Stimulatory role of substance P on gonadotropin release in ovariectomized rats

Substance P (SP) has been shown to be present in the hypothalamus and anterior pituitary. To evaluate a possible physiological role of endogenous SP in the control of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release, specific antiserum against SP (anti-SP) was injected intraventricularly (3 microliters into the third ventricle) or intravenously (50 or 200 microliters) into conscious, ovariectomized (OVX) rats. Third ventricular injection of the antiserum induced a significant decrease in both plasma LH and FSH levels when compared to values in control animals injected with normal rabbit serum (p less than 0.01 and p less than 0.025, respectively). The effect was observed within 10 mi and levels remained suppressed for 60 min. In contrast, intravenous injection of large doses of anti-SP had no effect on the release of both hormones. In order to confirm the stimulatory effect of SP itself, synthetic SP was injected intravenously and intraventricularly into estrogen-primed (E-primed), OVX rats. Synthetic SP dramatically stimulated LH release, but not FSH release when injected either intravenously or intraventricularly at doses of 10 and 50 micrograms (p less than 0.001, p less than 0.005 vs. control, respectively). To investigate any direct action of SP on gonadotropin release from the anterior pituitary gland, synthetic SP was incubated with dispersed anterior pituitary cells harvested from E-primed OVX rats. SP did not affect the release of gonadotropins in vitro. These results indicate that endogenous hypothalamic SP exerts a tonic stimulatory hypothalamic control of basal gonadotropin release in OVX rats.

Osteosarcoma: MR imaging after preoperative chemotherapy

The authors reviewed 76 magnetic resonance (MR) images of 38 patients with osteosarcoma treated with preoperative chemotherapy (intraarterial cisplatin with or without systemic chemotherapy). Histologic maps of the surgical tumor specimens in 33 cases were correlated with either late-chemotherapy or postchemotherapy MR images. There were four MR patterns--dark, mottled or speckled, homogeneous, and cystic--that corresponded to different amounts of tumor matrix, granulation tissue, hemosiderin deposits, fluid-filled cysts, and residual viable tumor. Nested foci of residual viable tumor could not be specifically identified, although tumor progression or skip metastases were accurately depicted in four patients. Other findings included (a) peritumoral edema in the soft tissues and intramedullary space that shrank with chemotherapy, (b) chemotherapy effect in the surrounding soft tissues, (c) a dark rim around the extramedullary component of the tumors corresponding to a collagenous capsule continuous with the periosteum, (d) development of metaphyseal hemorrhages and bone marrow infarcts, and (e) intramedullary vascular channels.

Indirect inhibition of myocyte RNA and protein synthesis by interleukin-1

Soluble mediators of the inflammatory response may directly influence myocardial function and metabolism in the absence of myocardial cell necrosis. Previous reported experimental data have demonstrated that the monokine interleukin-1 (IL-1) can produce myocardial depression and may influence muscle protein metabolism. To further investigate this hypothesis, IL-1 was added to neonatal rat cardiac muscle cell (MC) cultures with and without additional rat cardiac non-muscle cells (NMC). Incorporation of 3H-uridine or 14C-phenylalanine into acid-insoluble material was utilized as a measure of RNA or protein synthesis. IL-1 in concentrations of up to 500 units/ml had no effect on MC RNA or protein synthesis. When NMC were added to the MC culture, IL-1 exhibited a concentration-dependent inhibition of both RNA and protein synthesis, with effects apparent at concentrations as low as 5 units/ml. Supernatants from IL-1-treated NMC cultures exerted a dose dependent reduction on the incorporation of radiolabeled precursor into MC cultures, suggesting production of a soluble substance mediating the IL-1 effect. Supernatants from IL-1 treated rat skin fibroblasts or rat skeletal muscle myoblasts increased MC radiolabeled precursor incorporation slightly, in contrast to the decrease seen with NMC supernatant. Furthermore, IL-1 treated NMC supernatant had no inhibitory effect on skeletal myoblasts. We conclude that IL-1 decreases protein and RNA synthesis in MC cultures through a second mediator elaborated from the NMC population.

