The role of adrenocorticotropin testing in evaluating girls with premature adrenarche and hirsutism/oligomenorrhea.

To identify biochemical predictors for future development of hirsutism and/or oligomenorrhea (H/O) in girls with premature adrenarche (PA), we performed dexamethasone-suppressed ACTH stimulation tests in girls with PA (n = 46), young women (n = 44) with H/O, and adult women (n = 31). Cortisol, androstenedione, dehydroepiandrosterone, and 17-hydroxyprogesterone were measured. Seven girls with PA (15%) and seven with H/O (16%) had evidence of nonclassical adrenal steroid biosynthetic defects [nonclassical congenital adrenal hyperplasia (NCAH)]. Twenty-five girls with PA (54%) and 28 girls with H/O (64%) had the moderately elevated 17-hydroxyprogesterone response to ACTH that has been reported in obligate heterozygotes for 21-hydroxylase deficiency. There were no clinical features that distinguished the girls with NCAH from the others. ACTH testing is an important tool in distinguishing those girls with PA and H/O who have NCAH. Although we could find no differences in other adrenal steroid hormones that might predict which of the other girls with PA might late develop H/O, black girls comprised a substantially smaller fraction of the population with H/O than of the population with PA (2% vs. 26%; chi 2 = 8.5; P less than 0.005). This observation suggests that PA, in blacks who do not have NCAH, is more likely to be a benign condition/than in other ethnic groups.

Normal mouse peritoneum contains a large population of Ly-1+ (CD5) B cells that recognize phosphatidyl choline. Relationship to cells that secrete hemolytic antibody specific for autologous erythrocytes.

We have found that, in the peritoneums of normal adult mice, 5-15% of lymphocytes bind a fluorescent liposome probe. In ontogeny, cells with this specificity were shown to appear by 8 d after birth, and increase to the adult frequency by 2-3 wk. Some older mice contain an expanded population of these cells. We have shown that liposome binding occurs by cell surface IgM recognizing the common membrane phospholipid, phosphatidyl choline (PtC). Virtually all of these PtC-specific cells bear the cell surface marker Ly-1. Our results indicate that roughly 1 in 10 peritoneal Ly-1+ B cells has this single specificity. We have found that the precursors to all the cells that form plaques on protease-treated autologous erythrocytes (BrMRBC) are included in the PtC-specific population and can be isolated by FACS. We believe this is the first report of sorting large numbers of B cells with a single antigen specificity from normal, unimmunized animals. This method will allow for in vitro and in vivo studies of differentiative and proliferative properties of Ly-1+ B cells, which may help define their role in development and disease.

Technetium-99m MAG3, a comparison with iodine-123 and iodine-131 orthoiodohippurate, in patients with renal disorders.

A Phase I study in 12 patients with renal disorders compared the simultaneous clearances of 99mTc-labeled mercaptoacetyltriglycine (MAG3) and 131I-labeled orthoiodohippurate (OIH). The ratio of MAG3 to OIH clearance was 0.61 +/- 0.08 as a result of its smaller volume of distribution, ratio 0.65 +/- 0.09, for the clearance half-lives were similar, ratio 1.09 +/- 0.12. A Phase II study performed serially in 20 patients with equal doses of [99mTc]MAG3 and [123I]OIH gave images of equal quality. The relative renal functions were highly correlated (r = 0.97, p less than 0.001) and transit time analyses gave good correlations: parenchymal transit time index r = 0.81, p less than 0.05. We conclude that [99mTc]MAG3 has some advantages over [99mTc]DTPA and is a suitable replacement for [123I]hippuran in routine renal imaging, relative function, and transit time studies, but not for the accurate estimation of the renal plasma flow.

Imaging of phaeochromocytoma and adrenal medulla with 123I-meta-iodobenzyl guanidine.

A method for preparing meta-iodobenzyl guanidine (MIBG) labelled with 123I is described. This compound clearly imaged the normal adrenal medulla in seven out of eight patients with hypertension. The sites of metastases were demonstrated in two patients with malignant phaeochromocytoma.

