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Biomedical subjects

M Steele

Publications and source records attributed to M Steele.

At least 19 recordsLinked to original sources

Evaluation of accuracy and repeatability of identification of food-borne pathogens by automated bacterial identification systems.

The performances of five automated microbial identification systems, relative to that of a reference identification system, for their ability to accurately and repeatedly identify six common food-borne pathogens were assessed. The systems assessed were the MicroLog system (Biolog Inc., Hayward, Calif.), the Microbial Identification System (MIS; MIDI Inc., Newark, Del.), the VITEK system (bioMérieux Vitek, Hazelwood, Mo.), the MicroScan WalkAway 40 system (Dade-MicroScan International, West Sacramento, Calif.), and the Replianalyzer system (Oxoid Inc., Nepean, Ontario, Canada). The sensitivities and specificities of these systems for the identification of food-borne isolates of Bacillus cereus, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and verotoxigenic Escherichia coli were determined with 40 reference positive isolates and 40 reference negative isolates for each pathogen. The sensitivities of these systems for the identification of these pathogens ranged from 42.5 to 100%, and the specificities of these systems for the identification of these pathogens ranged from 32.5 to 100%. Some of the systems had difficulty correctly identifying the reference isolates when the results were compared to those from the reference identification tests. The sensitivity of MIS for the identification of S. aureus, B. cereus, E. coli, and C. jejuni, for example, ranged from 47.5 to 72. 5%. The sensitivity of the Microlog system for the identification of E. coli was 72.5%, and the sensitivity of the VITEK system for the identification of B. cereus was 42.5%. The specificities of four of the five systems for the identification of all of the species tested with the available databases were greater than or equal to 97.5%; the exception was MIS for the identification of C. jejuni, which displayed a specificity of 32.5% when it was tested with reference negative isolates including Campylobacter coli and other Campylobacter species. All systems had >80% sensitivities for the identification of Salmonella species and Listeria species at the genus level. The repeatability of these systems for the identification of test isolates ranged from 30 to 100%. Not all systems included all six pathogens in their databases; thus, some species could not be tested with all systems. The choice of automated microbial identification system for the identification of a food-borne pathogen would depend on the availability of identification libraries within the systems and the performance of the systems for the identification of the pathogen.

Bacillus cereus

A possible tetracycline-risperidone-sertraline interaction in an adolescent.

A 15-year-old adolescent male, with Asperger's disorder, Tourette's disorder and obsessive-compulsive disorder, on a tetracycline-risperidone-sertraline treatment regimen, had an acute exacerbation of motor and vocal tics. The increase in tics may have resulted from either a tetracycline-risperidone interaction leading to decreased levels of risperidone, or a tetracycline-sertraline interaction leading to increased levels of sertraline or the natural course of the Tourette's disorder. The sertraline dose was increased with no concomitant increase in tics, and subsequent discontinuation of tetracycline resulted in an improvement in tics, which indicates an interaction between tetracycline and risperidone. The addition of antibiotics to psychotropic medications requires close monitoring due to the potential interactions.

Adolescent

Epidemiological typing of Campylobacter isolates from meat processing plants by pulsed-field gel electrophoresis, fatty acid profile typing, serotyping, and biotyping.

Campylobacter spp. are a leading cause of bacterial gastroenteritis. Foods of animal origin, particularly under-cooked poultry, are common sources of Campylobacter species associated with disease in humans. A collection of 110 Campylobacter jejuni and 31 C. coli human and environmental isolates from different Ontario, Canada, abattoirs were analyzed by pulsed-field gel electrophoresis, fatty acid profile typing, and biotyping. Previously collected serotyping data for the same isolates were also analyzed in this study. Pulsed-field gel electrophoresis was found to be the most discriminatory of the typing methods, followed by serotyping, fatty acid profile typing, and biotyping. A wide variety of typing profiles were observed within the isolates, suggesting that several different Campylobacter sp. strains were present within the abattoirs.

Bacterial Typing Techniques

Evaluation of universal preenrichment broth for the recovery of foodborne pathogens from milk and cheese.

