenile justice facilities. A subsample of youths also received the Millon Adolescent Clinical Inventory (MACI) and the Youth Self-Report (YSR). The instrument was subsequently administered to 3,804 male and female youths in California Youth Authority custody.

RESULTS

Factor analyses of the 52 items identified seven scales that were conceptually associated with various mental, emotional, and behavioral problems of youths, which were generally confirmed by separate factor analyses with the California sample. The scales manifested adequate internal consistency and test-retest reliability. Most scales were substantially correlated with conceptually similar scales in the MACI and YSR, and they identified most youths who scored at clinically significant levels on those instruments.

CONCLUSIONS

The MAYSI-2 shows promise as a reliable and valid screening tool to assist juvenile justice staff in identifying youths who may need an immediate response to mental or emotional problems.

Early sexual abuse and low cortisol

Post-traumatic stress disorder (PTSD) is a mental health disorder precipitated by a stressful event that produces fear or terror in the individual. Post-traumatic stress disorder studies, particularly in early sexual abuse, have been associated with neuroendocrine dysfunction, most notably the hypothalamic-pituitary-adrenal (HPA) axis. Since the literature on PTSD and neuroendocrine factors in young subjects has been sparse, the present studies were designed to look at the basal functioning of the HPA axis in response to early sexual abuse in girls aged 5 to 7 years. Morning salivary samples were collected for cortisol determination from subjects and controls who were scheduled for a physical exam by their pediatrician. The present study shows that subjects who had been abused within the last couple of months had significantly lower cortisol in comparison to control subjects (age, social economic status and race matched). The data suggest that children may have an impaired HPA axis after early trauma.

A comparison of physostigmine and benzodiazepines for the treatment of anticholinergic poisoning

STUDY OBJECTIVE

To compare the efficacy and safety of physostigmine with benzodiazepines for the treatment of agitation and delirium associated with anticholinergic poisoning.

METHODS

We conducted a retrospective study of 52 consecutive patients referred to a university hospital toxicology consultation service who were treated with physostigmine, benzo-diazepines, or both for anticholinergic agitation and delirium. Patients treated with physostigmine were compared with those treated with benzodiazepines with respect to demographics, severity of poisoning, response to treatment, side effects of treatment, and complications.

RESULTS

Physostigmine controlled agitation and reversed delirium in 96% and 87% of patients, respectively. Benzodiazepines controlled agitation in 24% of patients but were ineffective in reversing delirium. Initial treatment with physostigmine (n=30) resulted in a significant decrease in the incidence of agitation (P <.001) and level of central nervous system stimulation (P <.001), whereas initial treatment with benzodiazepines (n=22) did not (P =.03 and P =.05, respectively). Patients treated initially with physostigmine had a significantly lower incidence of complications (7% versus 46%; P <. 002) and a shorter time to recovery (median, 12 versus 24 hours; P =. 004) than those treated initially with benzodiazepines. There were no significant differences between these groups in the incidence of side effects (7% versus 14%; P =0.6) and length of stay (median, 32 versus 39 hours; P =.15).

CONCLUSION

Results suggest that physostigmine is more effective and safer than benzodiazepines for the treatment of anticholinergic agitation and delirium. A prospective controlled study is necessary to confirm such findings.

Outcomes in work-related upper extremity and low back injuries: results of a retrospective study

BACKGROUND

The outcomes of treatment for work-related injuries and illnesses are multidimensional and complex, but have rarely been explored in detail. This study was intended to provide information on a sample of workers representing a range of jobs and employers typical of the workers compensation system.

METHODS

A mailed, self-report survey measuring multiple dimensions was conducted. Identified through the New Hampshire Division of Workers' Compensation First Report of Injury database, a sample of workers with injuries to their lower back (60%) or upper extremities (40%) a year prior to the study were surveyed. Response rate was 80% (N=169; upper extremity cases=70; low back cases=99).

RESULTS

Most (82.8%) were working one year post-injury. Over half reported residual effects of the injury on work or activities of daily living. Many working subjects reported persistent injury-related anxiety and pain at the end of the work day, worse in those with low back pain compared to those with upper extremity injuries. Almost 40% of those who returned to work suffered a reinjury. Forty-four percent of respondents suffered significant injury-related financial problems, which were worse in those who had been out of work for longer periods.

