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L Pinsky

Publications and source records attributed to L Pinsky.

At least 37 records · Page 2Linked to original sources
PubMed1987

Extracellular correction of the androgen-receptor transformation defect in two families with complete androgen resistance.

We have characterized the cellular and extracellular phenotype of the mutant androgen receptor (AR) from two families who have complete androgen resistance despite a normal androgen-binding capacity (Bmax) in their genital skin fibroblasts (GSF). The cellular receptors fail to up-regulate their basal AR activity in response to prolonged incubation with 5 alpha-dihydrotestosterone (DHT), or with two synthetic androgens, methyltrienolone (MT) and mibolerone (MB), and form A-R complexes with increased equilibrium (Kd) and non-equilibrium (k) dissociation constants. In addition, they are thermolabile when recently dissociated, but not in their native state. A-R complexes made in normal or mutant cytosol at 4 degrees C elute from DEAE-Sephacel at approximately 0.25 M KCl (untransformed), with or without prior passage through Sephadex G-25; when made in cells at 37 degrees C, extracted with 0.4 M KCl in a buffer containing 10 mM Na2MoO4, and desalted by G-25, they elute at less than or equal to 0.1 M KCl. Normal KCl-extracted DHT- and MB-R complexes dissociate (37 degrees C) at the same slow, linear rate as their in-cell counterparts (transformed); the mutant ones dissociated more slowly than their rapidly-dissociating in-cell counterparts and, to a variable extent, nonlinearly-an early faster phase, a later slower (transformed). Thus, as judged by two conventional criteria of steroid-R complex transformation, the mutant A-R complexes can transform, possibly in two steps, under certain cell-free conditions. This behavior differentiates a class of structural AR mutations whose molecular definition awaits application of recombinant DNA techniques to the X-linked AR locus.

Androgens↗
PubMed1986

Ligand-specific thermal misbehavior of synthetic androgen-receptor complexes in genital skin fibroblasts of subjects with familial ligand-sensitive androgen resistance.

We have used 5 alpha-dihydrotestosterone (DHT) and two synthetic, non-metabolizable androgens, methyltrienolone (MT) and mibolerone (MB), to study intact genital skin fibroblasts from four subjects with familial incomplete androgen resistance. In each, the free androgen receptor has normal binding capacity at 37 degrees C and normal half-lives at 37-43 degrees C. In three the mutant receptor misbehaves in a pattern that is ligand-specific and temperature-dependent. At 37 degrees C the equilibrium (Kd) and non-equilibrium (k) dissociation constants, and the ability to augment binding activity during prolonged exposure to androgen, are impaired with DHT, but not with MT; with MB, only the k is abnormal. Mutant MT-receptor complexes dissociate normally even at 42 degrees C; yet, in cells post-incubated at 42 degrees C with cycloheximide and a saturating concentration of ligand, their pool size decays in the rank order, MT greater than MB greater than normal. This measure of lability is nonlinear as a semilogarithmic function of time; it varies directly with temperature and the concentration of cycloheximide, but inversely with that of ligand. Thus, MT and MB evoke distinct forms of thermal dysfunction from the androgen receptor in ligand-sensitive androgen resistance. This observation will help to elucidate the combinatorial properties of normal androgen-receptor complexes that enable them to regulate gene transcription differentially in various androgen target tissues.

Androgens↗
PubMed1985

Deletion of the long arm of the Y chromosome and review of Y chromosome abnormalities.

We report on a patient whose karyotype is 45,X/46,X,del(Y) (pter----q11.212). We also present a review of literature on the Y chromosome in which evidence is presented that there are genes on the Y chromosome that prevent Ullrich-Turner syndrome manifestations; aid in testes maturation and spermatogenesis; and affect height, tooth size, and bone maturation.

Adult↗
PubMed1985

Reduced affinity of the androgen receptor for 5 alpha-dihydrotestosterone but not methyltrienolone in a form of partial androgen resistance. Studies on cultured genital skin fibroblasts.

