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Biomedical subjects

R E Perkins

Publications and source records attributed to R E Perkins.

At least 19 recordsLinked to original sources
PubMed1996

Mineralization of 2,4,6-trinitrophenol (picric acid): characterization and phylogenetic identification of microbial strains.

Four bacterial strains that use picric acid as their sole carbon and energy source were isolated. Mineralization of 14C-UL-picric acid showed that up to 65% of the radioactivity was released as 14CO2. HPLC and UV/Vis spectral analyses indicated complete degradation of picric acid by these organisms. HPLC and LC/MS analyses showed transient formation of 2,4-dinitrophenol during picric acid degradation. Degradation of picric acid was concomitant with stoichiometric release of three moles of nitrite per mole of picric acid. The four picric acid degraders were identified as close relatives of Nocardioides simplex (ATCC 6946) based on their small subunit (16S) rRNA gene sequences.

Base Sequence↗
PubMed1994

Antibiotic susceptibilities of AIDS-associated mycoplasmas.

Because mycoplasmas may be a cofactor in the progression of human immunodeficiency virus infection to AIDS, their susceptibilities to antibiotics need to be known in the event that appropriate therapy is required. The mycoplasmas studied were a stock culture strain of Mycoplasma fermentans, two strains of M. fermentans isolated from patients with AIDS, M. fermentans var. incognitus, Mycoplasma penetrans, and Mycoplasma pirum. The antibiotics tested were doxycycline, tetracycline, clindamycin, ofloxacin, erythromycin, azithromycin, and clarithromycin at levels consistent with the attainable levels in serum. By the macrodilution metabolic inhibition method, all six mycoplasma strains were susceptible to doxycycline, tetracycline, clindamycin, ofloxacin, azithromycin, and clarithromycin. M. penetrans was susceptible to erythromycin. The M. fermentans strains and M. pirum were resistant to erythromycin. The macrodilution metabolic inhibition method results showed agreement with the Sensititre Gram Positive MIC Panel results for tetracycline, clindamycin, and erythromycin. MICs of clarithromycin for all six mycoplasma isolates tested were low, indicating susceptibility.

AIDS-Related Opportunistic Infections↗
PubMed1993

Perception of problems in psychiatric inpatients: denial, race and service usage.

The importance of the ways in which people with psychiatric problems construe their difficulties is considered in this study. A study of 60 consecutive acute admissions to wards serving an inner city area in London (UK) is reported. The results indicated that 55.8% of the sample did not consider themselves to have psychiatric problems: 15.4% said that they had no problems at all and 40.4% thought they had physical or social problems rather than psychiatric ones. Although more younger people denied that they had problems and none of those who denied having problems sought the help of a general practitioner, there was a significant association between diagnosis and perception of problems, and when this was taken into account these associations disappeared. Of those who denied having any problems, only one person had no police involvement on admission. Significantly more of those who denied problems were compulsorily admitted and there were significant differences in the proportions of whites and African-Caribbeans reporting different types of problems. African-Caribbeans were both more likely to consider that they had no problems at all and to be compulsorily admitted. Although African-Caribbeans were also more likely to be diagnosed as experiencing psychotic disorders, it was their ethnic status rather than their diagnostic category that determined both their status on admission and the way in which they construed their problems. Denial among whites tended to take the form of somatisation or construction of problems in terms of social difficulties.

Adolescent↗
PubMed1993

A case of Ureaplasma urealyticum septic arthritis in a patient with hypogammaglobulinemia.

Patients with hypogammaglobulinemia have an increased susceptibility to certain infections. We describe the case of a patient with common variable hypogammaglobulinemia for whom the diagnosis of destructive monoarticular arthritis caused by Ureaplasma urealyticum was established after two nondiagnostic open biopsies had been performed. Mycoplasmal infection may involve a joint in hypogammaglobulinemic patients without causing macroscopic purulence in the joint. Histological examination of the bone may be helpful in the differentiation of an infectious process from the rheumatoidlike arthritis that occurs in such patients. Culture of involved bone in addition to synovium or synovial fluid may also be helpful in establishing the diagnosis.

Agammaglobulinemia↗
PubMed1993

Reconstitution of glucose uptake and chemotaxis in Pseudomonas aeruginosa glucose transport defective mutants.

Wild-type glucose uptake and glucose chemotaxis activities were restored in glucose transport defective Pseudomonas aeruginosa strains PFB360 and PFB362 after introduction of plasmid pPZ129, containing a 1.1-kilobase DNA fragment that is essential for the expression of the P. aeruginosa periplasmic glucose binding protein. The restoration of glucose uptake and chemotaxis to wild-type levels in these strains was also achieved by reconstitution with cold-shock fluid and purified glucose binding protein isolated from P. aeruginosa PA01 wild-type strain H103 grown in conditions resulting in the induction of the high-affinity glucose transport system. Glucose uptake was determined by whole cell uptake and shock fluid binding of D-[U-14C]glucose, using standard filter binding assays. Positive chemotaxis towards glucose was assessed by capillary assays using 10 mM glucose, the amount required for optimal chemotaxis, and judged by plating capillary contents accumulated after 30 min.