CONCLUSIONS

Occupational musculoskeletal injuries do result in significant, long-term adverse physical, economic, and psychological consequences, as demonstrated in self-reported surveys.

Clinical predictors of acute response with quetiapine in psychotic mood disorders

BACKGROUND

In controlled studies of patients with schizophrenia, the atypical antipsychotic quetiapine, 300 mg/day, has been shown to be as effective in the treatment of positive and negative symptoms as haloperidol. However, little is known about the efficacy of quetiapine in patients with psychotic mood disorders. The purpose of this study was to assess the efficacy of quetiapine in the treatment of psychotic mood disorders in comparison with nonaffective psychotic disorders and identify clinical factors associated with quetiapine response.

METHOD

In a naturalistic setting, by reviewing medical records, we assessed response to quetiapine and factors associated with response to quetiapine in 145 consecutive patients newly treated with the drug at a nonprofit academic psychiatric hospital. These patients had received a discharge diagnosis of bipolar disorder (manic, mixed, or depressive type), major depression with psychotic features, schizophrenia, schizoaffective disorder (bipolar or depressive type), delusional disorder, or psychosis not otherwise specified (NOS) according to DSM-IV criteria.

RESULTS

Patients with a diagnosis of bipolar disorder, manic, mixed, or depressed and schizoaffective disorder, bipolar type displayed higher response rates (> 74%) compared with patients with schizophrenia. However, this finding did not achieve statistical significance. A diagnosis of major depression with psychotic features (p = .02) and longer duration of illness (p = .03) were associated with less chance of responding.

CONCLUSION

Quetiapine may be a useful alternative or adjunctive treatment for patients with bipolar and schizoaffective disorders.

A meta-analysis of clonidine for symptoms of attention-deficit hyperactivity disorder

OBJECTIVE

Meta-analysis was used to review the literature on the clinical use of clonidine to treat symptoms of attention-deficit hyperactivity disorder (ADHD).

METHOD

A review of the literature from 1980 to 1999 revealed 39 studies that reported clonidine's efficacy and side effects for symptoms of ADHD and comorbid conditions. Of these, 11 reports provided sufficient information to be included in a meta-analysis.

RESULTS

Meta-analysis using weighted variables revealed clonidine demonstrates a moderate effect size of 0.58 +/- 0.16 (95% confidence interval = 0.27-0.89) on symptoms of ADHD in children and adolescents with ADHD and ADHD comorbid with conduct disorder, developmental delay, and tic disorders.

CONCLUSIONS

Clonidine may be an effective second-tier treatment for symptoms of ADHD, but it has an effect size less than that of stimulants. Clinical use of clonidine is associated with many side effects.

Physicians and smoking cessation. Development of survey measures

Data from a mailed survey to primary care physicians (N = 122) were used to construct and evaluate psychosocial scales related to performance of smoking cessation counseling. Scales measuring counseling barriers, self-efficacy, and motivation demonstrated considerable promise with excellent or reasonable internal consistency. The correlation for each scale with performance of cessation counseling and with stage of change was statistically significant. Physicians who report they are currently assisting patients had higher performance and self-efficacy rating. Physicians who had participated in formal smoking cessation training had higher self-efficacy; however, their scores on the Barriers, Motivation, and Performance Scales did not differ. Further study with a representative group is encouraged.

A pilot study of nadolol for overt aggression in developmentally delayed individuals

OBJECTIVE

The aim of this preliminary pilot study was to investigate the safety and efficacy of open-label nadolol as an adjunctive pharmacological treatment for aggression and/or inattention/overactivity in a developmentally delayed child, adolescent, and young adult population.

METHOD

Twelve subjects enrolled and completed (mean age 13.8 years, range 9 through 24) a 5-month, open, prospective protocol of nadolol (mean dose 109 mg, range 30 through 220 mg) with systematic baseline and outcome evaluations and weekly clinical assessment.

RESULTS

All subjects were developmentally delayed and most were cognitively delayed. Ten subjects (83%) showed clinical improvement while receiving nadolol. Significant improvements were noted on observer-rated overt categorical aggression, severity of illness, and global impressions of improvement. No significant effects were found for inattention/overactivity. Nadolol was well tolerated, with few side effects.

CONCLUSIONS

Overt categorical aggression presenting in developmentally delayed children, adolescents, and young adults may respond to nadolol treatment.