Detection of human cancer in an animal model using radio-labelled tumour-associated monoclonal antibodies.

Monoclonal antibodies to epithelial-cell antigenic determinants, labelled with 123I and 125I, were administered parenterally to immunodeficient mice bearing human tumours derived from a human cancer cell line. Anterior, posterior and lateral radioscans of the body were taken with a gamma scintillation camera at various times from immediately to 65 days after injection. Visual displays of the images were processed by standard computer techniques. The model used a human colon-cancer cell line, HT29, and the monoclonal antibody, AUA1, which is specific to an epithelial proliferating antigen. Tumour detection was achieved in all the mice. The smallest tumour detectable appeared to be about 1 mm in diameter. The degree of antibody uptake in a tumour depended on its size and the blood supply of its surrounding tissues We believe that the technology and skills are now available for accurate radioimmunodetection of cancer in man.

Clinical experience with 75Se selenomethylcholesterol adrenal imaging.

The results of quantitative adrenal imaging using 75Se selenomethylcholesterol in sixty-two subjects are analysed. The adrenal area was localized by a renal scan, lateral views of which enabled adrenal depth to be estimated. The first nineteen cases were scanned with a rectilinear scanner and the remaining forty-three cases imaged with a gamma camera. Quantitation of adrenal uptake was performed on computer-stored static images obtained 7 and 14 days post-injection of 75Se selenomethylcholesterol (3 and 6 days in the first ten cases studied). Normal uptake was found to be 0.07-0.30% of the administered dose. Overall predictive accuracy of the type of adrenal disorder of thirty-two patients with Cushing's syndrome ws 90.6%, this included twelve cases of Cushing's disease (mean uptake 0.58%), seven ectopic ACTH syndromes (mean uptake 0.69%), five unilateral adenomata (mean uptake 0.93%), three post adrenalectomy regrowths (mean uptake 1.37%), three adrenal carcinomas (mean uptake 0.01%), one congenital hyperplasia (mean uptake 3.4%) and one unilateral nodular hyperplasia. Overall predictive accuracy of the cause of Conn's syndrome in twenty-two cases was 86.4%; this included thirteen cases of bilateral hyperplasia (mean uptake 0.34%), eight unilateral adenomata (mean uptake 0.47%) and one patient with mineralocorticoid excess in whom the cause has not been confirmed. The mean uptake in the normal adrenal in cases of unilateral adenoma was 0.19% (range 0.07-0.30%). Causes of unsatisfactory adrenal imaging are examined. The procedure is recommended as the localizing and lateralizing technique of choice in Cushing's syndrome except where due to adrenal carcinoma, and as an important non-invasive technique in Conn's syndrome for the lateralization of adenoma.

Distribution of lysosomal hydrolases in human and bovine ocular tissues.

We have studied the distribution of the lysosomal sphingolipid hydrolases beta-glucosaminidase, beta-galactosaminidase, beta-galactosidase, alpha- and beta-glucosidases, and alpha-mannosidase in the bovine and human ocular tissues, choroid, cornea, lens, retina, and sclera using synthetic substrates in the form of the 4-methylumbelliferyl derivatives of the corresponding glycosides. As compared to the bovine ocular tissues, the human ocular tissues possessed higher levels of all the enzyme activities examined with the exception of beta-galactosidase, and alpha-glucosidase than the other bovine ocular tissues. In contrast to the retina, which is primarily a neural tissue, human and bovine lens have minimal or trace levels of all the lysosomal hydrolases examined. Human and bovine retina, cornea, sclera, and choroid possess enzyme activities which are higher than the lens. This would indicate a slow turnover of glycosphingolipids in lens tissue as compared to the other ocular tissues.

Selenium 75 selenomethyl cholesterol: a new agent for quantitative functional scintigraphy of the adrenals: physical aspects.

