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Biomedical subjects

R Harvey

Publications and source records attributed to R Harvey.

At least 73 records · Page 4Linked to original sources

Quality assurance in Australian hospitals: who does it and how?

OBJECTIVE: To seek information on the type, method and extent of quality assurance being undertaken in all public and private hospitals within Australia. METHOD: Mailed questionnaire. RESULTS: There was a predominance of two types of review being undertaken. Some important deficiencies in the quality assurance process were identified. Far more private than public hospitals reviewed medical records and surveyed patient satisfaction.

Australia↗

Death from drug-induced hemolytic anemia.

Fatal hemolytic anemia occurred in a 71-year-old man after trimethoprim-sulfamethoxazole was given for presumed cystitis. Administration of this combination has previously caused multiple hematologic reactions by affecting folic acid metabolism. Megaloblastic anemia and neutropenia have been produced by both of these agents, while sulfamethoxazole alone has induced acute hemolytic anemia in patients with hereditary deficiency of glucose-6-phosphate dehydrogenase. Although hematologic complications of trimethoprim-sulfamethoxazole treatment usually follow long-term or high-dose therapy, acute reactions apparently may occur at lower doses as well.

Aged↗

pp60c-src variants containing lesions that affect phosphorylation at tyrosines 416 and 527.

The biological and biochemical properties of pp60c-src are regulated, in part, by phosphorylation at Tyr-416 and Tyr-527. The tyrosine kinase and transforming activities of pp60c-src are suppressed by phosphorylation at Tyr-527, whereas full activation of pp60c-src requires phosphorylation at Tyr-416. To test specifically the significance of the negatively charged phosphate moieties on these tyrosine residues, we have substituted the codons for both residues with codons for either Glu or Gln. A negatively charged Glu at position 527 was unable to mimic a phosphorylated Tyr at this position, and, in consequence, the mutated pp60c-src was activated and transforming. Similarly, substitution of Tyr-416 with Glu was unable to stimulate the activities of the enzyme. However, mutagenesis of Tyr-416 to Gln (to form the mutant 416Q) activated the kinase activity approximately twofold over that observed for wild-type pp60c-src. When introduced into the mutant 527F (containing Phe-527 instead of Tyr), the double mutant 416Q-527F exhibited weak transforming activity. This is in contrast to the other double mutants 416E-527F and 416F-527F, which were nontransforming. The biochemical basis by which 416Q activates pp60c-src is not understood but probably involves some local conformational perturbation. Deletion of residues 519 to 524 (RH5), a region previously shown to be necessary for association with middle-T antigen, led to loss of phosphorylation at Tyr-527 and activation of the enzymatic and focus-forming activities of pp60c-src. Hence, the sequences necessary for complex formation with middle-T antigen may also be required by the kinase(s) which phosphorylates Tyr-527 in vivo. This suggests that normal cells contain cellular proteins which are analogous to middle-T antigen and whose action regulates the activity of pp60c-src by controlling phosphorylation or dephosphorylation at residue 527.

Animals↗

The organisation of quality assurance in Australian hospitals.

A mailed survey of all Australian hospitals, conducted by the Australian Institute of Health in 1987, sought information about quality assurance (QA) activities. Respondents were asked to describe aspects of the organisation of their hospital and its organisation of QA to permit the line of accountability for QA to be traced, from the person responsible on the ward to the person responsible for the overall quality of patient care to the governing body. This paper presents survey findings for public and private hospitals describing this line of accountability and the attributes of hospitals that were associated with an "adequate" range of reviews. It discusses the implications of these findings for the various parties involved in safeguarding quality of hospital care.

Australia↗

Peptide antibodies to the human c-fyn gene product demonstrate pp59c-fyn is capable of complex formation with the middle-T antigen of polyomavirus.

The c-fyn proto-oncogene is a member of a family of closely related genes of which c-src is the prototype. Using peptide antibodies which had been raised against sequences predicted to be specific for the human c-fyn gene product, the c-fyn protein was identified. It is a tyrosine kinase with apparent mol. wt of 59 kd that is also phosphorylated and myristylated. Like pp60c-src and pp62c-yes, pp59c-fyn is able to form a stable complex with middle-T antigen, the transforming protein of polyomavirus. The transformation-defective middle-T mutant NG59, which is unable to associate stably with pp60c-src does not associate with pp59c-fyn. In contrast to pp60c-src, complex formation with middle-T antigen does not lead to a significant increase in the tyrosine kinase activity of pp59c-fyn. These findings lead us to suggest that middle-T mediated transformation may be a consequence of the deregulation of several members of the src-family of protein tyrosine kinases.

Animals↗

Metabolic and thyroidal responses to mild cold are abnormal in obese diabetic women.

