Vascular epiphytes of the Atlantic Forest in the Sinos River basin, state of Rio Grande do Sul, Brazil: richness, floristic composition and community structure.

The Atlantic Forest, which has a vast epiphytic richness, is a priority area for preservation, listed as one of the five most important world hotspots. Vascular epiphyte richness, composition and community structure were studied in two fragments, one of the ombrophilous (29º43'42"S and 50º22'00"W) and the other of the seasonal (29º40'54"S and 51º06'56"W) forest, both belonging to the Atlantic Forest biome in the Sinos River basin, Rio Grande do Sul, Brazil. In each fragment, 40 trees, divided into four ecological zones, were analyzed. In each zone, the occurrence of the species was recorded, and the importance value of each species was calculated according to the frequency of phorophytes and intervals, and cover scores. The Shannon index was calculated for the two communities. In the fragment of the ombrophilous forest (F1), 30 epiphytic species were recorded, and in the seasonal forest (F2), 25. The highest importance value was found for Microgramma squamulosa (Kaulf.) de la Sota in both fragments. The diversity indexes for F1 (H'=2.72) and F2 (H'=2.55) were similar and reflected the subtropical location of the areas. The decrease in mean richness in both fragments in zone 3 (internal crown) to zone 4 (external crown) may be associated with time and space availability for epiphyte occupation and microclimate variations. Exclusive species were found in the areas, which suggest that a greater number of preserved fragments may result in a greater number of preserved epiphytic species in the Sinos River basin.

Childhood maltreatment in women with binge-eating disorder: associations with psychiatric comorbidity, psychological functioning, and eating pathology.

OBJECTIVE: To examine correlates of childhood maltreatment in women with binge-eating disorder (BED). METHOD: Semistructured interviews evaluated 137 women with BED for psychiatric disorders and eating psychopathology, and self-reported childhood maltreatment was assessed. RESULTS: Emotional abuse was reported by 52% of participants, physical abuse by 28%, sexual abuse by 31%, emotional neglect by 66%, and physical neglect by 48%. Maltreatment categories were not associated with most lifetime psychiatric diagnoses, although specific associations were observed for dysthymic disorder, posttraumatic stress disorder, and alcohol use disorders. Few associations were noted with eating pathology, but most forms of childhood maltreatment were negatively associated with self-esteem. DISCUSSION: Women with BED report rates of childhood maltreatment comparable to those for clinical groups, and much higher than community samples. Although prevalent in women with BED, childhood maltreatment is not generally associated with variability in eating pathology or with psychiatric comorbidity, but is associated with lower self-esteem.

Crystallization and preliminary crystallographic analysis of the proline dehydrogenase domain of the multifunctional PutA flavoprotein from Escherichia coli.

The PutA flavoprotein from Escherichia coli is a multifunctional protein that plays pivotal roles in proline catabolism by functioning as both a membrane-associated bifunctional enzyme and a transcriptional repressor. Peripherally membrane-bound PutA catalyzes the two-step oxidation of proline to glutamate, while cytoplasmic PutA represses the transcription of its own gene and the gene for a proline-transporter protein. X-ray crystallographic studies on PutA have been initiated to determine how the PutA structural scaffold enables it to be both an enzyme and a repressor, and to understand the mechanism by which PutA switches between its enzymatic and DNA-binding functions. To facilitate crystallization, a recombinant protein (PutA669) corresponding to the N-terminal 669 amino-acid residues of the 1320 residues of PutA was engineered. Activity assays demonstrated that PutA669 catalyzes the first step of chemistry performed by PutA, the conversion of proline to Delta1-pyrroline-5-carboxylate. Crystals of PutA669 have been obtained from PEG 3000 buffered at pH 6-7. The crystals occupy an I-centered orthorhombic lattice with unit-cell parameters a = 72.5, b = 140.2, c = 146.8 A; a 2.15 A data set was collected using a rotating-anode source. Assuming one molecule per asymmetric unit, the Matthews coefficient V(M) is 2.5 A(3) Da(-1), with a solvent content of 50%. The structure of PutA669 will be solved by multiple isomorphous replacement.

