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Biomedical subjects

K Nicol

Publications and source records attributed to K Nicol.

15 recordsLinked to original sources
PubMed2006

The endurance shuttle walking test: a responsive measure in pulmonary rehabilitation for COPD patients.

BACKGROUND: The endurance shuttle walk test (ESWT) is a standardized externally controlled constant paced field test for the assessment of endurance capacity in chronic lung disease. The ESWT has been advocated as a simple, acceptable, repeatable and responsive outcome measure for COPD patients undergoing pulmonary rehabilitation, but has not been formally compared with the more commonly used field walking test, the six-minute walk (6MW). We aimed to determine: 1) the responsiveness of the ESWT in COPD patients attending a hospital-based pulmonary rehabilitation programme, and 2) to compare the responsiveness of the ESWT with the 6MW. METHODS: Consecutive COPD patients, referred for a standard 8 week pulmonary rehabilitation programme, were recruited. Outcome parameters studied at baseline and completion of rehabilitation programme (8 weeks) included spirometric lung volumes, resting oxygen saturation, breathlessness scored pre and post exercise (modified Borg dyspnoea score), 6MW, ESWT, health-related quality of life (Chronic Respiratory Questionnaire) and Hospital Anxiety and Depression (HAD) scale. The incremental shuttle was employed to predict VO2 peak; 85% VO2 peak was used to determine the walk speed for the ESWT. RESULTS: Twenty stable COPD patients (11 male), mean (SD), age 71, (9) FEV1 0.95 (0.51), resting SpO2 95% (2) 6MW distance (m) 351 (104) and ESWT distance (m) 313 (193) were studied. Three patients did not complete their rehabilitation programme. Following rehabilitation, there were significant improvements in 6MW, ESWT, total CRQ and anxiety domain (HAD). The 6MW distance increased by 17% (47 m 95%CI 3, 90), while the ESWT increased by 92% (302 m 95%CI 104, 501). CONCLUSION: The ESWT is a simple, acceptable and highly responsive outcome measure for COPD patients undergoing a pulmonary rehabilitation programme. The ESWT has potential advantages in that it may be more responsive than the 6MW.

Aged↗
PubMed2004

Pityriasis versicolor: quality of studies.

OBJECTIVE: To evaluate the quality of the published literature on the treatment of pityriasis versicolor and to compare this evaluation with the number of times the work has been cited. METHODS: A search was performed using MEDLINE (1966-2002) to find publications evaluating the treatment of pityriasis versicolor. Two reviewers evaluated each clinical trial according to a list of pre-determined criteria including randomization and blinding, prior sample size calculation, treatment regimen clearly explained, and well-defined efficacy parameters. A maximum score of 20 could be attained by each publication. A citation count was performed using the ISI Web of Science Database (http://www.isinet.com/isi/products/citation/wos/). RESULTS: A total of 94 studies were included in this analysis of quality. Studies with a score of 8 or more were considered to be high quality, and 61 studies were rated as high-quality studies (65%). There was no significant correlation between paper quality and citation count. CONCLUSION: It is important for investigators and clinicians to be aware of the design of a high-quality protocol, since such high-quality studies are more likely to reflect accurate efficacy rates. Also, it is important for the information on the design and conduct of the trial to be conveyed to the reader so that a meaningful comparison between the studies can be made.

Bibliometrics↗
PubMed1998

Induction of bone morphogenetic protein-6 in skin wounds. Delayed reepitheliazation and scar formation in BMP-6 overexpressing transgenic mice.

Growth factors of the transforming growth factor-beta superfamily are involved in cutaneous wound healing. In this study we analyze the expression of the bone morphogenetic protein-6 (BMP-6) gene, a transforming growth factor-beta related gene, in skin wounds. In normal mouse skin high levels of BMP-6 mRNA and protein are expressed by postmitotic keratinocytes of stratified epidermis until day 6 after birth. BMP-6 expression is strongly reduced in adult epidermis with diminished mitotic activity. After skin injury we found large induction of BMP-6-specific RNA and protein in keratinocytes at the wound edge and keratinocytes of the newly formed epithelium as well as in fibroblast shaped cells in the wound bed. BMP-6-specific RNA was induced within 24 h after injury, whereas significant upregulation of BMP-6 on the protein level was detected only 2-3 d after injury. Protein was confined to outermost suprabasal epidermal layers, whereas BMP-6-specific RNA was distributed throughout all epidermal layers including basal keratinocytes and the leading edge of the migrating keratinocytes. We also detected high levels of BMP-6-specific RNA and protein in chronic human wounds of different etiology. In contrast to the overall distribution pattern of BMP-6-specific RNA, the protein was not detected in keratinocytes directly bordering the wound. In order to test the influence of BMP-6 abundance on the progress of wound healing, we analyzed the wound response of transgenic mice overexpressing BMP-6 in the epidermis. In these mice, reepitheliazation of skin wounds was significantly delayed, suggesting that strict spatial and temporal regulation of BMP-6 expression is necessary not only for formation but also for reestablishment of a fully differentiated epidermis.

