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Biomedical subjects

J Bramley

Publications and source records attributed to J Bramley.

12 recordsLinked to original sources
PubMed2001

Approaches to risk-adjusting outcome measures applied to criminal justice involvement after community service.

The ethic of fairness in program evaluation requires that measures of behavioral health agency performance be sensitive to differences in those agencies' caseload composition. The authors describe two traditional approaches to the statistical risk adjustment of outcome measures (stratification weighting and pre-post measurement) that are designed to account for differences in caseload composition and introduce a method that incorporates the strengths of both approaches. Procedures for deriving each of these measures are described in detail and demonstrated in the evaluation of a statewide system of community-based behavioral health care programs. This evaluation examines the degree to which service recipients get into trouble with the law after treatment. Three measures are recommended for inclusion in outcome-oriented "report cards," and the interpretation of each measure is discussed. Finally, the authors suggest formats for graphic and tabular presentation of the risk-adjusted evaluation for sharing findings with diverse stakeholder groups.

Adult↗
PubMed1999

Noninvasive 3-D ultrasound of atherosclerotic plaques in the Watanabe rabbit.

We have investigated the ability to quantitate atherosclerosis in the aortic arch of the Watanabe rabbit using noninvasive 3-D ultrasound. Our methodology utilizes postprocessing of videotaped freehand 2-D interrogations to form a compound 3-D data block. Structures may then be segmented on the attributed grey-scale level and volumes measured. Analysis of 3-D reconstructions revealed a low echo structure in the aortic arch of atherosclerotic rabbits, absent in nonatherosclerotic rabbits, at recognized sites of plaque predilection. This structure volume correlated closely with fatty streak volume determined from histology (r = 0.890). During a 30-week study, this structure volume increased in untreated animals, but was blocked by treatment with the antiatherosclerotic agent probucol. Thus, a new 3-D ultrasound methodology has been used noninvasively to detect and quantitate a low echo structure corresponding to fatty streaks in the Watanabe rabbit aortic arch. This new methodology could potentially aid plaque burden quantification in human peripheral arteries.

Algorithms↗
PubMed1998

Characterization of a sialyltransferase-deficient mutant of Neisseria gonorrhoeae strain F62: instability of transposon Tn1545 delta3 in gonococci and evidence that multiple genetic loci are essential for lipooligosaccharide sialylation.

Neisseria gonorrhoeae strain JB1 was previously shown to be defective in the sialylation of lipoologosaccharide (LOS) by exogenous CMP-NANA. The LOS components synthesized by the mutant now have been shown by mass spectrometry to be similar to those in the parental strain, F62, and to include the 4.5 kDa widely conserved lacto-N-neotetraose component that can be sialylated. The same two LOS components could be sialylated on the surface of the mutant and parental strains. One major component was sialylatable after chemical extraction of the LOS from either strain. These data confirm that the mutant, JB1, retains the ability to synthesize the LOS target required for the conversion by sialylation of serum-sensitive gonococci to serum resistance. A single base frame-shift mutation was found in the lst gene from the mutant, resulting in the replacement of the final 61 amino acids at the C-terminus of the sialyltransferase by four residues. Seventeen independent clones of the lst gene were isolated from the parental strain, but none of them complemented the sialyltransferase defect of the mutant and no sialyltransferase activity expressed from the clones could be detected in Escherichia coli. Although the data suggest that the mutant might be defective in genes at more than one chromosomal locus and that multiple loci are essential for sialyltransferase synthesis and activity, the alternative possibility, that DNA adjacent to the lst gene encodes a product which is toxic to E. coli, cannot be excluded. The site of insertion of the transposon Tn1545-Delta3 in strain JB1 was cloned and sequenced. The transposon is located in an intergenic region adjacent to genes for a putative ATP-dependent transport protein, but encoding no recognizable function relevant to LOS sialylation. Evidence that transposon Tn1545-Delta3 is unstable in gonococci is presented.