The use of universal preenrichment broth for the recovery of verotoxigenic Escherichia coli, Salmonella spp., and Listeria monocytogenes from milk and cheese was examined. Universal preenrichment broth supported the growth of low inoculum levels (10 cfu/ml) of these organisms in pure cultures and in mixed cultures containing higher levels of other pathogens or bacterial flora from raw milk. This medium also supported the recovery and growth of heat-injured Salmonella spp., L. monocytogenes, and verotoxigenic E. coli at inoculum levels of 10(2) cfu/ml to yield cell levels of 10(8) cfu/ml in pure cultures and at least 10(5) cfu/ml in the presence of high levels of known competitive pathogens or microflora of cheese samples after 24 h of incubation. Universal preenrichment broth performed better than Listeria enrichment broth in supporting the recovery and growth of heat-injured L. monocytogenes and equally as well as buffered peptone water or trypticase soy broth in supporting the growth of uninjured L. monocytogenes, Salmonella spp., and verotoxigenic E. coli. Coenrichment of these pathogens in universal preenrichment broth reduced the quantity of milk or cheese samples that were required for analysis and also reduced the cost and labor involved in preparing and processing separate preenrichment media.

Animals

Salmon calcitonin nasal spray in the prevention of corticosteroid-induced osteoporosis.

The objectives were to determine the efficacy and safety of nasal salmon calcitonin 200 IU daily in the prevention of corticosteroid-induced osteoporosis. A minimized, double-blind, placebo-controlled trial was carried out in corticosteroid-treated patients with polymyalgia rheumatica. The setting was a tertiary care university-affiliated hospital and a total of 31 patients were enrolled. The primary outcome measure was the percentage change in bone mineral density of the lumbar spine in the two treatment groups from baseline to 1 yr of follow-up. The mean +/- S.D. bone mineral density of the lumbar spine in the calcitonin-treated group decreased by 1.29 +/- 6.76% and in the placebo group by 4.95 +/- 3.50% after 12 months. The observed difference of 3.65 +/- 2.10% between groups is statistically significant (P < 0.05). Nasal salmon calcitonin prevented loss of bone in the lumbar spine as measured by dual-energy X-ray absorptiometry.

Absorptiometry, Photon

Analysis of whole-cell fatty acid profiles of verotoxigenic Escherichia coli and Salmonella enteritidis with the microbial identification system.

Differentiation of strains within bacterial species, based on gas chromatographic analysis of whole-cell fatty acid profiles, was assessed with 115 strains of verotoxigenic Escherichia coli and 315 strains of Salmonella enteritidis. Fatty acid-based subgroups within each of the two species were generated. Variability of fatty acid profiles observed in repeat preparations from the same strain approached that observed between subgroups, limiting the usefulness of using fatty acid profiles to subgroup verotoxigenic E. coli and S. enteritidis strains.

Bacterial Toxins

Bipolar disorder in children and adolescents: current challenges.

OBJECTIVE: To demonstrate the diagnostic and treatment challenges in juvenile-onset bipolar disorder. METHOD: Three case vignettes are outlined to demonstrate different bipolar presentations in children and adolescents. RESULTS: These case examples illustrate important issues in the diagnosis and management of juvenile-onset bipolar disorder. These issues include diagnostic confusion with atypical initial presentation and the effect of developmental factors on symptom expression. The relationship among genetic risk, early affective instability, and the stress generated by affectively ill family members is complex and circular. Comorbidity with disruptive behaviour disorders, as well as anxiety disorders, is demonstrated by the cases discussed. Comorbid disorders may affect outcome and require separate treatment intervention. There is evidence for the prophylactic antimanic effect of lithium carbonate in children and adolescents, but its specificity as an antimanic agent is still uncertain. There is less evidence, at present, for effectiveness of other mood stabilizers in this age group, although sodium valproate may prove more effective in mixed mania and rapid cycling, which are so often seen with early-onset bipolar disorder. CONCLUSIONS: While the existence of juvenile-onset bipolar disorder is no longer in dispute, several outstanding issues related to diagnosis and long-term management remain. Careful prospective research will be necessary to sort out these issues definitively.

Adolescent

Nucleotide sequence of equine MxA cDNA.

A 2.6 kb cDNA species has been isolated from a cDNA library prepared from interferon-alpha stimulated equine peripheral blood leucocytes and the nucleotide sequence determined. The cDNA has a single open reading frame potentially encoding a 660 amino acid polypeptide showing a high degree of homology with known mammalian Mx proteins, including the possession of three consensus GTP-binding motifs. The protein has a calculated pI = 6.1 and in accordance with proposed nomenclature we have designated it equine MxA.

Amino Acid Sequence

The relation of attachment status, psychiatric classification, and response to psychotherapy.

