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Phosphotyrosine proteins in platelets from patients with storage pool disease: direct relation between granule defects and defective signal transduction.

BACKGROUND AND OBJECTIVES: Storage pool diseases (SPD) are heterogeneous disorders associated with an abnormal presence of intraplatelet granules, which cause mild to moderate bleeding diathesis. We investigated signaling through tyrosine phosphorylation of proteins occurring in platelets with total or partial absence of dense- and alpha-granules in response to activation. DESIGN AND METHODS: We included a patient with severe delta-SPD, a patient with severe alpha-SPD or gray platelet syndrome, and six patients with partial deficiency of dense or a-granules. SPD was confirmed by electron microscopy evaluation of platelet ultrastructure. Platelet function was evaluated by bleeding time determination and conventional aggregometry. Platelet suspensions were activated with collagen and thrombin to analyze changes in tyrosine phosphorylation of proteins by electrophoresis and Western-blotting. RESULTS: Bleeding times were prolonged in all the patients included. Aggregation responses were slightly decreased in delta-SPD and normal in the rest of patients. Tyrosine phosphorylation in platelets from patients with partial forms of SPD was equivalent to that observed in control platelets, absent in response to collagen and thrombin activation in delta-SPD, and deficient only to thrombin activation in alpha-SPD. INTERPRETATION AND CONCLUSIONS: Tyrosine phosphorylation of proteins in activated platelets is highly dependent on the substances contained in the dense-granules and moderately dependent on those contained in the alpha-granules. A minimum amount of intraplatelet granules ensures signaling through tyrosine phosphorylation of proteins.

Adolescent↗

[Familial case of male pseudohermaphroditism due to 17-ketoreductase defect: late diagnosis in the "aunt" of a patient with the same defect (author's transl)].

A 42 year old (46 XY) subject with 17-ketosteroid reductase deficiency was investigated. The patient reared as female, has developed masculine features (facial hair, male distribution of body hair, male body habitus, acne and clitoridomegaly) at about 15 years of age but never consulted. She married at 22 years and for 20 years thought to have a "normal" female sex life. Only when her 14 year old "niece" was investigated (1) and treated for similar problems she realized hers. She had a small phallus with perineal urethra, vaginal pouch absence of labia minora and undescended testis, no breast development. Baseline peripheral studies showed plasma testosterone (T) in the range of Tanner II stade of puberty (150 ng/dl), elevated delta 4-androstenedione (delta 4) (930 ng/dl) and estrone (E1) (33,5 NG/DL) LEVELS 6--8 times above normal, but subnormal estradiol levels. Increased basal gonadotropins showed an hyper-response to LHRH stimulation. Dynamic tests (ACTH test, Dexamethasone suppression, and hCG stimulation) showed that abnormal delta 4 and E1 were not of adrenal origin. In the spermatic veins delta 4 levels were extremely high (239 micrograms/dl) but T levels low (11.4 micrograms/dl). delta 4/T ratio in the spermatic vein was much higher than in the peripheral blood suggesting intact peripheral conversion of delta 4 to T. After castration all hormone levels returned to the range usually seen in agonadic male or female adults.

17-Hydroxysteroid Dehydrogenases↗