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Biomedical subjects

B Rachmilewitz

Publications and source records attributed to B Rachmilewitz.

12 recordsLinked to original sources
PubMed1990

Serum cobalamin and transcobalamin levels in systemic lupus erythematosus.

PURPOSE: The purpose of this study was to assay serum cobalamin levels in patients with systemic lupus erythematosus (SLE) as there are few case reports on the association of pernicious anemia and SLE. PATIENTS AND METHODS: Serum cobalamin levels were assayed in 43 female SLE patients by a radio-dilution assay using purified intrinsic factor. RESULTS: Cobalamin levels were found to be significantly lower in the SLE group compared with a normal control group, eight of whom (18.6%) had serum cobalamin levels equal to or lower than 180 pg/mL (mean: 129.25 +/- 40.05 pg/mL). None of the SLE patients had been found to have pernicious anemia. The transcobalamin II level and unsaturated vitamin B12 binding capacity, but not the cobalamin level, were positively correlated with SLE activity. CONCLUSION: Our results may indicate a subtle cobalamin deficiency in SLE patients without pernicious anemia.

Adolescent↗
PubMed1986

The modulation of transcobalamin II (TC-II) production by cyclic adenosine 3',5'-monophosphate in the murine macrophage cell line J774: relationship to growth behavior.

We undertook a study to define the role of cyclic AMP [cAMP] in modulating the secretion of transcobalamin II (TC-II) in the mouse macrophage like cell line J774. J774 was observed to secrete large amounts of TC-II, particularly in the presence of 8-bromo cAMP or cholera toxin or when grown in medium supplemented with low concentrations of horse serum (1% or 5%) or in serum-free medium. Variant cell lines derived from J774 and deficient either in adenylate cyclase (ac -) or cAMP-dependent protein kinase (pk -) activity showed very low and intermediate levels of basal secretory activity of TC-II, respectively, compared to J774. Maximum secretory activity of TC-II was observed in J774 under conditions in which growth was poorest (in the presence of 8-bromo-cAMP or 1% or 5% horse serum-supplemented medium or in serum-free medium). Cells grown in serum-free medium were found to have elevated basal adenylate cyclase activity and cAMP levels compared to those grown in medium supplemented with 20% horse serum. The data from this study demonstrate a negative correlation between growth activity and TC-II secretion in the J774 cell line. The stimulatory effect of exogenous cAMP on TC-II secretion by J774, the reduced secretory activity of the variant lines ac- and pk- and the observed increase in cell cAMP levels under conditions of serum starvation in which TC-II secretion is considerably enhanced, suggest that cell cAMP is an important modulator of TC-II secretion and growth behavior in the J774 cell line.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1977

The transcobalamins in polycythaemia vera.

The unsaturated B12 binding capacity (UBBC) of the serum and the binding capacity of each of the 3 vitamin B12 binders--the transcobalamins (TC) I, II and III were determined in 21 patients with polycythaemia vera (PV) during the course of the disease and following treatment, using the recently described charged cellulose filter technique. High serum UBBC due to elevated serum TCIII was found in all patients. TCI was moderately elevated in patients who had leucocytosis with a shift to the left. The changes in serum TCIII and UBBC correlated with the activity of the disease. Chemotherapy resulted in a decrease in TCIII and UBBC. The decrease in TCIII and UBBC folowing chemotherapy may be observed before a decrease in the haematocrit and the leucocyte count occurs. Activation of the disease may be assessed by the elevation of TCIII and UBBC. The onset of acute myeloblastic crisis in 1 patient was associated with a decrease in TCIII and TCI levels and a rise in serum TCII. The determination of TCIII and UBBC may be helpful in differentiating true from secondary polycythaemia.

Blood Proteins↗
PubMed1977

The synthesis of transcobalamin II, a vitamin B12 transport protein, by stimulated mouse peritoneal macrophages.

The concentration of transcobalamin II (TCII), the vitamin B12 binding protein which delivers vitamin B12 to the tissues, was determined in stimulated and non stimulated mouse peritoneal exudate cells (PEC). Following a single intraperitoneal thioglycollate injection there was a marked increase in TCII which was shown to be produced by the adherent cells of the PEC i.e. the macrophages. It has been concluded that the PEC macrophages synthesize TCII.

Animals↗
PubMed1976

Fractionation of serum transcobalamins on charged cellulose filters.

A simple and rapid fractionation procedure of the three transcobalamins, TCI, TCII, and TCII, of human serum was achieved by filtration through a stack of charged cellulose filters composed of one cellulose-nitrate and three DEAE-cellulose (DE-81) disks. A reaction mixture containing microliter amounts of serum was incubated with excess of 57Co B12 of high specific activity, diluted with 0.1 M sodium borate buffer (pH 8.5), and passed through the filter stack by applying vacuum. Under these conditions TCII is selectively and quantitatively adsorbed to the cellulose-nitrate filter while both TCI and TCIII adsorb to the DE-81 filters. In the second step TCIII is selectively desorbed from the latter filters by a 0.05 M monopotassium phosphate solution of pH 4.6. Using sera of different distribution of transcobalamins the data obtained were comparable to those determined by the more laborious methods employing DE-52 column chromatography combined with procedures to remove TCII.

Blood Proteins↗
PubMed1975

Chronic eosinophilic leukemia complicated by epidural myeloblastoma.

Epidural myeloblastoma, which compressed the spinal cord, was the first evidence for chronic granulocytic leukemia, eosinophilic type, Ph chromosome negative. This manifestation was preceded by 3 years follow-up of a patient with persistent eosinophilia of 60% mature eosinophils. The only clues for the diagnosis of leukemia were splenomegaly and high serum vitamin B12, most of which was bound to transcobalamin I. The latter finding presents a useful diagnostic criterium in myeloproliferative disorders.

Adult↗