Showing papers by "St Thomas' Hospital published in 1988"

Quantification of arrhythmias using scoring systems: an examination of seven scores in an in vivo model of regional myocardial ischaemia

Abstract: Arrhythmia scores have been used in recent years to facilitate the analysis of arrhythmias, particularly in relation to regional myocardial ischaemia. The recent Lambeth Conventions recommended caution in the use of arrhythmia scores since their use may be misleading. In the present study seven scoring systems were examined in an attempt to validate the use of arrhythmia scores. A strong positive correlation was present between all seven scores. Furthermore, the scores all correlated with the incidences of ventricular fibrillation, ventricular tachycardia, and ventricular premature beats in early myocardial ischaemia. All seven scores successfully detected statistically significant reductions in the incidence of ventricular fibrillation resulting from the administration of two drugs. Some of the scores occasionally showed statistically significant reductions when effects on the raw arrhythmia data were not statistically significant. In this respect, parametric statistical analysis of arrhythmia scores may be a more sensitive method of quantifying arrhythmias than non-parametric analysis of binomially distributed raw data such as the incidence of ventricular fibrillation (in accordance with the power of such tests) indicating that the scores have precision. However, none of the scores incorrectly showed a statistically significant reduction when the raw data expressed a statistically significant or non-significant increase, indicating that the scores have accuracy. In conclusion, it is possible to design many arrhythmia scores that show changes in arrhythmia severity when more conventional analyses show only non-statistically significant trends. When used in conjunction with raw arrhythmia data, comprehensive drug dose ranges, and appropriate parametric statistical tests, arrhythmia scores facilitate the quantification of arrhythmias. It is recommended that arrhythmia scores should be used only for quantifying group data and model building and not for prognostic purposes in individuals.

Lichen sclerosus et atrophicus and autoimmunity--a study of 350 women.

Abstract: summary A study of autoimmune related phenomena in 350 women with histologically confirmed lichen sclerosus et atrophicus revealed that 21.5% had one or more autoimmune related diseases, 21% had one or more first degree relatives with an autoimmune-related disease, 42% had an autoantibody at a titre > 1:20, and 59.5% had one or more of these autoimmune-relateda phenomena. No statistically significant differences in the natural history of lichen sclerosus et atrophicus were demonstrated between those patients with autoimmune-related phenomena and those without.

Correlation between DNA flow cytometric and nucleolar organizer region data in non-Hodgkin's lymphomas.

Abstract: The argyrophilic staining (AgNOR) technique, novel in histopathology, was applied to a series of 20 non-Hodgkin's lymphomas (NHL) of established Kiel subtype. The method demonstrates nucleolar organizer regions (NORs) by virtue of sulphydryl groups on their associated proteins and the enumeration of AgNOR foci has been previously shown to discriminate between NHL of low- and high-grade histological types. This finding was confirmed and the results were compared with those obtained by means of DNA flow cytometry performed on paraffin wax-embedded tissue from the same lymphomas. There was a very good linear correlation between the mean numbers of AgNOR sites per nucleus and the percentage of S-phase cells for each case, both values being high in high-grade NHL and low in low-grade lesions. Conversely there was no significant correlation between the DNA index, representing DNA aneuploidy, and AgNOR counts. It is suggested that the numbers of AgNORs in a lymphoma may be related to the dividing fraction of cells rather than, as might be expected, to ploidy alone. It is also proposed that the AgNOR technique, which is rapid, simple, and inexpensive, may provide, at least, an adjunct to DNA flow cytometry in the assessment of neoplasm in histopathology.

