Biofilm formation as a developmental process.
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Biofilms↗
Biomedical subjects
L A Pratt
Publications and source records attributed to L A Pratt.
The changing profile of nursing home residents: 1985-1997.
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Activities of Daily Living↗
Trends in vision and hearing among older Americans.
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Black or African American↗
Risk of heavy drinking and alcohol use disorders in social phobia: a prospective analysis.
OBJECTIVE: The risks of heavy drinking and alcohol abuse/dependence were prospectively assessed among individuals with DSM-III social phobia and individuals with subclinical social phobia (irrational fear of social situations without significant impairment or avoidance). METHOD: The baseline interview for the Baltimore site of the Epidemiologic Catchment Area program was completed in 1981. Between 1993 and 1996 the original cohort was traced. Among the 1,161 individuals who did not have episodes of heavy drinking or current or prior alcohol abuse/dependence at baseline, logistic regression was used to assess the association of social phobia and subclinical social phobia with incident alcohol abuse/dependence and incident episodic heavy drinking. RESULTS: Among the 33 individuals with a DSM-III diagnosis of social phobia at baseline, only one developed heavy drinking by follow-up, and none developed alcohol abuse or dependence. Among the 84 individuals with a history of subclinical social phobia, the cumulative incidence rates of heavy drinking and alcohol abuse/dependence were 119 per 1,000 and 95 per 1,000, respectively. After adjustment for sex, age, race, education level, marital status, age at first alcohol intoxication, and history of other psychiatric or illicit drug use disorder, the estimated relative risk for heavy drinking among respondents with subclinical social phobia was 2.41, and the estimated relative risk for alcohol abuse/dependence was 2.30, relative to respondents without social phobia or subclinical social fears. CONCLUSIONS: The data may improve our understanding of the relationship of social phobia and risk for alcohol conditions, which may have important implications for preventive measures.
Adolescent↗
Mental disorders and the incidence of migraine headaches in a community sample: results from the Baltimore Epidemiologic Catchment area follow-up study.
BACKGROUND: The cross-sectional relation between migraine headaches and affective disorders has been demonstrated in studies of clinical and community populations. Few studies have investigated the prospective relation between psychiatric disorders and migraine headaches. METHODS: A prospective follow-up of the Baltimore, Md, cohort of the Epidemiologic Catchment Area Study assessed psychopathologic features in 1981 and again between 1993 and 1996. Interviews included a history of headaches at baseline and self-reported assessment of migraine headaches at follow-up. Risk estimates for incident migraine headaches by 1981 demographic variables and psychopathologic features were calculated. The cross-sectional association between prevalent migraine and lifetime psychiatric diagnoses was estimated. RESULTS: In the at-risk population of 1343, there were 118 incident cases of migraine headaches. The age- and sex-specific incident rates of migraine headaches followed the expected patterns, with younger age and female sex identified as risk factors. In cross-sectional analyses, major depression (odds ratio, 3.14; 95% confidence interval, 2.03-4. 84) and panic disorder (odds ratio, 5.09; 95% confidence interval, 2. 65-9.79) had the strongest associations, and alcohol and other substance abuse were not associated. In logistic regression models including age, sex, and psychiatric illness in 1981, only phobia was predictive of incident migraines (odds ratio, 1.70; 95% confidence interval, 1.11-2.58). Affective disorders were not predictive of incident migraine headaches. Including a history of tricyclic antidepressant use did not change the results. CONCLUSIONS: There is a strong cross-sectional relation between affective disorders and migraine headaches in this cohort. However, there is no association between antecedent affective disorders and incident migraine headaches in this population-based prospective study.
Adolescent↗
The outer membrane protein, antigen 43, mediates cell-to-cell interactions within Escherichia coli biofilms.
