Evaluation of velopharyngeal function using high-speed cine-magnetic resonance imaging based on T2-weighted sequences: a preliminary study.

The objective was to introduce a new technique for visualizing the three-dimensional (3D) movements of velopharyngeal-related muscles using high-speed cine-magnetic resonance imaging (MRI) based on T2-weighted sequences. The evaluation of phonation- and water swallowing-related events was performed in 11 healthy subjects. Specifically, whether cine-MRI could precisely visualize normal velopharyngeal function during these two events was examined. The 3D movements of the soft palate, superior pharyngeal constrictor muscles, and levator veli palatini muscles were visualized in all 11 subjects. A noteworthy finding was that the magnetic resonance signals of the superior constrictor pharyngeal muscles and the levator veli palatini muscles were significantly higher during phonation and during water swallowing than at rest. This initial study suggests that the 3D movements of velopharyngeal-related muscles can be successfully and precisely visualized without side effects. The magnetic resonance signal changes seen in the superior pharyngeal constrictor and levator veli palatini muscles using the technique described here should be useful to develop better methods of evaluation of velopharyngeal function.

Predicting the therapeutic effect of carbamazepine in trigeminal neuralgia by analysis of neurovascular compression utilizing magnetic resonance cisternography.

The aim of this study was to determine whether the evaluation of neurovascular compression (NVC) using new criteria on magnetic resonance (MR) cisternography improves the prediction of the curative effects of carbamazepine (CBZ) in trigeminal neuralgia (TN). In this study, a new analysis of NVC using MR cisternography was performed retrospectively for 280 patients with clinical signs and symptoms suggesting TN. The new analysis examined whether the site of the NVC was less than 3mm from the edge of the exit point and within the first third of the root entry zone on MR cisternography. Prediction of the curative effects of CBZ using the new evaluation of distance to the NVC improved on the predictive ability of the previous method of calculating the NVC volume (Mantel-Haenszel coefficient, P<0.01). In particular, initial treatment with CBZ 100mg/day for 2 weeks appeared more effective for patients with NVC volumes of ≤5mm3 plus a distance to the NVC of ≤3mm, than for those with NVC volumes >5mm3. The evaluation of NVC on MR cisternography using this new approach appears to be more useful than the previous method for predicting the initial treatment response in patients with TN.

Endothelin receptor-mediated responses in trigeminal ganglion neurons.

Recent evidence implicates endothelin in nociception, but it is unclear how endothelin activates trigeminal ganglion (TRG) neurons. In the present study, we investigated the expression of the endothelin receptors ETA and ETB and endothelin-induced responses in rat TRG neurons. Double-immunofluorescence studies demonstrated that ETA and ETB were expressed in TRG neurons and that 26% of ETA- or ETB-expressing neurons expressed both receptors. During whole-cell patch-clamp recording, endothelin-1 enhanced an induced current in response to capsaicin, a TRPV1 agonist, in approximately 20% of dissociated neurons. The enhancement was blocked by the PKC inhibitor chelerythrine and by the ETA antagonist BQ-123, but not by the ETB antagonist BQ-788. Ca(2+)-imaging showed that endothelin-1 increased the intracellular Ca(2+) concentration in more than 20% of the dissociated neurons. Importantly, unlike the effect of endothelin-1 on capsaicin-induced current, the Ca(2+) response was largely suppressed by BQ-788 but not by BQ-123. These results suggest that ETA-mediated TRPV1 hyperactivation via PKC activation and ETB-mediated Ca(2+) mobilization occurs in different subsets of TRG neurons. These endothelin-induced responses may contribute to the induction of orofacial pain. The ETB-mediated function in TRG neurons is a special feature in the trigeminal system because of no ETB expression in dorsal root ganglion neurons.

Central glial activation mediates cancer-induced pain in a rat facial cancer model.

