Somatosensory Evoked Potentials in Cerebral Infarction Model Rats Induced by Microsphere Injection to Cerebral Artery

Microspheres, monodisperse polystyrene beads, are used for the study of cerebral infarction by injection into the cerebral artery. Cerebral infarction model rats were made by injecting 2,600 microspheres into the right internal carotid artery in this study. Motor ability was assessed by the rotarod test in which cling duration on the accelerating rotating rod was measured. Significant decrease in the motor ability was recognized on 3 and 15 days after the embolization compared with before surgery (p<0.05). However, sham-operated rats did not show significant change of motor ability. Each rat was reanaesthetized 15 days after surgery, and somatosensory evoked potentials (SEPs) induced by stimulation of the sciatic nerve of the contralateral hind limb were averaged. Latencies of N_1 and N_2 waves in SEPs were compared between sham-operated rats and embolized rats 15 days after surgery. No significant differences in N_1 and N_2 latencies were recognized between the two groups. These results suggest that motor ability was impaired at chronic periods of the embolization, while SEPs recovered, although latencies of N_1 and N_2 in SEPs were reported to increase at acute periods in embolized rats

Key point in dermoscopic differentiation between early nail apparatus melanoma and benign longitudinal melanonychia

Longitudinal melanonychia presents in various conditions including neoplastic and reactive disorders. It is much more frequently seen in non-Caucasians than Caucasians. While most cases of nail apparatus melanoma start as longitudinal melanonychia, melanocytic nevi of the nail apparatus also typically accompany longitudinal melanonychia. Identifying the suspicious longitudinal melanonychia is therefore an important task for dermatologists. Dermoscopy provides useful information for making this decision. The most suspicious dermoscopic feature of early nail apparatus melanoma is irregular lines on a brown background. Evaluation of the irregularity may be rather subjective, but through experience, dermatologists can improve their diagnostic skills of longitudinal melanonychia, including benign conditions showing regular lines. Other important dermoscopic features of early nail apparatus melanoma are micro-Hutchinson's sign, a wide pigmented band, and triangular pigmentation on the nail plate. Although there is as yet no solid evidence concerning the frequency of dermoscopic follow up, we recommend checking the suspicious longitudinal melanonychia every 6 months. Moreover, patients with longitudinal melanonychia should be asked to return to the clinic quickly if the lesion shows obvious changes. Diagnosis of amelanotic or hypomelanotic melanoma affecting the nail apparatus is also challenging, but melanoma should be highly suspected if remnants of melanin granules are detected dermoscopically.ArticleJOURNAL OF DERMATOLOGY. 38(1):45-52 (2011)journal articl

Changes in the lactate threshold during treadmill exercise after microsphere-induced infarction in rats.

The aim of this study was to clarify changes in the lactate threshold (LT) in the acute period after cerebral infarction. Cerebral infarction was induced by the injection of microspheres (MS) into the right internal carotid artery. To estimate the degree of neurologic deficit caused by surgery, the behaviors of all rats were evaluated in terms of typical symptoms of stroke in rats. The rotarod test was used to evaluate equilibrium function. Rats were forced to perform stepwise treadmill exercises, and serial changes in blood lactate concentration were measured for determination of the LT. The average treadmill speed at the LT and the rotarod test performance in MS rats was significantly lower than those in sham-operated rats on postsurgery day 2. However, although neurologic deficits disappeared on postsurgery day 7 in MS rats, LT level and rotarod test performance were significantly lower than in sham-operated rats. These results suggest that the decrease in LT in the acute period after cerebral infarction might be induced by impaired equilibrium function. Other possibilities are discussed as well

High-frequency 30-MHz sonography in preoperative assessment of tumor thickness of primary melanoma: usefulness in determination of surgical margin and indication for sentinel lymph node biopsy