Transcription of the agn43 locus, which specifies an outer membrane protein of Escherichia coli, is regulated in a phase-variable fashion by the OxyR-DNA binding protein and Dam methylase. Despite its well-characterized regulation, the function of Ag43 has remained elusive until now. Previous studies indicated that Ag43 mediates autoaggregation of certain strains of E. coli in liquid culture. Given this phenotype, we examined the role of Ag43 in biofilm formation. Here, we report that Ag43 contributes to E. coli biofilm formation in glucose-minimal medium, but not in Luria-Bertani broth. In addition, we show that flagellar-mediated motility is required for biofilm formation in both rich and minimal environments. Altogether, our results suggest that E. coli uses both common and specific gene sets for the development of biofilms under various growth conditions.
Adhesins, Bacterial↗
Exopolysaccharide production is required for development of Escherichia coli K-12 biofilm architecture.
Although exopolysaccharides (EPSs) are a large component of bacterial biofilms, their contribution to biofilm structure and function has been examined for only a few organisms. In each of these cases EPS has been shown to be required for cellular attachment to abiotic surfaces. Here, we undertook a genetic approach to examine the potential role of colanic acid, an EPS of Escherichia coli K-12, in biofilm formation. Strains either proficient or deficient in colanic acid production were grown and allowed to adhere to abiotic surfaces and were then examined both macroscopically and microscopically. Surprisingly, we found that colanic acid production is not required for surface attachment. Rather, colanic acid is critical for the formation of the complex three-dimensional structure and depth of E. coli biofilms.
Bacterial Adhesion↗
Genetic approaches to study of biofilms.
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Bacteria↗
Genetic analyses of bacterial biofilm formation.
Bacterial biofilms are generally described as surface-associated bacterial communities comprising exopolysaccharide-surrounded microcolonies. Interspersed between these microcolonies are water-filled channels that may serve as primitive circulatory systems. Over the past few years, much progress has been made in our understanding of the development of bacterial biofilms. This progress is largely due to the recent focus on analyzing biofilms using genetic and molecular biological approaches. Specifically, researchers have begun to identify the genetic components required for the formation of single-species bacterial biofilms. These findings are leading us to an understanding of the steps involved in initiating biofilm formation and the cellular components required to accomplish these steps.
Bacteria↗
The psychiatric profile of patients with chronic diseases who do not receive regular medical care.
OBJECTIVE: To assess the relationship between psychiatric disorders and lack of regular medical care in individuals with chronic medical diseases. METHODS: Nine hundred sixty-three respondents to the household-based Baltimore Epidemiologic Catchment Area (ECA) Follow-Up Study were interviewed in 1981, 1982, and 1993-1996. The main outcome measures were: 1) not receiving regular care from a health professional for an active chronic medical condition in 1981, 2) persistent lack of regular medical care, and 3) leaving regular medical care. RESULTS: In cross-sectional analyses, having a psychiatric disorder (OR 1.70, 95% CI 1.17-2.48) was associated with not receiving regular medical care. This was mostly due to individuals with phobic disorder (OR 1.57, 95% CI 1.02-2.43). In prospective analyses, depression (RR 2.4, p < 0.04) and alcohol abuse (RR 2.9, p < 0.001) predicted leaving regular medical care one year later. Phobic disorder (RR 2.8, p < 0.001) predicted leaving care thirteen years later. CONCLUSIONS: Psychiatric disorders appear to place an individual at risk for irregular medical care. Studies of the quality and continuity of care for patients with chronic medical conditions should include measures of common psychiatric conditions.
Adolescent↗
Psychopathology as a predictor of disability: a population-based follow-up study in Baltimore, Maryland.