Mechanistic studies of methane biogenesis by methyl-coenzyme M reductase: evidence that coenzyme B participates in cleaving the C-S bond of methyl-coenzyme M.

Methyl-coenzyme M reductase (MCR), the key enzyme in methanogenesis, catalyzes methane formation from methyl-coenzyme M (methyl-SCoM) and N-7-mercaptoheptanoylthreonine phosphate (CoBSH). Steady-state and presteady-state kinetics have been used to test two mechanistic models that contrast in the role of CoBSH in the MCR-catalyzed reaction. In class 1 mechanisms, CoBSH is integrally involved in methane formation and in C-S (methyl-SCoM) bond cleavage. On the other hand, in class 2 mechanisms, methane is formed in the absence of CoBSH, which functions to regenerate active MCR after methane is released. Steady-state kinetic studies are most consistent with a ternary complex mechanism in which CoBSH binds before methane is formed, as found earlier [Bonacker et al. (1993) Eur. J. Biochem. 217, 587-595]. Presteady-state kinetic experiments at high MCR concentrations are complicated by the presence of tightly bound CoBSH in the purified enzyme. Chemical quench studies in which (14)CH(3)-SCoM is rapidly reacted with active MCRred1 in the presence versus the absence of added CoBSH indicate that CoBSH is required for a single-turnover of methyl-SCoM to methane. Similar single turnover studies using a CoBSH analogue leads to the same conclusion. The results are consistent with class 1 mechanisms in which CoBSH is integrally involved in methane formation and in C-S (methyl-SCoM) bond cleavage and are inconsistent with class 2 mechanisms in which CoBSH binds after methane is formed. These are the first reported pre-steady-state kinetic studies of MCR.

Stability and change of DSM-III-R personality disorder dimensions in adolescents followed up 2 years after psychiatric hospitalization.

We examined the stability of DSM-III-R personality disorder dimensions in a clinical sample of adolescents. Sixty adolescent inpatients were reliably assessed with the Personality Disorder Examination (PDE) soon after admission to the Yale Psychiatric Institute, and were independently reassessed with the same instrument 2 years following discharge. PDE symptom ratings were summed to create dimensional scores for each personality disorder. To assess the dimensional stability of personality disorders, intraclass correlation coefficients (ICCs) were computed. To assess the magnitude of the difference between baseline and follow-up scores, paired t tests were used. Significant ICCs were observed for histrionic, narcissistic, dependent, obsessive-compulsive, and passive-aggressive personality disorders. Compared to baseline, dimensional scores for most personality disorders were significantly lower at follow-up-and none was significantly higher. Diagnostic stability is a key defining feature of personality disorders. We observed low-to-moderate stability for dimensional measures of personality dysfunction in adolescents-suggesting that previous reports of modest personality disorder stability in this age group cannot be attributed solely to limitations of the categorical approach to such pathology. Alternatively, our findings may be viewed as consistent with reports in the adult literature that personality disorders may improve over time, and can potentially benefit from treatment.

Role of aromatic stacking interactions in the modulation of the two-electron reduction potentials of flavin and substrate/product in Megasphaera elsdenii short-chain acyl-coenzyme A dehydrogenase.

The effects of aromatic stacking interactions on the stabilization of reduced flavin adenine dinucleotide (FAD) and substrate/product have been investigated in short-chain acyl-coenzyme A dehydrogenase (SCAD) from Megasphaera elsdenii. Mutations were made at the aromatic residues Phe160 and Tyr366, which flank either face of the noncovalently bound flavin cofactor. The electrochemical properties of the mutants were then measured in the presence and absence of a butyryl-CoA/crotonyl-CoA mixture. Results from these redox studies suggest that the phenylalanine and tyrosine both engage in favorable pi-sigma interactions with the isoalloxazine ring of the flavin to help stabilize formation of the anionic flavin hydroquinone. Disruption of these interactions by replacing either residue with a leucine (F160L and Y366L) causes the midpoint potential for the oxidized/hydroquinone couple (E(ox/hq)) to shift negative by 44-54 mV. The E(ox/hq) value was also found to decrease when aromatic residues containing electron-donating heteroatoms were introduced at the 160 position. Potential shifts of -32 and -43 mV for the F160Y and F160W mutants, respectively, are attributed to increased pi-pi repulsive interactions between the ring systems. This study also provides evidence for thermodynamic regulation of the substrate/product couple in the active site of SCAD. Binding to the wild-type enzyme caused the midpoint potential for the butyryl-CoA/crotonyl-CoA couple (E(BCoA/CCoA)) to shift 14 mV negative, stabilizing the oxidized product. Formation of product was found to be even more favorable in complexes with the F160Y and F160W mutants, suggesting that the electrostatic environment around the flavin plays a role in substrate/product activation.

