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Biomedical subjects

G D Jackson

Publications and source records attributed to G D Jackson.

121 records · Page 7Linked to original sources
PubMed1975

Salmonella enteritidis infection in rats: antigens involved in cell-mediated immunity.

When rats are sub-lethally infected with S. entertidis by the intravenous route, there is a period of at least 14 days in which peritoneal exudate cells are unable to migrate from capillary tubes on to glass surfaces; thereafter they migrate as do macrophages from normal animals. The migration of peritoneal cells from rats infected 18-21 days previously is inhibited by lipopolysaccharide (LPS) prepared from homologous and heterologous strains of Salmonella. The apparent non-specificity of LPS activity in the macrophage migration inhibition test has been resolved by demonstrating that lipid A, containing less than 0.01% protein amino acids, is also capable of eliciting this test of cell-mediated immunity.

Animals↗
PubMedDate not supplied

Effect of tear-specific immunoglobulin A on the adhesion of Pseudomonas aeruginosa I to contact lenses.

PURPOSE: The aims of the study were (i) to determine the immunodominant antigens of Pseudomonos aeruginoso 1 (Paer1) to tear secretory immunoglobulin A (sIgA); (ii) to study the role of sIgA in inhibiting bacterial adhesion to contact lenses. METHODS: SDS-PAGE and Western blotting were used to study the interaction of tear sIgA with Paer1; an adhesion assay was used to study the effect of sIgA on the adhesion of Paer1 to the contact lenses. RESULTS: The results of our study showed that the immunodominant molecules of Paer1 which reacted with tear sIgA were of molecular masses of 105, 50, 45 kDa; the binding of sIgA to Paer1 resulted in a reduction of the adhesion of Paer1 to worn Etafilcon A contact lenses. CONCLUSIONS: In conclusion, Paer1-specific sIgA are present in tears; the immunodominant molecules of Paer1 may be adhesins and tear-specific sIgA might play an important role in protecting the eye from contact-lens-induced corneal infection by preventing bacterial attachment to contact lenses and the ocular surface.

Bacterial Adhesion↗
PubMedDate not supplied

Nuclear magnetic resonance detection of increased cortical GABA in vigabatrin-treated rats in vivo.

1H Nuclear magnetic resonance ([1H]NMR) spectroscopy was used to detect elevation of gamma-aminobutyric acid (GABA) in rat brain after administration of the antiepileptic drug vigabatrin (VGB). Rats were treated for 3 weeks with VGB added to their drinking water to deliver a dose of 250 mg/kg body weight per day. NMR spectroscopy was performed noninvasively in vivo, and a GABA concentration of 6.0 +/- 2.3 mmol/kg wet weight (mean +/- SD, n = 5) was measured. GABA could not be detected in control animals in vivo. Postmortem GABA levels of 1.3 +/- 0.5 and 4.5 +/- 1.0 mmol/kg (mean +/- SD, n = 5) were measured in perchloric acid extracts of frozen brain from control and treated animals, respectively. Noninvasive measurement of increased cerebral GABA should allow detailed studies of the pharmacology of GABA-increasing drugs in vivo. With future developments, these measurements may be feasible in human subjects.

Aminocaproates↗
PubMedDate not supplied

Experience with diffusion-weighted imaging in an acute stroke unit.

We performed diffusion-weighted MRI (DWI) on a standard 1.5-tesla MRI scanner using a high-speed stimulated echo pulse sequence (turboSTEAM) in 9 stroke patients and 9 control subjects to investigate whether this technique can be used clinically to assist in ischaemic stroke diagnosis within the time frame for potential therapy. Stroke patients underwent DWI between 3.75 h and 3 days after stroke onset. Three patients were studied on more than one occasion. DWI was normal in the 9 controls. Seven of 9 stroke patients showed areas of increased signal on DWI. DWI detected cerebral ischaemia 3.75 h after stroke onset when both CT and T2-weighted MRI were normal. In 6 DWI-positive patients studied at later times, increased signal on T2-weighted images was present at the same time. Two patients had normal CT, T2-weighted and DWI images; both made good neurological recoveries. For the routine assessment of stroke patients, DWI implemented on a standard MRI system can provide additional information of clinical value to that obtained with conventional pulse sequences. In particular it facilitates early detection of cerebral ischaemia during the first few hours after stroke.

Adult↗
PubMedDate not supplied

Infection and immune responses in chickens exposed to Salmonella typhimurium.

The transmission of Salmonella typhimurium among adult chickens maintained in wire-floored cages was examined. Within 6 days, organisms had spread from infected seed chickens to the majority of uninoculated chickens. Initially, organisms were found in the intestinal tract alone, but by day 20, all chickens were infected, and most of these had organisms in the liver, spleen, and intestinal tract. Antibodies to whole bacterial cells and lipopolysaccharide were detected in the serum and bile of all chickens from day 24. Clearance of organisms from the tissues was not apparent until after day 33. Cell-mediated immunity to salmonella antigens was also induced in chickens that naturally acquired the infection. The role of these parameters of immunity in the clearance of organisms is discussed.

Agglutination Tests↗
PubMedDate not supplied

Optimizing the diagnosis of hippocampal sclerosis using MR imaging.

PURPOSE: To establish the optimal imaging parameters and MR features of hippocampal sclerosis. METHODS: Twenty-five outpatients with intractable temporal lobe epilepsy and 10 control subjects were studied at 1.5T. Four features of hippocampal abnormality were specifically evaluated; increased hippocampal signal on T2-weighted images, decreased signal on T1-weighted images, hippocampal atrophy, and disruption of the internal hippocampal structure. RESULTS: Hippocampal sclerosis was diagnosed alone in 64% of patients and with ipsilateral pathology in a further 8%. In these 18 cases, increased hippocampal signal on T2-weighted images was seen in 77%, hippocampal atrophy in 83%, decreases signal on T1-weighted images in 83%, and disruption of the internal hippocampal structure in 89%. No abnormality was reported in any of the 10 control cases. CONCLUSIONS: Four MR features diagnostic of hippocampal sclerosis are reported. Inversion recovery images are very useful for identifying decreased signal in the hippocampus and loss of internal structure within the hippocampus. Based on an appreciation of these four features in optimized images, hippocampal sclerosis can be diagnosed with a high degree of accuracy and sensitivity.

Adolescent↗