Mild cold exposure (22 degrees C, with reference to 28 degrees C, thermoneutral) was studied by overnight whole-body indirect calorimetry in euthyroid women. Basal, sleeping, energy expenditure (EE) was significantly increased (+3.8%, P less than 0.05) in six normal weight women but reduced (-3.5%, P less than 0.05) in five obese type II diabetic women. Mixed responses were found in five women with simple obesity. Biochemical measurements were made on fasting blood samples taken at 0900 h after 12 h exposure to the two temperatures. Serum T4, free T3 and TSH were within the normal reference range in all subjects. Serum T4 did not show any differences between the groups, nor any effect from temperature. There was a significant increase in free T3 (P less than 0.05) at 22 degrees C in the control subjects, but no differences in the obese diabetic women. Serum thyroglobulin fell significantly in the diabetic group. Both TSH and free T3 responses to mild cold were significantly different between the groups, but both correlated positively (P less than 0.05) with the changes in sleeping energy expenditure at 22 degrees C with reference to 28 degrees C. Changes in TSH and free T3 were themselves significantly correlated within individuals (P less than 0.01). The normal physiological non-shivering thermogenesis of adult humans on exposure to a cool environment may thus be mediated by a pituitary-thyroid mechanism. The abnormal response of obese diabetic women was associated with impaired TSH and thyroid hormone responses, and may be a factor contributing to weight gain.

Adult↗

Vocal cord dysfunction: the importance of psychologic factors and provocation challenge testing.

We present three case reports involving patients with vocal cord dysfunction. The onset of symptoms in one case was coincident with a generalized cutaneous reaction to penicillin with laryngeal involvement. The other cases had been misdiagnosed as food allergy and chemical sensitivity. We describe the psychologic factors in these cases in terms of the primary and secondary gain operative in the somatoform disorder of conversion reaction and emphasize the importance of belief and learned sensitivity in the induction of symptoms. The necessity of considering psychologic factors and the use of blinded, controlled, provocation challenges to evaluate subjective symptomatology is underscored. This study emphasizes the heterogenicity of clinical presentations involving vocal cord dysfunction and illustrates the value of fiberoptic-assisted examination of laryngeal function in conjunction with provocation challenge testing in establishing causal relationships for specific clinical symptoms.

Adult↗

Regulation of translocated c-myc genes transfected into plasmacytoma cells.

We have transfected two translocated c-myc oncogene clones, derived from two human lymphomas carrying the t(8;14) chromosome translocation, into mouse plasmacytoma cells to study the regulation of their expression. In one case, the transfected clone contained the two coding exons of the c-myc oncogene translocated to an immunoglobulin heavy-chain switch region; in the other case, the two coding exons were translocated 5' of the enhancer element located between the heavy-chain joining region (JH) and the switch region S mu. Nuclease S1 protection experiments indicate that only the c-myc translocated 5' of the enhancer element is transcribed in the plasmacytoma cells. Thus, 5'-truncation of the c-myc gene per se does not lead to c-myc deregulation. Further, since the level of c-myc transcripts in the parental human lymphoma cells was 3- to 4-fold higher than in the transfectants, it seems likely that additional elements within the heavy-chain locus may play a role in the enhancement of c-myc gene transcription in lymphoma cells.

Animals↗

Site-directed mutagenesis of polyomavirus middle-T antigen sequences encoding tyrosine 315 and tyrosine 250.

Tyrosine residues of middle-T and tyrosine phosphorylation are thought to be important in the transformation of cultured rodent cells by polyomavirus. Of the potential tyrosine sites in the carboxyl-terminal half of middle-T, tyrosines 297, 315, and 322 have been studied previously, whereas tyrosine 250 has not. Two mutant plasmids, XD121 and pT250, encode polyomavirus middle-T species in which the tyrosine 250 residue is affected. XD121 is a deletion mutant in which the region encoding tyrosine 250, together with three adjacent amino acids, is deleted, whereas pT250 is a point mutant in which the tyrosine 250 codon has been converted to a phenylalanine codon. The plasmids were handicapped in transforming ability, as judged by focus formation on a monolayer of Rat-1 cells. Both demonstrated a reduction in the number of foci produced and a lag in the time of appearance of foci when compared with wild-type plasmid. The importance of residue 250 in this phenotype was indicated by the observation that plasmids containing multiple mutations proximal to the tyrosine 250 codon were wild type in their transforming ability. Furthermore, a revertant of pT250 (pT250-w.t.), which utilized the alternative tyrosine codon of TAC, was shown to regain full transforming activity. A combined-mutant plasmid, pTH, encodes a middle-T species in which both tyrosines 250 and 315 are converted to phenylalanine. This plasmid was totally defective in the transformation of rodent cells in a focus formation assay; however, it did impart a small measure of anchorage-independent growth when the encoded protein was expressed in NIH 3T3 cells. The in vitro kinase activity and pp60c-src association of the mutant middle-T antigens were examined. These assays demonstrated a reduction in phosphate acceptor activity for the middle-T species encoded by pT250 and pTH. Quantitative kinase assays showed that all of the tyrosine-mutant middle-T species, encoded by pAS131 (containing the tyrosine 315 codon-to-phenylalanine codon mutation), pT250, and pTH, were able to enhance pp60c-src kinase activity but only at levels which were intermediate and which reflected their transforming abilities relative to wild type.