Applicability of personality disorder criteria in late adolescence: internal consistency and criterion overlap 2 years after psychiatric hospitalization.

We examined internal consistency and criterion overlap of DSM-III-R personality disorder criteria in late adolescence, 2 years after psychiatric hospitalization. A total of 60 adolescents were assessed with the Personality Disorder Examination. Within-category cohesiveness (internal consistency) was evaluated by coefficient alpha and mean intercriterion correlation (MIC). Between-category criterion overlap was evaluated by examining intercategory mean intercriterion correlations (ICMIC) between all pairs of disorders. Internal consistency was low, with alpha less than .70 for all except borderline and dependent personality disorders. For most disorders, MIC values were higher than ICMIC values. Our findings suggest that personality disorder criteria sets have limited internal consistency in older adolescents. Although the criteria for most personality disorders correlate better with each other than with the criteria for other personality disorders, suggesting some degree of discriminant validity, comparison of these results with a similar analysis performed shortly after hospital admission raises questions about personality disorder construct validity during adolescence.

Redox properties of the PutA protein from Escherichia coli and the influence of the flavin redox state on PutA-DNA interactions.

The PutA flavoprotein from Escherichia coli is both a transcriptional repressor and a membrane-associated proline dehydrogenase. PutA represses transcription of the putA and putP genes by binding to the control region DNA of the put regulon (put intergenic DNA). Previous work has shown that FAD has a role in regulating the transcriptional repressor and membrane binding functions of the PutA protein. To test the influence of the FAD redox state on PutA--DNA interactions, we characterized the redox properties of the PutA flavoprotein from E. coli. At pH 7.5, an E(m)(E--FAD/E--FADH(2)) of --0.076 V for the two-electron reduction of PutA-bound FAD was determined by potentiometric titrations. Stabilization of semiquinone species was not observed during potentiometric measurements. Dithionite reduction of PutA, however, caused formation of red anionic semiquinone. The E(m) value for the proline/Delta(1)-pyrroline-5-carboxylate couple was determined to be --0.123 V, demonstrating the reduction of PutA by proline is favored by a potential difference (Delta E degrees ') of more than 0.045 V. Characterization of the PutA redox properties in the presence of put intergenic DNA revealed an E(m)(E(DNA)--FAD/E(DNA)--FADH(2)) of --0.086 V. The 10 mV negative shift in E(m) corresponds to just a 2.3-fold increase in the dissociation constant of PutA with the DNA upon reduction of FAD. Thus, it appears the FAD redox state has little influence on the overall PutA--DNA interactions.

Comorbidity of borderline personality disorder with other personality disorders in hospitalized adolescents and adults.

OBJECTIVE: The authors examined the comorbidity of borderline personality disorder with other personality disorders in a series of consecutively admitted adolescents. For comparison, the comorbidity of borderline personality disorder with other personality disorders was also examined in a series of adults consecutively admitted to the same hospital during the same period. METHOD: A total of 138 adolescents and 117 adults were reliably assessed with the Personality Disorder Examination, a semistructured diagnostic interview for DSM-III-R personality disorders. Sixty-eight adolescents and 50 adults met the diagnostic criteria for borderline personality disorder. The co-occurrence of other personality disorders in the group of subjects with borderline personality disorder was statistically compared to that in the group without borderline personality disorder, for adolescents and adults separately. RESULTS: For the adults, Bonferroni-corrected chi-square analysis revealed significant diagnostic co-occurrence with borderline personality disorder for antisocial personality disorder only. For the adolescents, borderline personality disorder showed significant co-occurrence with schizotypal and passive-aggressive personality disorders. CONCLUSIONS: In the adults, borderline personality disorder was significantly comorbid only with another cluster B disorder. The adolescents, by comparison, displayed a broader pattern of comorbidity of borderline personality disorder, encompassing aspects of clusters A and C. These results suggest that the borderline personality disorder diagnosis may represent a more diffuse range of psychopathology in adolescents than in adults.