Peripheral and central glial activation plays an important role in development of pain hypersensitivity induced by inflammation and nerve injury. However, the involvement of glial cells in cancer pain is not well understood. The present study evaluated the peripheral and central glial activation and the effect of an inhibitor of glial activation, propentofylline, on pain-related behaviors in a rat facial cancer model of the growth of Walker 256B cells in the unilateral vibrissal pad until days 3-4 post-inoculation. As compared with sham animals, the facial grooming period was prolonged, the withdrawal latency to radiant heat stimulation was shortened, and the withdrawal threshold by von Frey hair stimulation was decreased at the inoculated region, indicating the development of spontaneous pain, thermal hyperalgesia and mechanical allodynia. In immunostainings for Iba1 and glial fibrillary acidic protein (GFAP), although there were no morphological changes of GFAP-immunopositive satellite glial cells in the trigeminal ganglion, Iba1-immunopositive microglia and GFAP-immunopositive astrocytes in the medullary dorsal horn showed large somata with cell proliferation. After the daily i.p. administration of propentofylline beginning pre-inoculation, the central glial activation was attenuated, the prolonged facial grooming was partially suppressed, and the induced allodynia and hyperalgesia from day 2 were prevented, without a change in tumor size. These results suggest that glial activation in the CNS, but not in the peripheral nervous system, mediates the enhancement of spontaneous pain and the development of allodynia and hyperalgesia at an early stage in the facial cancer model.

Translocation of Salmonella typhimurium in rats; effect of enteral and parenteral nutrition.

OBJECTIVE: To study translocation of Salmonella typhimurium from ileal loops in rats fed enterally or parenterally. DESIGN: Laboratory experiment. SETTING: University departments of surgery and microbiology, Japan. SUBJECTS: Male Wistar rats and female BALB/C CrSlc mice. INTERVENTIONS: First experiment: portal venous blood and mesenteric lymph nodes from normally fed rats were cultured under aerobic and anaerobic conditions. Second experiment: various concentrations of S. typhimurium (GIFU 12142) were injected intraperitoneally in mice and their survival was monitored. Third experiment: 7 rats were given total parenteral nutrition for 14 days and 6 were given standard chow and water for the same period. Cultures of S. typhimurium were injected into closed ileal loops and portal and vena caval blood and mesenteric lymph nodes were cultured. MAIN OUTCOME MEASURES: Presence and number of bacteria in all samples, and survival of mice. RESULTS: In the first experiment 3/17 blood samples and 9/17 node samples grew enteric bacteria. In the second experiment all the mice died within 5 days. In the third experiment no sample grew bacteria in the enterally fed group, whereas at least some samples from 5/7 rats in the parenterally fed group grew organisms; the difference was significant (p = 0.02). CONCLUSION: Total parenteral nutrition encourages the translocation of S. typhimurium from ileal loops.

Primary intracardiac tumors in magnetic resonance imaging.

Fifteen patients suspected of having 18 intracardiac masses by two-dimensional echocardiography underwent MR imaging. In MR imaging, intracardiac masses were evaluated on both short TE (TE = 20-35 msec) and long TE (TE = 50-80 msec) spin echo sequences, and were differentiated from myocardium or papillary muscle. Three masses were excluded (they were papillary muscle) by MR imaging, and three were additionally found in patients with tuberous sclerosis. Fifteen masses were found by both echocardiography and MR imaging, one of which was stagnant blood. Cine MR imaging was needed to differentiate between thrombus and stagnant blood. MR imaging is useful for the evaluation of intracardiac masses. It is recommended in addition to echocardiography when cardiac tumors are suspected, especially in patients with tuberous sclerosis.

Pertussis toxin blocks an inhibition of hormone-stimulated glycogenolysis by prostaglandin E2 and its analogue in cultured hepatocytes.

Prostaglandin E2 (PGE2) and 16,16-dimethyl PGE2 were found to inhibit a hepatic glycogenolysis stimulated by epinephrine in the presence of propranolol (alpha 1-adrenergic response), isoproterenol (beta-adrenergic response) and glucagon in primary cultures of rat hepatocytes. The inhibitory effects to these stimulations were maximally increased (60-100%) in the cultures on day 2 or 3. Pretreatment of the cultured hepatocytes with pertussis toxin (islet-activating protein) resulted in a complete blockage of the prostaglandin-induced inhibition of glycogenolysis in a dose-dependent manner. Pertussis toxin had no significant effect on the glycogenolysis stimulated by these compounds in the absence of prostaglandin. The data suggest that the hepatic glycogenolysis stimulated by alpha 1- and beta-adrenergic responses and glucagon are modulated by the E series of prostaglandins via pertussis toxin-sensitive guanine nucleotide regulatory protein.

