A randomised controlled feasibility trial of a clinical protocol to manage hypotension during major non-cardiac surgery

Intra-operative hypotension is a risk factor for postoperative morbidity and mortality. Minimally invasive monitors that derive other haemodynamic parameters, such as stroke volume, may better inform the management of hypotension. As a prelude to a multicentre randomised controlled trial, we conducted a single-centre feasibility trial of a protocol to treat hypotension as informed by minimally invasive haemodynamic monitoring during non-cardiac surgery. We recruited adults aged ≥40 years with cardiovascular risk factors who underwent non-cardiac surgery requiring invasive arterial pressure monitoring. Participants were randomly allocated to usual care, or a clinical protocol informed by an arterial waveform contour analysis monitor. Participants, outcome assessors, clinicians outside operating theatres and analysts were blinded to treatment allocation. Feasibility was evaluated based on: consent rate; recruitment rate; structured feedback from anaesthesia providers; and between-group differences in blood pressure, processes-of-care and outcomes. The consent rate among eligible patients was 33%, with 30 participants randomly allocated to the protocol and 30 to usual care. Anaesthesia providers rated the protocol to be feasible and acceptable. The protocol was associated with reduced fluid balance and hypotension exposure in the peri-operative setting. Postoperative complications included: acute myocardial injury in 18 (30%); acute kidney injury in 17 (28%); and surgical site infection in 7 (12%). The severity of complications was rated as moderate or severe in 25 (42%) participants. In summary, this single-centre study confirmed the feasibility of a multicentre trial to assess the efficacy and safety of a physiologically guided treatment protocol for intra-operative hypotension based on minimally invasive haemodynamic monitors.

The meaning of critical thinking in diagnostic radiography

INTRODUCTION

The development and application of critical thinking skills is a requirement and expectation of higher education and clinical radiographic practice. There is a multitude of generic definitions of critical thinking, however, little is understood about what critical thinking means or how it develops through a course. Diagnostic radiography students struggle with demonstrating this skill to the desired expectation, and, in higher education it is assumed that students have an implicit understanding of what is required in relation to this expectation. This study explores radiography students' understanding and perceptions of the meaning of critical thinking in diagnostic radiography.

METHODS

The research framework sits within the interpretive paradigm and was designed as a longitudinal study conducted over a three-year study period. Semi-structured face-to-face interviews were employed as the means of gathering context-rich information from diagnostic radiography students (n = 13) who were purposively selected to participate in the study.

FINDINGS

Three themes were constructed following the analysis and interpretation of the interview data. The themes were logical thinking involving analysis and evaluation, the process of decision-making, and reflection and metacognition.

CONCLUSION

As participants progressed from year one to year three, they recognised that critical thinking comprised not only of cognitive skills but affective skills too. They attributed their developing understanding of the meaning of critical thinking to clinical placement learning, understanding written feedback, and the expectations of professional practice. Based on these findings a definition of critical thinking applicable to diagnostic radiography was developed.

IMPLICATIONS FOR RADIOGRAPHY EDUCATION AND PRACTICE

Understanding the meaning of critical thinking in relation to academic requirements and clinical placement learning is essential for diagnostic radiography students if they are to succeed in both settings.

0368 Sleep Health Among Transgender Women of Color in New York City: Preliminary Analyses of the Turnnt Study

Introduction

Little is known about sleep health among transgender and gender diverse populations. Even less is known about sleep among transgender women of color, a population that experiences considerable health disparity.

Methods

Interim baseline data were analyzed from the TURNNT (Trying to Understand Relationships, Networks and Neighborhoods among Transgender women of color) Study, an ongoing cohort of 350 HIV-negative transgender women of color in New York City. At baseline, items from the widely-used Pittsburgh Sleep Quality Index (PSQI) were used to measure typical sleep duration and subjective sleep quality. For example, typical sleep duration was measured with the PSQI item, “During the past month, how many hours of actual sleep did you get each night?”. Participant responses were analyzed descriptively; the Mann-Whitney U test was used to assess bivariate associations.

