A case of carcinosarcoma arising in the submandibular gland.

A 54-year-old man presented with an 8-year history of a hard asymptomatic mass of the left submandibular area. Total excision of the left submandibular gland with radical neck dissection was performed under a diagnosis of a submandibular tumor, probably a malignant mixed tumor. The pathologic diagnosis was carcinosarcoma consisting of carcinomatous and sarcomatous elements. The epithelial component was composed of squamous cell carcinoma, undifferentiated carcinoma, and adenocarcinoma. The nonepithelial component was composed of chondrosarcoma, osteosarcoma, spindle cell sarcoma, rhabdomyosarcoma, and liposarcoma. In the central area of the tumor, a few remnants of benign pleomorphic adenoma were identifiable. The finding suggested that in our patient, the carcinosarcoma arose from a preexisting pleomorphic adenoma. In view of the expected aggressive nature of the tumor, the patient was treated with postoperative radiotherapy of 60 Gy total, in 30 daily fractions of 2 Gy, and chemotherapy. He currently remains well and free of disease 24 months after treatment.     

Hypertrophy of medial globus pallidus and substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA: Implication for L‐DOPA‐induced dyskinesia in Parkinson's disease

The medial globus pallidus plays a crucial role in generation of L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. The 6‐hydroxydopamine‐lesioned rat exhibiting behavioral sensitization to L‐DOPA is one useful animal model for examining L‐DOPA‐induced dyskinesia. To determine neuropathological abnormality responsible for behavioral sensitization, the medial globus pallidus and the substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA were examined. Intermittent L‐DOPA treatment induced hypertrophy of the lesioned‐side of medial globus pallidus and substantia nigra reticulata of 6‐hydroxydopamine‐lesioned rats with behavioral sensitization to L‐DOPA. Additionally, coadministration of a 5‐HT_1A receptor agonist, 8‐hydroxy‐2(di‐n‐propylamino)tetralin with L‐DOPA, alleviated the hypertrophy with improvement of the behavioral sensitization. These results suggest that hypertrophy of the medial globus pallidus and substantia nigra reticulata is associated with induction of behavioral sensitization to L‐DOPA in 6‐hydroxydopamine‐lesioned rats. Therefore, neuropathological changes corresponding to hypertrophy might underlie L‐DOPA‐induced dyskinesia in patients with Parkinson's disease.     

A ruptured thoracic aortic aneurysm with 4 cm diameter]

The size of a thoracic aortic aneurysm (TAA) is an important factor of the operative indication. We experienced a ruptured TAA the diameter of which was only 4 cm. A 71 years old man was admitted due to the severe back pain under the shocked condition. We diagnosed him a ruptured TAA by CT scan. Because he had no progressive anemia and the hemodynamics was very stable, we followed him conservatively. Two months later, the operation was performed. We resected the aneurysm and inserted an aortic prosthetic graft. From the operative findings, the aneurysm was certified as a true aneurysm, and the maximal diameter was only 4 cm. First choice for the treatment of ruptured TAA is the emergent operation. But when the hemodynamics is extremely stable and the anemia does not progress at all, a conservative therapy can be selected. Even if the aneurysm is very small, the control of hypertension is quite important.     

A rare case of metastatic renal cell carcinoma resembling a nerve sheath tumor of the cauda equina.

We present a rare case of solitary metastasis to the cauda equina from the kidney. The patient was a 68-year-old man with a two-year history of low back pain. His past medical history revealed a renal cell carcinoma diagnosed seven years earlier. His lumbosacral MR imaging showed a well-demarcated, intradural extramedullary mass at the L3 level. He underwent an L2-4 laminectomy. The operative findings of the tumor quite resembled that of a nerve sheath tumor. It did not infiltrate into the subarachnoid space and involved only one spinal nerve. Pathology of the tumor was a metastasis of the renal cell carcinoma. Only 10 cases with such a metastasis to the cauda equina have been reported in the English literature. We added the 11th and reviewed the literature with reference to tumor pathologies, clinical findings and route of metastasis to the cauda equina.     

