Search Results - (Author, Cooperation:Critchley)

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Serial thermodilution and impedance cardiac output measurements in two critically ill patients are presented. Impedance cardiography failed to detect changes in cardiac output and provided values lower than those derived from thermodilution. Chest X-ray examination and changes in thoracic impedance suggested that these two patients had significantly increased extravascular lung water. This failure of impedance cardiography is attributed to aberrant electrical conduction though the lungs as a result of increased lung fluid that alters the impedance waveform. Although reliable when used in normal subjects, impedance cardiography appears not to provide accurate measurements in critically ill patients.

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1432-1238

Key words Cardiac output ; Bioimpedance ; Thermodilution ; Sepsis ; Pulmonary oedema ; Lung injury score

Springer Online Journal Archives 1860-2000

Medicine

Abstract Objectives: To investigate the relationship between the attenuation of impedance cardiac output (ICco) measurements and lung fluid content in critically ill patients.¶Design: Observational study.¶Setting: Intensive Care Unit of a major teaching hospital in Hong Kong.¶Patients: Twenty-four critically ill patients who required a pulmonary artery catheter.¶Measurements and main results: Triplicate thermodilution cardiac output (TDco) and BoMed NCCOM3 (ICco) measurements were made simultaneously on a single occasion in each patient. Lung fluid accumulation was assessed by: (a) thoracic impedance (Zo), (b) radiological assessment of chest X-rays using an alveolar consolidation score (0–4) and (c) scoring the degree of hypoxia and use of positive end-expiratory pressure (PEEP). Offsets (TDco–ICco)/TDco, expressed as percentage, were compared with these indices of excess lung fluid. Patients were divided into those with sepsis (n = 13), fluid balance problems (n = 5) and cardiothoracic problems (n = 6). Mean cardiac output values were: 6.7 l/min TDco (range 3.6–12.9) and 5.2 l/min ICco (range 2.7–9.0). Overall the TDco and ICco values showed great variance, with a bias and limits of agreement of 1.49 ± 4.16 l/min, or ± 69 %. In septic patients, increasing offset was correlated with decreases in Zo (r = 0.73, P = 0.005) and increases in alveolar consolidation score (r = 0.72, P = 0.005).¶Conclusions: The BoMed under-estimates cardiac output in critically ill patients. In septic patients the degree of attenuation of ICco can be related to the extent of lung injury and fluid accumulation within the thorax.

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1432-1343

Springer Online Journal Archives 1860-2000

Mathematics

Electronic Resource

1432-1343

Springer Online Journal Archives 1860-2000

Mathematics

Electronic Resource

1619-1560

tilting ; postural stress ; monitoring ; non-invasive ; blood pressure ; cardiac output ; impedance cardiography ; Finapres

Springer Online Journal Archives 1860-2000

Medicine

Abstract The haemodynamic effects of head-up tilt (HUT) at different tilt angles were investigated non-invasively in eight normal male subjects. Mean arterial pressure (MAP; by Ohmeda Finapres 2300), stroke volume (SV) and heart rate (HR; by BoMed NCCOM3-R7S) were continuously recorded whilst performing a series of HUTs (55°, 10°, 20°, 30° and 55°) lasting 3 min each. The response to HUT was proportional to the sine of the tilt angle. The magnitude of the response varied between subjects. HUT to 55° resulted in mean (95% confidence limits) increases in MAP by 16 (±16)% and HR by 11 (±24)% and a decrease in SV by −25 (±22)%. These results were repeatable after 30 min. At small tilt angles, i.e. ≤20°, MAP did not change and HR decreased by −3 (±4)%. A detailed analysis revealed immediate dynamic (0–30 s), late dynamic (30–90 s) and plateau (after 90 s) phases in the response to HUT. In conclusion, HUT produces reproducible haemodynamic effects, although differences exist among subjects. A detailed analysis of these effects can be successfully performed using non-invasive methods.