Biological Transport↗
PubMed1991

Routes to psychiatric inpatient care in an Inner London Borough.

A study is reported in which pathways to psychiatric inpatient care were investigated in an Inner London Borough. Data were collected on a series of 52 consecutive admissions of adults to the psychiatric wards serving the area. The most striking feature of the results was the variety of routes taken to inpatient care, combined with a high level of police involvement (23.1% of admissions) and low level of referral from General Practitioners (15.4% of admissions). Significant age differences in routes to care were found: those under 30 years were usually brought to hospital by the police or presented directly to psychiatric emergency services; those over 30 typically came via medical/surgical hospital services, domiciliary psychiatric services or psychiatric outpatients. There were no differences in the routes taken by Afro-Caribbean and white people or by men and women. Higher proportions of Afro-Caribbeans received a diagnosis of schizophrenia, considered themselves to have nothing wrong with them and were compulsorily detained. Higher proportions of whites were diagnosed as depressed and considered themselves to have physical problems rather than psychiatric ones. However, results clearly indicated that it was ethnic status rather than diagnostic category that accounted for the higher rates of compulsory detention of Afro-Caribbean people. The implications of the findings for service development and delivery are considered.

Adolescent↗
PubMed1991

Identity and coping with mental illness in long-stay psychiatric rehabilitation.

The literature on coping with mental illness is reviewed. A study is reported which was designed to operationalize and measure the responses to chronic psychiatric illness of denial or adoption of a sick role outlined by Wing & Morris (1981) and Shepherd (1984) and to investigate their correlates and relationship to identity as measured by Thompson (1988). On the basis of existing literature, it was anticipated that subjects who identified themselves as 'community members' would tend to cope by denial of psychiatric problems whilst those seeing themselves as a 'typical psychiatric patient' would exaggerate their disabilities. Although both types of response and identity were found within the group studied, this prediction was not confirmed: responses of patients to their illness were independent of identity, and had different sets of correlates. As compared with 'exaggerators', 'deniers', tended to have social networks within the hospital, and showed higher self-esteem and less subjective distress. Community identity, on the other hand, was related to actually going into the community, better overall functioning (especially in the areas of social activities and community skills), and poorer compliance with medication. The theoretical and practical implications of these findings are discussed.

Adaptation, Psychological↗
PubMed1991

Sex differences in service usage in long-term psychiatric care are women adequately served?

There is a paucity of research concerning service usage and needs of female long-term psychiatric patients. A series of studies comparing the provisions for chronically mentally ill men and women in a south London community-focused rehabilitation and continuing care service indicate marked differences in the services received by men and women, and raise questions concerning whether the needs of female patients are adequately served. As a group the women had been in contact with services for longer, had received less intensive input from services, and it appeared that the services had been less responsive to their changing needs. Among those in high contact with the services, the functioning of men and women did not differ, yet women were over-represented in workshops designed for those functioning at a lower level. Women over 45 years of age seemed to be particularly badly served by the organised activities offered.

Activities of Daily Living↗
PubMed1990

Group counselling for relatives of hospitalized presenile dementia patients: a controlled study.

A controlled study is reported in which the effects of time-limited group counselling for the relatives of hospitalized presenile dementia patients is evaluated. The results indicate that such group counselling was effective in increasing relatives' morale, increasing their knowledge about dementia, and increasing the number of activities performed with the patient during visits, but had no effect upon the frequency or duration of visits or the amount of verbal and non-verbal communication between patient and relative. All changes achieved were maintained at three month follow-up.

Adaptation, Psychological↗
PubMed1990

Analysis of cloned structural and regulatory genes for carbohydrate utilization in Pseudomonas aeruginosa PAO.

Five of the genes required for phosphorylative catabolism of glucose in Pseudomonas aeruginosa were ordered on two different chromosomal fragments. Analysis of a previously isolated 6.0-kb EcoRI fragment containing three structural genes showed that the genes were present on a 4.6-kb fragment in the order glucose-binding protein (gltB)-glucokinase (glk)-6-phosphogluconate dehydratase (edd). Two genes, glucose-6-phosphate dehydrogenase (zwf) and 2-keto-3-deoxy-6-phosphogluconate aldolase (eda), shown by transductional analysis to be linked to gltB and edd, were cloned on a separate 11-kb BamHI chromosomal DNA fragment and then subcloned and ordered on a 7-kb fragment. The 6.0-kb EcoRI fragment had been shown to complement a regulatory mutation, hexR, which caused noninducibility of four glucose catabolic enzymes. In this study, hexR was mapped coincident with edd. A second regulatory function, hexC, was cloned within a 0.6-kb fragment contiguous to the edd gene but containing none of the structural genes. The phenotypic effect of the hexC locus, when present on a multicopy plasmid, was elevated expression of glucokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydratase, and 2-keto-3-deoxy-6-phosphogluconate aldolase activities in the absence of inducer.

Carbohydrate Metabolism↗
PubMed1989

Resettlement of old long-stay psychiatric patients: the use of the private sector.