Effect of prostaglandins and their analogues on hormone-stimulated glycogenolysis in primary cultures of rat hepatocytes.

Hepatocytes were isolated by collagenase perfusion method from adult male rats, cultured and then prelabeled with [14C]glucose. The [14C]glycogen-labeled cells were used in experiments for effect of prostaglandins on hormone-stimulated glycogenolysis. Prostaglandin E1, prostaglandin E2 and 16,16-dimethylprostaglandin E2, but not prostaglandin D2 or prostaglandin F2 alpha, inhibited glycogenolysis stimulated by glucagon, epinephrine, isoproterenol (beta-adrenergic agonist) or epinephrine in the presence of propranolol (beta-antagonist) in primary cultured hepatocytes. The inhibitory effects on day 2 of cultures were approx. twice those on day 1. Dimethylprostaglandin E2 (10(-6)M) caused 60-70% inhibitions of the stimulations by these substances. In the case of the stimulation by glucagon, the inhibition further increased by 80-100% on day 3 of culture. Prostaglandin E1 and prostaglandin E2 caused less inhibition than dimethylprostaglandin E2 of all these stimulations. Dinorprostaglandin E1 (9 alpha,13-dihydroxy-7-ketodinorprost-11-enoic acid), which is a hepatocyte-metabolite of prostaglandin E1 and prostaglandin E2, and arachidonic acid did not have any inhibitory effects. These data indicate that the E series of prostaglandins may function as the regulation of hepatic glycogenolysis stimulated by epinephrine and glucagon, and that their rapid degradation system may contribute to the modulation of the action in liver.

Ovarian cystic teratomas: MR imaging.

Magnetic resonance (MR) imaging characteristics of ovarian cystic teratomas were evaluated in 18 patients with 23 surgically proved tumors. The fat within the tumor demonstrated characteristic intensity similar to that of subcutaneous fat and a pathognomic pattern of chemical shift artifact that helped differentiate ovarian cystic teratomas from endometrial cysts. In addition to fat, MR images of ovarian cystic teratomas had several other characteristics that allowed confident diagnosis, including gravity-dependent layering or floating debris, palm tree-like protrusions or rounded nodules (dermoid plugs), and, occasionally fat-fluid levels and globular calcification. MR images were diagnostic in 20 tumors and were able to depict a tumor measuring 2 cm in diameter. MR imaging appears to be valuable in problematic cases in which other modalities are not diagnostic.

Posterior lobe of the pituitary in diabetes insipidus: MR findings.

The posterior lobe of the pituitary gland was evaluated by 1.5 T magnetic resonance (MR) in five cases of diabetes insipidus (DI), including one primary (idiopathic) and four secondary DI cases due to germinomas (two), teratoma (one), and histiocytosis X (one). The normal posterior lobe displays high signal indistinguishable from fatty tissue on T1-weighted images (T1WI) (short T1 value). In all five DI cases the normal high signal of the posterior lobe was not detected in the pituitary fossa on T1WI. Hence, because of this characteristic finding, MR may greatly assist in the diagnosis of DI. We may speculate that the short T1 value of the posterior lobe is closely related to its functional integrity and may be due to the neurosecretory materials in the axons of the hypothalamohypophyseal tract.

Prostaglandin E1 binding protein on the surface of primary cultured hepatocytes.