Concurrent and predictive validity of the personality disorder diagnosis in adolescent inpatients.

OBJECTIVE: The authors investigated the concurrent and predictive validity of the DSM-III-R diagnosis of personality disorder in adolescents by means of baseline and follow-up assessments of inpatients treated at the Yale Psychiatric Institute. METHOD: One hundred sixty-five hospitalized adolescents were reliably assessed by using a structured interview for personality disorder diagnoses as well as two measures of impairment and distress--the Global Assessment of Functioning Scale and the SCL-90-R. Two years after initial assessment, 101 subjects were independently reassessed with the same measures; their functioning was also assessed at this time. RESULTS: At baseline, adolescents with personality disorders were significantly more impaired than those without personality disorders. At follow-up, adolescents with a personality disorder diagnosis at baseline had used significantly more drugs and had required more inpatient treatment during the follow-up interval. Over time, the scores on the Global Assessment of Functioning Scale and SCL-90-R of adolescents diagnosed with a personality disorder at baseline became more similar to the scores of adolescents without a personality disorder. CONCLUSIONS: The diagnosis of personality disorder in adolescent inpatients has good concurrent validity; however, the predictive validity of the diagnosis is mixed.

Case series: PTSD symptoms in adolescent survivors of "ethnic cleansing." Results from a 1-year follow-up study.

OBJECTIVE: The authors describe the psychiatric sequelae of "ethnic cleansing" in adolescent Bosnian refugees, via a 1-year follow-up study. METHOD: Ten Bosnian adolescent refugees from the war in Bosnia-Herzegovina received a baseline assessment within the first year after their resettlement and a follow-up assessment 1 year later. Evaluations included an assessment scale for posttraumatic stress disorder (PTSD) symptom severity. RESULTS: At baseline, 3 subjects met criteria for PTSD. At follow-up, this diagnosis persisted in none of these subjects, though 1 subject met criteria at follow-up only. For the group, mean PTSD severity scores at baseline and at follow-up were 8.9 and 4.0, respectively. At baseline, reexperiencing symptoms were present 43% of the time, avoidance symptoms were present 33% of the time, and hyperarousal symptoms were present 33% of the time; at follow-up, these proportions were 35%, 16%, and 18%, respectively. CONCLUSIONS: Overall, rates of PTSD symptoms diminished during the 1-year follow-up interval, suggesting that they may be transient and not representative of enduring psychopathology. This finding may reflect the relative resiliency of adolescents, as well as a variety of factors that facilitated adaptation in our particular group of adolescent refugees.

Applicability of personality disorder criteria to hospitalized adolescents: evaluation of internal consistency and criterion overlap.

OBJECTIVE: The authors examined the applicability of personality disorder criteria to adolescent inpatients by evaluating internal consistency and criterion overlap. METHOD: Thirty-eight adolescents and 28 adults were assessed with the Personality Disorder Examination. Within-category cohesiveness (internal consistency) of the criteria was evaluated by examining intercriterion correlations as well as coefficient alpha. In addition, between-category criterion overlap was evaluated by examining "intercategory" intercriterion correlations between all pairs of disorders. Separate analyses were conducted for adolescents and adults, and the groups were compared. RESULTS: Internal consistency appeared to be lower in adolescents, as measured by intercriterion correlation and coefficient alpha, with the largest differences being identified for most cluster B disorders. Intercategory analysis indicated that criterion overlap may be greater among adolescents. CONCLUSIONS: Overall, this psychometric analysis suggests that there may be limitations to the DSMs approach to categorizing personality disorders. For both adolescents and adults, modest degrees of within-category cohesiveness (internal consistency) and between-category criterion overlap were observed. Comparatively, personality disorder criteria in adolescents tended to have lower internal consistency and less discriminant validity. The data raise questions about the construct validity of these disorders--or the applicability of these criteria--within this age group.