To determine whether psychopathology is associated with disability as a result of underlying physical illness or whether such psychopathology antedates disability and is an independent determinant of disability, the authors conducted a nested case-control study within the Epidemiologic Catchment Area Follow-up Study in Baltimore, Maryland. From a 1981 random sample of 3,481 persons from Baltimore interviewed for psychopathology, disability, and other comorbidity, 1,920 who were alive in 1993 were traced and were reinterviewed with a similar instrument. Within the study population, 168 new cases of disability were identified as occurring between 1981 and 1993, as measured by the inability to perform activities of daily living. These cases were compared with 1,715 controls who reported no disability. The sociodemographic factors that were significantly related to incident disability in this analysis were age, female gender, and less than a high school education. These comparisons revealed associations of incident disability in activities of daily living with almost all antecedent chronic physical illnesses. Significant age- and gender-adjusted associations were observed between incident disability in activities of daily living and antecedent (in 1981) alcohol abuse and dependence (odds ratio (OR)=2.5, 95% confidence interval (CI) 1.5-4.2), major depressive disorder (OR=4.2, 95% CI 2.2-8.3), and phobia (OR=1.9, 95% CI 1.3-2.8). The adjusted odds ratio for the joint effect of antecedent depression and chronic physical illness on incident disability in activities of daily living was 17.0 (95% CI 6.9-41.7). There was a significant independent effect of antecedent major depression on activities of daily living disability. The effect of psychopathology on incident disability is nonspecific as to type of baseline chronic physical illness. Such a finding has important implications for defining strategies to prevent disability.
Adolescent↗
Crl stimulates RpoS activity during stationary phase.
RpoS, an alternative primary sigma factor, has been shown to be regulated at multiple levels, including transcription, translation and protein stability. Here, we present evidence that suggests that RpoS is regulated at yet another level by the product of the crl gene. The crl gene was first thought to encode the major curlin subunit of curli (curli are surface structures that are induced by growth into stationary phase under conditions of low osmolarity and low temperature). Later, it was determined that crl actually contributes in a positive fashion to stimulate transcription of csgBA, the true locus encoding for the major subunit of curli. RpoS is also required for normal stationary-phase induction of csgBA. We found that lesions in crl, like lesions in rpoS, cause increased transcription of ompF during stationary phase. Taken together, these observations prompted us to analyse the effects of crl on an additional RpoS-regulated phenomenon. We found that a crl null allele influences expression of RpoS-regulated genes in a fashion similar to an rpoS null allele. Genetic evidence suggests that crl and rpoS function in a single pathway and that Crl functions upstream, or in concert with, RpoS. Although the effects of Crl on RpoS-regulated genes is entirely dependent on the integrity of RpoS, the presence of a crl null allele does not decrease the level of RpoS protein. Thus, we propose that Crl stimulates the activity of the RpoS regulon by stimulating RpoS activity during stationary phase.
Bacterial Proteins↗
Genetic analysis of Escherichia coli biofilm formation: roles of flagella, motility, chemotaxis and type I pili.
We have used Escherichia coli as a model system to investigate the initiation of biofilm formation. Here, we demonstrate that E. coli forms biofilms on multiple abiotic surfaces in a nutrient-dependent fashion. In addition, we have isolated insertion mutations that render this organism defective in biofilm formation. One-half of these mutations was found to perturb normal flagellar function. Using defined fli, flh, mot and che alleles, we show that motility, but not chemotaxis, is critical for normal biofilm formation. Microscopic analyses of these mutants suggest that motility is important for both initial interaction with the surface and for movement along the surface. In addition, we present evidence that type I pili (harbouring the mannose-specific adhesin, FimH) are required for initial surface attachment and that mannose inhibits normal attachment. In light of the observations presented here, a working model is discussed that describes the roles of both motility and type I pili in biofilm development.
Bacterial Adhesion↗
Depression, psychotropic medication, and risk of myocardial infarction. Prospective data from the Baltimore ECA follow-up.