Results

As of November 2019, there were n=31 participants enrolled in TURNNT. Nearly half of participants earned less than $30,000 per year (48%) and in the 6 months before participation 61% had experienced food insecurity and 13% reported being unstably housed. Participants reported typically receiving 2-12 hours of sleep per night (median=6 hours). With short sleep defined as <7 hours per night, 55% reported this during the month prior to participation in the study, while 29% of participants rated their overall sleep quality as poor. Typical sleep duration was equivalent among participants with lower or higher incomes (5.5 vs 7 hours, p=0.3), but those who faced food insecurity reported less sleep (5 vs 7 hours, p<0.05) as did those who experienced housing instability (3.5 vs 7 hours, p<0.05).

Conclusion

Poor sleep health was common among our sample of transgender women of color, especially among those experiencing food insecurity and housing instability. Future research should examine multi-level correlates of poor sleep health such as network structures and neighborhood environments.

Support

The TURNNT (Trying to Understand Relationships, Networks and Neighborhoods among Transgender women of color) Study is funded through grants from the National Institute on Minority Health and Health Disparities (Grant Numbers: R01MD013554 and 3R01MD013554-02S1; Principal Investigator: Dustin T. Duncan, ScD).

Direct observations of submarine melt and subsurface geometry at a tidewater glacier

Ice loss from the world's glaciers and ice sheets contributes to sea level rise, influences ocean circulation, and affects ecosystem productivity. Ongoing changes in glaciers and ice sheets are driven by submarine melting and iceberg calving from tidewater glacier margins. However, predictions of glacier change largely rest on unconstrained theory for submarine melting. Here, we use repeat multibeam sonar surveys to image a subsurface tidewater glacier face and document a time-variable, three-dimensional geometry linked to melting and calving patterns. Submarine melt rates are high across the entire ice face over both seasons surveyed and increase from spring to summer. The observed melt rates are up to two orders of magnitude greater than predicted by theory, challenging current simulations of ice loss from tidewater glaciers.

Longitudinal study of CTX-M ESBL-producing E. coli strains on a UK dairy farm

The aim of this study was to investigate the bacterial strains and farm environment that may contribute to the persistence of ESBL-producing E. coli on a single UK dairy farm. A longitudinal study was conducted comprising 6 visits, between August and October 2010, followed by a further visit at approximately 69weeks after the initial visit. Faecal and environmental samples were collected from different parts of the farm. The persistence and extent of faecal shedding of ESBL E. coli by individual calves was also determined. Twenty two different PFGE types were identified. Four of these were persistent during the study period and were associated with serotypes: O98, O55, O141 and O33. The counts suggest that shedding in calf faeces was an important factor for the persistence of strains, and the data will be useful for parameterising mathematical models of the spread and persistence of ESBL strains within a dairy farm.

A survey of antimicrobial usage on dairy farms and waste milk feeding practices in England and Wales

The cause for the high prevalence of cefotaximase-producing Escherichia coli reported in dairy calves is unknown but may be partly due to the selective pressure of antimicrobial residues in waste milk (milk unfit for human consumption) fed to the calves. Antimicrobial use and waste milk feeding practices were investigated in 557 dairy farms in 2010/2011 that responded to a randomised stratified postal survey. The mean number of cases of mastitis per herd in the previous year was 47, and 93 per cent of respondents used antibiotic intra-mammary tubes to treat mastitis. The most frequently used lactating cow antibiotic tubes contained dihydrostreptomycin, neomycin, novobiocin, and procaine penicillin (37 per cent), and cefquinome (29 per cent). Ninety-six per cent of respondents used antibiotic tubes at the cessation of lactation ('drying off'). The most frequently used dry cow antibiotic tube (43 per cent) contained cefalonium. Frequently used injectable antibiotics included tylosin (27 per cent), dihydrostreptomycin and procaine penicillin (20 per cent) and ceftiofur (13 per cent). Eighty-three per cent of respondents (413) fed waste milk to calves. Of these 413, 87 per cent fed waste milk from cows with mastitis, and only one-third discarded the first milk after antibiotic treatment. This survey has shown that on more than 90 per cent of the farms that feed waste milk to calves, waste milk can contain milk from cows undergoing antibiotic treatment. On some farms, this includes treatment with third- and fourth-generation cephalosporins. Further work is underway to investigate the presence of these antimicrobials in waste milk.

