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Biomedical subjects

S Parker

Publications and source records attributed to S Parker.

At least 181 records · Page 10Linked to original sources
PubMed1988

Work of a rehabilitation medicine service.

The results of the work of the Edinburgh Rehabilitation Medicine Service in one year were evaluated. Over 1400 new patients were seen, of whom 525 were in hospital at the time. Patients most often referred were those who had had cardiovascular accidents, back pain, lower limb amputations, and head injuries and those convalescing after heart surgery. Most patients had several problems. Many were referred so that they could obtain wheelchairs or other appliances, or for assessment of their ability to drive. Only 3% of the referrals were considered inappropriate. Of the inpatients, 455 (87%) returned home after treatment, but 13 (2%) did not respond satisfactorily to rehabilitation. Twelve per cent (18% of the inpatients) were referred from other health boards, suggesting a need for similar facilities elsewhere.

Persons with Disabilities↗
PubMed1988

Left ventricular wall motion abnormalities in subarachnoid hemorrhage: an echocardiographic study.

Although electrocardiographic (ECG) abnormalities and autopsy evidence of myocardial necrosis are associated with subarachnoid hemorrhage, their relation to in vivo measures of left ventricular function in this condition has not been established. Thirteen patients with subarachnoid hemorrhage and no prior history of heart disease were studied by two-dimensional echocardiography, performed initially 10 to 48 h (mean 18) after admission and serially for less than or equal to 14 days. Serum creatine kinase (total and myocardial isoenzyme) was determined 5 times over the first 48 h; ECGs were performed daily. Neurologic state was assessed with the use of a standard grading system. Four patients (Group I) exhibited left ventricular wall motion abnormalities in one to eight segments. In two of these patients there was also left ventricular apical mural thrombus that embolized in one patient, leading to further neurologic deterioration. The initial creatine kinase myocardial isoenzyme was higher in Group I than in Group II (patients without wall motion abnormalities) (10.3 versus 2.1 U/liter, p less than 0.001), initial heart rate was higher (91 versus 61 beats/min, p less than 0.01), neurologic grade was higher (2.5 to 4.5 versus 1 to 2, p less than 0.001) and inverted T waves were more common (4 of 4 versus 1 of 9). Three of the four patients in Group I died; two of the three underwent autopsy and were found to have no significant coronary artery disease. No other patients died.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Effect of inhaled methacholine on gas mixing efficiency.

1. Pulmonary function tests, including alveolar mixing efficiency by the single-breath and multi-breath methods, and ventilation scans were performed on 16 volunteer subjects. The tests were repeated after the inhalation of a methacholine aerosol in sufficient dosage to increase airways resistance. 2. After inhalation of methacholine there was a significant fall in mean series dead space of 31 ml (P less than 0.05), and mean multi-breath alveolar mixing efficiency fell from 68% to 36% (P less than 0.001), a fall occurring in all subjects. Mean single-breath alveolar mixing efficiency measured on the first breath of the nitrogen washout fell from 76% to 70%, but this change did not reach statistical significance (0.1 greater than P greater than 0.05). 3. In eight of the subjects, technically adequate lung scans and pulmonary function tests were obtained both before and not more than 30 min after methacholine inhalation. In seven there were obvious visible defects on the ventilation scans, and in five of these the computer-calculated underventilation score became abnormal. 4. Thus inhalation of methacholine causes maldistribution of ventilation, a fall in alveolar mixing efficiency and a fall in series dead space, presumably brought about by bronchoconstriction. The parallel component of this maldistribution of ventilation, as judged by 81mKr ventilation scanning, does not of itself seem to be sufficient to explain the fall in alveolar mixing efficiency, and therefore a degree of diffusion limitation is probably involved as well.

Administration, Inhalation↗
PubMed1988

How hospital ward members treat learner nurses: an investigation of learners' perceptions in a British hospital.

Twenty-five learner nurses who had just completed their first two wards were questionned about the behaviour of other ward members towards them. Although many ward sisters' and charge nurses' behaviour was positive towards learners, just under 50% of learners' responses indicated that the ward sister/charge nurse was sometimes rude and did not make them feel 'at home'. The ward sister/charge nurse's behaviour was, on average, more negative than another liked qualified staff, whose behaviour was more negative than a more experienced student on the ward. The ward sister/charge nurse's behaviour was the major determinant of ward preference by the learner. However, the behaviour of ward members tended to correlate, providing evidence of a 'ward atmosphere'. There is a need for leadership and educational training for ward sisters and charge nurses.

Attitude of Health Personnel↗
PubMed1988

Doppler ultrasound of twin transfusion syndrome.

Doppler sonography of umbilical arteries was used to evaluate eight cases of twin transfusion syndrome (TTS). Data were collected regarding the Doppler and real-time sonographic evaluation, clinical course, and outcome. In addition, the literature was reviewed. An abnormal peak systolic velocity (A) to end diastolic velocity (B) ratio, as defined by Giles et al, was seen in at least one twin in five cases. A difference in the A/B ratios between the two twins was greater than 0.4 in all eight cases. Doppler studies were able to suggest which fetus was encountering greater placental resistance, however they could not differentiate donor from recipient or provide prognostic data regarding outcome. Doppler evaluation was helpful when there was uncertainty as to whether growth discrepancy in a twin pregnancy was significant enough to suggest a pathologic state. In the future, Doppler sonography may be helpful in evaluating the effectiveness of therapy in TTS. Variable Doppler findings confirm that TTS is an extremely complex dynamic physiologic state.

Blood Flow Velocity↗
PubMed1988

Rhinocerebral zygomycosis caused by Saksenaea vasiformis.

