Isolation of cardiac membrane proteolipids by high pressure liquid chromatography. A comparison of reticular and sarcolemmal proteolipids, phospholamban and calciductin.

Membrane-bound phosphorylatable proteolipids were reported to play a role in the regulation of transmembrane Ca2+ fluxes by catecholamines. A generally applicable purification procedure is described by which such proteolipids as the cardiac sarcoplasmic reticulum phospholamban is purified by solvent extraction followed by high pressure liquid chromatography on microparticulate silica. Phospholamban is thereby purified with a yield of 3.37 mg from 100 mg of sarcoplasmic reticulum proteins, significantly higher than that obtained by any of the previously reported procedures. It appeared homogeneous upon dodecyl sulfate-polyacrylamide gel electrophoresis where it is stained by Coomassie blue and detected by autoradiography. The same procedure is applicable to cardiac sarcolemmal calciductin. Both proteolipids exhibit the same Mr 11 000 and pI 3.7 upon two-dimensional gel electrophoresis. Their amino acid compositions are very similar if not identical. This raises the intriguing possibility that phospholamban and calciductin are identical though they obviously belong to different membranes.

Identification of placental alkaline phosphatase in human sera using polyacrylamide gel electrophoresis.

Polyacrylamide gradient gel electrophoresis may be used to separate placental alkaline phosphatase from other types of serum alkaline phosphatase. This method, of which specificity is demonstrated by the thermostability and immunological reaction of the placental form, is sensitive enough to detect an activity of 0.02 mU in a sample, and seems suitable for use in investigating placental isoenzyme in serum.

Cyfra 21-1, a new marker of lung cancer.

The are few outstanding serous markers in the treatment of bronchial cancer. ACE lacks sensitivity and specificity and cannot be used as a diagnostic marker. It has been described as a marker of tumoral mass, although not in our study. Prognostic significance was observed, but only in a univariate analysis. Sensitivity of SCC TA4 varied between studies. In our population, the ROC curve for SCC TA4 showed poor discrimination potential. NSE was shown to be a useful marker in the treatment of patients with small cell cancers. Cytokeratins are expressed by all bronchial cancers. Cytokeratin 19 is a sub-unit detected in simple epithelia and their neoplastic counterparts. During tumoral cell lysis, certain fragments of this cytokeratin may be liberated. The immunoradiometric assay described here is able to detect fragments of cytokeratin 19 (called Cyfra 21-1) in serum. Our study established a correlation between Cyfra 21-1 levels and the cancer stage for NCPC, but not for CPC. In addition, Cyfra 21-1 concentration may be used as a tumoral mass marker. Patients with high Cyfra 21 levels must undergo special treatment to find remote tumors.

Changing estrogen and progesterone receptor patterns in breast carcinoma during the menstrual cycle and menopause.

BACKGROUND: Estrogen receptor (ER) and progesterone receptor (PgR) status at the time of breast carcinoma surgery is used as a marker of both prognosis and hormone dependency to guide adjuvant therapy. The authors studied the influence of hormonal milieu at the time of surgery on ER and PgR levels. METHODS: A population of 2020 patients with breast carcinoma, including 575 premenopausal women, was analyzed. ER and PgR levels were determined by radioligand binding assays (cutoff values, 10 fmol/mg). Serum estradiol (E2), progesterone (Pg), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels obtained on the day of surgery were used to define the menstrual cycle phase in premenopause. RESULTS: In premenopause, there was a higher proportion of ER positive (ER+) tumors in the follicular phase (62%, n = 316) than in the ovulatory phase (51%, n = 59) and the luteal phase (53%, n = 200, P = 0.03). The mean ER level was also higher in the follicular phase (30 fmol/mg) than in the ovulatory phase (20 fmol/ mg) and the luteal phase (25 fmol/mg, P < 0.001). The percentage of PgR positive (PgR+) tumors tended to be higher in the ovulatory phase (85%) than in the follicular (78%) and luteal (72%) phases (P = 0.11). The mean PgR was also higher in the ovulatory phase (177 fmol/mg) than in the follicular and luteal phases (134 and 92 fmol/mg, respectively; P < 0.001). The percentage of ER+ tumors was higher among menopausal women than among premenopausal women (67% vs. 59%, respectively; P < 0.001). Conversely, the percentage of PgR+ tumors was lower among menopausal women than among premenopausal women (65% vs. 78%, respectively; P < 0.001). In premenopause, there was a weak negative correlation between ER and E2 levels. No correlations were found between levels of ER and Pg and levels of FSH and LH or among levels of PgR and E2, Pg, and FSH and LH in premenopausal and menopausal women. CONCLUSIONS: Changes in ER and PgR levels in breast carcinoma during the menstrual cycle and menopause suggest that interpretations of hormone dependency on the basis of steroid receptor values should take into account hormonal status at the time of surgery.