The effects of reserpine and hypoxia on the amine-storing granules of the hamster carotid body

The carotid bodies from control, reserpine-treated, and hypoxia-treated hamsters were fixed with phosphate-buffered glutaraldehyde and osmium tetroxide, s-Collidine-buffered osmium tetroxide, or phosphate-buffered glutaraldehyde followed by potassium dichromate incubation. Following glutaraldehyde-osmium tetroxide fixation no differences in density or population of the electron-opaque granules in the glomus cells of either control or experimental animals were observed. With s-Collidine-buffered osmium tetroxide and the glutaraldehyde-dichromate technique a marked decrease in density without an appreciable reduction in number of granules was noted after reserpine treatment, while in hypoxia-treated hamsters the density and population of the granules were not different from those of the controls. The results indicate that reserpine depletes the amines without granule disappearance and that hypoxia does not affect the amine content of the granules. It is suggested that following glutaraldehyde-osmium tetroxide double fixation, persistence of the density of the granules in reserpine-treated animals is due primarily to the nonamine content, and that the amines in the glomus cells are probably not directly involved in the respiratory reflex.

Biochemical features of maize tissues with different capacities to regenerate plants

Metabolic profiling using GC-MS and LC-MS analyses of soluble metabolites and cell wall bound phenolic compounds from maize calluses of different morphogenic competence revealed a number of biochemical characteristics that distinguish tissues with high plant regeneration ability from tissues that cannot efficiently regenerate plants in vitro. Maize cultures of different ages from H99 (compact type I callus) and HiII (friable type II callus) were divided into two different samples: regenerable (R) and non-regenerable (NR) based on known morphologies. Tissues from both genotypes with high morphogenic potential had higher asparagine and aspartate and indole-3-butenol concentrations, decreased sugar and DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) concentrations, low levels of 4-aminobutyric acid (GABA) and chlorogenic acid and lower levels of feruloyl- and sinapoyl glucosides compared to NR tissues. The ether bound cell wall phenolics of tissues with high regeneration potential had higher levels of the predominant G (guaiacyl) units and lower levels of H (p-hydroxyphenyl) and S (syringyl) units and higher ferulic acid/coumaric acid and ferulic acid/diferulic acid ratios. The same trends were found with the ester-bound phenolics of HiII, however, there were only small differences between the H99 R and NR tissues. Concentrations of the major sugars, organic acids, amino acids and soluble aromatic compounds tended to increase as the time after culture initiation increased. The results show that there are differences in general metabolism, phenolic secondary compounds and cell wall composition between R and NR cell types.

A comparison of bispectral index and entropy monitoring, in patients undergoing embolization of cerebral artery aneurysms after subarachnoid haemorrhage

BACKGROUND

Processed EEG monitoring of anaesthetic depth could be useful in patients receiving general anaesthesia following subarachnoid haemorrhage. We conducted an observational study comparing performance characteristics of bispectral index (BIS) and entropy monitoring systems in these patients.

METHODS

Thirty-one patients of the World Federation of Neurosurgeons grades 1 and 2, undergoing embolization of cerebral artery aneurysms following acute subarachnoid haemorrhage, were recruited to have both BIS and entropy monitoring during general anaesthesia. BIS and entropy indices were matched to clinical indicators of anaesthetic depth. Anaesthetists were blinded to the anaesthetic depth monitoring indices. Analysis of data from monitoring devices allowed calculation of prediction probability (P(K)) constants, and receiver operating characteristic (ROC) analysis to be performed.

RESULTS

BIS and entropy [response entropy (RE), state entropy (SE)] performed well in their ability to show concordance with clinically observed anaesthetic depth. P(K) values were generally high (BIS 0.966-0.784, RE 0.934-0.663, SE 0.857-0.701) for both forms of monitoring. ROC curve analysis shows a high sensitivity and specificity for all monitoring indices when used to detect the presence or absence of eyelash reflex. Area under curve for BIS, RE and SE to detect the absence or presence of eyelash reflex was 0.932, 0.888 and 0.887, respectively. RE provides earlier warning of return of eyelash reflex than BIS.

CONCLUSION

BIS and entropy monitoring perform well in patients who receive general anaesthesia after good grade subarachnoid haemorrhage.

