A survey into the number of times laryngeal masks are used.
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Equipment Reuse↗
Biomedical subjects
K Henderson
Publications and source records attributed to K Henderson.
Anaesthetic implications of osteo-odonto-keratoprosthesis surgery.
Patients with bilateral corneal blindness in whom corneal transplantation has either been unsuccessful or inappropriate may be considered for osteo-odonto-keratoprosthesis surgery. During a two-stage procedure the surface of the cornea is removed and covered with a graft of buccal mucosa. An optical cylinder, supported by an osteo-odonto lamina planed from a tooth is then inserted into the mucosa to act as a lens. The anaesthetic implications of this operation include care of patients from a wide age range, often with underlying medical problems undergoing two operations of prolonged duration. The eye can be 'open' during both stages of the operation and anaesthetic techniques directed towards prevention of rises in vitreal pressure are essential. This article outlines the surgical process of osteo-odonto-keratoprosthesis surgery with reference to our anaesthetic experiences from nine cases.
Adult↗
A dipstick immunoassay to rapidly measure serum oestrone sulfate concentrations in horses.
A dipstick, competitive immunoassay for rapidly measuring serum oestrone sulfate (OS) concentrations in horses was developed to distinguish mares 100 or more days pregnant from non-pregnant animals. 6-Ketoestrone 6-carboxymethyloxime conjugated to bovine serum albumin (oestrone CMO-BSA) was 'dotted' 25 mm from the bottom edge of 45 x 5 mm strips of polyester-film-supported cellulose nitrate membrane, pore size 3 microm. The strips were blocked, dried and a 15 x 5-mm cellulose absorbent sink attached 10 mm from the top of each strip. The manufactured dipsticks were stored with desiccant at room temperature until used. A monoclonal antibody recognizing OS was coated onto uniform, blue-dyed polystyrene microspheres (mean diameter, 0.31 microm) by adsorption. After blocking, several washes and resuspension by sonication, the antibody-coated microspheres were stored at 4 degrees C. The concentrations of oestrone CMO-BSA dotted onto the dipsticks and OS antibody coated onto the microspheres were optimized to produce a test that allowed maximum discrimination between the concentrations of OS found in serum of mares 100 or more days pregnant (i.e. >30 ng OS mL(-1)) relative to those found in non-pregnant mares (i.e. <10 ng OS mL(-1)). To perform the dipstick test, 30 microL of carrier buffer, 10 microL of OS antibody-coated microspheres and 10 microl of OS standard or serum sample were pipetted into a microwell and mixed. A dipstick was placed in the solution. All the liquid migrated up the dipstick into the absorbent sink within 15-20 min leaving a blue dot where the OCMO-BSA had been placed. The intensity of colour of the blue dot, which correlated inversely with the concentration of OS in the standard or serum sample, was assessed visually and by computer image analysis. An OS concentration less than 5 ng mL(-1) produced a deep blue dot, 20 ng/ml a light blue dot and a concentration greater than 50 ng mL(-1) a very faint blue dot, or none at all. Serum samples from 42 non-pregnant mares and 40 mares over 100 days pregnant were analysed by the dipstick test. All the serum samples from non-pregnant mares produced dipsticks with deep blue dots that ranged in intensity from 20 to 38 colour intensity units, equivalent to OS concentrations less than 7 ng mL(-1). Sera from all the pregnant mares generated dipsticks with either faint blue dots or none at all (i.e. < or =5 colour intensity units, equivalent to OS concentrations >40 ng mL(-1). It is concluded that this novel, rapid dipstick immunoassay offers a practical, alternative means of analysing serum OS concentrations in horses, and enables mares that are 100 or more days pregnant to be distinguished from those that are not pregnant.
Animals↗
Expression, crystallization and preliminary X-ray studies of the PDZ domain of Dishevelled protein.
Dishevelled (Dsh) protein is an important component of the Wnt signal-transduction pathway. It has three relatively conserved domains: DIX, PDZ and DEP. The PDZ domain of the Xenopus laevis homolog of Dsh, which consists of residues 254-348, was overexpressed as a soluble protein in Escherichia coli, purified and crystallized. The crystals were obtained by the vapor-diffusion method, using 1.4 M sodium formate as a precipitant. The crystals diffracted to 2.3 A resolution. The space group was determined to be P6(1)22 or P6(5)22, with unit-cell dimensions a = b = 95.9, c = 93.9 A.
Adaptor Proteins, Signal Transducing↗
False negative results using RT-PCR for detection of lactate dehydrogenase-elevating virus in a tumor cell line.
