Simultaneous activation of N-methyl-D-aspartate and neurokinin-1 receptors modulates c-Fos and Zif/268 expression in the rat trigeminal nucleus caudalis.

We examined the acute expression of c-Fos or Zif/268 by simultaneous activation of N-methyl-D-aspartate receptor and neurokinin-1 receptor of the trigeminal nucleus caudalis in anesthetized rats. A selective N-methyl-D-aspartate receptor agonist, N-methyl-D-aspartate, and/or a selective neurokinin-1 receptor agonist, substance P, was applied topically to the dorsal surface of the spinal trigeminal tract. Immunohistochemically stained nuclei for c-Fos and Zif/268 at laminae I and II of the trigeminal nucleus caudalis were counted. Ipsilateral c-Fos and Zif/268 were increased significantly dose-dependently by N-methyl-D-aspartate (at 136 and 340 microM, and at 68, 136 and 340 microM, respectively). On the contralateral side, only Zif/268 increased significantly (at 68, 136 or 340 microM). These increases were abolished by D-2-amino-5-phosphonovaleric acid (at 25 mM), a selective N-methyl-D-aspartate receptor antagonist. Substance P (at 3.7 or 7. 4 microM) significantly increased dose-dependently ipsilateral c-Fos and Zif/268. On the contralateral side, only c-Fos was significantly increased (at 3.7 and 7.4 microM). These increases were abolished by D-2-amino-5-phosphonovaleric acid (at 25 mM) and L-703,606 (at 10 microM), a selective neurokinin-1 receptor antagonist. The combined application of N-methyl-D-aspartate 340 microM + substance P (at 0.74 or 3.7 microM) significantly increased ipsilateral c-Fos compared to either agent alone. Combined application of N-methyl-D-aspartate 340 microM + substance P at 0.74, 3.7 or 7.4 microM significantly increased ipsilateral Zif/268 expression compared to either drug alone. Other combinations did not increase c-Fos and Zif/268. Our results indicate that activation of N-methyl-D-aspartate or neurokinin-1 receptor of the trigeminal nucleus caudalis contributes to the acute induction of both c-Fos and Zif/268 on the ipsilateral superficial layer of this nucleus and simultaneous activation of both receptors by their agonists with specific concentrations produces a marked expression of these proteins. Simultaneous activation of N-methyl-D-aspartate and neurokinin-1 receptors under some specific conditions may augment synaptic transmission, contributing to long-term neuronal change.

Effects of previous noxious stimulus applied to remote areas on noxious stimulus-evoked c-Fos expression in the rat trigeminal nucleus caudalis.

Noxious stimulus-evoked c-Fos expression in the spinal dorsal horn is modulated by noxious stimuli applied previously to remote areas of the body. To confirm the existence of such modulation in c-Fos expression in the trigeminal system, changes in c-Fos expression in the trigeminal nucleus caudalis induced by formalin injection into the rat whisker pad were examined by previously injecting formalin into different areas (contralateral whisker pad, ipsilateral or contralateral forepaw) of the body. Formalin injection-evoked c-Fos expression in this nucleus was significantly reduced by previous formalin injection into the contralateral whisker pad or ipsilateral forepaw but not into the contralateral forepaw. The interval between the two injections of formalin that produced a maximal reduction of formalin injection-evoked c-Fos expression was 1 h, and the reduction of c-Fos expression was less when the interval of the two noxious stimuli was longer or shorter than 1 h. These results suggested that noxious stimulus-evoked c-Fos expression in the trigeminal nucleus caudalis is reduced by noxious stimulus applied previously to remote areas, and the reduction is dependent on the area of previous noxious stimulation and interval between the two noxious stimuli.

[MR imaging of bone and soft tissue tumors].

One hundred sixty-one patients with tumors of bone or soft tissues underwent MRI. We believe to be able to differentiate benign from malignant lesions on the basis of imagings at internal, marginal, and peripheral properties. MR imagings demonstrated specific morphologic features that suggest the correct tissue diagnosis. MR imagings with STIR method or Gd-DTPA were more valuable. Because of the high contrast between the tumors and normal tissue, especially by STIR method, MRI provides improved detection and delineation of bone soft tissue tumors when compared to other diagnostic modalities.

[Computed tomography of obturator foramen hernia].

A 89 year-old female was admitted with the complaint of right hypochondralgia. And also she complained of right thigh pain after admission. On hospital day 4, she underwent CT examination in order to evaluate right thigh with severe pain. The preoperative diagnosis of obturator foramen hernia was performed.

[Bronchial atresia of additive anomalous bronchus].

A case of bronchial atresia of additive anomalous bronchus in right middle lobe was reported. A mass and emphysematous lung were found on the chest roentgenogram. CT, and MRI, and it is not difficult to diagnose.

[Hilar and mediastinal lymph node metastases from lung cancer; detection with CT and MR imaging].

Sixty-one patients with primary lung cancer, who had CT and MR imaging before surgery, were studied. MR imaging used spin-echo sequences with T1 weighted image and T2 weighted image (C-MRI), and included STIR technique (Stir-MRI). The accuracy of diagnosis of mediastinal lymphadenopathy (regarding 10 mm or larger in short transverse diameter as positive) was 89% by CT, 84% by C-MRI and 89% by Stir-MRI. The accuracy of diagnosis of hilar lymphadenopathy was 42% by CT, 67% by C-MRI, and 75% by Stir-MRI. The accuracy of diagnosis of mediastinal lymph node metastases was 89% by CT, 94% by C-MRI and 96% by Stir-MRI. The accuracy of diagnosis of hilar lymph node metastases was 78% by CT, 87% by C-MRI and 89% by Stir-MRI. The possibility of enhancement of diagnostic accuracy of lymph node metastases from lung cancer was suggested by combining MR imaging included STIR technique with CT.