Meeting everyday water needs--a company's contribution

As a packaged consumer goods company serving mass markets around the world for household and personal hygiene products, laundry detergents and foods, Unilever's business is inextricably linked with consumers' interest in meeting their everyday water needs. Once the basic need for drinking water is met, almost all other "everyday" water needs derive from consumption associated with the type of products Unilever sells. Use of some of these products, such as basic toilet soap, involve "actual" water consumption; others, such as margarine, concern "virtual" water consumption through agricultural production. Global scenarios for water and sanitation present a major challenge to long-term business strategies that assume sustained economic growth particularly in emerging and developing markets. Responsibility for finding and delivering solutions lies with all major actors in society. For companies such as Unilever, a priority is to help break the link between economic development on the one hand, and increased water use and water degradation on the other. Water catchment level perspectives are central to realising this vision. Unilever uses such a framework, building an experience-based model that demonstrates how a "consumer" company can engage in meeting everyday water needs with a sustained positive impact.

A concise synthesis of turneforcidine via a metalloiminium ion cyclization terminated by the 2-(methylthio)-3-(trimethylsilyl)-1-propenyl moiety

A concise synthetic route to racemic turneforcidine (1) is described that relies on the stereocontrolled cyclization of the 2-(methylthio)-3-(trimethylsilyl)-1-propenyl bearing imine 5 in the presence of TiCl(4). Reaction: see text.

Parents who report using illicit drugs: findings and implications from the DRUGNET study

In recent years, a national discussion has emerged concerning what parents should tell their children about their own past drug use. DRUGNET is an ongoing, on-line survey of successful, healthy, adults who occasionally use illicit drugs. This paper reviews data from a subset of this survey, namely, those respondents who were parents with self-reported use of at least one illicit drug. The sample (n = 325) was predominantly white men who reported having above average education and household incomes. Their mental health as measured by the General Well-being Schedule was similar to the national norm. Respondents reported using drugs to manage parental stress and expressed concerns over how to communicate with their children and legal risks related to their own drug use. The limitations and the implications of these data are discussed.

Drug use and mental well being among a sample of undergraduate and graduate college students

Stress related disorders in college students are widespread and largely preventable. Students do not have the preventative skills necessary to manage stress in their lives and, because of the inability to cope, students may turn to alcohol and drugs to alleviate the pressures they are experiencing. The purpose of this study was to describe the association between stress and alcohol and drug use. A total of 772 undergraduate and graduate students from a small, elite, private university were randomly selected from 4000 students to complete two anonymous questionnaires. The Core Alcohol and Drug Survey identified the frequency and consequences of alcohol and drug use, and the General-Well Being Schedule was used to assess subjective well being and mental health status. The results of this study revealed that, for this sample of students, health behaviors such as using drugs recreationally and drinking alcohol played an associative role with general well being. A significant relationship was also found between student participation in intramural or club sports and positive mental well being.

Characterization of active-site mutants of Schizosaccharomyces pombe phosphoglycerate mutase. Elucidation of the roles of amino acids involved in substrate binding and catalysis

The roles of a number of amino acids present at the active site of the monomeric phosphoglycerate mutase from the fission yeast Schizosaccharomyces pombe have been explored by site-directed mutagenesis. The amino acids examined could be divided broadly into those presumed from previous related structural studies to be important in the catalytic process (R14, S62 and E93) and those thought to be important in substrate binding (R94, R120 and R121). Most of these residues have not previously been studied by site-directed mutagenesis. All the mutants except R14 were expressed in an engineered null strain of Saccharomyces cerevisiae (S150-gpm:HIS) in good yield. The R14Q mutant was expressed in good yield in the transformed AH22 strain of S. cerevisiae. The S62A mutant was markedly unstable, preventing purification. The various mutants were purified to homogeneity and characterized in terms of kinetic parameters, CD and fluorescence spectra, stability towards denaturation by guanidinium chloride, and stability of phosphorylated enzyme intermediate. In addition, the binding of substrate (3-phosphoglycerate) to wild-type, E93D and R120,121Q enzymes was measured by isothermal titration calorimetry. The results provide evidence for the proposed roles of each of these amino acids in the catalytic cycle and in substrate binding, and will support the current investigation of the structure and dynamics of the enzyme using multidimensional NMR techniques.

Organization of orthopaedic trauma services: a survey of the Orthopaedic Trauma Association

OBJECTIVES

This study was undertaken to collect information about the organization of orthopaedic trauma services in different types of hospitals, with particular emphasis on hospital support arrangements in different practice situations.