Adult↗
PubMed1997

Coupling force distribution and finite element model for calculating the consequences of distributed force input.

INTRODUCTION:: The aim of the study is to repeat an important step in the development of biomechanics in relation to pressure distribution measurements. Just one decade ago (a) one channel force measurement and (b) 'one channel models' were developed to a certain level of sophistication so that the force could be used by the model to calculate movement and load of the body. In contrast, work in the field of pressure distribution was focused to (a) multi-channel measurement, but (b) no models were used to calculate the consequences of the forces measured. In the following, a multi-channel Finite Element Model (FEM) is introduced for that purpose. The body studied is a mattress; the results attained are helpful under two aspects. Firstly, the FEM provides information on the stress inside the mattress; this aspect is of interest for nearly all bodies. The second aspect is a special problem of mattresses and the like: as the user covers the surface of the mattress, there is no direct information on the shape of mattress and the human body, and measuring procedures for the shape are quite difficult and coarse. METHODS:: The mattress is modelled as a set of a(*)b(*)c vertical springs where c springs are standing on top of each other. The springs are interconnected in a horizontal direction. On top of the set an extra layer with very strong horizontal coupling is placed, which is the model of the cover fabric. Pressure distribution measurements showed that the fabric is responsible for the so called 'hammock effect' which significantly reduces the quality of the mattress. a(*)b forces are input into the model; each force influences all springs because of the horizontal coupling. The distance of the springs is designed according to the distance of the force sensors, which in turn reflect the importance of the mattress area studied. In the trunk area the springs are spaced 15(*)30 mm, in the remaining mattress area the spacing is 72.5(*)43 mm; two springs are standing on top of each other. Each spring defines a volume element, the corner points of each element are connected to the neighbouring element, transferring stress and strain this way. The constraints are specific for the mattress type. APPLICATION:: Utilizing this model and a software package I-DEAS installed on a work station, stress and displacement to three axes of each volume are calculated, moreover the shape of the mattress surface and thus the shape of the body lying on it are attained. The standard measuring procedure is as follows: 1. A mattress is loaded by boards and balls so that the shape of the surface under pressure is known; from pressure distribution measurements the model calculates the spring data. 2. Various subjects are placed on the mattress and measured; the model calculates the surface shape of their body utilizing the spring data. 3. Data of lying quality (concerning comfort and support) are assessed from the body shape and recommendations concerning improvement of the mattress are derived.

Journal Article↗
PubMed1997

Comparative study of ovomucoid isolated from Muscovy duck (Cairina moschata), domestic goose (Anser anser) and domestic duck (Anas platyrhynchos).

1. Ovomucoids were purified from Muscovy duck, domestic duck and domestic goose. 2. Peptide maps of cyanogen bromide-cleaved ovomucoids from Muscovy duck and domestic duck were very similar to one another, but differed from that of goose. 3. Muscovy duck ovomucoid showed the same protease inhibitory pattern as ovomucoid from domestic duck, inhibiting trypsin in the molar ratio of 1:2 and chymotrypsin 1:1. 4. Inhibitory complexes could be detected between chymotrypsin and ovomucoid from both Muscovy and domestic duck, but not from goose, by using non-denaturing gels. 5. No complexes could be detected between DFP-inactivated chymotrypsin and any of the ovomucoids. 6. The results show that of ovomucoid from Muscovy duck more closely resembles that from domestic duck than goose.

Animals↗
PubMed1996

Acid-activatable cysteine proteinases in the cellular slime mold Dictyostelium discoideum.

Studies of the cysteine proteinases of the cellular slime mold Dictyostelium discoideum have been aided by a simple acid treatment step that was incorporated into the standard one-dimensional gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis assay procedure. The step involved immersing the separating gel in 10% (v/v) glacial acetic acid for 30-60 s immediately after electrophoresis. This modified approach revealed the presence of acid-activatable forms of some enzymes with noticeable increases in their ability to hydrolyze gelatin, a substrate present in the sodium dodecyl sulfate-polyacrylamide gels, and peptidyl amidomethylcoumarins. The activation has been analyzed using extracts of dormant spores from which cysteine proteinase activity had previously appeared low or virtually absent. The major acid-activatable proteinase had an apparent molecular mass of 48 kDa. Its activation was not due to autocatalysis as it was not prevented by mercuric chloride, an inhibitor of the enzyme, and was not accompanied by a significant change in electrophoretic mobility. It was most likely due to a conformational change and/or the removal of a low molecular weight inhibitor. The acid treatment has also revealed the presence of acid-activatable cysteine proteinases in vegetative cells, in which cysteine proteinase activity is present at high levels, as well as among enzymes from the developmental cells which have much lower cysteine proteinase activity. Indeed novel developmental forms were detected at some stages. These results provide additional insight concerning cysteine proteinase expression at various stages during development in the slime molds. A developmental model is presented which suggests that the crypticity of the cysteine proteinases in dormant spores may be governed by proton pumps and endogenous lysosomotropic agents.

Acetates↗
PubMed1994

[Optimal design of seating shells for communication disordered multi-handicapped patients with Nicol's capacitative pressure distribution].

Pressure distribution measurements have come into use in the 1930s. The technique started as a qualitative procedure, was developed to a semi-quantitative state and has recently attained a strongly quantitative status. An outline is given of the development of the technique, and the capacitive measuring procedure and its area of application are described. The article is focussed on the adaptation of seats for persons with multiple disability.

Biomechanical Phenomena↗
PubMed1993

Pressure distribution on mattresses.

Measurements of pressure distribution are usually performed on a hard base, such as those in gait analysis or tire research; measurements on soft surfaces are avoided because of technical problems. A sensor mat was developed which consists of 512 pressure sensors, glued to arbitrary locations of a fabric. The mat can be bent to spherical and saddle shapes so that it can be utilised on soft and flexible surfaces like chairs and beds. Performance of eight hospital mattresses concerning decubitus prophylactics and support in supine and side position was studied in four subjects representing extreme body build. It was found that one particular mattress served well for three subjects, whereas no mattress was suitable for the high and heavy type. It was concluded that measurement of pressure distribution is a valuable tool for designing and selecting.

Beds↗
PubMed1989

Ontogeny of pulsatile gonadotrophin secretion and pituitary responsiveness in male puberty in man: a mixed longitudinal and cross-sectional study.

The onset of puberty is characterized by a sleep-associated increase in pulsatile LH secretion which is not observed in adults. The ontogeny of gonadotrophin secretion during pubertal maturation may reflect changes in endogenous LHRH secretion, pituitary sensitivity to LHRH and/or alterations in gonadal steroid feedback. To understand the interplay between these mechanisms, we have examined the pulsatile pattern of plasma LH, FSH, testosterone, oestradiol and prolactin between 20.00 and 09.00 h and the pituitary response to repeated exogenous LHRH stimulation in 16 boys with delayed puberty (age 16.3 +/- 2.7 (S.E.M.) years) on one to four occasions in a mixed longitudinal/cross-sectional analysis. Physical maturity was determined by Tanner G staging (1-5) and clinical progress followed for a mean duration of 22.4 +/- 8.5 months during which 33 hormone profiles were obtained. Nocturnal (23.00-09.00 h) LH pulse frequency increased to a peak of 0.54 +/- 0.03/h at stage 2 which was followed by a gradual decline to 0.42 +/- 0.04/h at stage 5. The appearance of LH pulses in the evening (20.00-23.00 h), probably representative of the rest of the day, was delayed until mid-puberty from which point frequency increased to a peak of 0.53 +/- 0.08/h at stage 5. LH pulse amplitude showed a linear increase from stages 1 to 5, with nocturnal pulse amplitudes being higher than evening pulses throughout. FSH did not show a clear pulsatile pattern. The LH:FSH ratio reversed from less than 1 to greater than 1 at stage 2. The LH response to exogenous LHRH increased in parallel with LH pulse amplitude. There was no difference in the pattern of LH response to repeated LHRH stimulation as puberty advanced; the first stimulus always elicited a greater response than subsequent doses. In contrast, the FSH response to LHRH was maximal at stage 1 and became attenuated thereafter. The estimated mean nocturnal LHRH concentration or amplitude did not show any increase during pubertal maturation from 20.42 +/- 11.57 at stage 1 to 35.96 +/- 20.83 ng/l at stage 5. In conclusion, the sequential changes in this study suggest that the sleep-entrained increase in LHRH pulse frequency plays a key role at the onset of puberty. By enhancing pituitary responsiveness and setting in motion a cascade of events, this peripubertal augmentation of LHRH pulse frequency can account for most of the subsequent changes in LH, FSH and testosterone secretion during pubertal development in the male without any apparent alteration in LHRH pulse amplitude.

Adolescent↗
PubMed1987

Laboratory and diagnostic performance of a coated well immunoradiometric assay for serum thyrotrophin.

A new, coated well immunoradiometric assay (IRMA) for thyrotrophin (TSH) in serum has been evaluated with a view to its use as a first-line test of thyroid function. The Amerwell TSH IRMA is simple, rapid to perform (2.5 h) and the assay sensitivity was 0.07 mU/L with a working range (intra-assay CV less than 10%) of 0.3-100 mU/L. The mean inter-assay CV was 6.6% for TSH concentrations of 0.30-30.7 mU/L. The method compared favourably with an in-house TSH radioimmunoassay and an alternative commercial IRMA. In consecutive referrals to a thyroid clinic all patients with overt hyperthyroidism (n = 103) had undetectable TSH concentrations and in those with subclinical hyperthyroidism (n = 14). TSH was undetectable in 10 and below the reference range in four. The 95% confidence interval for 63 euthyroid serum samples was 0.36-4.3 mU/L. All hypothyroid patients (n = 20) had increased TSH concentrations. TSH concentrations in pregnancy did not differ significantly from euthyroid TSH values. From 1916 routine tests, 13 undetectable TSH values were found in which thyroid hormone levels were normal and the patients had no known thyroid disorder. The assay appears suitable as a first-line test of thyroid function, but further assessment in a routine laboratory setting is required.

Humans↗
PubMed1985

Evidence for the association between blood prolactin and androgen receptors in BPH.

The purpose of this study was to investigate the relationship between prostatic androgen receptors and plasma prolactin and testosterone in patients with benign prostatic hyperplasia. Cytosolic and KCl extractable nuclear androgen receptors were measured in 22 patients and these were in turn correlated to the hormone concentrations in blood specimens taken on the morning before the day of operation. The mean +/- S.E.M. concentrations of cytoplasmic androgen receptors, KCl extractable nuclear androgen receptors, plasma testosterone and plasma prolactin were respectively 115 +/- 18 fmoles/gm. tissue, 198 +/- 40 fmoles/gm. tissue, 15.6 +/- 1.2 nmol./l. and 128 +/- 17 mU/l. Plasma prolactin was highly correlated with cytosolic androgen receptors (r = 0.784, p less than 0.01; no. = 15) though not with nuclear androgen receptors (r = 0.453, p greater than 0.05; no. = 15). However, when the androgen receptor levels were expressed as fmoles/mg. protein both cytosolic and nuclear levels were proportional to plasma prolactin (p less than 0.01 and p less than 0.02 for both the cytosolic and nuclear receptors respectively; no. = 15). There was no correlation between either cytosolic and nuclear androgen receptors and plasma testosterone levels. The results suggest that plasma prolactin may be involved in the regulation of androgen receptor content in the benign prostate.

Aged↗
PubMed1982

Is testicular endocrine function abnormal in young men with spinal cord injuries?

Plasma concentrations of FSH, LH, testosterone and prolactin have been studied in seventeen men, aged 19 to 38 years, with traumatic paraplegia. Plasma testosterone, FSH and LH values were normal in all patients. The median LH concentration in patients was significantly higher (P less than 0.05) than in controls but there was no difference for FSH or testosterone. Plasma prolactin was high in five patients and the median prolactin concentration in patients was significantly greater (P less than 0.001) than in controls. It is concluded that there is no evidence of primary testicular failure in young paraplegics but it is possible that testicular hypofunction in some paraplegics may be related to increased prolactin production.

Adult↗
PubMed1982

The behavioural effects of testosterone undecanoate in adult men with Klinefelter's syndrome: a controlled study.

The behavioural effects of exogenous testosterone in men with marginally low circulating androgen levels were investigated. Four adult men with Klinefelter's syndrome, low normal testosterone levels and normal sexual activity and interest were given testosterone undecanoate (TU 160 mg daily by mouth; Organon International) and placebo using a double blind cross-over design. A modest increase in sexual interest was observed during TU administration compared to placebo, though there were no effects on self-reported mood or energy, or on erectile responsiveness in the laboratory. Increase in circulating hormone levels during TU administration was more marked for DHT than for testosterone. The possible implications of this are discussed.

Adult↗
PubMed1980

Clinical evaluation of long-term treatment with levo-norgestrel and testosterone enanthate in normal men.

Thirteen healthy men (25-35 years) with proven fertility were scheduled for long-term treatment (> 12 months) with levo-norgestrel (500 micrograms daily) and testosterone enanthate (200 mg monthly). The volunteers were regularly investigated prior to, during and after treatment. Seven volunteers withdrew from medication after 1 to 12 months of treatment; three due to psychological side effects, one because of stiffness of a finger joint, two for personal reasons and one for unspecified reasons. Sperm counts were significantly decreased during treatment and in 7 volunteers the sperm counts were < 5 x 10(6)/ml. However, two of these volunteers exhibited a breakthrough in sperm counts after 12 and 13 months of a 16-month treatment period. Serum testosterone, serum LH and serum FSH were significantly decreased during treatment, but returned, as did sperm counts, to normal levels after withdrawal of treatment. No rebound effect was seen. Potency and libido remained unchanged. No toxicological side effects were observed and finally no consistent changes were seen in blood coagulation parameters.

Adult↗