Evaluation of the integrity of the blood-brain barrier after meningeal trauma.

RATIONALE AND OBJECTIVES. The authors used magnetic resonance imaging (MRI) techniques to examine the effect of meningeal trauma produced by cisterna magna puncture on the integrity of the blood-cerebrospinal fluid barrier (BCB) in a rat model. METHODS. Intravenous gadolinium-DTPA (Gd-DTPA), a relaxation rate modifier which normally does not cross the BCB, was used as a probe to follow leakage of fluid across the BCB. After Gd-DTPA injection, cerebrospinal fluid (CSF) serial samples were obtained through the needle used to create the experimental trauma. These samples were subsequently examined in vitro by MRI to obtain their T1 relaxation rates and assayed by mass spectrometry for gadolinium and elemental iron concentrations. RESULTS. The iron levels reflected the severity of puncture-related subarachnoid hemorrhage. Rats with ongoing meningeal damage showed significantly higher CSF levels of gadolinium and significantly higher CSF T1 relaxation rates than controls at all samples times over 1 hour after the puncture. Blood in the CSF could not explain these changes because the CSF iron levels did not significantly differ from control levels. CONCLUSIONS. Intravenously administered Gd-DTPA can gain access to the subarachnoid space through minor defects in the BCB and cause significant increases in CSF T1 relaxation rates.     

Positive feedback effect of oestradiol in superovulated women.

To investigate the mechanism of blockage of the luteinizing hormone (LH) surge in superovulated women, six normally ovulating women were studied in three cycles: a spontaneous cycle treated with exogenous oestrogen (oestradiol benzoate cycle), a cycle treated with follicle stimulating hormone (FSH; 225 IU/day; FSH cycle) and a cycle treated with FSH plus exogenous oestrogen (FSH + oestradiol benzoate cycle). Oestradiol benzoate was injected i.m. on cycle days 4 (0800 and 2000 h), 5 (0800 h) and 6 (0800 h) at doses of 0.5, 1.0, 2.0 and 2.5 mg respectively to achieve supraphysiological levels of serum oestradiol. Exogenous oestrogen (supraphysiological oestradiol levels) induced an LH surge in all six women in the oestradiol benzoate cycles, but failed to stimulate an LH surge in three of the six patients during treatment with FSH. In three patients treated with FSH, an LH surge was stimulated both by supraphysiological (FSH + oestradiol benzoate cycles) and 'high normal' oestradiol levels (FSH cycles), while in three patients treated with FSH only, the LH surge was blocked, although the threshold level for the positive feedback effect had been exceeded by cycle day 9. We conclude that in women, supraphysiological concentrations of oestradiol exert a positive feedback effect on LH secretion. It is suggested that the occurrence of an LH surge in cycles superovulated with FSH is not dependent on serum oestradiol concentrations, but mainly on the strength of ovarian inhibitory substances.     

Pneumopericardium secondary to esophageal carcinoma.

The authors describe a case of squamous cell carcinoma of the esophagus that was initially diagnosed as hydropneumopericardium at radiography. The patient subsequently underwent computed tomography (CT) and esophagography. CT revealed pneumopericardium, pericardial thickening, a mass in the esophagus, and bilateral effusion. Esophagography demonstrated perforation of the mid-thoracic esophagus and marked irregularity of the esophageal mucosa. To the authors' knowledge, this is the only reported instance of esophageal carcinoma initially diagnosed as hydropneumopericardium. CT can be used as a primary method to investigate spontaneous pneumopericardium.     

Progesterone derivatives that bind to the digitalis receptor: synthesis of 14 beta-hydroxyprogesterone. A novel steroid with positive inotropic activity

The synthesis of 14-hydroxy-14 beta-pregn-4-ene-3,20-dione (14 beta-hydroxyprogesterone) is described. This novel steroid is about 10 times more potent than progesterone and one-tenth as potent as ouabagenin in an [3H]ouabain radioligand binding assay and is the first in a series of progesterone congeners that interact at the cardiac glycoside receptor both to possess the C/D cis ring junction and to enhance contractility of isolated cardiac tissue.     

The pelvic ileal reservoir

In an experimental study the function of the 3-loop (Parks) pelvic ileal reservoir was compared with that of the 2-loop (Utsunomiya) reservoir. Both types achieved satisfactory degrees of continence and evacuation when tested in the defunctioned state. Following restoration of intestinal continuity, the stools of dogs with 3-loop pouches were usually liquid (69 percent) compared to the more formed stools (72 percent) in the 2-loop group,P<0.001. At postmortem the reservoirs of the 3-loop group were found to have undergone much greater dilatation (P<0.05). These findings suggest that construction of the 3-loop (Parks) pelvic reservoir may lead to retention with overflow if catheterization is not used. It is not clear whether the superior function of the 2-loop pouch is attributable to better motor function or the absence of an efferent limb which allows it to be placed deep in the pelvis. Mr. J. L. Templeton was in receipt of a Research Grant from the Eastern Health & Social Services Board, Northern Ireland.