DESIGN

A survey was sent to all members of the Orthopaedic Trauma Association (OTA) as part of the organization's newsletter. Fractoids. In addition, the survey was distributed by the OTA's E-mail discussion list, ORT-1.

MAIN OUTCOME MEASUREMENTS

The survey included questions about the size and nature of the hospital, resident involvement, academic affiliation, number of orthopaedic physician staff, training of the staff, presence of an organized orthopaedic trauma service, distribution of call and patients, and hospital support.

RESULTS

Fifty-seven responses were received from North American centers, of which six were duplications. Responses came from institutions of all types and sizes, although most came from urban, Level 1 trauma centers with academic affiliation. Twenty-nine hospitals had a designated orthopaedic trauma service, and twenty-six had a director. Eighteen institutions had ancillary staff (nurses, physician's assistants, etc.) assigned to the orthopaedic trauma service. Hospitals with an academic affiliation were statistically more likely to have a designated orthopaedic trauma service and to distribute trauma patients by subspecialty expertise. In hospitals with a designated orthopaedic trauma service or director, it was more common to have ancillary support staff and to have it funded by the hospital, although the differences did not rise to statistical significance.

CONCLUSIONS

There are differences in organization of orthopaedic trauma care between hospitals, which may be related to hospital size, academic affiliation, and orthopaedic department organization. Further study is necessary to determine whether organizational differences translate into differences in patient outcome after trauma.

The relationship of self-injurious behavior and aggression to social skills in persons with severe and profound learning disability

In this study, we investigated differences in social skills among four groups of individuals with severe and profound learning disabilities. The comparison groups were composed of individuals engaging in self-injurious behavior, aggression, both behaviors, or neither of the behaviors. We measured social skills using the Matson Evaluation of Social Skills for Individuals with Severe Retardation, a standardized assessment of social skills in persons with severe or profound learning disability. The results indicated that individuals displaying maladaptive behaviors exhibited a restricted range of social behaviors compared to controls. Also, group membership based on self-injury and aggression was predicted based on profiles of scores on the Matson Evaluation of Social Skills for Individuals with Severe Retardation. These findings are consistent with reports in other studies that note social skills deficits in aggressive and self-injurious persons with learning disabilities. However, in this case a standardized assessment of these deficits was possible and specific skills problems were identified. Implications of the findings for identification and treatment of self-injury and aggression are discussed.

The spineless-aristapedia and tango bHLH-PAS proteins interact to control antennal and tarsal development in Drosophila

The Drosophila spineless (ss) gene encodes a basic-helix-loop-helix-PAS transcription factor that is required for proper specification of distal antennal identity, establishment of the tarsal regions of the legs, and normal bristle growth. ss is the closest known homolog of the mammalian aryl hydrocarbon receptor (Ahr), also known as the dioxin receptor. Dioxin and other aryl hydrocarbons bind to the PAS domain of Ahr, causing Ahr to translocate to the nucleus, where it dimerizes with another bHLH-PAS protein, the aryl hydrocarbon receptor nuclear translocator (Arnt). Ahr:Arnt heterodimers then activate transcription of target genes that encode enzymes involved in metabolizing aryl hydrocarbons. In this report, we present evidence that Ss functions as a heterodimer with the Drosophila ortholog of Arnt, Tango (Tgo). We show that the ss and tgo genes have a close functional relationship: loss-of-function alleles of tgo were recovered as dominant enhancers of a ss mutation, and tgo-mutant somatic clones show antennal, leg, and bristle defects almost identical to those caused by ss(−) mutations. The results of yeast two-hybrid assays indicate that the Ss and Tgo proteins interact directly, presumably by forming heterodimers. Coexpression of Ss and Tgo in Drosophila SL2 cells causes transcriptional activation of reporters containing mammalian Ahr:Arnt response elements, indicating that Ss:Tgo heterodimers are very similar to Ahr:Arnt heterodimers in DNA-binding specificity and transcriptional activation ability. During embryogenesis, Tgo is localized to the nucleus at sites of ss expression. This localization is lost in a ss null mutant, suggesting that Tgo requires heterodimerization for translocation to the nucleus. Ectopic expression of ss causes coincident ectopic nuclear localization of Tgo, independent of cell type or developmental stage. This suggests that the interaction of Ss and Tgo does not require additional signals, unlike the ligand-dependent interaction of Ahr and Arnt. Despite the very different biological roles of Ahr and Arnt in insects and mammals, the molecular mechanisms by which these proteins function appear to be largely conserved.