[Ferritin and breast cancer]. / Ferritine et cancer du sein.

Studies of human breast cancers show that tumoral tissues have a much higher ferritin content (mean : 4,5 times) than normal tissues. However, only 10% of patients without metastasis present raised levels of serum ferritin, whereas hyperferritinemia is observed in almost 95% of patients with liver, bone or lung metastasis.

[Evidence for one atypic variant of an alkaline phosphatase from human placenta (author's transl)]. / Mise en évidence et purification partielle d'une variante atypique de la phosphatase alcaline placentaire humaine.

A variant of a partially purified Placental Alkaline Phosphatase, showing a slow electrophoretic mobility but the same kinetic caracteristics as the common type, has been found. This variant also differs from the D type by its insensibility to L-leucine inhibition.

Study of human isoferritins from liver, spleen, heart and placenta by the microcomplement fixation technique.

Ferritin, iron storage protein, presents two types of subunits, H and L, the respective proportions of which varying with the tissue of origin and defining molecules called isoferritins. This work attempts to compare four human ferritins (from liver, spleen, heart and placenta) by means of the microcomplement fixation technique. Results show that placenta and liver ferritins are closely related, while slight but significant differences appear between liver, spleen and heart ferritins. These differences are obviously less important compared to those observed between ferritins from different species of origin, as shown by the results expressed in terms of index of dissimilarity or immunological distance. Those results are fully consistent with the elementary aminoacid composition as well as with the relative proportions of H and L subunits among the various types of human isoferritins we have studied.

Variation of bcl-2 expression in breast ducts and lobules in relation to plasma progesterone levels: overexpression and absence of variation in fibroadenomas.

Some women with benign breast disease eventually develop breast cancer. The mammary gland undergoes tissue remodelling according to hormonal influences, involving a balance between quiescence, proliferation, and mechanisms of cell death. Proliferation and/or apoptotic events could therefore be investigated to help understand the mechanisms of benign lesion formation and identify mastopathies with a poor prognosis. bcl-2 expression was analysed by immunohistochemistry in 75 benign mastopathies. Protein levels were quantitated with an image analyser in various epithelial structures on frozen sections, including adenoses, fibroadenomas, ductal epithelial hyperplasias, cysts, and apparently normal surrounding lobules and ducts. bcl-2 levels were equivalent in apparently normal lobules and ducts, as well as in cysts and ductal hyperplasias. bcl-2 staining was significantly higher in fibroadenomas, known to be of lobular origin [mean = 10.1, quantitative immunochemistry score (QIC) arbitrary units (AU), n = 19], than in normal lobules (mean = 5.1 AU, n = 43, P = 7 x 10(-5). bcl-2 levels in normal lobules and ducts varied according to the menstrual cycle, being higher during the follicular than the luteal phase (P = 1.8 x 10(-2) and P = 1.7 x 10(-2), respectively). This was further supported by a statistical link (P = 5 x 10(-3) between high levels of circulating progesterone and weak bcl-2 staining in lobules and ducts. This progesterone-dependent variation was absent in fibroadenomas. No statistical correlation was found between bcl-2 expression and circulating levels of oestradiol, and follicle-stimulating or luteotrophic hormones. Although these are only preliminary results, they suggest an influence of progesterone on bcl-2 expression which might be lost in fibroadenomas. A hypothesis is proposed concerning the potential involvement of altered regulation of the apoptotic process in the formation of such benign lesions.