Electrochemical and spectroscopic properties of the iron-sulfur flavoprotein from Methanosarcina thermophila.

An iron-sulfur flavoprotein (Isf) from the methanoarchaeaon Methanosarcina thermophila, which participates in electron transfer reactions required for the fermentation of acetate to methane, was characterized by electrochemistry and EPR and Mössbauer spectroscopy. The midpoint potential (Em) of the FMN/FMNH2 couple was -0.277 V. No flavin semiquinone was observed during potentiometric titrations; however, low amounts of the radical were observed when Isf was quickly frozen after reaction with CO and the CO dehydrogenase/acetyl-CoA synthase complex from M. thermophila. Isf contained a [4Fe-4S]2+/1+ cluster with g values of 2.06 and 1.93 and an unusual split signal with g values at 1.86 and 1.82. The unusual morphology was attributed to microheterogeneity among Isf molecules. The Em value for the 2+/1+ redox couple of the cluster was -0.394 V. Extracts from H2-CO2-grown Methanobacterium thermoautotrophicum cells catalyzed either the H2- or CO-dependent reduction of M. thermophila Isf. In addition, Isf homologs were found in the genomic sequences of the CO2-reducing methanoarchaea M. thermoautotrophicum and Methanococcus jannaschii. These results support a general role for Isf in electron transfer reactions of both acetate-fermenting and CO2-reducing methanoarchaea. It is suggested that Isf functions to couple electron transfer from ferredoxin to membrane-bound electron carriers, such as methanophenazine and/or b-type cytochromes.

Nucleotide excision repair in the third kingdom.

Nucleotide excision repair, a general repair mechanism for removing DNA damage, is initiated by dual incisions bracketing the lesion. In procaryotes, the dual incisions result in excision of the damage in 12- to 13-nucleotide-long oligomers, and in eucaryotes they result in excision of the damage in the form of 24- to 32-nucleotide-long oligomers. We wished to find out if Archaea perform excision repair. Using cell extracts from Methanobacterium thermoautotrophicum, we found that this organism removes UV-induced (6-4) photoproducts in the form of 10- to 11-mers by incising the sixth to seventh phosphodiester bond 5' to the damage and the fourth phosphodiester bond 3' to the damage.

PTSD symptoms in Bosnian refugees 1 year after resettlement in the United States.

OBJECTIVE: The authors' goal was to describe the characteristics of posttraumatic stress disorder (PTSD) symptoms on resettlement in the United States and at 1-year follow-up among Bosnian refugees as well as possible factors affecting the PTSD symptom profile among these refugees. METHOD: They used standardized instruments to assess 34 Bosnian refugees for PTSD at resettlement in the United States and 1 year later. RESULTS: Fifteen of the refugees were diagnosed with PTSD at 1-year follow-up, compared with 25 at initial assessment. The average PTSD severity score at follow-up was 12.5, compared with 20.6 at initial assessment. At 1-year follow-up, 25 of the refugees experienced a decrease in severity of PTSD symptoms, one remained the same, and eight experienced an increase in severity. Older refugees were significantly more likely to have PTSD than younger refugees, and older refugees had more severe symptoms. CONCLUSIONS: The level of PTSD diagnosis and symptoms in Bosnian refugees remained substantial 1 year after their resettlement in the United States, although there were notable overall decreases. Older refugees appeared to be at greater risk.

Activation of methyl-SCoM reductase to high specific activity after treatment of whole cells with sodium sulfide.

