Quality control for estrogen and progesterone receptor assay in human breast cancer: the influence of computation methods on intra and interlaboratory variability.

The importance of evaluating receptors for estrogen and progestin in human breast cancer has been pointed out by many authors. In the absence of a reference standard, receptor assays must be controlled by intra and interlaboratory quality control programs. Much interlaboratory variability exists due to non-uniform analytical protocols, non-uniform ligands, intrinsic errors and also errors in computation methods.

Quality assurance for steroid receptor assay in human breast cancer: six years experience of the Italian Committee.

Since 1979 the quality control design proposed by the Italian ad hoc Committee has evaluated several lyophilized preparations with scalar receptor content; this permits the identification by linear regression analysis of systematic and non systematic errors. At present 41 laboratories from most of the national regions have joined the Italian Committee. The overall results of five years application of quality assurance in Italy show that there was a different pattern of imprecision with satisfactory indexes for intralaboratory performances but major variations in interlaboratory controls.

Thyroid hormone levels in human breast cyst fluid.

Radioimmunoassayable levels of total and free 3,5,3'-triodothyronine (T3) and thyroxine (T4), thyroid stimulating hormone (TSH), thyroxine binding globulin (TBG) and prolactin (Prl) were measured in a series of samples of breast cyst fluid (BCF) aspirated from 73 pre-menopausal women with gross cystic disease of the breast and in coincidental blood samples. In BCF free T3 and free T4 were consistently higher than in plasma (P less than 0.001) as was also total T3 in the majority of cases (P less than 0.

Evidence for a transcortin-like component in human breast cyst fluid.

The occurrence of a specific glucocorticoid binding activity was investigated in breast cyst fluid (BCF) samples aspirated from 481 women under treatment for breast cystic disease. [3H]cortisol was incubated with BCF at 4 degrees C with and without 100-fold molar excess of non-radioactive steroid in order to account for non-specific binding. Corticosterone, progesterone and dexamethasone-binding activities were also investigated in about 50% of the specimens.

Correlation between levels of dehydroepiandrosterone-sulphate and prolactin in human breast cyst fluid.

Concentration of dehydroepiandrosterone sulphate (DHAS), cortisol (F), aldosterone (A) and prolactin (PRL) were measured in 70 samples of breast cyst fluid (BCF) obtained by needle aspiration from patients having gross cystic disease of the breast. DHAS concentrations in our series of BCF were scattered over a broad range, up to values 200-fold higher than in plasma, with ample interindividual variability; cortisol was present in BCF in very small amounts. Aldosterone and PRL values were in the same order of plasma levels; moreover, a significant correlation was found between DHAS and PRL concentrations in BCF.

Circadian and circaseptan rhythmicities in corticosteroid-binding globulin (CBG) binding activity of human milk.

It has been demonstrated that human milk contains a corticosteroid-binding globulin (CBG, transcortin) which is very similar to that isolated from plasma. It is agreed, moreover, that the cortisol environment of the breast is important for the synthesis of major milk proteins. It was of interest, therefore, to investigate whether milk transcortin exhibits circadian variations in the binding activity as does the plasma counterpart.

Circannual rhythmicities of cortisol levels in the peripheral plasma of healthy subjects.

Seasonal variations of endocrine function have been extensively studied both in rodents and in man. However, only few studies have attempted to concomitantly evaluate and compare circadian and circannual components by inferential rhythmometric procedures. We have examined [9] circadian profiles (single cosinor: P less than 0.

Immunoglobulin levels in breast cyst fluid: apparent connection with intracystic transcortin (CBG) binding activity.

Immunoglobulin levels of the major classes of IgG, IgA and IgM have been measured by radial immunodiffusion in 74 samples of breast cyst fluid (BCF) aspirated by women with "Gross Cystic Disease". Appreciable levels of Ig were found in all samples. No significant correlation was observed between intra-cystic Ig levels and the corresponding levels measured on coincidental blood specimens.

Circadian patterns of plasma cortisol and testosterone in chronic male alcoholics.

Twelve alcoholic men (28-55 yr) presenting hypogonadal features but without overt liver failure were hospitalized and examined still consuming alcohol regularly. Sleep was approximately from 2200 to 0600; three equicaloric meals were served at 0700, 1200, and 1800. Blood samples were drawn at 4-hr intervals throughout a 24-hr span starting from 0800.

Circadian profile of plasma cortisol and aldosterone in post-traumatic comatose patients under high-dose dexamethasone treatment.

Six comatose patients hospitalized in an intensive care unit immediately following an acute trauma with severe brain injury (road or industrial accident) were examined through out three consecutive 24-h cycles in the first week after trauma, when receiving intramuscularly 12 mg daily of dexamethasone-21-phosphate. Intravenous or enteral nutrition was supplied continuously. Plasma cortisol and aldosterone were measured on blood samples drawn at 4-h intervals.