Amino Acid Sequence↗

A survey of practising psychiatrists' views on the treatment of schizophrenia.

Practicing psychiatrists' views about the treatment of schizophrenia were investigated as part of a Quality Assurance Project. A questionnaire which asked for treatment recommendations for each of four case descriptions of patients with schizophrenia was mailed to a one-in-six random sample of Australian psychiatrists; 90% responded. Psychiatrists almost uniformly advocated the use of antipsychotic drugs and usually recommended concurrent supportive psychotherapy or family/social intervention procedures. The recommendations varied systematically, according to the initial history obtained and to the initial response to treatment.

Attitude of Health Personnel↗

Immunoprecipitation of some forms of simian virus 40 large-T antigen by antibodies to synthetic peptides.

Antibodies were raised against six synthetic peptides corresponding to overlapping amino acid sequences (106 through 145) from a putative DNA binding domain in simian virus 40 (SV40) large-T antigens. All six antipeptide sera immunoprecipitated large-T from crude extracts of SV40-transformed cells, but the efficiency varied widely; in general, antibodies to the longer peptides produced the strongest anti-large-T activity. Antisera were purified by immunoaffinity chromatography on immobilized peptide. The purified antisera recognized only some forms of large-T; full-sized large-T from transformed cells, super-T from SV3T3 C120 cells, and 70,000-dalton T-antigen from Taq-BamHI cells were immunoprecipitated, whereas large-T from productively infected cells reacted irreproducibly, and the full-sized protein, synthesized in vitro or eluted from sodium dodecyl sulfate-containing gels, and the 33,000- and 22,000-dalton truncated large-Ts from Swiss SV3T3 and MES2006 cells, respectively, were not immunoprecipitated. This pattern of reactivity was explained when extracts were fractionated by sucrose density centrifugation, and it was found that only rapidly sedimenting forms of large-T were immunoprecipitated by the antipeptide sera; that is, large-T complexed with nonviral T antigen was detected, whereas lighter forms were not detected. Cascade immunoprecipitations did not support the view that this result was caused by the low affinity of the peptide antisera for large-T, and Western blotting experiments confirmed that the peptide antisera react directly with immobilized, monomeric large-T but not with nonviral T antigen. Immunoprecipitation assays to detect large-T:nonviral T antigen complexes bound specifically to fragments of SV40 DNA showed that under conditions of apparent antibody excess, DNA still bound to the complex.

Animals↗

An antibody to a synthetic peptide recognizes polyomavirus middle-T antigen and reveals multiple in vitro tyrosine phosphorylation sites.

Antibodies were raised against three synthetic peptides corresponding to sequences surrounding tyrosine 315, a putative in vitro phosphorylation site in polyomavirus middle-T antigen. Only one of the peptides (called C and corresponding to residues 311 to 330) elicited antibodies that recognized middle-T efficiently. Middle-T present in immunoprecipitates formed with purified anti-C serum still accepted phosphate on tyrosine in an in vitro kinase reaction. This implies that tyrosines other than 315 and 322 that lie within the antibody binding region are phosphorylated under these conditions. This conclusion was supported by the altered partial V8 proteolysis fingerprint of the labeled middle-T. Two-dimensional tryptic fingerprint analysis of 32P-labeled middle-T showed that several tryptic peptides identified as including tyrosine 315 and 322 were missing from middle-T labeled in anti-C immunoprecipitates compared with middle-T labeled in immunoprecipitates made by using anti-tumor cell serum. However, one major labeled peptide remained. This peptide was also present in fingerprints of 32P-labeled middle-T coded by M45, dl23, pAS131, and dl1013, but a peptide with altered mobility was present in dl8 middle-T. This identified the peptide as including tyrosine 250. We deduce from these data that (i) the presence of the antibody against peptide C inhibits phosphorylation of tyrosines 315 and 322; (ii) middle-T labeled in the kinase reaction after immunoprecipitation with anti-C serum is phosphorylated on tyrosine 250; and (iii) when anti-tumor cell serum is used in the in vitro kinase reaction, middle-T is phosphorylated at multiple sites, including residues 250, 315, and 322.

Amino Acids↗