A follow-up study of 17 old long-stay psychiatric patients resettled in private facilities for the elderly is reported. Resident satisfaction with the placement and functioning (using the CAPE Behaviour Rating Scale) was assessed, together with the quality of the physical and social environment, and the regime characteristics in the establishments. All residents were satisfied with life and their functioning had improved significantly. The private facilities were more resident-orientated, and had a generally superior social environment to their local authority 'old people's home' counterparts. The physical amenities, safety features, and architectural choice available were of a similar standard to those in local authority old people's homes, but there were fewer prosthetic and orientational aids and on-site recreational amenities.

Activities of Daily Living↗
PubMed1986

Secondary tensor and supinator muscles of the human proximal radio-ulnar joint.

A gross anatomical study was made of the human elbow. Three very small muscles were found that are not described in contemporary anatomical publications. A lateral tensor muscle of the annular ligament was observed in seven of every ten cadavers; its action is to tense or pull the annular ligament laterally during supination. A medial tensor muscle of the annular ligament was found in two of every ten cadavers; its action is to tense the annular ligament, pulling it medially and distally, and to assist in supination. An accessory supinator muscle was found in four of ten cadavers; its action is to assist in supination. These muscles would be synergistic to the primary supinator muscles of the radio-ulnar joint.

Elbow Joint↗
PubMed1985

Cognitive and affective aspects of boredom.

It is argued that previous research may have been mistaken in assuming that monotony in sensory stimulation is a necessary and sufficient cause of boredom. Five investigations are reported which used personal construct theory and repertory grid techniques to investigate three hypotheses: that boredom is associated with subjective monotony, that boredom is associated with a high degree of frustration and that boredom arises when stimulation lacks meaning for the individual. Results supported hypotheses (1) and (2) but no evidence was found to support hypothesis (3).

Adult↗
PubMed1985

Towards a model of boredom.

On the basis of the authors' own research it is suggested boredom may be viewed as having cognitive and affective components. The cognitive component is subjective monotony and the affective component is a high level of frustration. An attempt is made to integrate the evidence supporting this view of boredom with other evidence from the literature to present an integrated model of boredom in which the roles of personality, situational and task characteristics influencing boredom are outlined. Psychophysiological changes occurring during the performance of boring tasks are examined. It is argued that the nature and extent of changes in heart rate and heart-rate variability are not a consequence of boredom but of a task feature (mental load). It is concluded that no clear psychophysiological component of boredom can be detected at present.

Affect↗
PubMed1983

The complete amino acid sequence of yeast phosphoglycerate kinase.

The complete amino acid sequence of yeast phosphoglycerate kinase, comprising 415 residues, was determined. The sequence of residues 1-173 was deduced mainly from nucleotide sequence analysis of a series of overlapping fragments derived from the relevant portion of a 2.95-kilobase endonuclease-HindIII-digest fragment containing the yeast phosphoglycerate kinase gene. The sequence of residues 174-415 was deduced mainly from amino acid sequence analysis of three CNBr-cleavage fragments, and from peptides derived from these fragments after digestion by a number of proteolytic enzymes. Cleavage at the two tryptophan residues with o-iodosobenzoic acid was also used to isolate fragments suitable for amino acid sequence analysis. Determination of the complete sequence now allows a detailed interpretation of the existing high-resolution X-ray-crystallographic structure. The sequence -Ile-Ile-Gly-Gly-Gly- occurs twice in distant parts of the linear sequence (residues 232-236 and 367-371). Both these regions contribute to the nucleoside phosphate-binding site. A comparison of the sequence of yeast phosphoglycerate kinase reported here with the sequences of phosphoglycerate kinase from horse muscle and human erythrocytes shows that the yeast enzyme is 64% identical with the mammalian enzymes. The yeast has strikingly fewer methionine, cysteine and tryptophan residues.

Amino Acid Sequence↗
PubMed1982

Conservation of high efficiency promoter sequences in Saccharomyces cerevisiae.

The position of the yeast phosphoglycerate kinase (PGK) gene has been mapped on a 2.95kb Hind III fragment. We have determined the nucleotide sequence of the 5' flanking region and compared this sequence with those from 16 other yeast genes. PGK, like all other yeast genes has an adenine residue at position -3. It has two possible TATA boxes at positions -114 and -152 and a CAAT box at -129. In addition we have defined a structure at position -63 to -39 that is common to all yeast genes that encode an abundant RNA. This structure is a CT-rich block followed, about 10 nucleotides later, by the sequence CAAG.

Amino Acid Sequence↗
PubMed1982

Sequence and structure of yeast phosphoglycerate kinase.

The structure of yeast phosphoglycerate kinase has been determined with data obtained from amino acid sequence, nucleotide sequence, and X-ray crystallographic studies. The substrate binding sites, as deduced from electron density maps, are compatible with known substrate specificity and the stereochemical requirements for the enzymic reaction. A carboxyl-imidazole interaction appears to be involved in controlling the transition between the open and closed forms of the enzyme.

Amino Acid Sequence↗