Epidemic methicillin-resistant Staphylococcus aureus

Abstract: We contrast the experiences, in our Health Authority in South-East London, with the particular epidemic methicillin-resistant Staphylococcus aureus (the EMRSA) strain that has recently spread widely around London and South-East England, and with the other MRSA (OMRSA) strains encountered there. Our isolates of the EMRSA were identical by chromosomal restriction enzyme analysis, and the chromosomal and plasmid phenotypes were similar to those described in North London and Eastern Australia. Experimental phage-typing distinguished them from OMRSA encountered in 1984 to 1986. Between 1984 and 1985, the EMRSA caused increased infection and patient colonization compared to the years 1969 to 1983. A change in infection control procedures was usually required to control the EMRSA and in 1986 isolates had returned to their pre-1984 levels. Between 1984 and 1986 OMRSA were still encountered, but did not spread or require changes in infection control procedures. The distribution of other resistant isolates was examined; c 94% of neomycin-resistant isolates were in-patients or clinic patients. Forty-five different phage-type/antibiogram patterns were found in 88 isolates from 66 patients between 1982 and 1985, and patient clusters were uncommon. The ability of the EMRSA to spread is discussed and is probably not purely organism related. Our experience supports the contention that some MRSA are truly epidemic, whilst others do not behave in this manner.

Antiphospholipid antibodies--autoantibodies with a difference.

Abstract: Antiphospholipid antibodies may be detected by solid phase anticardiolipin antibody tests, the lupus anticoagulant test, or standard tests for syphilis (STS). The occurrence of these antibodies has been associated with venous or arterial thrombosis, fetal loss, and possibly thrombocytopenia. Other suggested features that may be associated with these antibodies include livedo reticularis, migraine, chorea, and heart valve lesions. Uncontrolled studies of small numbers of affected women with recurrent fetal loss suggest that prednisone and aspirin therapy during pregnancy may improve pregnancy outcome. Anticoagulant therapy is recommended for patients with thrombosis for as long as antiphospholipid antibodies persist.

A study of the role of house dust mite in atopic dermatitis.

Abstract: Subjects with positive skin-prick tests to house dust mite (HDM) solution, including those with and without atopic dermatitis, participated in a double-blind, controlled study of the role of HDM exposure in the pathogenesis of atopic dermatitis. HDM solution and diluent control were applied daily to mildly eczematous or clinically uninvolved skin of the antecubital or popliteal fossae, without prior abrasion, for 5 days. Responses were assessed by a clinical grading system and by measurement of area of dermatitis; pruritus was recorded on visual analogue scales. The clinical grading system showed that marked or moderate delayed local reactions developed in one third of patients with atopic dermatitis in response to HDM application to both mildly eczematous and clinically uninvolved skin. Relative to control sites, significant increases in area of dermatitis and degree of pruritus were also recorded in response to HDM application to mildly eczematous sites. Application of HDM solution to normal, unabraded skin of prick test positive subjects without a history of dermatitis, produced pruritus and immediate urticarial responses which were not seen at control sites, findings which demonstrate that HDM antigen may be rapidly absorbed in normal skin. Application of vehicle or antigen solution to which subjects were negative on prick testing, produced no significant local reactions. This study provides objective evidence for a role for cutaneous HDM exposure in the pathogenesis of atopic dermatitis.

Paediatric anaesthetists' perceptions of neonatal and infant pain.

Abstract: A questionnaire was sent to all members of the Association of Paediatric Anaesthetists in the U.K. and Eire, enquiring into their attitudes towards the perception of pain, its assessment and the use of opioids and regional anaesthesia in neonates and infants under 1 year of age. Sixty members returned completed forms out of a total of 66. The results showed that although most anaesthetists in the survey believe that even neonates feel pain, they are reluctant to prescribe analgesia. It was found that the objective signs considered to be most indicative of pain were potentially misleading.

The presence of neutrophils in human cutaneous ultraviolet-B inflammation.

Abstract: summary We report the first observation of neutrophils in the dermal inflammatory infiltrate in human skin soon after moderate ultraviolet-B (UVB) irradiation. Thus human UVB-induced cutaneous inflammation, in this as in other respects, appears to resemble other human acute inflammatory responses to injury.

Cryotherapy compared with trichloroacetic acid in treating genital warts.

Abstract: In an observer blind comparative study, 130 men with penile warts were randomly allocated to treatment with either cryotherapy or trichloroacetic acid (TCAA). There was no significant difference in response to treatment, side effects, or recurrence rates between the two treatments. Warts resolved in 81% of patients treated with TCAA compared with 88% of those treated with cryotherapy. Early recurrence occurred in 36% of patients treated with TCAA and in 39% of those treated with cryotherapy.

Brain tissue concentrations of ATP, phosphocreatine, lactate, and tissue pH in relation to reduced cerebral blood flow following experimental acute middle cerebral artery occlusion.