Here, we report a method to generate the active form of methyl-SCoM reductase (MCR) from Methanosarcina thermophila. The protocol involves adding sodium sulfide to a growing cell culture prior to harvest to yield a "ready" (MCRox1) state of the enzyme. This method can also generate a ready state of the Methanobacterium thermoautotrophicum (strain Marburg) MCR. Experiments using sodium 35S-labeled sulfide indicate the ready state that is generated involves a Ni-S adduct. As was shown earlier for the Mb. thermoautotrophicum MCRox1 [Goubeaud, M., Schreiner, G. and Thauer, R. K. (1997) Eur. J. Biochem. 17, 2374-2377], this ready state is converted to the highly active MCRred1 form by reductive activation with Ti(III) citrate. The reduction of MCRox1 to MCRred1 with concomitant increase in activity demonstrated that MCRred1 is the active form of MCR from Ms. thermophila. We also observed the loss of the 35S-sulfide label from the enzyme when MCRox1 was converted to MCRred1. Other states of MCR could be generated in the whole cells by adding different potential ligands to the cell medium; for example, the MCRox2 state was generated by treating cells with sodium sulfite or sodium dithionite.

Individual change after genocide in Bosnian survivors of "ethnic cleansing": assessing personality dysfunction.

The authors used the SCID-DES (disorders of extreme stress) instrument to assess for personality change in Bosnian survivors of "ethnic cleansing." Twenty four refugees underwent systematic, trauma-focused, research assessments, including the SCID-DES interview. Overall, this group of Bosnian survivors had been severely traumatized as a result of the Serbian nationalists' genocide. However, no subject met diagnostic criteria for DES. The SCID-DES yields far lower rates of trauma-related personality change in Bosnian survivors of genocide than in adult survivors of prolonged early life traumas. Therefore, the DES construct may have better application to prolonged, interpersonal, early life traumas than to the prolonged, communal traumas of genocide.

Controlled study of psychiatric comorbidity in psychiatrically hospitalized young adults with substance use disorders.

OBJECTIVE: The purpose of this study was to examine DSM-III-R axis I and axis II comorbidity in psychiatrically hospitalized young adults with substance use disorders. METHOD: Structured diagnostic interviews were given to 117 consecutive inpatients. Seventy patients with substance use disorders and 47 patients without substance use disorders were compared. RESULTS: High rates of co-occurrence of axis I disorders were observed, but no disorder coexisted in the group with substance use disorders at a significantly higher rate than in the group without substance use disorders. Among axis II disorders, borderline personality disorder was diagnosed significantly more frequently in the group with substance use disorders. CONCLUSIONS: Significant additional diagnostic co-occurrence, defined as comorbidity, was observed only between borderline personality disorder and substance use disorders. The use of a relevant psychiatric comparison group allows for finer distinctions between covariation based on shared severity and comorbidity possibly based on shared pathophysiology.

Diagnostic comorbidity in hospitalized adolescents with conduct disorder.

We compared the diagnostic comorbidity of DSM-III-R axis I and axis II disorders in a sample of hospitalized adolescents with conduct disorder (CD) and a comparison group of hospitalized adolescents without conduct disorder (non-CD). Of 138 consecutively evaluated adolescents, 76 patients met criteria for CD and 62 did not. On axis I, CD was significantly comorbid with attention-deficit hyperactivity disorder (ADHD) and substance use disorders (SUDs). None of the personality disorders assessed showed differential association with CD. The comorbid relationships found within this sample suggest a strong association between CD, ADHD, and SUD in hospitalized teenagers. This finding underscores the clinical importance of conducting a thorough developmental assessment and, when indicated, of treating ADHD and SUD in conduct-disordered adolescents.

Psychiatric comorbidity differences in male and female adult psychiatric inpatients with substance use disorders.

To examine gender differences in the co-occurrence of DSM-III-R axis I disorders and axis II personality disorders in young adult psychiatric inpatients with substance use disorders (SUDs), a consecutive series of 70 inpatients (33 men and 37 women) with SUD were reliably assessed with structured diagnostic interviews. Higher rates of dysthymia and eating disorders were observed in SUD females and higher rates of cluster A personality disorders were observed in SUD males. No gender differences were found for depression or anxiety in our SUD inpatients; these findings contrast with gender ratios for these disorders in the general population. In conclusion, relatively few gender differences were found in young adult inpatients with SUD, even where they would be expected based on general population gender patterns.