A fatal rhinocerebral zygomycotic infection caused by Saksenaea vasiformis in a 71-year-old man was diagnosed based on the presence of broad, infrequently septate, branched, hyaline hyphae in tissue obtained from the right and left base of the skull, soft tissue, both maxillary sinuses and the sphenoid sinus; isolation of S. vasiformis from the tissue; and demonstration of mucoraceous antibodies by enzyme-linked immunosorbent assay. Fluorescent antibody studies carried out with a Rhizopus arrhizus conjugate, stained hyphal fragments in tissue with a 2+ intensity.

Aged↗
PubMed1987

Synthesis and characterization of O6-(2-chloroethyl)guanine: a putative intermediate in the cytotoxic reaction of chloroethylnitrosoureas with DNA.

The chloroethylnitrosoureas are useful antitumor agents which evidently exert a significant part of their cytotoxic action through the formation of a unique 1-(3-deoxycytidyl), 2-(1-deoxyguanosinyl)ethane cross-link in DNA. It has been suggested that this cross-link is formed from O6-(2-chloro-ethyl)guanine, an initial product of DNA alkylation by the chloroethylnitrosoureas; however, O6-(2-chloroethyl)guanine has never been described. We have synthesized this derivative from the reaction of thionyl chloride with O6-(2-hydroxyethyl)guanine, and have found that it decomposes to 1-(2-hydroxyethyl)guanine through an intermediate, presumably 1,O6-ethanoguanine. Its half life at 37 degrees and pH 7.4 is 17.8 min.

Chemical Phenomena↗
PubMed1987

Evidence for the involvement of calmodulin in natural cytotoxicity using a range of calmodulin antagonists of varying potency and improved specificity.

The calmodulin antagonist W7 and 4 of its analogues were examined for their ability to inhibit human NK cell mediated cytotoxicity. With the exception of one of these compounds, which is extremely hydrophobic, there was a good correlation between the ability of drugs to inhibit human NK antitumour cytotoxicity and calmodulin-dependent phosphodiesterase activity in vitro. The most potent of the compounds, 5-iodo-1-C8, an analogue of W7, has an IC50 of 3 microM upon biological and biochemical assay. This particular compound is both more potent and specific than the parent compound W7, is non-toxic to cells over the range used and is also capable of inhibiting the biological activity of NK cells upon pre-treatment of the effector cells, inferring the mechanism of NK cytotoxicity to be calmodulin dependent.

Calmodulin↗
PubMed1987

Transfection of mammalian cells with plasmid DNA by scrape loading and sonication loading.

Scrape loading and sonication loading are two recently described methods of introducing macromolecules into living cells. We have tested the efficacy of these methods for transfection of mammalian cells with exogenous DNA, using selection systems based either on resistance to the drug G418 (Geneticin) or on acquisition of the ability to utilize the salvage pathway of pyrimidine biosynthesis. These loading methods can be employed to generate cell lines that express the gene product of the transfected DNA molecules both transiently and stably. Optimal transfection is observed when the DNA is added to cells in physiological saline lacking divalent cations and containing K+ in place of Na+. DNA molecules 7.1 to 30 kilobases long have been introduced by the scrape loading procedure. In addition, the scrape loading procedure has been employed for cotransfection and subsequent expression of nonselectable genes encoded on DNA molecules added in a mixture with DNA molecules whose expression is selected. Cell lines expressing oncogenes or proteins that are important for regulation of cell growth and division have been obtained by this procedure. The scrape loading procedure is also useful for studies of the cellular changes that occur upon expression of an exogenous gene. As many as 80% of cells scrape loaded with the plasmid pC6, which encodes the simian virus 40 large tumor antigen, contained this protein in the nucleus between 1 and 5 days after transfection. Thus, scrape loading and sonication loading are simple, economical, and reproducible methods for introduction of DNA molecules into adherent and nonadherent cells, and these methods may be useful in the future for experimentation at both fundamental and applied levels.

Animals↗
PubMed1987

Effect of PUVA on plasma and skin immunoreactive alpha-melanocyte stimulating hormone concentrations.

Plasma alpha-melanocyte stimulating hormone (alpha-MSH) concentrations were measured in patients receiving PUVA therapy as treatment for mycosis fungoides, and PUVA or UVB as treatment for psoriasis. Skin immunoreactive alpha-MSH was also measured in those patients who received PUVA. The mean plasma and skin alpha-MSH concentrations after 2-3 weeks of PUVA were not significantly different from pre-treatment values and showed no relationship either to skin type or to the degree of tanning that occurred in response to PUVA. Plasma alpha-MSH concentrations were also unchanged after UVB. There was also no short term change in plasma alpha-MSH concentrations in patients after receiving their first treatment with PUVA. It would appear that circulating and skin alpha-MSH levels are unaffected by UV and show no causal relationship to PUVA induced pigmentation.

Adult↗
PubMed1986

Reaction of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) with guanosine: evidence for a new mechanism of DNA modification.

When guanosine reacts with 1,3-bis(2-chloro-2,2-dideuteroethyl)-1-nitrosourea in a mixture of pH 7.1 buffer and DMSO, the 7-chloroethylguanosine which is isolated contains two deuterium atoms located next to the guanine ring and beta to the chlorine atom as shown by electron impact mass spectrometry. It is proposed that initial attack by DNA bases occurs on the number 2 carbon of the haloethylnitrosourea with displacement of the chloride ion. In accordance with this proposed mechanism, 7-bromoethylguanosine is isolated as a major product when BCNU is reacted with guanosine in the presence of high concentrations of KBr. These results suggest that the antitumor activity of various haloethylating antitumor agents may be determined by structural changes which affect their mechanisms of reaction with DNA.

Carmustine↗