A sequential analysis of the mother-adolescent interactions of ADHD, ADHD/ODD, and normal teenagers during neutral and conflict discussions

The sequential interactions of three groups of teenagers conversing with their mothers during both neutral and conflict discussion situations were evaluated. Groups consisted of (1) attention deficit hyperactivity disorder (ADHD) alone (n = 21), (2) ADHD with comorbid oppositional defiant disorder (ADHD/ODD; n = 40), and (3) a community control group of adolescents (n = 49). All groups had been followed concurrently for the past 8 to 10 years before being reevaluated in this study. Results indicated that (1) teens and parents in all groups interacted in a tightly linked manner, with the behavior of each member being significantly related only to the immediate antecedent behavior of the other; (2) mothers in all groups were more likely than teens to initiate positive behaviors; (3) teen interactions could be characterized as tit-for-tat while mothers could be typified as be-nice-and-forgive; (4) mother-teen dyads in the ADHD/ODD group displayed significantly higher rates of conflict behaviors than dyads in the other two groups, who did not differ significantly from each other on most measures; and (5) mothers in the ADHD/ODD group responded in a manner similar to their teens (greater negativity) and less like that of mothers in the other groups. The majority of conflict between ADHD children and their parents seemed due to comorbid ODD and such ODD is a family, not just a teen, characteristic.

Head injury in partner-abusive men

Research into etiology of marital aggression has focused primarily on psychosocial, political, and cultural factors, to the exclusion of physiological influences. Fifty-three partner abusive men, 45 maritally satisfied, and 32 maritally discordant, nonviolent men were evaluated for past history of head injury, by a physician who was not informed of group membership and aggression history. Logistic regressions confirmed that head injury was a significant predictor of being a battered. The implications of these findings for both marital aggression and post-head injury rehabilitation are discussed.

Primary structure of the human platelet serotonin 5-HT2A receptor: identify with frontal cortex serotonin 5-HT2A receptor

Previous radioligand binding studies have demonstrated human platelet serotonin2A (5-HT2A) receptor binding sites. Pharmacological similarities between platelet and frontal cortex 5-HT2A receptor binding parameters have been demonstrated. However, it is not clear whether the platelet 5-HT2A receptor primary structure is identical to that of the brain receptor. Three overlapping cDNAs were obtained to span completely the coding region of the 5-HT2A receptor. These clones were sequenced with external and internal primers. The nucleotide sequence of human platelet 5-HT2A cDNA was identical to that reported for the human frontal cortex 5-HT2A receptor, except for nucleotide 102 (T-->C), which has been reported to represent a normal DNA polymorphism that does not alter the amino acid sequence. This finding may have implications in the study of neuropsychiatric disorders for which altered platelet 5-HT2A receptor binding has been demonstrated.

Head-injured males: a population at risk for relationship aggression?

Several recent studies suggest that head injury may be a potentially useful factor in explaining some types of aggressive behavior. In our research, we have been able to demonstrate an association between head injury and marital aggression using a sample of male batterers and appropriate comparison groups. Anecdotal and empirical literature also supports the hypothesis that aggression, relationship problems, and negative changes in personality and behavior are common sequelae to a head injury. This article explores the hypothesis that flows intuitively from the above, namely, that head-injured males are at increased risk for physical aggression in their intimate relationships. Empirical data are presented identifying several risk factors for relationship aggression and marital discord that may be sequelae of a significant head injury. Nevertheless, head-injured men were not found to be more physically aggressive with their female partners. The implications of these results are discussed.

Pharmacotherapeutic management strategies for mentally ill substance abusers

In order to determine psychiatrists' strategies for managing the pharmacotherapy and treatment of mentally ill substance abusers, the authors constructed a series of standardized clinical vignettes, each with five multiple-choice treatment interventions. The vignettes, based on clinical experience, depict difficult dilemmas involving the use of medication in the treatment of a variety of dually diagnosed patients. The authors surveyed a heterogeneous reference group of 112 psychiatrists with these vignettes. The psychometric properties of the resultant Scale for Treatment Integration of the Dually Diagnosed (STIDD) are briefly described. The ten vignettes and the treatment interventions chosen by the reference group are described in detail. The results indicate that most clinicians favor an integrated treatment approach which attempts to address both diagnoses.

