PubMed Health⌕ Search

Biomedical subjects

J Woodrow

Publications and source records attributed to J Woodrow.

13 recordsLinked to original sources

Bathocuproine-assisted reduction of copper(II) by human albumin.

Human albumin (studied here as the recombinant protein rHA), a copper-binding protein in blood plasma, is shown to reduce Cu(II) to Cu(I) in the presence of a Cu(I) chelator, bathocuproinedisulfonate (BD). This reaction was accelerated at low pH, when there was little binding of Cu(II) to rHA. The addition of a competitive metal ion, Ni(II), or an increase in the concentration of BD, enhanced the reduction of Cu(II) to Cu(I). It was concluded that the oxidant was the Cu(II) complex of BD, which is likely to bind strongly to albumin. The free thiol at Cys34 was ruled out as the sole reducing agent, since Cys34-blocked albumin also gave rise to Cu(I) in the presence of BD. Reactions with amino acids and peptides suggested that Tyr and possibly His side-chains are potential reductants. BD and its homologues are frequently used as Cu(I)-specific chelators in biological experiments, but the strong oxidant activity of [Cu(II)(BD)2]2- and its ability to bind to biological macromolecules should not be overlooked, and may artificially trigger/accelerate Cu(II) reduction.

Albumins↗

Cisplatin binding sites on human albumin.

Reactions of cisplatin (cis-[PtCl2(NH3)2]) with albumin are thought to play an important role in the metabolism of this anticancer drug. They are investigated here via (i) labeling of cisplatin with 15N and use of two-dimensional 1H,15N NMR spectroscopy, (ii) comparison of natural human serum albumin with recombinant human albumin (higher homogeneity and SH content), (iii) chemical modification of Cys, Met, and His residues, (iv) reactions of bound platinum with thiourea, and (v) gel filtration chromatography. In contrast to previous reports, it is shown that the major sulfur-containing binding site involves Met and not Cys-34, and also a N ligand, in the form of an S,N macrochelate. Additional monofunctional adducts involving other Met residues and Cys-34 are also observed. During the later stages of reactions of cisplatin with albumin, release of NH3 occurs due to the strong trans influence of Met sulfur, which weakens the Pt-NH3 bonds, and protein cross-linking is observed. The consequences of these findings for the biological activity of cisplatin-albumin complexes are discussed.

Ammonia↗

Comparative studies of recombinant human albumin and human serum albumin derived by blood fractionation.

Recombinant human albumin produced in the yeast Saccharomyces cerevisial and human serum albumin derived from blood fractionation were compared by a series of analytical techniques. These demonstrated that the two proteins were equivalent structurally. However, differences observed in some of the assays indicated that the recombinant product had lower levels of structural heterogeneity than the blood-derived protein.

Albumins↗

Site-specific N-terminal auto-degradation of human serum albumin.

Human serum albumin prepared by blood fractionation for clinical purposes was found to degrade when stored at or above 30 degree C. Mass spectrometry and N-terminal sequencing of the protein identified degradation corresponding to the loss of the first two residues, aspartic acid and alanine. The reaction was shown to be dependent upon temperature and the N-terminal alpha-amino group. In addition, comparison with serum albumins derived from other species showed that the instability of the N-terminus was specific to the human albumin sequence. An intact aspartyl-alanyl dipeptide, purified from degraded albumin solutions, differed substantially from a synthetic dipeptide on amino acid analysis, N-terminal sequencing and NMR. It is suggested that the released dipeptide may be cyclic, implying a novel cleavage mechanism.

Amino Acid Sequence↗

Does the incidence, severity, or case fatality of stroke vary in southern England?

STUDY OBJECTIVES: To determine differences in incidence and case fatality of stroke in district health authorities with differing standardised mortality ratios (SMR) for stroke in residents aged under 65 years in whom death from stroke is considered 'avoidable'. DESIGN: Registration of first ever strokes in three district health authorities. Patients were assessed and followed up over one year by one of three observers. SETTING: West Lambeth, Lewisham and North Southwark, and Tunbridge Wells District Health Authorities in south east England. PARTICIPANTS: Patients under the age of 75 years having a first ever in a lifetime stroke between 15 August 1989 and 14 August 1990. MEASUREMENTS AND MAIN RESULTS: Age specific incidence rates and survival time from stroke to death. Severity was assessed in terms of the level of consciousness and the presence of speech, urinary, and motor impairment within the first 24 hours of the stroke. Altogether 386 strokes were registered. There was a significant difference in the incidence rate between district health authorities in those aged under 65 (p < 0.01). The overall case fatality was 26% at three weeks with no significant difference between the districts. Poor survival was associated jointly with increased age and with coma, incontinence, and swallowing impairment in the first 24 hours after a stroke. CONCLUSIONS: The SMRs for stroke in those aged under 65 in these three health districts reflect the incidence of stroke. Case fatality at three weeks does not vary between these districts and consequently would not be a sensitive indicator of the quality of care. This also suggests that differences in services between the districts did not lead to changes in prognosis. In districts with high SMRs for stroke there is a need for further study and reduction of risk factors, thereby reducing the incidence and burden of stroke locally. This study provides a framework for assessing the needs for stroke prevention and treatment in both rural and urban areas without an elaborate protocol and detailed neurological assessment.