Blotting, Southern↗
PubMed1996

Lactic acid is the factor in blood cell extracts which enhances the ability of CMP-NANA to sialylate gonococcal lipopolysaccharide and induce serum resistance.

In previous work, a factor which enhances the ability of cytidine 5'-monophospho-N-acetyl neuraminic acid (CMP-NANA) to sialylate gonococcal lipopolysaccharide (LPS) was liberated at 4 degrees C in diffusates from high M(r) fractions of blood cell sonicates. The diffusates also contained CMP-NANA and converted serum susceptible gonococci to resistance. The enhancer has now been separated from CMP-NANA and material absorbing at 260 nm by HPLC on mu Bondapak-10 NH2. Resistance inducing activity was found only in fractions containing CMP-NANA and recovery was poor (about 25%). However, addition of enhancer fractions to CMP-NANA substantially increased its resistance inducing activity. Blood cell sonicates dialysed at 18-20 degrees C released enhancer in diffusates. These were ultrafiltered (nominal cut off 3000 Da) and fractionated on Biogel P2 which removed saccharides and most material absorbing at 260 nm. Over 90% of a fraction which was enhancer-active in nanogram quantities was identified by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography/mass spectometry (GC/MS) as lactic acid. A fraction with similar properties was obtained from a different batch of diffusate by fractionation on Dowex 1. Authentic lithium L-lactate in nanogram quantities enhanced LPS sialyation by CMP-NANA and increased its serum resistance inducing activity. These results have important implications for gonococcal pathogenicity.

Blood Cells↗
PubMed1996

Lactate enhancement of sialylation of gonococcal lipopolysaccharide and of induction of serum resistance by CMP-NANA is not due to direct activation of the sialyltransferase: metabolic events are involved.

Lactate enhances lipopolysaccharide (LPS) sialylation and induction of serum resistance in gonococci by CMP-NANA. To investigate whether the enhancement is due to a direct effect on the sialyltransferase, an improved extraction of the enzyme and a reliable quantitative assay were devised. Gonococci (strain F62) were disrupted in a French pressure cell and the bacterial membranes were extracted for 1 h at 37 degrees C with a detergent, NONIDET (1% v/v). The assay involved sialylation of LPS by CMP-14CNANA and scintillation counting of the labelled LPS after fixing it on filter paper strips by trichloracetic acid (TCA) and washing away unincorporated CMP-14CNANA. It was rapid, reproducible and, although the enzyme preparations contained endogenous LPS, was dependent upon added LPS for maximum activity. At 37 degrees C the rate was constant for up to 5 min and proportional to the concentration of extract in the assay. A wide range of concentrations of lithium-L-lactate did not enhance the activity of the extracted sialyltransferase. At concentrations above 22 microM, it was inhibitory. Pre-incubation of gonococci with lactate enhanced subsequent LPS sialylation and induction of serum resistance by CMP-NANA. Hence, the process whereby lactate enhances the effect of CMP-NANA is separate from the action of CMP-NANA itself. Both processes were inhibited by a sublethal concentration of chloramphenicol, indicating that metabolic events are required. Evidently, the enhancement process does not involve a direct activation of the sialytransferase.

Blood Bactericidal Activity↗
PubMed1996

Functional characterization of a sialyltransferase-deficient mutant of Neisseria gonorrhoeae.