The relation of patterns of attachment and psychiatric status was studied in 82 nonpsychotic inpatients and 85 case-matched controls using the Adult Attachment Interview (AAI). AAI transcripts rated (masked to case vs. control status and treatment) were classified using M. Main and R. Goldwyn's (1991) system. Psychiatric patients, diagnosed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.) I and II structured interviews, were more likely to be classified as preoccupied and unresolved with respect to loss or abuse. On Axis I, anxiety was associated with unresolved status, and AAI scales were able to discriminate depression and eating disorder. On Axis II, borderline personality disorder (BPD) was linked to experience of severe trauma and lack of resolution with respect to it. BPD patients were also rated significantly lower on a scale measuring awareness of mental states. Preliminary outcome results suggest that individuals rated as dismissing on the AAI are more likely to show improvements in psychotherapy.

Borderline Personality Disorder

Use of risperidone in pervasive developmental disorders: a case series.

A series of 14 children and adolescents (ages 9-17 years, 10 males) were treated with risperidone for pervasive developmental disorder. The rationale for using an atypical neuroleptic agent is based on its ability to target both positive and negative symptoms of schizophrenia. It was postulated that symptoms similar to the positive and negative symptoms of schizophrenia may be observed in the pervasive developmental disorders and might respond favorably to risperidone. Twelve of the 14 youths had been treated previously with several psychotropic drugs, often concurrently. Risperidone was initiated at a starting dose of 0.25 mg twice daily and increased in 0.25 mg/day increments every 5-7 days. Optimal dosages ranged from 0.75 to 1.5 mg daily in divided doses. Thirteen of the 14 youths appeared to benefit from risperidone. Improvement in functionality on the Children's Global Assessment Scale was demonstrated in 13 of 14 cases. Disruptive behaviors, when present, markedly decreased on risperidone. Ten patients showed a marked reduction in agitation and anxiety. Social awareness improved markedly in 10 patients, moderately in 3, and only slightly in 1. All but 1 patient demonstrated a lessening in obsessional behaviors. Effects on attention were uniformly positive. Side effects were minimal at the dosages used in this study; 5 patients had initial sedation. Neither extrapyramidal side effects nor agitation was observed in any case. Ten of 14 youths could be managed with risperidone monotherapy. During the follow-up period (mean 7 months), none of the patients experienced a major relapse while taking risperidone. Positive and negative symptoms, as typically characterized in schizophrenia, were both found to improve equally well with risperidone treatment. Based on these findings, a prospective clinical trial with a randomized controlled design is warranted.

Adolescent

Case study: anorexia nervosa and autistic disorder in an adolescent girl.

The development of anorexia nervosa in a high-functioning, early adolescent, autistic female is described. This case raises the issue of co-occurrence of childhood-onset disorders sharing the phenomena of obsessions and compulsions. The role of dysregulation of the serotonergic neurotransmitter system as a common underlying mechanism in these disorders is suggested. Psychoactive agents affecting the serotonin system and in particular the atypical neuroleptic risperidone may be of value in these disorders. There is added benefit to the combined use of biological and behavioral therapies.

Adolescent

Epidemiological typing of Bacillus spp. isolated from food.

Biotypes, fatty acid profiles, and restriction fragment length polymorphisms of a PCR product (PCR-RFLP of the cereolysin AB gene) were compared for 62 isolates of the Bacillus cereus group. Eleven isolates originated from various foods, and 51 isolates were obtained from pasteurized milk which had been processed by two different dairies. The isolates were clustered into 6 biotypes, 10 fatty acid groups, or 7 PCR-RFLP clusters. Isolates with mesophilic or psychrotrophic characteristics were preferentially distributed into specific fatty acid or PCR-RFLP groups (P = 0.004). Unique fatty acid clusters were predominantly found in milk samples of each dairy (P < 0.0001), suggesting that certain dairy plants may harbor plant-specific B. cereus which might constantly contribute to postpasteurization contamination.

Animals

Intermittent cyclic therapy with etidronate prevents corticosteroid-induced bone loss: two years of follow-up.

The purpose of this study was to evaluate the efficacy of intermittent cyclic therapy (ICT) with etidronate in preventing the loss of lumbar vertebral bone mineral density (BMD) in patients taking corticosteroids. The study population was a cohort of patients taking corticosteroids for at least two years for polymyalgia rheumatica, asthma, rheumatoid arthritis, systemic lupus erythematosus or other conditions. A tertiary care university teaching hospital-affiliated rheumatology office practice. Inclusion and exclusion criteria yielded eighty-eight patients taking corticosteroids for at least two years who had not taken estrogen or fluoride and had no causes of secondary osteoporosis. Changes relative to baseline in individual vertebral (L2-L4) BMD measurements after one and two years were compared between patients who had taken ICT with etidronate (n = 42) and those who had not (n = 46). We found that BMD in the lumbar spine increased significantly over baseline in patients who had taken ICT with etidronate, by 3.9% after one year and by 5.6% after two years, whereas it decreased by 3.7-3.8% in patients who had not. We conclude that ICT with etidronate prevents corticosteroid-induced osteoporosis and progressively ameliorates BMD over two years. Double blind trials are underway to evaluate whether this increased BMD is associated with reductions in vertebral fracture rates.

