PubMed Health⌕ Search

Biomedical subjects

J F Alexander

Publications and source records attributed to J F Alexander.

At least 19 recordsLinked to original sources
PubMed2001

Microbiological quality of Australian beef.

A survey of the microbiological quality of beef carcasses and boneless beef produced in Australia was conducted during the period June to November 1998. Sponge samples were collected from 1,275 carcasses, and meat samples were drilled from 990 cartons of frozen boneless beef. Carcass and boneless beef samples were respectively collected from 21 and 27 establishments that concentrated on export and from 38 and 3 establishments supplying the Australian domestic market of which 31 were very small plants slaughtering no more than 150 cattle equivalents per week. The mean log total viable counts (TVCs) were 2.42/cm2 and 2.52/g for carcasses and boneless meat, respectively. Escherichia coli was detected on 10.3% of carcasses and 5.1% of boneless beef samples and coagulase-positive staphylococci on 24.3% of carcasses and 17.5% of boneless beef. Salmonella was detected on 0.2% of carcasses and 0.1% of boneless beef and E. coli O157:H7 recovered from 0.1% of carcasses but not detected on 990 boneless beef samples. Mean log TVCs/cm2 differed significantly (P < 0.05) between establishment types. They were lower on carcasses from export establishments (2.20) compared with domestic (2.61) and very small plants (3.10). There were no significant differences in prevalence of Salmonella or E. coli O157:H7 between establishment types. Excision samples were taken from 670 carcasses to make comparisons with the first baseline study of Australian meat, carried out in 1993 to 1994. While there were differences in sampling and microbiological techniques between the two studies that require detailed consideration, there were small but significant improvements in several microbiological criteria for carcasses and boneless meat.

Abattoirs↗
PubMed2001

Microbiological quality of Australian sheep meat.

Microbiological quality of sheep carcasses and boneless sheep meat produced in Australia was surveyed during the period June to November 1998. Sponge samples were collected from 917 carcasses, and meat samples were drilled from 467 cartons of frozen boneless meat. Carcass and boneless meat samples were respectively collected from 7 and 10 establishments that concentrated on export, and from 36 and 5 establishments supplying the Australian domestic market of which 31 were very small plants slaughtering cattle and sheep but no more than 1,200 sheep equivalents per week. The mean log total viable counts were 3.55/cm2 and 3.30/g for carcasses and boneless meat, respectively. Escherichia coli was detected on 29.2% of carcasses and 24.5% of boneless meat samples and coagulase-positive staphylococci on 24.1% of carcasses, and 38.6% of boneless meat samples. Salmonella was detected on 0.1% of carcasses and 1.3% of boneless meat samples. E. coli O157:H7 was recovered from 0.7% of carcasses and 1.3% of boneless sheep meat. There were statistically significant differences between establishment types for some microbiological criteria, although there were no significant differences in prevalence of Salmonella or E. coli O157:H7 between establishment types. While there were differences in sampling and microbiological techniques between this study and another conducted in 1993 to 1994 that require detailed consideration, there were small but significant improvements in several microbiological criteria for boneless meat. While data that would allow for comparison of carcass data were not gathered, it is unlikely that improvements in the microbiological quality of boneless sheep meat could accrue without improvements to carcasses.

Abattoirs↗
PubMed2000

Disrupting defensive family interactions in family therapy with delinquent adolescents.

This study compared the immediate impact of therapist reframing, reflection, and elicit-structure interventions on family-member defensive communications in the initial session of family therapy with a delinquent adolescent. Defensive statements included family-member statements that criticized, blamed, or disagreed with other family members. Sequences of behaviors following defensive family-member statements were examined to determine which therapist interventions were the most effective in disrupting defensive family interactions. Thus, every sequence included a defensive family-member behavior, a therapist intervention, and a family-member response (sequence: family defensive-->therapist intervention-->family response). Results indicated that therapist reframing is more effective than other therapist interventions in reducing family-members' defensive statements. Moreover, adolescents responded more favorably to reframes than did fathers.

