Shin-ichi Kita

Differentiation between benign and metastatic cervical lymph nodes with ultrasound

OBJECTIVE The differentiation between benign and metastatic lymph nodes with ultrasound (US) is based primarily on the evaluation of size, shape, margin and internal echo structure. The aim of this study is to determine whether these parameters are reliable indicators and to correlate internal echo structure and histopathological findings. MATERIALS AND METHODS Seventy-one nodes in 21 patients with pathologically proven oral squamous cell carcinoma were examined. The shortest diameter, the short/long diameter ratio (S/L ratio), margins and internal echo structure of the lymph node were evaluated by US. The internal echo structure was divided into six patterns: homogeneous hypoechoic, homogeneous hyperechoic, heterogeneous, eccentric hyperechoic, centric hyperechoic and anechoic pattern. In addition, internal echo structure was correlated with histopathological findings. RESULTS In 71.4% of the metastatic nodes, the shortest diameter was more than 10 mm and the S/L ratio was higher than that of benign nodes (average 0.71). Eleven (84.6%) of the 13 lymph nodes with irregular margins were metastatic. Heterogeneous and anechoic patterns were observed in metastatic nodes, whereas homogeneous hypoechoic and eccentric hyperechoic patterns were present in benign nodes. On ultrasonography with the corresponding histopathological findings, echogenic areas in the homogeneous hyperechoic, heterogeneous and centric hyperechoic patterns of metastatic nodes proved to be necrosis or fibrosis. Eccentric hyperechoic areas in benign nodes corresponded to the hilus and surrounding fatty tissue. CONCLUSIONS The shortest diameter, S/L ratio, margin and internal echo structure were considered to be critical indicators to differentiate between benign and metastatic nodes. Secondary changes caused by tumour infiltration, necrosis, or fibrosis should be assessed when metastatic lymph nodes are differentiated from benign ones by internal echo structure.

A disintegrin and metalloprotease with thrombospondin type1 motifs (ADAMTS-1) and IL-1 receptor type 1 mRNAs are simultaneously induced in nerve injured motor neurons

Following rat hypoglossal nerve injury, expression of mRNAs for a disintegrin and metalloprotease with thrombospondin type1 motifs (ADAMTS-1) and IL-1 receptor type 1 (IL-1RT1) are induced in the injured motor neurons. Although N1E-115 (N1E) cells, which were treated with IL-1 alpha, showed no alteration of ADAMTS-1 mRNA expression, a substantial increase of ADAMTS-1 mRNA expression was observed in the N1E cells expressing IL-1RT1. These findings suggest that nerve injury promotes IL-1RT1 expression in the injured neurons and thereby ADAMTS-1 transcription was induced in response to IL-1 released from glial cells.

Effects of injecting GABAergic agents into the medullary reticular formation upon swallowing induced by the superior laryngeal nerve stimulation in decerebrate cats

The purpose of this study was to elucidate the role of the GABAergic system in the medullary reticular formation (MRF) in the control of swallowing. In acutely decerebrated cats (n = 12), swallowing was induced by electrical stimulation (0.3-6 V at 10-20 Hz for 10-20 s every minute) applied to the superior laryngeal nerve (SLN). The stimulus intensity was adjusted so that swallowing was induced two or four times during the period of the stimulation. Bicuculline, a GABA(A) receptor antagonist, was then injected (0.10-0.15 microl, 5 mM) into the MRF through a stereotaxically placed glass micropipette. In a total of 62 injections, 19 injections (30.6%) increased the frequency of SLN-induced swallowing when it was injected into the lateral part of the MRF corresponding to the nucleus reticularis parvocellularis (NRPv). In eight of the effective injections (42.1%) which increased the frequency of SLN-induced swallowing, SLN stimulation also induced coughing. With two injections, stimulation of the SLN-induced coughing but not facilitation of swallowing. On the other hand, an injection of 0.10-0.15 microl of 5 mM muscimol, a GABA(A) receptor agonist, into the NRPv decreased the frequency of SLN-induced swallowing. These results suggest that the NRPv neurons which are responsible for evoking swallowing are under the tonic inhibitory control of the GABAergic system.

Sarcomas in the Temporomandibular Joint Region: Report of 2 Cases

Abstract Two cases of sarcoma in the temporomandibular joint region are presented — an osteosarcoma and a chondrosarcoma. These tumours in the maxillofacial region, particularly in the temporomandibular joint, are very rare. The patients underwent surgical treatment alone. The follow-up periods were 9 and 6 years, respectively, and no local recurrence or distant metastases were encountered.