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Biomedical subjects

R Nicolson

Publications and source records attributed to R Nicolson.

10 recordsLinked to original sources
PubMed1996

Bridging the gap between theory and practice: a multimedia tutorial for students of voice therapy.

A computer-based tutorial for speech and language therapy students is described in which a digitized video-recording of a diagnostic interview with a voice-disordered client was dynamically linked to an on-screen transcript window. A student-centered tutorial package, which provided guidance through questions, assessment tasks, and commentary from an experienced speech and language pathologist as well as the lecturer in voice disorder, was constructed. Evaluation of the tutorial as an aid to active learning, including feedback from students and supervising clinicians, is reported and the role of this type of program as a preparation for clinical practice is discussed.

Adult↗
PubMed1994

The effect of oleic acid on the secretion of thyrotrophin and growth hormone by cultured rat anterior pituitary cells.

Elevation of non-esterified fatty acids (NEFA) in vivo is associated with abnormal control of TSH. To determine whether TSH secretion is directly inhibited by NEFA, as has been reported for GH, cultured rat anterior pituitary cells were exposed for 20 h to oleic acid in medium containing 7.7 x 10(-5) mol/l bovine serum albumin (BSA). In a molar ratio with albumin of 1.2 (total oleic acid 9 x 10(-5) mol/l), or greater, oleic acid inhibited basal GH secretion (maximum inhibition to 40% of control) while basal TSH was less affected, a ratio of 3 (2.3 x 10(-4) mol/l oleic acid) or greater causing a smaller degree of inhibition (maximum inhibition to 80% of control). In the presence of 10(-9) mol/l growth hormone-releasing hormone or 10(-8) mol/l TRH, inhibition was achieved at a ratio of 12 (9 x 10(-4) mol/l oleic acid) or greater. Basal TSH was less sensitive to inhibition by thyroxine (T4) in the presence of oleic acid/albumin at a ratio of 6 or greater, and inhibition by oleic acid was less than additive with T4 at a ratio of 6 or greater. Responses to tri-iodothyronine (T3) were unaffected at a ratio of 6 (4.6 x 10(-4) mol/l oleic acid), but a ratio of 12 inhibited the effects of both T3 and T4 on TSH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Nucleotide sequence, organisation and structural analysis of the products of genes in the nirB-cysG region of the Escherichia coli K-12 chromosome.

The DNA sequence and derived amino-acid sequence of a 5618-base region in the 74-min area of the Escherichia coli chromosome has been determined in order to locate the structural gene, nirB, for the NADH-dependent nitrite reductase and a gene, cysG, required for the synthesis of the sirohaem prosthetic group. Three additional open reading frames, nirD, nirE and nirC, were found between nirB and cysG. Potential binding sites on the NirB protein for NADH and FAD, as well as conserved central core and interface domains, were deduced by comparing the derived amino-acid sequence with those of database proteins. A directly repeated sequence, which includes the motif -Cys-Xaa-Xaa-Cys-, is suggested as the binding site for either one [4Fe-4S] or two [2Fe-2S] clusters. The nirD gene potentially encodes a soluble, cytoplasmic protein of unknown function. No significant similarities were found between the derived amino-acid sequence of NirD and either NirB or any other protein in the database. If the nirE open reading frame is translated, it would encode a 33-amino-acid peptide of unknown function which includes 8 phenylalanyl residues. The product of the nirC gene is a highly hydrophobic protein with regions of amino-acid sequence similar to cytochrome oxidase polypeptide 1.

Amino Acid Sequence↗
PubMed1986

Serum relaxin in pregnancy.

Serum relaxin immunoactivity was measured by means of a porcine radioimmunoassay in a cross-sectional study of 302 normal singleton pregnancies. Concentrations in the third trimester were lower than in early and mid pregnancy. At term, relaxin levels in patients who went into spontaneous labour within a week of sampling were significantly lower than in those who did not. However, relaxin levels were highest during labour and fell almost to non-pregnant levels by the third postnatal day. Levels in twin pregnancies in the third trimester were higher than those in singleton pregnancies. Serial samples from 4 patients with a history of premature labour showed declining, very low levels in the only patient who subsequently had a preterm delivery. These results are compatible with the proposed roles of relaxin during pregnancy: namely, to maintain myometrial quiescence, facilitate uterine stromal remodelling during uterine growth, and promote cervical ripening at the onset of parturition.

Female↗
PubMed1986

Serum relaxin and pelvic pain of pregnancy.

Serum relaxin immunoreactivity was measured by means of a porcine relaxin radioimmunoassay in 35 patients with severe pelvic pain and pelvic joint instability during late pregnancy. Results were compared with a control group of 368 samples obtained throughout pregnancy from normal singleton pregnancies. Most of the relaxin concentrations in the study group were above the 95% confidence limits of the median for the corresponding gestational age in the control group. The difference in relaxin levels between the study and control groups in the third trimester was highly significant. Relaxin levels in patients with pelvic pain were close to normal non-pregnant levels by the third postnatal day. The highest relaxin levels during pregnancy were found in the patients who were the most incapacitated clinically. The results suggest that there may be an association between high serum relaxin levels and pelvic pain and joint laxity during late pregnancy.

Female↗
PubMed1986

Ripening of the human cervix and induction of labor with intracervical purified porcine relaxin.

In a randomized double-blind placebo-controlled trial involving 71 patients, a viscous gel containing distilled water or 1 or 2 mg pure porcine relaxin was instilled in the cervical canal on the evening before the surgical induction of labor. Eleven of 48 patients receiving relaxin labored overnight, whereas only one of 23 patients went into labor. Only the 2-mg dose significantly improved the mean cervical score compared with the placebo treatment; the effect was greatest in primigravid patients with unripe cervixes. Intracervical application appeared to confer no benefit over vaginal application in effecting cervical ripening or inducing labor. Systemic absorption of the porcine relaxin after its intracervical application was confirmed by the measurement of immunoreactive relaxin in a homologous porcine relaxin radioimmunoassay. Thus, the cervical ripening effect of exogenous relaxin may be mediated either systemically or by direct action at the site of local application. This trial confirms the responsiveness of the human term cervix to exogenous relaxin and supports the suggestion that endogenous relaxin may play a similar role at term in facilitating cervical ripening and parturition.

Administration, Intravaginal↗
PubMed1981

Oestrogen receptors and survival in early breast cancer.

Oestrogen receptor status was related to survival in 414 patients with primary breast cancer. Women with oestrogen receptors in their tumours survived significantly longer than those without receptors; this was true for both premenopausal and postmenopausal women and also when the patients were subdivided into those with and without axillary metastases. Patients with axillary metastases and no oestrogen receptors in their tumours had the worst prognosis, while women with axillary metastases and oestrogen receptors had a death rate similar to that of women with no axillary metastases and no receptors. Patients without oestrogen receptors and with no axillary metastases were identified as a high-risk group, and it would seem appropriate to include such patients in future trials for adjuvant therapy in early breast cancer.

Breast Neoplasms↗