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Biomedical subjects

W Jacobson

Publications and source records attributed to W Jacobson.

59 records · Page 4Linked to original sources
PubMed1968

The electrophoretic mobility of normal and leukaemic cells of mice.

1. The pH-mobility relationships for saline-washed cells from a mouse strain of acute lymphoblastic leukaemia were examined before and after treatment with lower aldehydes, diazomethane and neuraminidase (EC 3.2.1.18). 2. The content of sialic acid released into the supernatant fluid of neuraminidase-treated cells was measured. 3. The stability of the charge-determining structures to temporary changes in environment (pH and ionic strength) was established. 4. Similar measurements were made on lymph-node cells obtained from non-leukaemic mice (a resistant and a leukaemia-susceptible strain were examined). 5. It is deduced that both the malignant and the non-malignant cell possess two dissociable acid functions at the cell surface, a carboxyl group of sialic acid and another acidic group(s), probably carboxyl, of pK 3.0-4.5. The malignant cells, however, have a basic dissociable function not present in the non-malignant types. 6. Suggestions are made as to how the difference in surface chemistry may be related to the problem of malignancy.

Aldehydes↗
PubMedDate not supplied

Mu-opioid ([3H]DAGO) binding in slices of rat brain: inhibition by sodium ions, guanyl-5'-yl imidodiphosphate and by the adrenergic neurotoxins DSP4 and xylamine.

We have characterized and quantified the specific binding of the mu-agonist [3H] DAGO to 300 microM slices of hypothalamus and cerebral cortex. The receptors have many of the opioid characteristics previously demonstrated in homogenate assays. Binding is reversible, saturable, stereospecific and of high affinity. The delta-opioids DTLET and DSLET are 36- and 30-fold respectively, less effective than DAGO in competing for the binding site. Assays can be routinely performed in the presence of physiological concentrations of sodium, though in TRIS buffer the affinity and the number of receptors is increased. Protection of the ligand against proteolytic degradation is unnecessary. Unexpectedly, we observed that GppNHp inhibits [3H] DAGO binding to brain slices. This suggests an allosteric modification of the mu-receptor in the membranes of intact cells. The mu-receptors are also blocked by the adrenergic neurotoxins DSP4 and xylamine. This re-emphasizes our contention that care should be exercised in the use of these drugs. The technique is simple, rapid and involves minimal disruption of tissue. It should provide new opportunities for the study of cell surface opioid receptor subtypes in intact tissue.

Animals↗