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Animals↗
Epidural anaesthesia for caesarean section in a patient with severe Takayasu's disease.
Takayasu's arteritis or disease is a rare, idiopathic, chronic inflammatory disease which causes narrowing, occlusion or aneurysms of blood vessels. It preferentially affects large arteries such as the aorta and its branches and hence its alternative names of pulseless disease, occlusive thromboaortopathy or aortic arch syndrome. Although most commonly found in oriental women, it occurs sporadically throughout the world. We present the case of an elderly primigravida with long-standing Takayasu's disease complicated by hospital and needle phobia who underwent a successful Caesarean section under epidural anaesthesia. Her management is discussed in the light of current opinion regarding pregnancy and Takayasu's disease.
Adult↗
Effect of chronic sodium cyanate administration on O2 transport and uptake in hypoxic and normoxic exercise.
Systemic O2 transport during maximal exercise at different inspired PO2 (PIO2) values was studied in sodium cyanate-treated (CY) and nontreated (NT) rats. CY rats exhibited increased O2 affinity of Hb (exercise O2 half-saturation pressure of Hb = 27.5 vs. 42.5 Torr), elevated blood Hb concentration, pulmonary hypertension, blunted hypoxic pulmonary vasoconstriction, and normal ventilatory response to exercise. Maximal rate of convective O2 transport was higher and tissue O2 extraction was lower in CY than in NT rats. The relative magnitude of these opposing changes, which determined the net effect of cyanate on maximal O2 uptake (VO2 max), varied at different PIO2: VO2 max (ml. min-1. kg-1) was lower in normoxia (72.8 +/- 1.9 vs. 81. 1 +/- 1.2), the same at 70 Torr PIO2 (55.4 +/- 1.4 vs. 54.1 +/- 1.4), and higher at 55 Torr PIO2 (48 +/- 0.7 vs. 40.4 +/- 1.9) in CY than in NT rats. The beneficial effect of cyanate on VO2 max at 55 Torr PIO2 disappeared when Hb concentration was lowered to normal. It is concluded that the effect of cyanate on VO2 max depends on the relative changes in blood O2 convection and tissue O2 extraction, which vary at different PIO2. Although uptake of O2 by the blood in the lungs is enhanced by cyanate, its release at the tissues is limited, probably because of a reduction in the capillary-to-tissue PO2 diffusion gradient secondary to the increased O2 affinity of Hb.
Animals↗
Microdeletion 22q11.2: clinical data and deletion size.
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Abnormalities, Multiple↗
Magnetic field exposure assessment: a comparison of various methods.
The accurate and valid measurement of personal exposure to magnetic fields poses a major challenge for epidemiologic studies. When considering the various methods to assess exposure, it is unclear which measures are most relevant for studies of human disease, if any. Given these uncertainties, the Electromagnetic Fields and Breast Cancer on Long Island Study (EBCLIS) undertook a pilot study to develop the data collection protocol for a case-control study of breast cancer and magnetic fields. The pilot study used and compared various methods to assess residential exposures to magnetic fields, and related these measures to personal exposures. It included 31 women without breast cancer (mean age, 63+/-7 yr) who lived in their present homes for at least 15 yr. The pilot study consisted of an in-home interview, spot and 24-h magnetic field waveforms and broadband recordings, ground currents, wire coding, and personal 24-h broadband measurements. From the regression analyses, the model that best predicted personal magnetic field exposures included 24-h measurements in the bedroom and in the most lived-in room; as well as ground current test loads taken at the center of this most lived in room (r(2)=86%). The addition of other variables in this regression model yielded only small and nonsignificant increases in r(2). As a direct result of this pilot, EBCLIS will include ground current measurements in its protocol, which have not previously been collected as part of an epidemiologic study. Ground currents may be important because they may be richer in 180 Hz components than are the other currents in a power system. EBCLIS will have the opportunity to examine the ground-current hypothesis in the context of female breast cancer.
Air Pollution, Indoor↗
Deaths from low dose paracetamol poisoning.
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Acetaminophen↗
Aqueous solubilization of transmembrane peptide sequences with retention of membrane insertion and function.