The stability of dimensions of behavior in ADHD and normal children over an 8-year followup

The present study reports on standardized behavioral ratings received by a large sample of hyperactive children meeting research diagnostic criteria (n = 108) and a community control sample of normal children (n = 61) who were followed prospectively over 8 years into adolescence. On some parent-report measures both groups declined in the severity of their behavior problems across time, while on other measures only the hyperactive group declined, but the hyperactives always remained more deviant than the controls at followup. The hyperactives and controls also differed on most teacher and self-report ratings at followup. The greatest degree of agreement between raters at adolescence was between parent and youth ratings. These results are consistent with previous research demonstrating more deviant scores for hyperactive children than controls on various rating scales at adolescent followup. They also are consistent with research showing significant longitudinal continuity of both internalizing and externalizing behavioral pathology.

The adolescent outcome of hyperactive children: predictors of psychiatric, academic, social, and emotional adjustment

OBJECTIVE

To investigate predictors of adolescent outcome in a large sample of hyperactive children.

METHOD

123 hyperactive children were followed prospectively over an 8-year period. Multiple linear and logistical regression equations were used to relate childhood predictor variables to adolescent academic, psychiatric, social, and emotional adjustment.

RESULTS

Adolescent academic skills were related to childhood cognitive and academic competence while school conduct was predicted by other variables including early family stress. Duration of mental health treatment received often was negatively related to outcome, apparently serving as a marker variable for severity of disturbance in the child. Childhood impulsivity-hyperactivity and paternal antisocial acts were associated with later oppositional-defiant behaviors. Only child defiance and not hyperactivity predicted later arrests, however. Emotional problems in adolescence were predicted by more special education enrollment. Adolescent social competence was associated with parental personal competence, whereas maternal mental health status at outcome was related to variables unassociated with child adjustment.

CONCLUSIONS

Various outcome domains had different sets of predictors; no single predictor cut across all domains. Although a limited amount of variance in outcome was explained, findings suggest that promoting family and parental competence as well as assessing and treating defiance and aggression very early may improve outcome.

Clonidine treatment of hyperactive and impulsive children with autistic disorder

Many autistic children have associated problems of inattention, impulsivity, and hyperactivity that limit the effectiveness of educational and behavioral interventions. Few controlled psychopharmacologic trials have been conducted in autistic children to determine which agents may be effective for these associated features. Eight male children (8.1 +/- 2.8 years) with autistic disorder, diagnosed by DSM-III-R criteria, completed a placebo-controlled, double-blind crossover trial of clonidine. Subjects were included in the study if they had inattention, impulsivity, and hyperactivity that was excessive for their developmental level. Subjects had not tolerated or responded to other psychopharmacologic treatments (neuroleptics, methylphenidate, or desipramine). Teacher ratings on the Aberrant Behavior Checklist irritability, stereotypy, hyperactivity, and inappropriate speech factors were lower during treatment with clonidine than during treatment with placebo. Attention deficit disorder with hyperactivity: Comprehensive Teacher's Rating Scale ratings were not significantly improved during the study, except for oppositional behavior. Parent Conners Abbreviated Parent-Teacher Questionnaire ratings significantly improved during clonidine treatment. Clonidine led to increased ratings of the side effects of drowsiness and decreased activity. Clinician ratings (Children's Psychiatric Rating Scale Autism, Hyperactivity, Anger and Speech Deviance factors; Children's Global Assessment Scale; Clinical Global Impressions efficacy) of videotaped sessions were not significantly different between clonidine and placebo. Clonidine was modestly effective in the short-term treatment of irritability and hyperactivity in some children with autistic disorder.

Effectiveness of a meditation-based stress reduction program in the treatment of anxiety disorders

OBJECTIVE

This study was designed to determine the effectiveness of a group stress reduction program based on mindfulness meditation for patients with anxiety disorders.

METHOD

The 22 study participants were screened with a structured clinical interview and found to meet the DSM-III-R criteria for generalized anxiety disorder or panic disorder with or without agoraphobia. Assessments, including self-ratings and therapists' ratings, were obtained weekly before and during the meditation-based stress reduction and relaxation program and monthly during the 3-month follow-up period.

RESULTS

Repeated measures analyses of variance documented significant reductions in anxiety and depression scores after treatment for 20 of the subjects--changes that were maintained at follow-up. The number of subjects experiencing panic symptoms was also substantially reduced. A comparison of the study subjects with a group of nonstudy participants in the program who met the initial screening criteria for entry into the study showed that both groups achieved similar reductions in anxiety scores on the SCL-90-R and on the Medical Symptom Checklist, suggesting generalizability of the study findings.