Adult↗

Patterns of acute stroke care in three districts of southern England.

OBJECTIVE: To quantify the use of health care services by acutely ill stroke patients in three district health authorities. DESIGN: A follow up study of all patients recorded in population based registers who had a first ever stroke in three district health authorities, with assessment following the onset and three months after the stroke. SETTING: West Lambeth, Lewisham and North Southwark, and Tunbridge Wells District Health Authorities in south east England. SUBJECTS: All first time stroke patients under the age of 75 years who presented between 15 August 1989 and 14 August 1990. MEASUREMENTS AND MAIN RESULTS: Hospital admission rates, rates of use of rehabilitation services, and contact with medical practitioners together with assessment of disability and handicap were determined. A total of 386 strokes were registered. Seventy eight per cent were treated in hospital and younger and incontinent patients were significantly more likely to be admitted. The median stay was 21 days. Patients in West Lambeth, those paralysed, and those who stayed longer in hospital were more likely to receive physiotherapy. Altogether 265 patients were followed up, 117 having died within three months of the stroke. During the three months, 150 (57%) had seen a hospital physician and 181 (69%) their general practitioner, but 18 (7%) had seen neither. Sixty seven (26%) patients were moderately or severely disabled. Twenty seven per cent of inpatients had received no inpatient physiotherapy and 67% of all patients no outpatient physiotherapy during the three months. CONCLUSIONS: The hospital admission rates were high, with long lengths of stay. There were significant differences in the amount of rehabilitation received in each district. This was low overall, especially for those not admitted to hospital. As expected, patients admitted for long periods were the most likely to receive therapy. Before district policies for admission and management of stroke patients can be drawn up, increased knowledge of which aspects of stroke management are effective is needed. Policies should aim to provide planned, coordinated care between hospital and the community. It is striking that many patients received no form of rehabilitation therapy.

Acute Disease↗

Psychosexual and psychosocial sequelae of closed head injury.

A series of 36 patients who had been hospitalized following closed head injury (CHI) were followed up 4.06 (SD 3.71) years after the injury. Measures were taken of degree of psychosexual dysfunction (Golombok Rust Inventory of Sexual Satisfaction-GRISS), general psychiatric morbidity (General Health Questionnaire-GHQ), and clinical anxiety and depression (Hospital Anxiety and Depression Scale-HAD). These measures were completed by patients and partners. Resulting data revealed that 50% of male patients with current sexual partners produced psychosexual profiles that fell within the dysfunctional range. For both male patients and their partners, the chief psychosexual complaint was infrequency. Of the patients studied, 61% were classified (using the GHQ) as having degrees of emotional distress that would fall within the range of psychiatric 'caseness', while 25% of patients achieved HAD criteria for clinical anxiety and 22% met HAD criteria for depression. Of the partners, 41% met GHQ criteria for psychiatric 'caseness', 18% being classified using the HAD as anxiety cases and 6% as depression cases. No effects of severity of injury were observed on any of the main outcome measures. Age and time since injury were related to measures of psychosexual dysfunction. These results are discussed in relation to the existing literature on psychosocial outcome in closed head injury, and recommendations for therapeutic intervention are made.

Adult↗

Stroke registers: a way to improve care.

The authors describe their continued involvement in a research project to assess the incidence, case-fatality and management of stroke in three health authorities of Southern England. The article focuses on how the findings of their research have been used in two of the districts, and the role research can play in beginning to improve the services for people who have had strokes.

Cerebrovascular Disorders↗

Investigating stroke.

Explore the source record for details and available documents.

Activities of Daily Living↗

Criteria for determining steam sterilization cycles for lubricated and nonlubricated mechanical equipment.

Requirements and procedures for determining steam sterilization cycles for lubricated and nonlubricated, complex, mechanical equipment are established. Factors affecting exposure times are discussed, as are procedures and data needed to determine the penetrability of steam into mechanical equipment, and the effect of lubricating oil in impeding steam penetration to the spore. The total effects of these factors in sterilizing times are presented. Sterilizers with a prevacuum cycle, which can remove air from the equipment efficiently and replace it with saturated steam, are recommended for complex mechanical equipment.

Equipment and Supplies, Hospital↗