Subtotal cystectomy and antirefluxing hepaticoduodenostomy for choledochus cyst in children

Total cystectomy with Roux-en-Y hepaticojejunostomy for choledochus cyst often causes malabsorption and other problems as a result of jejunal biliary diversion bypassing the duodenum. Restoration of near normal anatomy can only return the normal physiological harmony and assure normality. A simple antirefluxing hepaticoduodenostomy has proved successful.

Role of substance P in suppressing growth hormone release in the rat

To evaluate a possible physiological role of endogenous substance P (SP) in the control of growth hormone (GH; somatotropin) secretion, a specific antiserum against SP (anti-SP) was injected intraventricularly (3 microliters into the third cerebral ventricle) in unanesthetized unrestrained normal male rats. Control rats received an equivalent volume of normal rabbit serum (NRS). Intraventricular injection of the NRS lowered plasma GH concentrations significantly. The lowering was detected on first measurement at 10 min after injection and was maximal at 30 min. This was followed by a return toward the initial levels. Third ventricular injection of antiserum significantly increased plasma GH in comparison with control animals injected with NRS. The effect was observed within 10-20 min, and levels remained elevated for the 120-min duration of the experiment. To confirm the possible inhibitory role of endogenous SP on GH release, 3 microliters of 0.9% NaCl (saline) alone or saline containing a specific antagonist of SP, [D-Pro2,D-Trp7,9]SP, was injected into the third ventricle of normal male rats. The antagonist also increased plasma GH significantly (P less than 0.005) within 5 min compared with values in the saline-injected control group. Levels remained elevated for 30 min but had returned toward control values 60 min after injection. In contrast, synthetic SP significantly decreased plasma GH when injected intravenously or intraventricularly compared with plasma GH in the control saline-injected group. To investigate a possible direct action of SP on GH release from the anterior pituitary gland, we incubated synthetic SP with dispersed anterior pituitary cells for 1 hr. The release of GH from incubated anterior pituitary cells was not affected at any dose of SP (10(-9) to 10(-6) M) tested. These data strongly indicate that endogenous SP has a physiological inhibitory role in the control of GH secretion at the level of the hypothalamus in the male rat.

Traumatic epidural hematoma of the cervical spine: diagnosis with magnetic resonance imaging. Case report

A traumatic epidural hematoma of the cervical spine is reported in a 13-year-old girl. The patient recovered spontaneously over several days without surgical intervention. The diagnosis was made on magnetic resonance (MR) imaging, which also demonstrated subsequent resolution of the hematoma. The etiological factors of spinal epidural hematomas are reviewed and the utility of MR imaging in differentiating other causes of acute spinal cord injury is emphasized.

Clot embolic stroke in the vertebrobasilar system of rabbits: a transfemoral angiographic technique

Previous animal models of thromboembolic stroke have focused upon the carotid artery system. An alternative approach utilizing the vertebrobasilar system in rabbits is presented here. Left vertebral artery catheterization was accomplished relatively simply in this model using transfemoral angiographic techniques. Twenty-four-hour-old clot emboli with calculated volumes in the range of 0.007-0.11 cc were delivered by this route and found to lodge at the juncture of the basilar tip and the Circle of Willis in 11 of 13 rabbits. Intra-arterial infusion of streptokinase in one animal resulted in angiographically complete clearing of clot. Certain technical advantages in this particular approach are discussed.

Pelvic exenteration: role of CT in follow-up

Fifty-five computed tomography (CT) scans of the pelves and abdomens of 33 patients who had undergone pelvic exenteration were reviewed. There were 27 gynecologic and six colorectal malignancies. The interval between surgery and the first CT scan ranged from 2 weeks to 37 months (median, 8 months). CT findings included abnormal fluid collections (33.3%), abnormalities of the neovagina (30.3%) and presacral soft tissues (36.4%), increased hydronephrosis (54.5%), and lymphocysts (6.1%). Tumors recurred in 17 of 33 patients (51.5%) at a median interval of 9 months after surgery and had several CT manifestations. The most common of these was a soft-tissue mass of variable density and shape, but pelvic fluid collections as well as abnormalities of the neovagina and presacral soft-tissue layer were also associated with tumor recurrence. The surgical indications, methods, and potential post-operative complications of pelvic exenteration were reviewed and the role of CT in the follow-up of these patients was emphasized.