We have studied a child with posterior labial fusion, clitoral phallus, female urethra, and a short, blind vagina born to a mother with decreased axillary and pubic hair. Her karyotype is 46,XY. At 2 yr of age, the child's basal level of plasma testosterone was less than 0.35 nM and after human chorionic gonadotropin stimulation, it rose to 2.6. Testis and epididymis histology were normal. Her cultured genital (labial) skin fibroblasts have normal testosterone 5 alpha-reductase activity, and metabolize 5 alpha-dihydrotestosterone (DHT) normally, but they do not augment (up-regulate) their basal androgen-receptor binding activity during prolonged incubation with DHT. With DHT, the androgen receptor in her genital skin fibroblasts has a normal binding capacity (maximum binding capacity = 25 fmol/mg protein), but an increased rate constant of dissociation (k = 11.6 X 10(-3) min-1; normal, 6 +/- 1.2 (+/- SD)), and a decreased apparent equilibrium binding affinity (Kd = 0.6 nM; normal, 0.22 +/- 0.09) that is evident in the results of 2-h assays but not of those lasting 0.5 h. With the synthetic androgen, methyltrienolone, all three binding properties of the receptor are normal, and her receptor activity up-regulates normally. We interpret these results to mean that the subject has a ligand-selective defect in the time-dependent transformation of initial, low-affinity androgen-receptor complexes to serial states of higher affinity, presumably as the result of a structural mutation at the X-linked locus that encodes the androgen receptor protein.

Cells, Cultured↗
PubMed1979

Complete androgen insensitivity with a normal amount of 5 alpha-dihydrotestosterone-binding activity in labium majus skin fibroblasts.

We have studied labium majus skin fibroblast strains from six unrelated, previously unreported, patients with complete androgen insensitivity (CAI). Four have markedly reduced specific 5 alpha-dihydrotestosterone-binding (DHT-binding) activity (receptor-negative). The other two (receptor-positive) have normal activities in whole-cell homogenates, the 100,000g supernatant of cell sonicates prepared in 0.4 MKCl, purified whole nuclei, and the nuclear fraction that resists extraction with 0.4 MKCl. In one of the two, the DHT-binding macromolecules in the cytosol and 0.4 M KCl-extractable nuclear fraction have normal molecular sieving profiles and binding activities. One of the receptor-positive patients has maternally related affected relatives in three successive genetations. Appreciable unexplained interexperimental variation of the DHT-binding activities in genital skin fibroblast strains demands that multiple assays be performed on a strain before its receptor status is classified quantitatively. In our experience to date with genital skin fibroblasts, four of 13 propositi with CAI have been receptor-positive.

Adolescent↗
PubMed1978

5alpha-reductase activity of genital and nongenital skin fibroblasts from patients with 5alpha-reductase deficiency, androgen insensitivity, or unknown forms of male pseudohermaphroditism.

Serially subcultured fibroblast strains from genital (foreskin, labium majus) skin, as a group, have considerably more steroid (testosterone) 5alpha-reductase activity than those form nongenital skin. Foreskin strains varied 40-fold and labial strains even more. Labial strains overlapped nongenital strains of either sex more frequently than did prepuce strains. The activity of foreskin strains from two siblings with proven 5alpha-reductase deficiency was clearly lower than that of any of 18 control stains. The comparative behavior of the various strain types indicates that labial and nongenital strains should not be used to support a clinical suspicion of male pseudohermaphroditism due to 5alpha-reductase deficiency. The activities of labial strains from patients with complete androgen insensitivity (testicular feminization) - five with the receptor-negative variety and two with the receptor-positive type - were as variable as those of control labial strains. The decreased 5alpha-reductase activity observed in fresh skin slices of some patients is probably and expression of their functional estrogen/androgen imbalance in vivo.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1978

The syndromology of anorectal malformation (atresia, stenosis, ectopia).