We recently reported that the peptide C-K4-M2GlyR mimics the action of chloride channels when incorporated into the apical membrane of cultured renal epithelial monolayers. C-K4-M2GlyR is one of a series of peptides that were prepared by the addition of lysine residues to the N- or C-terminus of the M2 transmembrane sequence of the brain glycine receptor. This study addresses how such modifications affect physical properties such as aqueous solubility, aggregation, and secondary structure, as well as the ability of the modified peptides to form channels in epithelial monolayers. A graded improvement in solubility with a concomitant decrease in aggregation in aqueous media was observed for the M2GlyR transmembrane sequences. Increases in short-circuit current (I(SC)) of epithelial monolayers were observed after treatment with some but not all of the peptides. The bioactivity was higher for the more soluble, less aggregated M2GlyR peptides. As described in our previous communication, sensitivity of channel activity to diphenylamine-2-carboxylate, a chloride channel blocker, and bumetanide, an inhibitor of the Na/K/2Cl cotransporter, was used to assess changes in chloride selectivity for the different assembled channel-forming peptides. The unmodified M2GlyR sequence and the modified peptides with less positive charge are more sensitive to these agents than are the more highly charged forms. This study shows that relatively insoluble transmembrane sequences can be modified such that they are easier to purify and deliver in the absence of organic solvents with retention of membrane association, insertion, and assembly.
Amino Acid Sequence↗
Comparison of the merits of measuring equine chorionic gonadotrophin (eCG) and blood and faecal concentrations of oestrone sulphate for determining the pregnancy status of miniature horses.
The relative merits of measuring blood concentrations of equine chorionic gonadotrophin (eCG, previously known as pregnant mare serum gonadotrophin (PMSG)), or oestrone sulphate (OS), or faecal OS concentrations for determining pregnancy status in miniature horses were investigated. Pregnant mares between 40 and 140 days after mating had serum eCG concentrations > 1 I.U. mL-1, with the highest concentrations occurring between days 50 and 120. However, eCG measurements were susceptible to returning a 'false positive' diagnosis of pregnancy. Plasma OS concentrations ranged from 0.1 to 3.6 ng mL-1 in non-pregnant mares, whereas pregnant mares beyond 100 days post-mating all had plasma OS concentrations > 30 ng mL-1. Faecal OS concentrations ranged from 4 to 89 ng g-1 in non-pregnant mares. For faecal samples collected from pregnant mares 150 days or more after mating, 97% of samples had OS concentrations > 85 ng g-1, the value 3 standard deviations above the mean non-pregnant value. None had values below 67 ng g-1, the value 2 standard deviations above the mean non-pregnant value. These results show that measurement of eCG is suitable for determining pregnancy status in miniature mares between 40 and 100 days post-mating. However, mares returning a 'pregnant' diagnosis should undergo a blood OS test 100 or more days after mating to eliminate the possibility of a 'false positive' diagnosis. Measuring blood OS is recommended as the method of choice for determining pregnancy status in miniature mares 100 or more days after mating. Faecal OS measurements provide a non-invasive alternative to blood OS testing from 150 days post-mating. However, the discrimination between 'pregnant' and 'non-pregnant' levels of OS is not as great in faeces as it is in blood.
Animals↗
Total quality management in the delivery of public health services: a focus on North Carolina WIC programs.
Principles of quality improvement have been successfully implemented in the for-profit sector of the United States economy. The purpose of this study is to test the use of quality improvement strategies including development of leadership skills, a focus on internal quality, ongoing training and staff development, and efficient use of resources in the delivery of services in the public sector. The emphasis of this study is strategies for improving the delivery of nutrition education and supplemental foods to high-risk women, infants, and children through a federally funded program called WIC.
Child Health Services↗
Genetically modified ruminal bacteria protect sheep from fluoroacetate poisoning.
Four strains of Butyrivibrio fibrisolvens, transformed with a gene encoding fluoroacetate dehalogenase, maintained a combined population of 10(6) to 10(7) cells ml-1 in the rumens of test sheep. Five inoculated sheep showed markedly reduced toxicological symptoms after fluoroacetate poisoning when behavioral, physiological, and histological effects were compared with those of five uninoculated control sheep.
Animals↗
A framework for practice with women survivors of childhood sexual abuse.
Women who are victims of prolonged childhood sexual abuse involving penetration, and physical and emotional abuse are more likely to develop major psychiatric distress. These survivors may use defence mechanisms to block out the past, and their distress may only come to the attention of health professionals at times of crisis. However, health practitioners do not routinely assess for a history of sexual abuse. This state of affairs is compounded by limited research on survivors of childhood sexual abuse and a readiness to label them with adult psychopathology. Such labels result from a failure to listen and from a willingness to blame, processes replicated from the dominant culture.
Adult↗
A synthetic peptide derived from glycine-gated Cl- channel induces transepithelial Cl- and fluid secretion.