Adolescent↗
PubMed1996

Cloning and characterization of the Saccharomyces cerevisiae C-22 sterol desaturase gene, encoding a second cytochrome P-450 involved in ergosterol biosynthesis.

The ERG5 gene from Saccharomyces cerevisiae was cloned by complementation of an erg5-1 mutation using a negative selection protocol involving screening for nystatin-sensitive transformants. ERG5 is the putative gene encoding the C-22 sterol desaturase required in ergosterol biosynthesis. The functional gene was localized to a 2.15-kb SacI-EcoRI DNA fragment containing an open reading frame of 538 amino acids (aa). ERG5 contains a 10-aa motif consistent with its role as a cytochrome P-450 (CyP450) enzyme and is similar to a number of mammalian CyP450 enzymes. Gene disruption demonstrates that ERG5 is not essential for cell viability.

Amino Acid Sequence↗
PubMed1994

The identification of a gene family in the Saccharomyces cerevisiae ergosterol biosynthesis pathway.

The Saccharomyces cerevisiae ERG24 gene, encoding sterol delta 14 reductase (Erg24p), was cloned by selecting strains carrying sequences on a 2 mu-based vector for resistance to the morpholine fungicide, fenpropimorph (Fp). Four distinct plasmid inserts which conferred Fp resistance (FpR) were recovered (plasmids pML99, pML100, pML101 and pM103). Although Fp is reported to inhibit activity of Erg24p and sterol delta 8-delta 7 isomerase (Erg2p; encoded by ERG2), none of the inserts had restriction maps resembling ERG2. In addition, a 2 mu plasmid overexpression of the ERG2 sequence did not produce FpR. Characterization studies were focused on plasmid pML100, because it was the only plasmid to confer FpR consistently when tested in a number of different genetic backgrounds. Tests with a panel of fungicides indicated that pML100 conferred significant resistance only to compounds (Fp, tridemorph, fenpropidin and azasterol) which have a shared site of action, Erg24p. An insertional disruption of pML100 resulted in an obligate anaerobic phenotype, indicating a lesion in sterol biosynthesis. Sterol analysis of the disrupted mutant demonstrated the accumulation of ignosterol, indicating a loss of Erg24p activity. A SphI-XbaI fragment of pML100 was sequenced, revealing the presence of an ORF encoding a 438-amino-acid protein, which is highly similar to those encoded by two previously reported yeast drug sensitivity genes, sts1+ (Schizosaccharomyces pombe) and YGL022 (S. cerevisiae). Analyses of these genes demonstrated that strains carrying disruptions of sts1+ or YGL022 have ergosterol biosynthesis defects in the enzyme, sterol C-24(28) reductase (Erg4p; encoded by ERG4).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Type A behavior and marital interaction: hostile-dominant responses during conflict.

Previous research has indicated that the risk conferred by men's Type A versus B behavior depends, in part, on the personality characteristics of their spouses. In the present study of 60 married couples, we found that couples consisting of two Structured Interview-defined Type A's showed a larger increase in hostile/dominant behavior during discussions of marital conflicts than did couples consisting of two Type B's or a Type A husband and a Type B wife. Couples consisting of a Type B husband and a Type A wife displayed an intermediate level of hostile dominance. These results are consistent with previous speculations about interpersonal dynamics in Type A behavior and interaction patterns which might underlie spouse effects on Type A behavior and coronary risk.

Adolescent↗
PubMed1990

What does the cook and medley hostility scale measure? Affect, behavior, and attributions in the marital context.

The Cook and Medley (1954) Hostility (Ho) scale has been used in several important studies evaluating potential health consequences of hostility. A relative lack of compelling information about the construct validity of the Ho scale, however, has raised concerns about the appropriate interpretation of previous research. In this study, 60 married couples discussed a low conflict topic, a high conflict topic, and then a second low conflict topic. High Ho men responded to the high conflict topic with significant increases in self-reported anger and anxiety and overt hostile behavior, but low Ho men did not. Furthermore, compared to low Ho men, high Ho men blamed their wives more for their usual disagreements on the high conflict topic and saw their disagreement-engendering behavior as more intentional. Among women, Ho scores were weakly related only to overt hostile behavior. Finally, couples consisting of two low Ho persons displayed a uniquely agreeable interactional style.

