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Biomedical subjects

J D North

Publications and source records attributed to J D North.

At least 19 recordsLinked to original sources

Variation at the apo AI/CIII/AIV gene complex is associated with elevated plasma levels of apo CIII.

A number of studies have reported that a variant allele (S2) of the apo AI/CIII/AIV complex is associated with high plasma lipid levels in some populations and furthermore that the frequency of this allele is 2-5-fold higher in patient groups with premature coronary heart disease compared to control groups. This study shows in the healthy "English" population that the S2 allele is associated with elevated plasma apo CIII levels but not with low apo AI levels. In addition, it shows that the allele is associated with elevated plasma levels of apo B in men. Regression analysis shows in both men and women that apo CIII levels are positively correlated with plasma triglyceride levels and moreover that they are a stronger predictor of this parameter than apo AI, B or AIV. Apo CIII levels are also an independent predictor of total plasma cholesterol and HDL-cholesterol levels in males and females, respectively. Together these data suggest that a genetic predisposition to develop elevated plasma levels of apo CIII, alone or in combination with elevated plasma apo AIV levels, is the primary defect responsible for the association of the S2 allele with hyperlipidemia and/or premature CHD.

Adult

The apolipoprotein B gene is constitutively expressed in HepG2 cells: regulation of secretion by oleic acid, albumin, and insulin, and measurement of the mRNA half-life.

The objective of this study was to establish conditions whereby apoB secreted from HepG2 cells could be regulated over a wide range, and to determine whether changes of output were correlated with the level of apoB mRNA. The presence of oleate (complexed to 3% albumin at a molar ratio of 1.7:1) resulted in a 3.5-fold stimulation of apoB secretion that was apparent after only 3 h. Insulin halved the rate of apoB output and the inhibition was detectable within the physiological insulin range, but was not apparent until 12-16 h. Albumin in the culture medium had a dose-dependent inhibitory effect on apoB production. Overall, apoB secretion from HepG2 cells was modulated over a 7-fold range. However, when apoB mRNA was assayed by slot-blot hybridization, no change was detectable under any of the conditions that modulated apoB output. Quantitative solution hybridization was used to confirm that oleate did not affect the level of apoB mRNA. Kinetic analysis of the decay of [3H]uridine-labeled apoB mRNA showed that the half-life of apoB mRNA was 16 h. We conclude from these studies that the apoB gene is constitutively expressed in HepG2 cells and that the mechanism of acute regulation of apoB production by these cells must involve co- or post-translational processes.

Albumins

Streptococcus suis bacteraemia.

Streptococcus suis is a zoonotic pathogen which causes meningitis, arthritis and septicaemia in pigs, and rarely meningitis or septicaemia in humans. This organism has recently been isolated from pigs in New Zealand, where it appears to be widely distributed in pig herds. This case is the first report of human infection in New Zealand.

Adult

The pattern of management after stroke.

A large population-based study of stroke is used to describe the pattern of management and the relative contribution of hospital care and community care in the year following an acute stroke episode. Two thirds of the 680 patients registered in the study were admitted to a public hospital during the acute stage of their illness, while almost one quarter of all patients were managed entirely at home. One month after the initial episode the majority of patients admitted to hospital had either died or had been discharged. Overall, four-fifths of the care during the first year after the onset of the stroke took place out of hospital, either at home or in private long-term institutions.

Adolescent

Immunological enhancement in the pathogenesis of pyelonephritis.

The role of the immune response in pyelonephritis was investigated by manipulation of the host's immune capacity using the immunosuppressive drugs 6-mercaptopurine, cyclophosphamide and thiamphenicol. Treatment with 6-mercaptopurine depressed the humoral immune response but did not have an adverse effect on the course of renal infection. Thiamphenicol administration prevented the development of pathological lesions but this was due to the anti-bacterial activity of thiamphenicol and not to its immunosuppressive activity. Pyelonephritic animals treated with cyclophosphamide did not produce anti-bacterial antibody. Despite this, cyclophosphamide-treated animals were able to eliminate organisms more readily from the infected kidney than untreated animals with a normal humoral immune response. We believe that blocking of the phenomenon of immunological enhancement explains these unexpected results and that the immune response to renal infection may have an immunoenhancing role protecting the bacterial cell from otherwise effective host defence mechanisms.

Animals

Use of antilymphocyte globulin after cadaveric renal transplantation.

Antilymphocyte globulin (A.L.G.) was prepared by injecting fresh frozen splenic cells subcutaneously into horses. The IgG fraction of the serum was concentrated by a batch technique using diethylaminoethanol-Sephadex. Fourteen patients given this material by intramuscular injection after cadaveric renal transplants, in addition to azathioprine and prednisone, had less evidence of rejection compared with patients previously treated with azathioprine and prednisone only, despite a reduction of the mean daily prednisone dose from 65 to 45 mg. Toxicity, especially local reaction, fever, and hypotension, limited the amount of A.L.G. that was given.

Animals

Reticulum cell sarcoma after renal homotransplantation and azathioprine and prednisone therapy.

Two patients developed reticulum cell sarcomata after they had been treated with azathioprine and prednisone in the course of cadaveric renal transplantation. Both had terminal widespread herpes simplex virus infection.Immunosuppressive therapy could be responsible for an increased risk of malignant lymphomata either directly or by facilitating infection with oncogenic viruses.

Adult