Adrenal Cortex Hormones

Associations among attachment classifications of mothers, fathers, and their infants.

Associations are reported among classifications of Adult Attachment Interviews (AAIs) obtained from expectant parents and subsequent classifications of their infants in the Strange Situation Procedure (SSP). Mothers' AAIs predicted infant-mother SSPs (chi 2 = 41.87, N = 96, df = 9, p < or = .0001), and fathers' AAIs predicted infant-father SSPs (chi 2 = 18.94, N = 90, df = 6, p < or = .005). Associations between parents' AAIs and infant-parent SSPs were lessened by the failure to predict the insecure-resistant pattern with mother and the absence of this pattern with father. Counter to expectation, infant-father SSPs were associated with infant-mother SSPs (chi 2 = 3.78, N = 90, df = 1, p < or = .05), which could not be accounted for in terms of an overlap between parental AAIs. A secondary analysis of the data suggested that this dependency effect of SSPs may be explained by the influence of maternal AAIs upon child-father SSPs. Results are discussed in terms of intergenerational and relationship-specific influences upon attachment during infancy, the possible influence of infant temperament, and the relative influence of mother and father upon the child's evolving representations of attachments within the family.

Adult

Vitamin D and calcium in the prevention of corticosteroid induced osteoporosis: a 3 year followup.

OBJECTIVE: To determine the efficacy and safety of vitamin D 50,000 units/week and calcium 1,000 mg/day in the prevention of corticosteroid induced osteoporosis. METHODS: A minimized double blind, placebo controlled trial in corticosteroid treated subjects in a tertiary care university affiliated hospital. The sample was 62 subjects with polymyalgia rheumatica, temporal arteritis, asthma, vasculitis, or systemic lupus erythematosus. The primary outcome measure was the percentage change in bone mineral density (BMD) of the lumbar spine in the 2 treatment groups from baseline to 36 mo followup. RESULTS: BMD of the lumbar spine in the vitamin D and calcium treated group decreased by a mean (SD) of 2.6% (4.1%) at 12 mo, 3.7% (4.5%) at 24 mo, and 2.2% (5.8%) at 36 mo. In the placebo group there was a decrease of 4.1% (4.1%) at 12 mo, 3.8% (5.6%) at 24 mo, and 1.5% (8.8%) at 36 mo. The observed differences between groups were not statistically significant. The difference at 36 mo was-0.693% (95% CI -5.34, 3.95). CONCLUSION: Vitamin D and calcium may help prevent the early loss of bone seen in the lumbar spine as measured by densitometry of the lumbar spine. Longterm vitamin D and calcium in those undergoing extended therapy with corticosteroids does not appear to be beneficial.

Adrenal Cortex Hormones

Characterization of concanavalin A-binding glycoproteins from procyclic culture forms of Trypanosoma congolense, T. simiae and T. brucei brucei.

Concanavalin A-binding glycoproteins were obtained from procyclic culture forms (PCFs) of Trypanosoma congolense, T. simiae, and T. b. brucei strains. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that glycoproteins of 38.5, 30.5, and 27 kDa were conserved between the different species and strains of the procyclic parasites. There were few similarities in the profiles of the high-molecular-weight glycoconjugates between the parasites. Monoclonal antibody analysis revealed that the 38.5- and 27-kDa glycoproteins were intracellular molecules and that they contained cross-reactive antigenic determinants. Surface biotinylation of PCF T. congolense K45/1 identified surface-accessible glycoproteins of 81.5, 59, and 38-42 kDa. By use of lectin blots and enzymatic deglycosylation studies, we demonstrated that the 81.5-, 59-, 38.5-, and 27-kDa glycoproteins contained N-linked oligosaccharide chains with both high-mannose-type and complex-type oligosaccharides, and the 81.5- and 59-kDa surface glycoproteins contained sialic acid residues. The glycoproteins identified in this study provide a starting point for further structure and function studies.

Animals