The folding and assembly of the dodecameric type II dehydroquinases

The dodecameric type II dehydroquinases (DHQases) have an unusual quaternary structure in which four trimeric units are arranged with cubic 23 symmetry. The unfolding and refolding behaviour of the enzymes from Streptomyces coelicolor and Mycobacterium tuberculosis have been studied. Gel-permeation studies show that, at low concentrations (0.5 M) of guanidinium chloride (GdmCl), both enzymes dissociate into trimeric units, with little or no change in the secondary or tertiary structure and with a 15% loss (S. coelicolor) or a 55% increase (M. tuberculosis) in activity. At higher concentrations of GdmCl, both enzymes undergo sharp unfolding transitions over narrow ranges of the denaturant concentration, consistent with co-operative unfolding of the subunits. When the concentration of GdmCl is lowered by dilution from 6 M to 0.55 M, the enzyme from S. coelicolor refolds in an efficient manner to form trimeric units, with more than 75% regain of activity. Using a similar approach the M. tuberculosis enzyme regains less than 35% activity. From the time courses of the changes in CD, fluorescence and activity of the S. coelicolor enzyme, an outline model for the refolding of the enzyme has been proposed. The model involves a rapid refolding event in which approximately half the secondary structure is regained. A slower folding process follows within the monomer, resulting in acquisition of the full secondary structure. The major changes in fluorescence occur in a second-order process which involves the association of two folded monomers. Regain of activity is dependent on a further associative event, showing that the minimum active unit must be at least trimeric. Reassembly of the dodecameric S. coelicolor enzyme and essentially complete regain of activity can be accomplished if the denatured enzyme is dialysed extensively to remove GdmCl. These results are discussed in terms of the recently solved X-ray structures of type II DHQases from these sources.

The role of the C-terminal region in phosphoglycerate mutase

Removal of the C-terminal seven residues from phosphoglycerate mutase from Saccharomyces cerevisiae by limited proteolysis is associated with loss of mutase activity, but no change in phosphatase activity. The presence of the cofactor 2, 3-bisphosphoglycerate, or of the cofactor and substrate 3-phosphoglycerate together, confers protection against proteolysis. The substrate alone offers no protection. Replacement of either or both of the two lysines at the C-terminus by glycines has only limited effects on the kinetic properties of phosphoglycerate mutase, indicating that these residues are unlikely to be involved in crucial electrostatic interactions with the substrate, intermediate or product in the reaction. However, the double-mutant form of the enzyme is more sensitive to proteolysis and is no longer protected against proteolysis by the presence of cofactor. The proteolysed wild-type and two of the mutated forms of the enzyme show a reduced response to 2-phosphoglycollate, which enhances the instability of the phospho form of the native enzyme. The phosphoglycerate mutase from Schizosaccharomyces pombe, which lacks the analogous C-terminal tail, has an inherently lower mutase activity and is also less responsive to stimulation by 2-phosphoglycollate. It is proposed that the C-terminal region of phosphoglycerate mutase helps to maintain the enzyme in its active phosphorylated form and assists in the retention of the bisphosphoglycerate intermediate at the active site. However, its role seems not to be to contribute directly to ligand binding, but rather to exert indirect effects on the transfer of the phospho group between substrate, enzyme, intermediate and product.

Purification and characterization of pyruvate kinase from Schizosaccharomyces pombe: evidence for an unusual quaternary structure

Earlier attempts to purify and characterize nonrecombinant pyruvate kinase from Schizosaccharomyces pombe proved difficult due to problems associated with the instability of the protein. The enzyme has been overexpressed in Saccharomyces cerevisiae strain AH22, permitting studies to determine the conditions required to stabilize the enzyme during purification. Recombinant S. pombe pyruvate kinase was purified by a combination of ion-exchange chromatography and gel filtration. The purified enzyme showed sigmoidal kinetics with respect to PEP; in the presence of FBP, the kinetics were restored to Michaelis-Menten behavior. With respect to ADP, the Hill coefficient was not affected by FBP. Determination of the molecular mass of the purified enzyme by ultracentrifugation showed that it behaved as a dimer-tetramer system with a Kd of approximately 1 microM.