Electronic Resource

1573-2614

Measurement techniques: thermodilution ; Measurement techniques: impedance cardiography ; Measurement techniques: Doppler ; Measurement techniques: Fick ; cardiac output ; statistical methods

Springer Online Journal Archives 1860-2000

Computer Science

Medicine

Abstract Introduction. Bias and precision statistics have succeeded regression analysis when measurement techniques are compared. However, when applied to cardiac output measurements, inconsistencies occur in reporting the results of this form of analysis. Methods. A MEDLINE search was performed, dating from 1986. Studies comparing techniques of cardiac output measurement using bias and precision statistics were surveyed. An error-gram was constructed from the percentage errors in the test and reference methods and was used to determine acceptable limits of agreement between methods. Results. Twenty-five articles were found. Presentation of statistical data varied greatly. Four different statistical parameters were used to describe the agreement between measurements. The overall limits of agreement in studies evaluating bioimpedance (n = 23) was ±37% (15–82%) and in those evaluating Doppler ultrasound (n = 11) ±65% (25–225%). Objective criteria used to assess outcome were given in only 44% of the articles. These were (i) limits of agreement approaching ±15–20%, (ii) limits of agreement of less than 1 L/min, and (iii) more than 75% of bias measurements within ±20% of the mean. Graphically, we showed that limits of agreement of up to ±30% were acceptable. Conclusions. When using bias and precision statistics, cardiac output, bias, limits of agreement, and percentage error should be presented. Using current reference methods, acceptance of a new technique should rely on limits of agreement of up to ±30%.

Electronic Resource

book

2005

Beobachtung ; Schüler ; Leistungsbeurteilung ; Frage ; Textarbeit

English

book

2004

German

2018-05-26

The American Society for Microbiology (ASM)