CONCLUSIONS

A group mindfulness meditation training program can effectively reduce symptoms of anxiety and panic and can help maintain these reductions in patients with generalized anxiety disorder, panic disorder, or panic disorder with agoraphobia.

Adolescents with attention deficit hyperactivity disorder: mother-adolescent interactions, family beliefs and conflicts, and maternal psychopathology

A group of 83 adolescents with attention deficit hyperactivity disorder (ADHD) were subdivided into those with ADHD alone (n = 27) and those with ADHD and oppositional defiant disorder (ADHD/ODD, n = 56). They were compared to each other and a community control group (n = 77) on measures of family conflicts, family beliefs, maternal adjustment, and observations of mother-adolescent interactions during both a neutral and conflict discussion. Both ADHD groups had more topics on which there was conflict and more angry conflicts at home than control adolescents on parent reports. Only the ADHD/ODD adolescents reported more such conflicts, endorsed more extreme and unreasonable beliefs about their parent-teen relations, and demonstrated greater negative interactions during a neutral discussion than the control teenagers. Similarly, only mothers of the ADHD/ODD teens displayed greater negative interactions during a neutral discussion, more extreme and unreasonable beliefs about their parent-teen relations, greater personal distress, and less satisfaction in their marriages than the mothers in the control group. Most findings for the ADHD only group were between the control group and the group with mixed ADHD/ODD but did not differ from either group. Results imply that it is the combination of ODD symptoms with those of ADHD that is associated with the greater-than-normal conflicts, anger, poor communications, unreasonable beliefs, and negative interactive styles seen in ADHD adolescents. These same characteristics typify their mothers' interactions as well such that both the adolescents' ODD symptoms and maternal psychological distress (hostility) make unique contributions to the degree of conflict and anger in the parent-teen relations of ADHD adolescents.

Observation of pain behavior in rheumatoid arthritis patients during physical examination. Relationship to disease activity and psychological variables

This study examined the reliability and validity of a behavioral observation method for the assessment of arthritis pain in a clinical practice setting. Trained observers measured the occurrence of seven pain behaviors in a group of 61 rheumatoid arthritis patients undergoing physical examinations. These observations were compared with videotaped observations of the patients in a laboratory setting. Significant differences were found between the pain behavior frequencies observed during the examinations and those observed during videotaped sessions. Total pain behavior scores obtained in both settings were significantly correlated with patients' self-reports of pain and with disease activity measures. Pain behavior observed during the exams was significantly associated with patients' self-reports of anxiety and depression.

Adolescents with ADHD: patterns of behavioral adjustment, academic functioning, and treatment utilization

Adolescents with attention deficit hyperactivity disorder (ADHD) were compared with a control group on a comprehensive assessment battery. More ADHD teenagers had oppositional defiant disorder (68%) and conduct disorder (39%) and were rated as more impaired in social competence, behavioral and emotional adjustment, and school performance by parents and teachers than control teens. The ADHD youths, however, rated themselves as better adjusted than did their parents and teachers, differing only from controls in depressive symptoms and antisocial acts. Poorer performances in verbal learning and vigilance and greater ADHD behaviors during a math task also distinguished the ADHD from control teenagers.

The scale for treatment integration of the dually diagnosed (STIDD): an instrument for assessing intervention strategies in the pharmacotherapy of mentally ill substance abusers

The authors developed a series of 15 multiple-choice vignettes which pose common dilemmas in the pharmacotherapy of patients suffering from psychoactive substance use disorders coexisting with other mental disorders. Fourteen judges standardized the treatment options along a 'treatment integration continuum'. The authors surveyed 112 psychiatrists with the vignettes and 3 subscales of the Substance Abuse Attitude Survey. Ten of the 15 vignettes were taken to form the normally distributed Scale for Treatment Integration of the Dually Diagnosed (STIDD), which is described in terms of its reliability, validity and potential use as a teaching and research tool.

Dental silicate cements. XI. Electron probe studies

Electron probe studies on polished sections of dental silicate cement show that it consists of well-defined particles embedded in a phosphate matrix. The matrix contains phosphorus, aluminum, and calcium but no silicon. The calcium and aluminum originate from the particle surface, which becomes an aluminosilica gel, whereas the phosphorus is derived from the cement liquid.