Alcoholic patients' experience and attitudes on pharmacotherapy for alcoholism

Clinical studies have demonstrated that pharmacotherapies may improve alcoholism treatment, when combined with traditional psychosocial therapies. Recently, the opioid antagonist, naltrexone, has been approved as an adjunct in alcoholism treatment, and several other pharmacotherapies for alcoholism are under development. Because of the abstinence orientation of many patients, we assessed attitudes regarding medications, and explored whether alcoholic patients would consider taking medication as part of their alcoholism treatment. Active patients (n = 127) in three alcohol treatment settings were surveyed with an anonymous questionnaire which asked demographics, personal alcoholism history and questions about medication use. They were asked whether they felt disulfiram and naltrexone were helpful for alcoholics and whether they would take the medications. The findings indicate that the patients were divided about the use of pharmacotherapy for the treatment of alcoholism. The strongest predictor of willingness to take medication was a belief that the medication would be helpful.

Structure of the Shigella dysenteriae haem transport locus and its phylogenetic distribution in enteric bacteria

The ability to transport and use haemin as an iron source is frequently observed in clinical isolates of Shigella spp. and pathogenic Escherichia coli. We found that many of these haem-utilizing E. coli strains contain a gene that hybridizes at high stringency to the S. dysenteriae type 1 haem receptor gene, shuA. These shuA-positive strains belong to multiple phylogenetic groups and include clinical isolates from enteric, urinary tract and systemic infections. The distribution of shuA in these strains suggests horizontal transfer of the haem transport locus. Some haem-utilizing pathogenic E. coli strains did not hybridize with shuA, so at least one other haem transport system is present in this group. We also characterized the chromosomal region containing shuA in S. dysenteriae. The shuA gene is present in a discrete locus, designated the haem transport locus, containing eight open reading frames. Several of the proteins encoded in this locus participate with ShuA in haem transport, as a Salmonella typhimurium strain containing the entire haem transport locus used haem much more efficiently than the same strain containing only shuA. The haem transport locus is not present in E. coli K-12 strains, but the sequences flanking the haem transport locus in S. dysenteriae matched those at the 78.7 minute region of E. coli K-12. The junctions and flanking sequences in the shuA-positive pathogenic E. coli strains tested were nearly identical to those in S. dysenteriae, indicating that, in these strains, the haem transport locus has an organization similar to that in S. dysenteriae, and it is located in the same relative position on the chromosome.

Abscisic acid-regulated Glb1 transient expression in cultured maize P3377 cells

In a study of the 5'-flanking sequence of the Zea mays L. (maize) Glb1 gene in vitro, serial promoter deletions were generated and linked with the β-glucuronidase (GUS) reporter gene. The promoter deletion-GUS fusions were introduced into the maize P3377 cell line by particle bombardment. GUS assays indicated that treatment of the maize cultured cells with abscisic acid (ABA) was required for Glb1-driven GUS transient expression, and that the -272-bp sequence of the Glb1 promoter was sufficient for ABA-regulated expression of GUS. The longest undeleted sequence used, -1391 GUS, showed relatively low expression which could be indicative of an upstream silencer element in the Glb1 promoter between -1391 and -805. Further studies show that the Glb1-driven GUS activity of bombarded maize P3377 cells increases with increasing ABA concentration (up to 100-300 μM). Site-directed mutagenesis of a putative ABA response element, Em1a, abolished GUS expression in P3377 cells. This observation indicated that the Em1a sequence in the Glb1 5' regulatory region is responsible for the positive ABA regulation of gene expression.

Antidepressant interactions with warfarin

The interactions between warfarin and antidepressants can have potentially serious consequences resulting from enhanced or reduced anticoagulant activity. Information about such interactions was obtained from a Medline and hand search of the published literature, and by directly contacting manufacturers. The different classes of antidepressants are discussed in turn. The possible mechanisms are considered with particular reference to the cytochrome p450 system. From currently available data on the newer antidepressants our conclusions are that citalopram, nefazodone and sertraline may be relatively less likely to interact with warfarin. Fluoxetine, fluvoxamine, paroxetine and moclobemide appear to have the highest potential of the antidepressants for interactions. There is insufficient data on venlafaxine to make a prediction. The clinical implications of these findings are discussed and specific recommendations for International Normalized Ratio monitoring are suggested.