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Biomedical subjects

D G Jones

Publications and source records attributed to D G Jones.

At least 235 records · Page 13Linked to original sources
PubMed1976

The elbow.

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Animals↗
PubMed1976

Amyloid deposits in the trachea and esophagus ultrastructural confirmation.

The clinical details of two patients suffering from amyloid infiltration of the trachea and esophagus respectively are presented. The "amyloid tumor" in the trachea presented with dysphonia and a swelling in the lower subglottic region. Attempts at complete surgical excision of it were unsuccessful. The patient with esophageal amyloid presented acutely with dysphagia and features of dehydration and malnutrition. Systematized amyloidosis was discovered at autopsy, but no primary initiating cause for it was found. In both cases it was possible to confirm the diagnosis by electron microscopy. The current views on the composition, structure, causation and treatment of amyloid disease are reviewed.

Aged↗
PubMed1976

Slow reacting substance as a preformed mediator from human lung.

Homogenates from human lung contained a preformed slow reacting substance (pSRS). The pattern of contraction on the guinea-pig ileum by pSRS was indistinguishable from that of SRS-A. The activity of pSRS could not be attributed to the presence of K+, Na+, Ca2+ and Mg2+ ions, or any prostaglandin including PGF2 or its 15-oxo derivative. As with SRS-A, pSRS could be absorbed onto Amberlite XAD-2 and silicic acid. Both were eluted from the former with 80 per cent ethanol and from the latter with a mixture of ethanol, ammonia and water. Both pSRS and SRS-A were resistant to the action of NaOH whereas their activities were destroyed by boiling in HCl. Arylsulphatase II B destroyed the activities of both pSRS and SRS-A. An antagonist of SRS-A, FPL55712, inhibited the action of pSRS at comparable concentrations to that of SRS-A. These experiments suggest that pSRS and SRS-A are identical. Thus SRS joins histamine and ECF-A as a preformed mediator. Although SRS was present in a preformed state the amount of material extractable was more than doubled by the anaphylactic reaction. The extraction of slow reacting substance from human lung without apparent requirement for antigen or antibody points to a possible role of this mediator in inflammatory reactions evoked by mechanisms independent of IgE and other tissue-sensitizing antibodies.

Antigens↗
PubMed1976

Tissue inactivation of slow reacting substance of anaphylaxis.

The release of slow reacting substance of anaphylaxis (SRS-A) from sensitized guinea-pig lung challenged with antigen was followed by a fall in the activity of this mediator in the diffusate when the incubations were continued for 3 h. The inactivating principle was also present in normal lung in addition to other normal guinea-pig tissues such as the liver, kidney, spleen, ileum and skin. No acitivity was found in muscle. Evidence is provided that some of this SRS-A-inactivating activity was due to tissue arylsulphatases. These were measured by hydrolysis of p-nitrophenyl sulphate (p-NPS) and p-nitrocatechol sulphate (p-NCS), which reflect activities of arylsulphatase II A and II B respectively. Hydrolytic activity for p-NCS was present in all tissues with SRS-A-inactivating properties, whereas only lung, liver and skin tissue hydrolysed p-NCS and p-NPS. Following passage of a cell-free lung homogenate through a column of Sephadex G-200 the p-NCS hydrolysing and SRS-Z-inactivating activities eluted together, with molecules having a molecular size of approximately 150,000 Daltons, p-NPS hydrolysing activity being destroyed during the preparation of the homogenate. The release of arylsulphatase from sensitized tissue was not dependent on the presence of specific antigen. These experiments suggest that inactivation of SRS-A is related to tissue arylsulphatase and that these enzymes may play a role in the expression of the effective levels of this mediator within the tissues.

Animals↗
PubMed1975

Biochemical and morphological studies of the short and long term survival of isolated nerve-endings.

The respiratory rate, potassium, amino acid, ATP and phosphocreatine content of cortical synaptosomes were measured over periods from one hour to 5 days. Incubation medium or tissue culture medium at 37 degrees C was employed. In suspensions, synaptosomes show diminished levels of all these parameters after 3 or 4 h, but synaptosome beds showed no loss of potassium, ATP or phosphocreatine at this time. Morphologically the synaptosomes showed good preservation of structure during the first 24 h in tissue culture. Respiratory response to electrical pulses was detectable even after 24 h in culture when basal respiration was low.

Adenosine Triphosphate↗
PubMed1975

Pectineus muscle resection as a treatment for hip dysplasia in dogs.

Pectineus muscle resection was performed on 100 dogs with hip dysplasia. The degree of dysplasia was estimated by radiography and by joint manipulation. The effects of the procedure on 81 dogs were determined by personal reinspection (34), or by means of owner-reports (47). Improvement was noted in 80 per cent but only 35 per cent reached a high level of recovery. The operation has a role in the treatment of hip dysplasia but it does not cure the condition and it will be several years before the long-term results are known.

Animals↗
PubMed1975

The effect of enzyme digestions on the activity of eosinophil chemotactic factor of anaphylaxis (EFC-A).

Preparations of ECF-A derived from anaphylactic guinea-pig lung diffusates were subjected to a variety of enzymatic degradations. The enzymes employed had specificityonly for their appropiate subtstates. No effect was found following treatmentwith relatively high doses of trypsin, alpha-chymotrypsin, pronase, alkaline phosphataseand sialidase. In contrast a loss of activity was demonstated in a dose-dependent fashion following incubation with tyrosinase, aryl sulphatase and leucine aminopeptidase, suggesting that ECF-A contains a phenolic hydroxyl group, a sulphate ester anda peptide linkage with a free alpha-amino group.

Alkaline Phosphatase↗