BACKGROUND: There is suggestive evidence that depression increases risk of myocardial infarction (MI), but there are no prospective studies in which the measure of depression corresponds to clinical criteria. This study examines prospectively whether a major depressive episode increases the risk of incident MI and evaluates the role of psychotropic medication use in this relationship. METHODS AND RESULTS: The study is based on a follow-up of the Baltimore cohort of the Epidemiologic Catchment Area Study, a survey of psychiatric disorders in the general population. A history of major depressive episode, dysphoria (2 weeks of sadness), and psychotropic medication use were assessed in 1981, and self-reported MI was assessed in 1994. Sixty-four MIs were reported among 1551 respondents free of heart trouble in 1981. Compared with respondents with no history of dysphoria, the odds ratio for MI associated with a history of dysphoria was 2.07 (95% CI, 1.16 to 3.71), and the odds ratio associated with a history of major depressive episode was 4.54 (95% CI, 1.65 to 12.44), independent of coronary risk factors. In multivariate models, use of barbiturates, meprobamates, phenothiazines, and lithium was associated with an increased risk of MI, whereas use of tricyclic antidepressants and benzodiazepines was not. Among individuals with no history of dysphoria, only lithium use was significantly associated with MI. CONCLUSIONS: These data suggest that a history of dysphoria and a major depressive episode increase the risk of MI. The association between psychotropic medication use and MI is probably a reflection of the primary relationship between depression and MI.
Adolescent↗
The response regulator SprE controls the stability of RpoS.
In Escherichia coli, the sigma factor, RpoS, is a central regulator in stationary-phase cells. We have identified a gene, sprE (stationary-phase regulator), as essential for the negative regulation of rpoS expression. SprE negatively regulates the rpoS gene product at the level of protein stability, perhaps in response to nutrient availability. The ability of SprE to destabilize RpoS is dependent on the ClpX/ClpP protease. Based on homology, SprE is a member of the response regulator family of proteins. SprE is the first response regulator identified that is implicated in the control of protein stability. Moreover, SprE is the first reported protein that appears to regulate rpoS in response to a specific environmental parameter.
ATPases Associated with Diverse Cellular Activitie↗
Description of antipanic therapy in a prospective longitudinal study.
The authors present a summary scale for assessing the percentage of patients in a large longitudinal study of panic disorder who received proven effective psychopharmacologic treatment. Such a scale provides a means for assessing and comparing somatic treatments of panic disorder across medication classes. The antipanic therapy levels were applied to data on medication treatment received by 492 patients participating in a naturalistic study and reflect psychopharmacologic treatment prescribed in 11 academic centers. Results show that among patients treated by psychiatrists at major teaching hospitals only 54% of the most symptomatic groups received optimal pharmacologic treatment. Among less symptomatic patients, who nonetheless met full criteria for panic disorder with or without agoraphobia, only 43% received maximal therapy.
Adult↗
From acids to osmZ: multiple factors influence synthesis of the OmpF and OmpC porins in Escherichia coli.
In Escherichia coli, levels of the two major outer membrane porin proteins, OmpF and OmpC, are regulated in response to a variety of environmental parameters, and numerous factors have been shown to influence porin synthesis. EnvZ and OmpR control porin-gene transcription in response to osmolarity, and the antisense RNA, MicF, influences ompF translation. In contrast to these characterized factors, some of the components reported to influence porin expression have only modest effects and/or act indirectly. For others, potential regulatory roles, although intriguing, remain elusive. Here we review many of the components that have been reported to influence porin expression, address the potential regulatory nature of these components, and discuss how they may contribute to a regulatory network controlling porin synthesis.
Acids↗
Suicidal behavior in patients with panic disorder: retrospective and prospective data.
This paper examines factors associated with suicidal behavior in patients with anxiety disorders. HARP is a naturalistic, prospective, longitudinal follow-up study. This paper examines 527 subjects with panic disorder (with or without agoraphobia). 9% of the subjects reported past suicidal behavior. Factors associated with suicidal behavior were depressive disorders, substance abuse, eating disorders, PTSD and personality disorders as well as having early onset of the first anxiety or depressive disorder. Subjects had a 4.5% P of suicidal behavior during the first 30 months of follow-up. All prospectively recorded suicidal behavior occurred in subjects with depressive disorders. In these panic disorder patients, suicidal behavior rarely occurred in the absence of affective disorders. Certain nondepressive disorders also substantially increased the risks of suicide attempts/gestures.
Adolescent↗