A PKC epsilon-ENH-channel complex specifically modulates N-type Ca2+ channels

Multiple protein kinase C (PKC) isozymes are present in neurons, where they regulate a variety of cellular functions. Due to the lack of specific PKC isozyme inhibitors, it remains unknown how PKC acts on its selective target(s) and achieves its specific actions. Here we show that a PKC binding protein, enigma homolog (ENH), interacts specifically with both PKCepsilon and N-type Ca2+ channels, forming a PKCepsilon-ENH-Ca2+ channel macromolecular complex. Coexpression of ENH facilitated modulation of N-type Ca2+ channel activity by PKC. Disruption of the complex reduced the potentiation of the channel activity by PKC in neurons. Thus, ENH, by interacting specifically with both PKCepsilon and the N-type Ca2+ channel, targets a specific PKC to its substrate to form a functional signaling complex, which is the molecular mechanism for the specificity and efficiency of PKC signaling.     

An ambulatory respirometer (Hotmate) as a tool for screening of sleep apnea syndrome

The gold standard diagnostic method for sleep apnea syndrome(SAS) is overnight polysomnography(PSG), but is costly in terms of time and money. We studied the usefulness of a 24-hour ambulatory respirometer equipped with oximeter(Hotmate) for screening of SAS. Seventy-six cases of suspected SAS were enrolled(68 males and 8 females, mean age 51). The correlation between data from Hotmate and PSG was evaluated in 24 cases who underwent both of the tests for the final diagnosis of SAS. There was a good correlation between the two parameters of the data obtained by Hotmate(H) (H-apnea index(AI) vs H-desaturation index(DI)). Among 24 cases who underwent both Hotmate and PSG, there was a good correlation between the data from PSG and Hotmate(PSG-AI vs H-AI: r = 0.80, p < 0.001). Both sensitivity and specificity were highest when screening criteria of H-DI > 15 was utilized(sensitivity = 91.7%, specificity = 66.7%). Our findings suggest that the respiromonitor with oximeter is useful for the screening the patients with SAS.     

Different expression of T-cell receptor beta-chain variable region genes in lymph nodes of lpr mice with different alleles of the major histocompatibility complex.

In order to search for a possible role of abnormally proliferating T cells in developing autoimmune disease in lpr mice, and to define the difference of the T cells among various lpr-congeneic mice with different clinicopathological findings, the T-cell receptor (TcR) V beta gene expression in the enlarged lymph nodes (LN) of C3H/HeJ-lpr/lpr (C3H-lpr), C57BL/6-lpr/lpr (B6-lpr) and MRL/Mp-lpr/lpr (MRL-lpr) mice was analysed. A RNA blot analysis using several V beta-specific probes showed that the V beta 3 gene, whose products are important for recognizing Mlsb/a, was used in B6-lpr and MRL-lpr with the Mlsb/b but not in C3H-lpr with the Mlsb/a. The V beta 5 gene, which is selectively related to I-E molecules, was predominantly used in B6-lpr(I-E-) but not in C3H-lpr(I-E+) nor MRL-lpr(I-E+). Similarly, the V12 gene was also expressed in B6-lpr but not in C3H-lpr. To compare in detail in V beta repertoire among lpr mice with different major histocompatibility complex (MHC) backgrounds, the V beta gene sequences in the cDNA libraries from LN cells of C3H-lpr were analysed, following the recent investigation of B6-lpr mice (Ohga et al., 1989). Eleven beta-chain cDNA out of 32 beta cDNA in B6-lpr and 24 beta-chain cDNA out of 55 beta cDNA in C3H-lpr were found to contain sequences with open reading frames that potentially encode functional TcR beta-chain. The frequencies of the messages in the cDNA libraries from these mice were consistent with the RNA blot analysis using V beta 3- and V beta 5-specific probes. It was notable that 36% of the functional beta-chain mRNA in B6-lpr and 50% of the beta mRNA in C3H-lpr expressed the V beta 8 gene family. When the TcR V beta gene expression was compared between the LN cells in C3H-lpr, B6-lpr and MRL-lpr, as reported by Singer et al. (1986), the usage of V beta genes other than the V beta 8 gene family in B6-lpr (H-2b) LN cells differed significantly from those in C3H-lpr (H-2k) and MRL-lpr (H-2k). The results presented here indicate that the usage of V beta genes is heavily influenced by the genetic background of lpr mice, similar to normal mice, but with preferential usage of the V beta 8 gene family as a common structural feature in lpr gene-induced cell populations.