Fifty-two patients with suspected or known adrenal disorders have been studied with 75Se selenomethyl cholesterol using a rectilinear scanner or gamma camera computer system. Radiation dosimetry was estimated from the blood clearance and whole body retention of 75Se selenomethyl cholesterol. A method of quantitation of adrenal uptake is described, use of which is essential for the separation of normal from hyperactive adrenal glands. The adrenal depth was found to vary between 4.4 and 12 cm. The lack of need for thyroid suppression and the availability and ease of handling and storage of 75Se selenomethyl cholesterol make it preferable to 131I iodo-cholesterol derivatives and the current agent of choice for adrenal imaging.

Relation of plasma aldosterone concentration to diuretic treatment in patients with severe heart disease.

To assess the relation of hyperaldosteronism and potassium depletion to the intensity of diuretic therapy we have measured plasma aldosterone by radioimmunoassay and total exchangeable potassium by radioisotope dilution in 24 patients when they were stable at the end of their preparation for cardiac operation. Some patients required intensive frusemide therapy to reach an optimal state for operation and many showed hyperaldosteronism. Plasma aldosterone was significantly related to daily dose of frusemide (r=0.77). Depletion of total exchangeable potassium expressed in terms of predicted weight was significantly related to plasma aldosterone (r= -0.64). The reduction in total exchangeable potassium is interpreted as chiefly related to loss of lean tissue mass from the wasting that leads to cardiac cachexia, but evidence is presented on the basis of measurements of extracellular fluid volume as sulphate space (20 patients) of entry of sodium into the cells which may indicate a true cellular potassium loss. Although plasma potassium is usually easily maintained with oral potassium supplements or aldosterone antagonists, we postulate that intensive diuretic therapy in severe heart disease may provoke hyperaldosteronism which accentuates potassium loss and may contribute to wasting and to intracellular potassium depletion in critical tissue, such as myocardium.

Demonstration of cross-reacting material in Tay-Sachs disease.

Antibodies against placental hexosaminidase A and kidney alpha-subunits were raised in rabbits after cross-linking the antigens with glutaraldehyde. Anti-(alpha(n)-subunit) antiserum (anti-alpha(n)) precipitated hexosaminidase A but not hexosaminidase B, whereas anti-(hexosaminidase A) antiserum precipitated both hexosaminidases A and B. Specific anti-(hexosaminidase A) antiserum was prepared by absorbing antiserum with hexosaminidase B. Both anti-alpha(n) and anti-(hexosaminidase A) antisera precipitated the CR (cross-reacting) material from eight unrelated patients with Tay-Sachs disease. Immunotitration, immunoelectrophoresis, double-immunodiffusion and radial-immunodiffusion techniques were used to demonstrate the presence of CR material. The CR-material-antibody complex was enzymically inactive. Antiserum raised against kidney or placental hexosaminidase A, without cross-linking with glutaraldehyde, failed to precipitate the CR material, implying that treatment of the protein with glutaraldehyde exposes antigenic determinants that are hidden in the native protein. Since anti-(hexosaminidase B) antiserum did not precipitate the CR material during the immunoelectrophoresis of Tay-Sachs liver extracts, it is suggested that altered alpha-subunits do not combine with beta-subunits. By using immunotitration we have demonstrated the competition between the hexosaminidase B-free Tay-Sachs liver extract and hexosaminidase A for the common binding sites on monospecific anti-(cross-linked hexosaminidase A) antiserum. The amount of CR material in the liver samples from seven cases of Tay-Sachs desease was found to be in the same range as theoretically calculated alpha-subunits in normal liver samples. Similar results were obtained by the radial-immunodiffusion studies. The present studies therefore suggest that Tay-Sachs disease is caused by a structural-gene mutation.

Potassium depletion in severe heart disease.

Exchangeable sodium and potassium, total body water, and sulphate space were measured in 42 patients with severe valvular heart disease who were free of oedema. Compared with normal subjects of the same height, no increase in exchangeable sodium was found but a mean potassium depletion of 27% was shown. This depletion was not related to diuretic therapy, and no relationship between the degree of depletion and postoperative arrhythmias was found. It is concluded that the major cause of the low exchangeable potassium is the reduction in cell mass that occurs in chronic heart disease, and that there is no significant fall in the intracellular potassium concentration.