Adult↗
PubMed1989

The minimizing of blaming attributions and behaviors in delinquent families.

Parents' data were evaluated in three studies of families with a delinquent adolescent. Families were provided with different forms of a positive versus negative interactional (attributional) context. Study 1 demonstrated that the negative context elicited significantly more negative behaviors than did the positive context when parents interacted with each other and with their delinquent adolescent. Study 2 demonstrated that the dispositional attributions of parents were influenced by the manipulation of set, with a dissatisfied set producing negative blaming attributions and a satisfied set producing nonblaming, positive attributions. Study 3 demonstrated that parents' negative sets regarding their adolescent's negative behaviors, once established and discussed by the family for 5 min, were unresponsive to a subsequent positive reattribution regarding those behaviors. Taken together, the data provide some support for reattribution techniques such as relabeling. Yet, the data question the ease with which such techniques can be successful and challenge proponents of such techniques to develop methodologically sound empirical demonstrations of their effectiveness.

Adolescent↗
PubMed1984

Immunologic responses to conjugates of antigen E in patients with ragweed hay fever.

Allergens conjugated with several simple repeating polymers have reduced allergenicity in man, but large doses retain the ability to suppress ongoing allergen-specific IgE synthesis in strains of high-responder mice. To determine whether suppression of IgE antibodies could be induced in man, preliminary trials of immunologic responses to conjugates in man were carried out in ragweed hay fever patients treated with antigen E (AgE) coupled to methoxypolyethylene glycols ( MPEGs ) of 5000 and 2000 daltons, lauryloxypolyethylene glycol of 1200 daltons, and a random copolymer of D-lysine and D-glutamic acid of 69,000 daltons. In varying degrees all these conjugates had reduced allergenicity by basophil histamine release when these conjugates were compared with native AgE and could suppress IgE response in mice. Patients received one of these conjugates or native AgE in a series of subcutaneous injections and were observed for allergic reactions. The conjugates induced a lower rate of systemic reaction than native AgE but failed to induce early suppression of IgE antibodies. Instead, early rises in IgE antibody occurred in the several groups and were followed by a slow decline during a year or more that was similar to that observed with standard immunotherapy. Because the conjugates eventually caused local and systemic allergic reactions as the dose was raised, it was not possible to test the IgE-suppressive effects at doses similar to those used in mice. In contrast, rapid sustained rises in IgG antibodies occurred in all groups. The MPEG conjugates appeared to be more effective than native AgE in this regard. The reduced rate of systemic reaction and rapid rise in IgG antibody that was noted with MPEG conjugates make them worth further exploration as agents for immunotherapy.

Allergens↗
PubMed1977

The measurement of the effect of toothbrushes on soft tissue abrasion.

The effect of toothbrushes on soft tissue abrasion was measured using hamster cheek pouch tissue brushed mechanically for various intervals. The detection of protein removed during brushing was used as an index of tissue abrasion. The method was found to be sensitive in detecting the effects of brush load, number of strokes applied, and the texture of the brush. The results further showed that the mechanical removal of sharp edges from bristle tips substantially reduced the level of soft tissue abrasion while a dentifrice polishing agent applied to the tissue with a brush did not increase the abrasive effect of the brush.

Animals↗
PubMed1976

Family therapy research in applied community settings.

This paper discusses family therapy research in applied settings and highlights those methodological issues relevant to the program evaluator as compared to those relevant to the basic researcher. Four general methodological issues are discussed: design adequacy, issues related to dependent measures, situational factors, and issues of generalization and duration of treatments. Two specific, well-validated applications of family therapy are elaborated; and finally several conclusions are drawn regarding future research strategies.

Behavior Therapy↗