RESUMO
Studies of calcium oxalate crystals in urine suggest similarities to crystal growth in calcium oxalate renal calculi. Previous reports indicate that urinary crystals in patients in whom stones form are larger than those in normal subjects. We report herein a study on crystal size by structure and habit (shape) based on direct microscopic measurement of crystals in urine of 27 normal subjects and in 6 of 22 patients in whom stones form. The mean size of all crystals in normal subjects is 12.0 plus or minus 7.8 micrometers. Calcium oxalate monohydrate crystals are significantly smaller than calcium oxalate dihydrate (p less than 0.01). In 22 patients with stones there was no correlation between crystalluria and severity or duration of disease. The mean crystal size in 6 patients did not support the conclusion that patients in whom stones form excrete larger crystals than normal subjects.
Assuntos
Oxalato de Cálcio/urina , Cálculos Renais/urina , Cristalização , Humanos , Cálculos Renais/patologiaRESUMO
Significant suppression of the hypothalamic-pituitary-adrenal axis has been found in patients hospitalized with psoriasis vulgaris and receiving topical fluorinated steroid therapy. Depression of thyroid function and involvement of autoimmune processes is also suggested by the data.
Assuntos
Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Psoríase/tratamento farmacológico , Esteroides Fluorados/farmacologia , 17-Cetosteroides/urina , Adolescente , Adulto , Idoso , Feminino , Humanos , Hidrocortisona/sangue , Hidroxiesteroides/urina , Masculino , Pessoa de Meia-Idade , Hormônios Hipofisários/sangue , Esteroides Fluorados/uso terapêutico , Hormônios Tireóideos/sangueRESUMO
Calcium oxalate crystals were obtained from urine specimens submitted to a hospital laboratory. The incidence of crystalluria was 4.2 per cent of 42 times the maximum reported incidence of urinary calculi. In our opinion the crystalluria was real and not artifactual. The crystalline structure was determined by polarized light, x-ray diffraction and electron microprobe analysis. Calcium oxalate occurs in several forms--the dihydrate as bipyramidal and dodecahedral prisms, the monohydrate as biconcave ovals, dumbbell shapes and intermediate forms.
Assuntos
Cálcio/urina , Oxalatos/urina , Cálculos Urinários/epidemiologia , California , Humanos , Concentração de Íons de HidrogênioRESUMO
Prostaglandin E2 has previously been shown to enhance the shape transformation of sickle prone erythrocytes (8) and to reduce the oxygen resaturation of Hemoglobin SS within intact sickle cell erythrocytes after deoxygenation (15). In view of the recent importance attributed to calcium transport in maintaining erythrocyte shape and viability (10) and the suggestion that prostaglandins may act via a calcium ionophore mechanism (9) on cell membranes, erythrocyte ghosts were prepared following the method of Lepke and Passow (12) from normal and sickle cell anemia erythrocytes. These two classes of ghosts are shown to display differing patterns of sodium and calcium transport, whith calcium influx being preferentially stimulated by prostaglandin E2 in sickle cell ghosts. It is suggested that in hypoxic, stasis conditions in vivo, prostaglandins may play a role in accelerating sickling of sickle prone erythrocytes via stimulation of calcium influx.