Abstract: Local CBF (LCBF) was compared with the corresponding local tissue concentration of ATP, phosphocreatine (PCr), and lactate in anaesthetized baboons subjected to focal ischaemia produced by middle cerebral artery occlusion (MCAO). LCBF hydrogen electrodes were implanted in cortical regions where MCAO had been previously shown to produce severe and penumbral ischaemia and in posterior regions where blood flow is not altered. Metabolites were assayed in small tissue samples collected either by cryoprobe biopsy in the regions where LCBFs were measured (series 1) or by sampling appropriate regions of the rapidly frozen brain (series 2). Subsequent topographical study of brain tissue pH with umbelliferone was performed in this latter series. The results from these two series are compared and discussed in terms of the more appropriate way to perform simultaneous electrode measurements and analysis of tissue samples for studying focal ischaemia in the primate brain. They confirm that the concentrations of ATP and...

Is insulin atherogenic

Abstract: Revue d'etudes utilisant les methodes epidemiologiques: l'hypothese selon laquelle l'hyperinsulinemie par/et l'insulinoresistance causent l'atherosclerose, requiert encore quelques observations et demonstrations experimentales

The Action of the Prostaglandins on Isolated Human Ureteric Smooth Muscle

Abstract: Summary— A study has been carried out on the actions of the prostaglandins E2 and F2α and their synthesis inhibitors, indomethacin and diclofenac sodium, upon isolated human ureteric smooth muscle, using the technique of microsuperfusion designed to ensure good tissue viability. Indomethacin and diclofenac sodium were shown to abolish almost completely the contractile response of ureteric muscle to electrical field stimulation. Contractile activity, in the presence of the inhibitors, could be restored by prostaglandin E2 or F2α or by increasing the external potassium concentration, [K+]o, of the superfusate. Prostaglandin E2 or F2α alone were shown to increase dramatically both the phasic and tonic component of the electrically stimulated contractions, on occasions inducing spontaneous activity. A possible mechanism of action was elucidated with an electrophysiological technique using intracellular microelectrodes. The mean membrane potential recorded was 54.7 mV (SD ± 10 mV, n=15). The depolarising action of raising [K+]o was demonstrated and prostaglandin F2α (3 times 10-6M) was shown to produce a small depolarisation of the ureteric muscle cell membrane.

Chronic enteric virus infection in two T-cell immunodeficient children.

Abstract: Enteric virus infections were studied in two children with congenital T-cell immunodeficiency. One patient (LC) with cartilage hair hypoplasia developed persistent diarrhea and malabsorption following acute gastroenteritis. Electron microscope (EM) examination of feces revealed excretion of rotavirus for more than 450 days with concurrent astrovirus infection for at least 225 days, associated with the persistent diarrhea. Prolonged infection with poliovirus type 2 following vaccination had previously been noted in this patient. The second patient (DT), with the CHARGE association and DiGeorge syndrome, had two episodes of loose stools. EM of fecal extracts demonstrated rotavirus excretion for at least 66 days following the initial episode. Virus-specific immune responses were assayed in these two patients. LC showed a poor serum neutralizing antibody response to polio vaccination, no detectable antibody response (by immune EM and ELISA) to rotavirus, and no detectable antibody response to astrovirus (by immune EM). Rotavirus specific cell mediated immunity was also not detectable. DT showed no detectable serum antibody response to rotavirus (by ELISA). Rotavirus isolates from both patients were found to be group A viruses and were further analyzed by polyacrylamide gel electrophoresis. Atypical genome profiles, with multiple additional bands between segments 3-7 of the normal rotavirus profile, were obtained throughout the course of each illness, including the earliest specimens available (day 41, LC; day 7, DT). These results indicate that chronic virus infection of the gut can occur in patients with T-cell immunodeficiency. Such chronic infection may be associated with persistent diarrhea and can cause considerable problems of management.

Neuronal and behavioural consequences of chemical inflammation of rat urinary bladder.

Abstract: Exposure of the urinary bladder of rats to chemical irritants such as turpentine produces a long lasting inflammatory response. Chemosensitive primary afferent fibres supplying the bladder are excited by the irritants. Dorsal horn cells in L6, S1 are also excited, and show slowly developing and persistent increases in ongoing activity, responses to electrical stimulation of vesical afferents and distension of the bladder. These changes may provide an explanation for the sensory and reflex disturbances that occur in cystitis in man.

