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Biomedical subjects

R Goren

Publications and source records attributed to R Goren.

6 recordsLinked to original sources

Quail (Coturnix japonica) protamine, full-length cDNA sequence, and the function and evolution of vertebrate protamines.

Using the chicken protamine gene as a probe, we have isolated and sequenced several positive clones from a quail testis cDNA library which reveal the complete sequence for the quail protamine cDNA. The predicted amino acid sequence for the quail protamine contains the N-terminal tetrapeptide ARYR present in the N-terminal region of the mammalian protamines as well as several conserved motifs and arginine clusters. In addition the size of the quail protamine (56 amino acids) is closer to that of mammals (50 amino acids) than that of the chicken (61 amino acids). Altogether this data strongly suggests the existence of an avian-mammalian protamine gene line during evolution. Southern blot analysis suggests a small number of copies (2) per haploid genome (similar to that of chicken). The reported quail protamine cDNA sequence is the second avian protamine for which the amino acid sequence is available so far and provides new insights into vertebrate protamine function and evolution.

Amino Acid Sequence

Normal immunosuppressive protein purification and quantitative estimation experiments.

An improved method for the preparation and purification of normal immunosuppressive protein (NIP) is described. The purified material has a molecular weight between 10,000 and 25,000. Its biological and serological activity is approximately 10--20 times higher than that of the crude fraction. An antibody to normal immunosuppressive protein prepared in rabbits made the quantitative estimation of NIP by a haemaggluination inhibition test possible. Similarly, a very sensitive assay for the quantitative determination of NIP by its inhibitory effect on the proliferation of EL-4 tumor cells is also described. Eluates prepared from polyacrylamide gels were active in inhibiting EL-4 tumor cell proliferation and neutralized the anti-NIP activity in the haemagglutination inhibition test.

Animals

Plasma cholesterol esterification in hypertriglyceridaemia.

Plasma cholesterol esterification was assessed in hypertriglyceridaemic patients and normal subjects by two in vitro methods, one using autologous substrate and one using exogenous substrate. There was a significant negative correlation between cholesterol esterification rate and the plasma triglyceride concentration when this was assessed with autologous substrate or with substrate from a hypertriglyceridaemic donor. The percentage of esterified cholesterol in plasma and the esterification rate were always reduced when the plasma triglyceride concentration exceeded 7 mmol/1 and the rate of esterification rose significantly with appropriate triglyceride-lowering therapy in such patients. Evidence is presented that the impaired cholesterol esterification observed in severe hypertriglyceridaemia is secondary to a reduced concentration of substrate high density lipoprotein cholesterol, as well as to an excess of large triglyceride-rich lipoproteins.

Adult

Plasma lipids in extra hepatic biliary obstruction.

Detailed studies of plasmsa lipids and lipoproteins were carried out on a large number of patients with proven extra hepatic biliary obstruction (EHO) to determine if changes are confined to the phospholipids and cholesterol fractions or whether the hypertriglyceridaemia, found previously in isolated studies, is present consistently and to a significant degree. Plasma lipids were also compared before and after surgical relief of the obstruction. In 15 patients with EHO (aged 16 to 78 years), compared to 23 controls (aged 18 to 63 years), there was an increase in total cholesterol due to an increase in the unesterified fraction, increase in unesterified to esterified cholesterol ratio, increase in phospholipids and increase in phospholipid to cholesterol ratio. The most striking finding was a marked and persistent elevation of triglyceride. Furthermore the increase in triglyceride was of a similar magnitude to cholesterol and phospholipid. Following relief of pbstruction the triglyceride returned to normal. The hypertriglyceridaemia in cases of EHO was associated with a clear serum and negative cold aggregation test in contrast to the changes in cases of endogenous (type IV) hypertriglyceridaemia. Hypertriglyceridaemia in EHO was associated with a broad beta fraction on the electrophoretogram. Lipoprotein-X was also detected and persisted after the relief of the obstruction despite the return of other lipid changes to normal.

Adolescent