Biomedical subjects
Publications and source records attributed to R H Wu.
Plasma luteinizing hormone, follicle-stimulating hormone, and estradiol were measured at 20-minute intervals for 24-hours in seven pubertal premenarchal girls whose sleep was monitored polygraphically. A circadian variation in plasma estradiol was demonstrated with the highest values occurring during the day (1400-1600 hours) and lowest values during sleep, a time when gonadotropin secretion was augmented.
Growth Hormone (GH) secretion was studied in a 61-year-old woman with idiopathic orthostatic hypotension (IOH) or Shy-Drager Syndrome. The 24-hour pattern of GH secretion showed multiple daytime peaks and little nighttime activity. The largest daytime peak of 35.0 ng/ml is much greater than the levels observed in seven studies using five age-matched normal women. There were few secretory episodes during sleep in the patient and the control subjects. Paradoxical GH responses occurred during oral glucose tolerance tests, despite high blood glucose. GH was also detected in three studies using TRH. These data suggest that our patient with IOH has abnormal regulation of GH secretion. This is a sign of hypothalamic-pituitary dysfunction in a diffuse neurological disease.
A 22-year-old man with hypogonadism, Leydig cell hypoplasia, high plasma LH, and normal plasma FSH was given human chorionic gonadotropin (hCG) and human luteinizing hormone (hLH) in order to assess testicular testosterone responses to exogenously administered gonadotropins. The maximal testosterone level detected after six doses of hCG, 5000 IU per dose given intramuscularly (IM) was 256 ng/dl. After eight doses of hLH, 550-1100 IU per dose given IM, the plasma testosterone level was unchanged, 100-200 ng/dl. The lack of a response to exogenously administered gonadotropins in our patient suggests that there is a primary testicular lesion causing the hypogonadism. Our patient's own LH is probably biologically active since there was no response to human LH, a pituitary extract with a known biopotency (LER 1549). Our patient's endocrine abnormality is apparently another facet in the spectrum of findings described in patients with Leydig cell hypoplasia or aplasia. Other features of this entity can include female pseudohermaphroditism, ambiguous genitalia, hypogonadism, delayed puberty, and the presence of biologically inactive LH.
PURPOSE: Our goal was to evaluate the role of relative blood volume (rBV) measurements in monitoring the embolization effect in meningiomas by using maps of susceptibility-weighted first pass MR data. METHOD: Eighteen examinations of nine patients before and following partial embolization were performed on a 1.5 T scanner. Embolization was achieved by injection of particles (45-150 microns). During dynamic imaging a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. RESULTS: The tumor rBV/gray matter rBV ratio was 3.11 +/- 1.40 for untreated tumors and 0.12 +/- 0.09 for successfully embolized tumors. The regional rBV in embolized meningiomas was significantly lower than that in untreated meningiomas (t test, p < 0.001). Vital tumor tissue showed positive enhancement in T1 and high rBV; nonvital tissue lacked T1 enhancement and bolus effect in the first pass, thus leading to low or missing rBV values. However, we also observed lack of bolus formation despite T1 enhancement (6/9 postembolization regions), possibly due to slow collateral flow. One of the patients treated with embolization bled during surgery. CONCLUSION: Maps of relative regional cerebral BV provide hemodynamic information in meningiomas and monitor the treatment effect of embolization in meningiomas more precisely than T1-weighted contrast-enhanced imaging.