Previous studies indicate that sialylation of lipopolysaccharide (LPS) by host CMP-N-acetylneuraminic acid (CMP-NANA) catalyzed by bacterial sialyltransferase rendered gonococci resistant to killing by phagocytes, to entry into epithelial cell lines, to killing by immune serum and complement, and to absorption of complement component C3. These results have been confirmed by comparing a sialyltransferase-deficient mutant (strain JB1) with its parent (strain F62) in appropriate tests. In contrast to F62, JB1 was very susceptible to killing by human polymorphonuclear phagocytes in opsonophagocytosis tests and incubation with CMP-NANA did not decrease the level of killing. The inherent resistance of F62 in these tests was probably due to LPS sialylation by CMP-NANA and lactate present in the phagocytes. A JB1 variant expressing the invasion-associated Opa protein was as able to enter Chang human conjunctiva epithelial cells as an Opa-positive variant of F62, suggesting that the sialyltransferase is not required for Opa-mediated entry. After incubation with CMP-NANA, the number of F62 variant gonococci entering cells but not that of JB1 variant gonococci was drastically reduced. Both JB1 and F62 were killed by incubation with rabbit antibody to gonococcal major outer membrane protein, protein I, and human complement, but only F62 was rendered resistant to the killing by incubation with CMP-NANA. Finally, both JB1 and F62 absorbed similar amounts of complement component C3 and the binding was decreased by incubation with CMP-NANA only for the wild type, F62.

Animals↗
PubMed1995

A serum-sensitive, sialyltransferase-deficient mutant of Neisseria gonorrhoeae defective in conversion to serum resistance by CMP-NANA or blood cell extracts.

A stable, sialyltransferase-deficient mutant of Neisseria gonorrhoeae strain F62 totally defective in CMP-NANA-dependent lipopolysaccharide (LPS) sialylation was isolated by insertion mutagenesis with transposon Tn 1545-delta 3 and screened for unlabelled colonies following incubation with CMP-14C-NANA. In contrast to the parental strain which became serum resistant on incubation with CMP-NANA or blood cell extracts, the mutant, JB1, remained serum sensitive. French press extracts of strain F62 catalysed LPS sialylation, but corresponding extracts of the mutant were inactive. Five LPS components were detected by SDS-PAGE in the parental strain. Five components of the same Mr were also found in the mutant. Three identical components were detected by Western blotting using MAb 3F11, which recognizes the Gal beta 1-4GlcNAc groups in the conserved LPS components of F62 which can be sialylated. The mutant, JB1, is therefore deficient in the sialyltransferase that is essential for both LPS sialylation and conversion of serum-sensitive gonococci to serum resistance by either CMP-NANA or blood cell extracts. No evidence was obtained for an LPS sialylation pathway by blood cell extracts that is independent of CMP-NANA.

Antibodies, Monoclonal↗
PubMed1995

Employment, retirement and elderly persons with an intellectual disability.

A national Australian study of people with an intellectual disability of 55 years of age and over investigated their employment and retirement patterns, attitudes to work and retirement, and the degree to which they were involved in leisure or recreational programmes. Two cohorts were recruited: one included all known members of the target group who agreed to participate in the study in the states of Queensland and Western Australia; and the second was a proportional, random sample drawn from a national database on a state population basis. A large number of the participants had never been involved in full- or part-time employment, either in a competitive or supported environment, or in workshops. The majority of those who had worked expressed strong positive attitudes toward employment and concern about retirement, suggesting the need for pre-retirement programmes including transition and choice-making skills to prepare participants for the future.

Aged↗
PubMed1995

Residential circumstances of older Australians with mental retardation.

Residential circumstances of Australians 55 years or older with mental retardation were investigated. Data were collected via interviews from 446 individuals living in Queensland and Western Australia who were identified following an extensive national search. Although survey results indicated that older people lived in a wide variety of residential settings, the majority still resided in large private or public institutions. There is evidence that deinstitutionalization had occurred, although it affected only 35% of the cohort. One important finding in the study concerns the relatively minor role participants play in determining their future care and residential needs. Interviews established that less than 10% of those in each sample would be involved in future decision-making processes.

Aged↗
PubMed1983

Coliform mastitis.

The majority of coliform mastitis cases are relatively mild and self-limiting. Teat dipping and dry cow therapy will not prevent coliform problems, neither do they cause them. Bad housing and poor milking time hygiene lead to coliform mastitis. Efforts to control coliform mastitis must be directed at reducing exposure to the bacteria. In acute cases fluid therapy is indicated to counteract endotoxic shock.

Animals↗