Analysis of peripheral maternal blood samples for the presence of placenta-derived cells using Y-specific probes and McAb H315.

Abstract: Using flow cytometry, a small number of cellular elements expressing on their surface an antigen (H315) produced by placental trophoblast have been observed in the peripheral blood of pregnant women. This is in agreement with previous observations (Covone et al., 1984a,b) and recent results documenting the presence of a small number of H315-positive cells in the peripheral circulation of pregnant women (Pool et al., 1987; Caligaris-Cappio and Camaschella, personal communication). When DNA extracts, prepared from H315-positive cells sorted from maternal samples were tested by Southern transfer using Y-specific probes (Y190 or Y411), a Y-specific band could not be detected in any sample analysed, irrespective of the sex of the fetus. In control samples from healthy male donors, a Y-specific band could be detected with as few as 800 46,XY cells without interference from contaminating 46,XX cells. H315-positive cellular elements, sorted by flow cytometry from the maternal peripheral blood, were also examined in interphase using Y-specific probes (Y190 and Y431) and an in situ biotin-avidin fluorescent hybridization technique. The great majority of the sorted H315-positive cellular elements did not show a fluorescent Y body, even in samples from mothers who later delivered a male infant. While previous investigations had failed to demonstrate the in vitro uptake of H315 antigen onto the surface of leucocytes from healthy males incubated in maternal sera, the present studies demonstrate that cells from male donors could adsorb this antigen following incubation in extracts prepared from retroplacental blood. These findings thus suggest that the majority of H315-positive nucleated cells previously detected by flow cytometry in the peripheral circulation of pregnant women are maternal cells which have adsorbed H315 antigen in vivo, either in soluble form or as small cell membrane fragments.

Developmental and age-related changes in rat brain glycosaminoglycans.

Abstract: The quantities of each major class of glycosaminoglycan were determined in rat cerebrum from postnatal day 5 to 30 months of age. Chondroitin sulphate, dermatan sulphate, heparan sulphate, heparin, and hyaluronate were found, but no keratan sulphate was detected. Large and rapid changes in glycosaminoglycan content were observed during the period of brain maturation, and thereafter relatively steady levels were maintained until after the age of 12 months. The most remarkable change in the aged rat cerebrum was the ratio by weight of hyaluronate to chondroitin sulphate, which was approximately 1:1 from postnatal day 10 to 18 months but increased to 2.6:1 by the age of 30 months. In immature rats, the proportion of nonsulphated and 6-sulphated disaccharides derived from chondroitinase AC digests of brain glycosaminoglycans was much greater than in adults. In mature rats, chondroitin sulphate was composed almost entirely of 4-sulphated disaccharide subunits. The possibility that these changes could affect the permeability properties of the cerebral extracellular space and ionic equilibria in the brain is discussed.

The late sequelae of poliomyelitis.

Abstract: Progressive functional deterioration following poliomyelitis has been reported after a prolonged period of stability. We present follow up data on 209 patients; the period from the original illness to December 1985 or death was between two and 73 years (mean 33.9). One hundred and sixty-three (78 per cent) patients developed late functional deterioration. This was due to purely respiratory factors in 99 cases, new neurological signs in 20 cases, and orthopaedic problems in 17 cases; 31 patients deteriorated due to a combination of factors. The commonest cause of respiratory deterioration was the development of nocturnal alveolar hypoventilation, sometimes associated with late progressive scoliosis. Eighty-six patients needed respiratory support beginning between one year and 66 years (mean 28.5) after the acute illness. New neurological signs had a clearly defined cause in each of 20 patients. No cases of motor neurone disease or post-poliomyelitis muscular atrophy (PPMA) were identified. This series shows that late sequelae following poliomyelitis are common. There were no patients with functional deterioration after poliomyelitis in whom a clear underlying cause could not be shown. The major causes of deterioration may be treatable or avoidable, and in particular, those who develop chest infections or new respiratory symptoms should be treated with caution as respiratory failure may rapidly supervene.