Prostaglandin E1 (PGE1) was bound to primary cultured rat hepatocytes in a receptor-dependent manner in serum-free medium at 4 degrees C. When added at a concentration of 2 X 10(-9) M, maximal specific binding occurred within 60-90 min. Trypsin treatment of the cells reduced the binding capacity to about 50% of that of untreated cells. Scatchard-analysis of the binding data showed that the cells had an apparent dissociation constant of 1.2 X 10(-8) M and a binding capacity of 580 fmol (approximately 3.5 X 10(11) PGE1 receptors)/mg of protein. In experiments at 37 degrees C, maximal specific binding occurred within 5 min and was 6-7 times that at 4 degrees C, but the amount of bound PGE1 decreased rapidly after 5 min due to metabolism of PGE1 in the hepatocytes. Thin-layer chromatographic analysis showed that the material bound to the cell surface consisted of intact PGE1 and its metabolites at 37 degrees C, but PGE1 only at 4 degrees C.

Metabolism of prostaglandins D2 and F2 alpha in primary cultures of rat hepatocytes.

3H-Labeled prostaglandins D2 and F2 alpha rapidly degraded to more-polar metabolites in primary cultured rat hepatocytes. The metabolites of prostaglandins D2 and F2 alpha accumulated in the culture medium. The metabolites extracted by ethyl acetate at pH 3 were purified by silicic acid column and thin-layer chromatography of silica gel, and were analysed by gas chromatography-mass spectrometry. The major metabolites from prostaglandin D2 were identified as dinor-prostaglandin D1 (7 alpha,13-dihydroxy-9-ketodinorprost-11-enoic acid) and tetranor-prostaglandin D1 (5 alpha,11- dihydroxy-7-ketotetranorprost-9-enoic acid). Those from prostaglandin F2 alpha were identified as dinor-prostaglandin F1 alpha (7 alpha,9 alpha,13-trihydroxydinorprost-11-enoic acid), tetranor-prostaglandin F1 alpha (5 alpha,7 alpha,11-trihydroxytetranorprost-9-enoic acid) and 9 alpha,11 alpha,15-trihydroxyprost-13-ene-1,20-dioic acid. These data indicate that prostaglandins D2 and F2 alpha mainly degraded by beta-oxidation, which is the same process as reported earlier for prostaglandins E1 and E2, and that prostaglandin F2 alpha was also subjected to omega-oxidation.

[Computerized control system for administration of the radioisotope use].

An on-line computer system for administration of the radioisotope use has been developed. This system consists of a multi-job type host computer and two sets of personal computers with identification card-readers. The personal computers are employed as terminal devices for radioisotope users. By the use of an identification card, entrance and leaving times are recorded automatically. Furthermore, an easy operation of the personal computer permits users to access to the information of their registered radioisotopes, such as nuclides, chemical forms, updated activities, storage locations, and history of usage. A recording sheet on which those data are printed is provided from the personal computer. After the use of radioisotopes, users can record their data on the recording sheets. These records are used as the input data to this system to update the data of the used radioisotopes. Owing to the concise format of the recording sheet and various sorting programs developed in present work, this system enables us to grasp the exact flow of the radioisotopes from purchase to disposal. Out-put data from high-speed kanji printer can provide many important books which are legally requested to be kept for administration of the radioisotope use.

Identification of prostaglandin E metabolites from primary cultures of rat hepatocytes.

Primary cultured rat hepatocytes were shown to bind to prostaglandins E1, E2, D2 and F2 alpha and then rapidly degrade at 37 degrees C. 6-Ketoprostaglandin F1 alpha and thromboxane B2, which are inactive metabolites of prostaglandin I2 and thromboxane A2, respectively, bound less effectively to the cells and were not degraded. Incubation of hepatocytes with 3H-labeled prostaglandins, treatment of the cells at an acidic pH, and analysis of the acid solution by thin-layer chromatography, showed that the radioactive material was bound to the cell surface and consisted of intact prostaglandin and its metabolites. The metabolites of prostaglandin E that accumulated in the culture medium were purified by silicic acid column and silica gel thin-layer chromatographies, and analyzed by gas chromatography-mass spectrometry. Prostaglandins E1 and E2 gave exactly the same metabolites, which were identified as dinorprostaglandin E1 and tetranorprostaglandin E1, representing products of beta-oxidation. These data suggest that part of the carboxyl side chain of prostaglandins, but not of inactive metabolites, was eliminated by a beta-oxidation system in the hepatocytes, while the rest of the molecule was not degraded appreciably and was rapidly transferred to the outside of the cells.