M2GlyR is a synthetic 23-amino acid peptide that mimics the second membrane-spanning region of the alpha-subunit of the postsynaptic glycine receptor. This peptide has been shown to form an anion-selective channel in phospholipid bilayers. We have investigated the possibility that the peptide may incorporate into the apical membrane of secretory epithelia and induce the secretion of Cl- and water. We improved the solubility of this peptide by adding four lysine residues to the carboxy terminus, C-K4-M2GlyR, and assayed its channel-forming activity using a subculture of Madin-Darby canine kidney (MDCK) cells. The addition of 100 microM C-K4-M2GlyR to the apical surface of MDCK monolayers significantly increased short-circuit current (Ise), hyperpolarized transepithelial potential difference, and induced fluid secretion. The increase in Ise was inhibited by 100 microM bumetanide and by Cl- channel inhibitors. The effectiveness of the channel blockers followed the sequence niflumic acid > or = 5-nitro-2-(3-phenylpropylamino)benzoate > diphenylamine-2-carboxylate (DPC) > glibenclamide. The effect of the peptide was not inhibited by 4.4'-diisothiocyanostilbene-2-2'-disulfonic acid. Removing Cl from the bathing solutions also inhibited the effect of the peptide. The Cl- efflux pathway induced by C-K4-M2GlyR differs from the native pathway activated by the adenosine 3',5'-cyclic monophosphate (cAMP) agonist, forskolin. First, intracellular cAMP levels were unaffected. Second, the concentration of DPC required to inhibit the effect of the peptide was much lower than that needed to block the forskolin response (100 microM vs. 3 mM). These results support the hypothesis that the synthetic peptide C-K4-M2GlyR can from Cl -selective channels in the apical membrane of secretory epithelial cells and can induce sustained transepithelial secretion of Cl- and fluid.
Amino Acid Sequence↗
Multilineage differentiation of cloned HRA-19 cells in serum-free medium: a model of human colorectal epithelial differentiation.
Colorectal epithelium is composed of polarised absorptive enterocytes, mucus-producing goblet cells and enteroendocrine cells. All these cell lineages are thought to arise from multipotential stem cells located near the base of the crypt, but the mechanisms which control differentiation and commitment of cells to a particular lineage are poorly understood. We have used the human rectal adenocarcinoma cell line, HRA-19, to investigate the regulation of expression of lineage-specific markers. HRA-19 cells have multipotential characteristics, forming absorptive, mucous and endocrine cells when grown as xenografts. However, HRA-19 cells grown in vitro in culture medium containing 10% foetal calf serum show negligible expression of the differentiated phenotypes observed in vivo. These findings initially suggested that the absence of positive stimuli from extracellular matrix, stromal cells and/or soluble factors present in vivo resulted in the lack of differentiation in vitro. The subsequent demonstration of a marked inhibitory effect of foetal calf serum on differentiation provided an alternative explanation for the differences between in vivo and in vitro differentiation. In addition, the inhibition of differentiation differed widely between batches of foetal calf serum and limited the usefulness of the system for studying the regulation of differentiation. This manuscript describes the development of chemically defined culture conditions (Dulbecco's Eagles medium supplemented with insulin, transferrin and ascorbic acid) which reproducibly induced the multilineage differentiation of HRA-19 cells into absorptive, mucous and endocrine cells. Morphological characteristics and the expression of lineage-specific markers, as determined by immunocytochemistry, identified absorptive, goblet and endocrine cells in HRA-19 monolayers grown in this serum-free medium. Differentiation of cloned HRA-19 cells in to the three cell lineages proceeds in the absence of stromal cells and without exogenous extracellular matrix, although these factors may subsequently be shown to modulate the rate of cell differentiation. These chemically defined culture conditions will facilitate the study of differentiation in the HRA-19 cell line in the absence of the complex mixture of growth factors, hormones and differentiation inhibitory factor(s) present in foetal calf serum.
Cell Differentiation↗
Morphological analysis of gastro-esophageal diseases by molecular cell techniques.
The molecular cell sciences have had a great impact in the analysis of the genetic and epigenetic events of esophageal and gastric tumorigenesis. In other regions of the alimentary tract such as the colon, the serial identification of the molecular events in the corresponding morphological lesions is perhaps most advanced. This is, in part, due to the relative ease of the histological characterisation of the premalignant lesions. In this regard the analysis of morphological and molecular adaptation in the alimentary tract is inextricable. This review aims, therefore, to judiciously assess the relative applications of contemporary techniques in investigative histopathology.
Adenocarcinoma↗