0066-4804

1098-6596

Biology

Medicine

2018-04-14

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To investigate the oestrogen and progesterone receptor distribution in endometrium from reproductive age and perimenopausal women with and without menorrhagia.Design A comparative observational study.Subjects Forty-five women with objective menorrhagia (27 categorised as reproductive age and 18 as perimenopausal) and a control group of 44 women (31 reproductive age and 13 perimenopausal) with menstrual blood loss of less than 80 ml per period.Main outcome measures Oestrogen receptor and progesterone receptor semi-quantitative immunostaining scores.Results Comparison of control and menorrhagic endometrium in this study (whether from reproductive age or perimenopausal subjects) failed to demonstrate any major differences in either sex steroid receptor mean immunostaining score. The results demonstrated a great degree of variability in sex steroid receptor immunoreactivity between individuals. Irrespective of clinical group, significant increases in immunostaining were demonstrated in the proliferative phase of the cycle for immunoreactivity of oestrogen receptor in glands (P 〈 0.0005), and stromal (P= 0.002) compartments of endometrium and progesterone receptor immunoreactivity in glands (P= 0.009). Progesterone receptor immunostaining in the stromal compartments did not significantly decline (P= 0.06) in the secretory phase.Conclusions Endometrium from women with objective evidence of menorrhagia is indistinguishable in terms of sex steroid immunoreactivity from endometrium of women with normal monthly blood loss. This pattern of sex steroid receptor immunostaining pattern was maintained into the perimenopausal years.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: The fate of tetanus toxin bound to neuronal cells at 0°C was followed using an anti-toxin 125I-protein A assay. About 50%; of surface-bound toxin disappeared within 5 min of warming cells to 37°C. Experiments with 125I-toxin showed that much of this loss was due to dissociation of bound toxin into the medium. Some toxin was however rapidly internalised, and could be detected only by permeabilising cells with Triton X-100 prior to assay. To investigate the mechanism of internalisation, tetanus toxin was adsorbed to colloidal gold. Toxin-gold was shown to be stable, and to recognise the same receptor(s) as free toxin. Quantitation of the distribution of toxin-gold particles bound to the cell body at 4°C showed that it was concentrated in coated pits. After 5 min at 37°C, toxin-gold appeared in coated vesicles, endosomes, and tubules. After 15 min, it was found largely in endosomes, and at 30 min in multivesicular bodies. The involvement of coated pits in internalisation of tetanus toxin, but not cholera toxin, was confirmed using the free toxins, anti-toxins, and protein A-gold. Toxin-gold also entered nerve terminals and axons via coated pits, accumulating in synaptic vesicles and in-traaxonal uncoated vesicles, respectively.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Binding of tetanus toxin to rat brain membranes was of lower affinity and capacity when binding was determined in 150 mM NaCl, 50 mM Tris-HCl (pH 7.4) than in 25 mM Tris-acetate (pH 6.0). Binding under both conditions was reduced by treating the membranes with neuraminidase. Pronase treatment, however, reduced toxin binding only in the Tris-saline buffer (pH 7.4). In addition, the concentration of gangliosides required to inhibit toxin binding was 100-fold higher in Trissaline compared to Tris-acetate buffer. The toxin receptors in the membranes were analyzed by ligand blotting techniques. Membrane components were dissolved in sodium dodecyl sulfate, separated by polyacrylamide gel electrophoresis, and transferred to nitrocellulose sheets, which were overlaid with 125I-labeled toxin. Tetanus toxin bound only to material that migrated in the region of the dye front and was extracted with lipid solvents. Gangliosides isolated from the lipid extracts or other sources were separated by TLC on silica gel and the chromatograms were overlaid with labeled tetanus toxin. The toxin bound to areas where the major rat brain gangliosides migrated. When equimolar amounts of different purified gangliosides were applied to the chromatogram, binding of the toxin was in the order GDlb≅ GTlb≅ GQ1b 〉 GD2 〉 GD3≫ GD1a≅ GM1. Thus, the toxin appears to have the highest affinity for gangliosides with a disialyl group linked to the inner galactosyl residue. When binding of tetanus toxin to transfers and chromatograms was determined in the Tris-saline buffer (pH 7.4), the toxin bound to the same components but the extent of binding was markedly reduced compared with the low-salt and -pH conditions. Our results indicate that the interaction of tetanus toxin with rat brain membranes and gangliosides is greatly reduced under more physiological conditions of salt and pH and raise the possibility that other membrane components such as sialoglycoproteins may be receptors for the toxin under these conditions.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To study the effect of total body irradiation (14.4 Gray) in childhood and adolescence on ovarian and uterine characteristics, and to investigate the response to physiological sex steroid serum concentrations.Design All long term post-pubertal female survivors of total body irradiation who had been treated in paediatric centres in Scotland were identified. Their ovarian and uterine characteristics were studied.Setting Recruitment was from follow up oncology clinics.Sample Nine women were identified, eight of whom were assessed and five progressed to detailed investigation. A control population of 12 women treated for acute leukaemia, but not treated with total body irradiation, and five healthy women with no history of childhood malignancy were recruited as controls.Methods Ovarian function was determined by measurement of serum gonadotrophins