The syndromes, associations, and developmental field defects that include anorectal dysgenesis (atresia, stenosis, ectopia) as a principal or facultative sign are discussed. Most of these disorders are identifiable by their genetic or teratogenic etiology, their distinctive phenotype, or both. Their precise diagnosis is crucial for estimation of recurrence risk and other aspects of reproductive counseling, and it is essential for classificatory progress. The "VACTERL association" should not be used to label a patient with anorectal malformation and other anomalies except by exclusion; this rule is particularly relevant when the patient lacks tracheoesophageal malformation. The degree (or variety) of anorectal malformation that occurs in a given pattern of multiple congenital anomalies may be inconstant. Furthermore, anorectal malformation may be a solitary expression of a familial syndrome.

Abnormalities, Multiple↗
PubMed1978

Some properties of the specific androgen-binding activities in cultured human genital skin fibroblasts.

Specific 5 alpha-dihydrotestosterone (DHT)-binding activity in the cytosol (C) and 0.4 M KCl-extractable nuclear fraction (N) of cultured human fibroblast cell strains developed from preputial (n = 12) and labium majus (n = 12) skin were analyzed by gel exclusion chromatography, sucrose gradient sedimentation, and thermostability. Both fractions had activities that were excluded from Sephacryl S-200 columns; another component (mol wt, 20,000) was present in the N fraction. The C was more thermostable than a homologous N activity, and addition to the former of KCl to 0.4 M had no effect. There was large, overlapping variation in thermostability of the C and N activities among strains from either site, sister strains developed from a single skin biopsy, and even among serial subcultures within a strain; likewise, the variable sedimentability of the C (4-7S) and N (3.2-5.9S) activities prevented their consistent discrimination. Each type of variation occurred despite excellent intraexperimental replication. The thermostability of a given N activity varied directly with its sedimentation coefficient. By cluster analysis, the data relating thermostability of a given N activity with the percentage of 0.4 M KCl-resistant nuclear activity segregated into two populations; within each population these two measurements were related inversely. We suggest that these coordinate behaviors of the N activity reflect intrinsic properties of the androgen-receptor system in normal genital skin fibroblasts which may be useful for defining qualitative aberrations of the system in receptor-positive forms of congenital androgen insensitivity.

Adolescent↗
PubMed1977

Male pseudohermaphroditism: diagnosis in cell culture.

Testicular feminization is a classic form of complete male pseudohermaphroditism. The individuals have a normal XY karyotype but unambiguously female external genitalia. They have congenital complete insensitivity to androgen due to an X-linked mutation. In four patients (from tow families with several affected members) with the typical phenotype of testicular feminization, a severe deficit of specific androgen-binding activity was detected in cultured fibroblasts from labium majus skin. Measurement of this activity in genital skin fibroblasts improves the differential diagnosis in patients with complete or imcomplete male pseudohermaphroditism before puberty.

Adolescent↗
PubMed1977

Expression of androgen-responsive properties in human skin fibroblast strains of genital and nongenital origin.

Specific 5alpha-dihydrotestosterone (DHT) binding capacity (Bmax) has been determined for human skin fibroblast strains from non-genital areas of males and females (N = 8), as well as prepuce and labium majus (N = 9). Genital strains had a mean three times that of non-genital ones (32 vs. 11 fmol/mg cell protein). There were no sex differences. Variation among strains was not simply correlated with donor age; that within strains was unrelated to in vitro age. The lowest values for genital strains overlapped the nongenital ones; those of the nongenital strains approached the limit of detectability. These results parallel those for delta4-3-ketosteroid 5alpha-reductase activity. Thus, serially cultured genital and nongenital skin fibroblasts express their relative differentiative ancestry as androgen target cells. This expression may affect the diagnosis of androgen insensitivity and certain inborn errors of metabolism; its variability is discussed in terms of clonal heterogeneity.

Age Factors↗