The original publication is available at www.springerlink.comHigh-frequency sonographic imaging has been used for the preoperative evaluation of primary malignant melanoma. In the present study, to identify the usefulness of 30-MHz sonography for determination of the surgical margin and indication for sentinel lymph node biopsy, the correlation between sonometric and histometric tumor thickness was investigated. A total of 74 primary melanomas, in patients seen at the dermatology clinic, Shinshu University Hospital, from 1998 to 2006, were evaluated using high-frequency sonographic equipment with two probes (15 MHz and 30 MHz), and tumor thickness was measured using electronic calipers before surgical treatment. All the primary lesions were surgically excised and Breslow's tumor thickness was measured histologically. In 68 melanomas, excluding 2 lesions of melanoma in situ and 4 lesions with poor sonographic images, sonographic and histologic thickness showed good correlation (r = 0.887). Particularly, in 26 melanomas affecting the soles of the feet, sonographic and histologic thickness showed excellent correlation (r = 0.945). Regarding the T categorization, in which T1-T4 are divided at 1, 2, and 4 mm in thickness, the categories determined with sonometry corresponded very well to those determined with histometry. The correspondence was particularly excellent in thinner primary lesions with thickness around 1 mm. We excised almost all these primary melanomas with surgical margins based on the sonometric thickness. In 22 patients with sonometric thickness more than 1 mm, sentinel lymph node biopsy and/or radical lymphadenectomy was performed. High-frequency sonography (30-MHz) is very useful in the preoperative prediction of tumor thickness, particularly in thinner primary lesions, which allows us to determine surgical margins and indication for sentinel lymph node biopsy.ArticleINTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY. 14(5):426-430 (2009)journal articl

A case of spontaneous mesenteric hematoma successfully diagnosed and treated with aggressive imaging

Introduction: Spontaneous mesenteric hematoma is an uncommon syndrome triggered by bleeding localized in the mesenteric vascular tree of a bowel segment for no apparent underlying reason. We herein report a surgical patient with an extremely rapidly growing spontaneous mesenteric hematoma that we successfully diagnosed using careful radiologic examination. Presentation of case: A 56-year-old old male presenting sudden onset lower abdominal pain was referred to our emergency department. At the time of admission, his physical examination revealed stable vital signs without radiological abnormality. On the following day, the patient suddenly presented hypotension, tachycardia, and increased abdominal pain. Contrast-enhanced computed tomography examination showed a mass with both high- and low-density areas with a 130 mm maximum diameter bordering the transverse colon. Since interventional radiologists were not available, we decided to perform emergency exploratory laparotomy. On laparotomy, a 13 × 8 cm hematoma was found in the mesentery of the transverse colon. As bleeding was noted from the branches of the middle colic artery and gastrocolic artery, these responsible vessels were ligated. The patient was finally given the diagnosis of spontaneous mesenteric hematoma. Discussion and conclusion: The present case, initially diagnosed as enterocolitis, suddenly manifested hypovolemic shock. Close monitoring for any signs of further deterioration, as well as aggressive imaging diagnosis, enabled us to avoid delays in treatment. Early diagnosis and treatment of mesenteric hematomas are essential to prevent them from rupturing and triggering life-threatening adverse events

Therapeutic regimen of l-arginine for MELAS: 9-year, prospective, multicenter, clinical research

ObjectiveTo examine the efficacy and safety of the therapeutic regimen using oral and intravenous l-arginine for pediatric and adult patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).MethodsIn the presence and absence of an ictus of stroke-like episodes within 6 h prior to efficacy assessment, we correspondingly conducted the systematic administration of oral and intravenous l-arginine to 15 and 10 patients with MELAS in two, 2-year, prospective, multicenter clinical trials at 10 medical institutions in Japan. Subsequently, patients were followed up for 7 years. The primary endpoint in the clinical trial of oral l-arginine was the MELAS scale, while that for intravenous l-arginine was the improvement rates of headache and nausea/vomiting at 2 h after completion of the initial intravenous administration. The relationships between the ictuses of stroke-like episodes and plasma arginine concentrations were examined.ResultsOral l-arginine extended the interictal phase (p = 0.0625) and decreased the incidence and severity of ictuses. Intravenous l-arginine improved the rates of four major symptoms—headache, nausea/vomiting, impaired consciousness, and visual disturbance. The maximal plasma arginine concentration was 167 μmol/L when an ictus developed. Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. No treatment-related adverse events occurred, and the formulations of l-arginine were well tolerated.ConclusionsThe systematic administration of oral and intravenous l-arginine may be therapeutically beneficial and clinically useful for patients with MELAS

日本における統計学の発展 第５２巻

昭和55，56，57年度文部省科学研究費総合（A）研究代表者西平重喜による速記録話し手：久我, 通武聞き手：豊田, 尚1982-1-25 | 1982-2-