and sex steroids. Uterine response to physiological sex steroid replacement was investigated in women with ovarian failure, and to endogenous sex steroid production in women with ovarian function by ultrasound scan. The physiological sex steroid replacement was achieved with transdermal oestradiol patches and self administered vaginal progesterone pessaries.Main outcome measures Determination of ovarian function and uterine response to physiological sex steroid serum concentrations.Results Six of eight women treated with total body irradiation had ovarian failure; preservation of function was seen in two girls treated pre-pubertally who had biochemical evidence of incipient ovarian failure. Four women with ovarian failure had reduced uterine volume, undetectable blood supply and absent endometrium at baseline assessment; after three months of physiological sex steroid replacement treatment uterine blood supply and endometrial response were not significantly different from controls; uterine volume improved but remained significantly smaller than controls and correlated with age at total body irradiation.Conclusions Ovarian failure after total body irradiation is common and risk relates to age at treatment. Physiological sex steroid replacement improved uterine measures and these women may benefit from assisted reproductive technology.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To investigate the effects of a hormone replacement therapy regime of continuous oestrogen and interrupted progestogen, administered transdermally, on the endometrium of postmenopausal women, the pattern of bleeding and relief of menopausal symptoms.Design Volunteer pilot study of up to six months duration involving weekly application of an oestrogen-only skin patch releasing 50 μg oestradiol per day interspersed with a combined oestrogen and progestogen patch releasing 50 μg oestradiol and 250 μg norethisterone acetate per day for three days. Transvaginal ultrasound measurements of endometrial thickness and endometrial biopsies were performed in the third month of treatment at the end of both an oestrogen-only phase of treatment and a combined oestrogen-progestogen phase.Setting Specialist community menopause clinic, Dean Terrace Centre, Edinburgh.Participants Fifteen healthy postmenopausal women.Main outcome measures Effect of treatment on endometrial histology, the immunolocalisation of oestrogen and progesterone receptors and the cell proliferation marker Ki 67 after three months of treatment and the proportion of women without bleeding at six months.Results Treatment provided relief of hot flushes and by the sixth month of study 10 of the 14 women who completed treatment had no vaginal bleeding (71 %). No endometrial hyperplasia or atypical changes were observed in biopsies and ultrasound measurements of endometrial thickness demonstrated a thin endometrium. Reduced immunostaining for Ki 67 was observed in endometrium from the combined phase of treatment compared with the oestrogen-only phase, consistent with a progestogenic-antagonism of proliferation. Exposure to progestogen did not suppress steroid receptors as similar immunostaining was observed in both treatment phases.Conclusions Continuous oestrogen and interrupted progestogen administered transdermally offers promise as a novel bleed-free hormone replacement therapy for postmenopausal women.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Objective To investigate the impact of premature ovarian failure due to whole abdominal radiotherapy (DXT) in childhood on uterine physical characteristics and blood flow and measuring the uterine response to exogenous sex steroid replacementDesign A comparative observational studySubjects 10 women with premature ovarian failure due to treatment with whole abdominal irradiation in childhood. A comparison group of 22 women with premature ovarian failure who had not received whole abdominal DXT.Main outcome measures Uterine length and uterine blood flow measurement plus serial assessment of endometrial thickness during a cycle of exogenous sex steroid replacement.Results Uterine length was significantly less (P〈0.01) in women who had been exposed to whole abdominal DXT in childhood (mean 4.1 cm, 2SE 0.8) compared with a mean of 7.3 cm (2SE 0.6) in the comparison group. The three women in the DXT group who were studied serially had no increase in endometrial thickness in response to physiological sex steroid replacement therapy and most of the 10 irradiated women had no detectable uterine blood flow with Doppler ultrasound.Conclusions Uterine musculature and blood flow are irreversibly affected by high dose irradiation in childhood. Non-invasive assessment of this nature may predict potential for pregnancy following ovum donation and embryo transfer.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Summary. Eighteen women with a premature menopause underwent assessment of serial serum oestradiol (E2) and progesterone levels and endometrial histology and function. Patients received continuous transdermal E2, and progesterone either orally or vaginally for 14 days. Physiological levels of E2 were attained. Significantly higher levels of progesterone were achieved with vaginal progesterone (P〈0.01). Endometrial biopsies obtained during E2 replacement demonstrated normal proliferative features. Expression of an oestrogen related antigen (ER-Ag) was localized in the cytoplasm of the epithelium. After 3 days of progesterone replacement the endometrium showed normal secretory features and expression of ER-Ag in the stroma as well as in the glands. After 7 days of progesterone supplementation, vaginal administration produced a more consistent physiological appearance than oral administration. Thus transdermal E2 combined with vaginal progesterone is a highly satisfactory combination for establishing a physiological endometrium in women with premature ovarian failure.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource