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Biomedical subjects

C J Jones

Publications and source records attributed to C J Jones.

At least 217 records · Page 12Linked to original sources
PubMed1987

A combined approach to the assessment of neurological dysphagia.

The dysphagia encountered by patients with neurological disorders can be both distressing and life threatening because of the associated problems of aspiration. Decisions regarding management are often difficult because the exact nature of the underlying disorder varies from patient to patient and is frequently complex. A new approach to the assessment and evaluation of acquired neurological dysphagia is presented. Management of the first 50 patients assessed by this method is described. The advantages of a joint dysphagia clinic comprising neurology, speech therapy, ENT and radiology departments are discussed.

Combined Modality Therapy↗
PubMed1987

Electrophysiological and dye-coupling studies on secretory, myoepithelial and duct cells in human eccrine sweat glands.

1. Electrophysiological properties and dye-coupling status of secretory, myoepithelial and coiled duct cells in isolated human eccrine sweat glands have been assessed by single-micro-electrode studies and intracellular micro-iontophoresis of the fluorescent naphthalimide dye Lucifer Yellow CH (molecular weight 457). Treated glands were embedded in LKB HistoResin and examined by transmission fluorescence microscopy, first as wholemounts and then as 5 microns serial sections. Sections positive for Lucifer Yellow were photographed and then stained with Toluidine Blue for observation by conventional microscopy to confirm the site of penetration. 2. Out of forty-five successful micro-iontophoreses, three were confirmed in secretory cells, twelve in myoepithelial cells and thirty in cells of the coiled duct wall. The latter were identified as the most penetrable in the coiled part of the isolated human eccrine sweat gland. 3. Of the three secretory cells labelled (resting potentials -40, -52 and -63 mV), all demonstrated dye coupling to neighbouring secretory cells although in one case this was found to be selective. Not every secretory cell was involved in coupling. No fluorescent label spread to the myoepithelial cells which form a network on the basal surface of the secretory tubule. 4. When myoepithelial cells were penetrated, they demonstrated dye coupling to neighbouring myoepithelial cells but not to secretory cells with which they also made contact. Basal resting potentials of -35 to -65 mV were recorded (mean = -52 mV, S.E. of mean = +/- 2.4 mV, n = 12) and, in eight out of the twelve cells penetrated and labelled, spontaneous depolarizing transients were also observed whose amplitude but not frequency increased with increasing membrane polarization. Administration of acetylcholine to produce a final concentration of 10(-6) to 10(-7) M produced either depolarization or micro-electrode dislodgement. 5. Of the thirty cells labelled in the coiled duct, twenty-six showed obvious dye spread to neighbouring cells in both layers of the wall. There was no relation between dye-coupling status and basal resting potential which lay in the range -40 to -82 mV (mean = -60 mV, S.E. of mean = +/- 2.4 mV, n = 30). Repeated doses of acetylcholine produced either no response from cells in this range or depolarization in cells with resting potentials more negative than -70 mV and hyperpolarization in cells with resting potentials more positive than -70 mV. In addition, there was a biphasic response, depolarization followed by hyperpolarization in a cell of resting potential -67 mV.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗
PubMed1987

Identification of proteins of the outer (L and P) rings of the flagellar basal body of Escherichia coli.

Synthesis of the Salmonella typhimurium hook protein from the gene cloned on a multicopy plasmid results in partial suppression of the flagellar assembly defects of certain classes of Escherichia coli mutants (K. Ohnishi, M. Homma, K. Kutsukake, and T. Iino, J. Bacteriol, 169:1485-1488, 1987). This phenomenon allowed hook-basal body complexes from such mutants to be purified and analyzed by electron microscopy and gel electrophoresis. The absence of the P and L rings in such structures was found to correlate with the absence of proteins of apparent molecular weight 39,000 and 26,000, respectively. Gene-polypeptide correlations from other studies enabled us to complete gene-polypeptide-structure correspondences for these two proteins as flaM----39-kilodalton protein----P ring and flaY----26-kilodalton protein----L ring.

Bacterial Proteins↗
PubMed1987

Structure and function of the nematosome.

The ultrastructural morphology of human placental and mouse placental nematosomes has been investigated. The description includes a three-dimensional analysis of the shape of the organelles based on serial sectioning, measurements of the repeat distance of the subunit fibre of the organelle derived by optical diffraction analysis and the results of an ultrastructural cytochemical study designed to test whether the organelle contains nucleic acid.

Animals↗
PubMed1987

Predicting plantar fasciitis in runners.

Ninety-one runners were studied to determine whether specific variables were indicative of runners who had suffered with plantar fasciitis either presently or formerly vs runners who had never suffered with plantar fasciitis. Each runner was asked to complete a running history, was subjected to several anatomical measurements, and was asked to run on a treadmill in both a barefoot and shoe condition at a speed of 3.35 mps (8 min mile pace). Factor coefficients were used in a discriminant function analysis which revealed that, when group membership was predicted, 63% of the runners could be correctly assigned to their group. Considering that 76% of the control group was correctly predicted, it was concluded that the predictor variables were able to correctly predict membership of the control group, but not able to correctly predict the presently or formerly injured sufferers of plantar fasciitis.

Age Factors↗
PubMed1986

A post-embedding avidin-biotin peroxidase system to demonstrate the light and electron microscopic localization of lectin binding sites in rat kidney tubules.

A post-embedding method for the light and electron microscopic demonstration of lectin binding sites in rat kidney tubules is described. The use of biotinylated lectins, followed by treatment with avidin peroxidase and the DAB-H2O2 sequence, produced intense staining of acrylic sections at the electron microscope level: brush borders and associated structures, cytoplasmic granules, basal infoldings and basement membrane-plasmalemmal interfaces of proximal tubules bound erythrophytohaemagglutinin, while distal tubules were mainly unstained. At the light microscope level, epoxy resin sections showed a similar staining pattern after etching, as did acrylic resin sections after intensification of the final reaction product. The binding of wheatgerm agglutinin to cytoplasmic granules and brush border structures in the proximal tubules was abolished, at both the light and electron microscope levels, by the competing sugar tri-N-acetylchitotriose. Epoxy resin ultrathin sections required etching before staining was achieved in the electron microscope, and results were far inferior to those obtained with acrylic resin. This method allows rapid and inexpensive screening of large numbers of lectins, if required, at both the light and electron microscope levels, using reagents that are stable for long periods of time.

Animals↗
PubMed1986

The structure of the basement membrane of human lymph node high endothelial venules: an ultrastructural, histochemical and immunocytochemical study.

The structure of the basement membrane of the high endothelium of reactive human lymph nodes was investigated by techniques selective for carbohydrates (periodic acid-Schiff; critical electrolyte concentration staining with Alcian Blue; lectin histochemistry), specific proteins (immunohistochemistry for laminin and fibronectin) and by conventional techniques of light and transmission electron microscopy. Adjacent small lymphocytes were assigned to B and T cell subsets by use of monoclonal antibodies and they were analysed for non-specific esterase, beta-glucuronidase, beta-N-acetylglucaminidase and proteolytic activities. The basement membranes were shown to be distinctive and to contain three layers, of differing laminin, glycosaminoglycan and glycoprotein oligosaccharide content. Certain lymphocytes (probably T) contained enzymes potentially able to degrade some components of these basement membranes.

Basement Membrane↗
PubMed1986

Isoflurane and halothane for outpatient dental anaesthesia in children.

A trial was undertaken in children to compare the use of halothane and isoflurane in outpatient dental anaesthesia. A wholly inhalation technique was chosen and nitrous oxide in oxygen was delivered from a Boyle's machine via a coaxial (Bain) breathing system and was supplemented with either halothane or isoflurane. Isoflurane produced significantly fewer arrhythmias than halothane but the induction of anaesthesia took longer and proved more difficult.

Adolescent↗
PubMed1986

Ventilation and the oculocardiac reflex. Prevention of oculocardiac reflex during surgery for squints: role of controlled ventilation and anticholinergic drugs.

A randomised prospective study was carried out in children undergoing surgery for squint correction, to determine the value of controlled ventilation as a prophylaxis against the occurrence of the oculocardiac reflex. One hundred patients anaesthetised with nitrous oxide/oxygen and halothane were randomly assigned to either ventilated or spontaneously breathing groups of 50 each. Half the patients in each group received glycopyrronium 7.5 micrograms/kg intravenously at the time of induction of anaesthesia. Heart rate, rhythm, blood pressure and end tidal CO2 concentration were monitored throughout. A positive oculocardiac reflex, defined as a fall in heart rate of 20% or more and/or the occurrence of dysrhythmias, was observed in 72% of spontaneously breathing patients and in 100% of ventilated patients not receiving prophylactic intravenous glycopyrronium. The incidence of a positive reflex in patients receiving glycopyrronium was 10% (4 and 16% respectively in spontaneously breathing and ventilated patients). It is concluded that controlled ventilation is of no value as a preventive measure against the occurrence of the oculocardiac reflex in patients undergoing squint surgery and that prophylaxis is safely achieved with the use of intravenous glycopyrronium.

Adolescent↗
PubMed1986

Electrophysiological studies on isolated human eccrine sweat glands.

Human eccrine sweat glands were isolated by shearing and the potential differences across the basolateral membranes determined using bevelled micro-electrodes filled with 4 M potassium acetate. Stable resting potentials of up to -81 mV were recorded. Alterations in external potassium concentration from 1.2 to 100 mM caused the membrane potential to change over a 70 mV range in cells of high resting potential, indicating that the basolateral membrane is largely potassium permeable. Input impedance was determined by constant current injection and found to be in the range 4-80 M omega. On giving a bolus injection of acetylcholine to produce a final concentration of 10(-6)-10(-7) M, four types of response were observed: depolarization, in a proportion of cells with resting potentials of -66 to -80 mV (n = 19), hyperpolarization, in a group of cells with resting potentials of -47 to -70 mV (n = 22), no change, in some cells of -40 to -81 mV resting potential (n = 22) and micro-electrode dislodgement (n = 8). In cells depolarizing to acetylcholine, the depolarization was short-lived and in thirteen cases was followed by a 'rebound' hyperpolarization. Input impedance decreased during depolarization in one-third (n = 5) of the cells in which satisfactory measurement could be made and increased during the final phase of depolarization or during rebound hyperpolarization. In cells hyperpolarizing to acetylcholine, the hyperpolarization was usually accompanied by an increase in input impedance. In ten of the twenty-two cells which showed no change to a first dose of acetylcholine, the agonist was administered at least two more times. In two cells (resting potentials -62 mV, -64 mV) a hyperpolarization was observed whereas in three others (resting potentials -66 mV, -70 mV, -81 mV) depolarization occurred. The effects of acetylcholine, whether depolarizing or hyperpolarizing, were reversibly inhibited by atropine and irreversibly reduced by ouabain. Experiments performed on glands maintained for up to 30 h in supplemented RPMI 1640 tissue culture medium yielded essentially similar results to those performed on freshly isolated glands.

Acetylcholine↗
PubMed1986

Genetic evidence for a switching and energy-transducing complex in the flagellar motor of Salmonella typhimurium.

The flaAII.2, flaQ, and flaN genes of Salmonella typhimurium are important for assembly, rotation, and counterclockwise-clockwise switching of the flagellar motor. Paralyzed and nonchemotactic mutants were subjected to selection pressure for partial acquisition of motility and chemotaxis, and the suppressor mutations of the resulting pseudorevertants were mapped and isolated. Many of the intergenic suppressor mutations were in one of the other two genes. Others were in genes for cytoplasmic components of the chemotaxis system, notably cheY and cheZ; one of the mutations was found in the cheA gene and one in a motility gene, motB. Suppression among the three fla genes was allele specific, and many of the pseudorevertants were either cold sensitive or heat sensitive. We conclude that the FlaAII.2, FlaQ, and FlaN proteins form a complex which determines the rotational sense, either counterclockwise or clockwise, of the motor and also participates in the conversion of proton energy into mechanical work of rotation. This switch complex is probably mounted to the base of the flagellar basal body and, via binding of the CheY and CheZ proteins, receives sensory information and uses it to control flagellar operation.

Chemotaxis↗
PubMed1985

Prevention of herpesvirus infections in renal allograft recipients by low-dose oral acyclovir.

Forty patients with serum antibody against herpes simplex virus (HSV) were enrolled in a randomized, placebo-controlled, double-blind investigation of acyclovir given orally in a low dosage as prophylaxis against recurrent HSV infection after renal transplantation. During 30 postoperative days of medication, 14 of 21 placebo-treated and one of 19 acyclovir-treated patient(s) developed reactivation of HSV infection. Eleven of the former, but not the latter, had herpetic lesions. The protection against active infection with HSV during the period of prophylaxis with acyclovir is statistically highly significant. From 30 to 90 days after transplantation when no antiviral medicine was given, 60% (3/5) of the remaining placebo recipients and 44% (7/16) of the acyclovir patients developed active HSV infections. Herpetic lesions occurred in two of three and two of seven of infected people in the respective groups. No adverse effects of the drug were observed. The results show that HSV infections in immunosuppressed renal allograft recipients can be safely prevented, deferred, and ameliorated by an initial period of prophylaxis with a low dose of oral acyclovir.

Acyclovir↗
PubMed1985

The distribution of cells of the monocytic-lineage in reactive lymph nodes and non-Hodgkin's lymphomata. Characterization using protein histochemistry, lectin binding and monoclonal antibodies.

In this study cells of putative monocytic origin have been investigated in lymph nodes, using a battery of cytochemical investigations on fixed and frozen tissue. In reactive lymph nodes involved in non-Hodgkin's lymphomata six types of presumed monocyte-derived cells have been identified on the basis of morphology and/or cytochemistry. These cells can be divided into two distinct groups. Certain cell types have distinctive distributions in reactive and non-Hodgkin's lymphomata and this taken in conjunction with their morphology and staining properties may give important clues to their function.

Antibodies, Monoclonal↗