Abutment region dosimetry for the monoisocentric three-beam split field technique in the head and neck region using asymmetrical collimators

Creating non-divergent field edges using asymmetric collimators and a single isocentre can improve matchline dosimetry owing to decreased reliance on operator skills and avoidance of couch movement. However, asymmetic jaws have an associated tolerance that can cause abutment to be misaligned. The matching area dose for monoisocentric three-beam split fields commonly used in head and neck cancer treatments using mismatched and matched collimators is the subject of this work. X-ray verification film was exposed in a solid-water phantom, and the dose at the matching area was evaluated using mismatched and matched collimators. In the case of mismatched (consistently overlapped) collimators, digital displays of an asymmetric collimator position within the tolerance indicated in the manufacturer's specifications were investigated for the three-beam split field technique. The effect of this technique on the junctional dose was also determined using matched collimators. Although the collimators showed a consistent overlap, a perfect dose distribution could be obtained at the matching area. The three-beam split field technique yielded an 8% overdose at the matchline using matched collimators. In conclusion, an awareness of the effects of the abutting technique and digital display tolerance is necessary to achieve good junction uniformity using asymmetric collimators.     

Significance of plasminogen-activation system in the formation of macroscopic types and invasion in esophageal carcinoma

BACKGROUND: The roles of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in the formation of macroscopic types and invasion were investigated. MATERIALS AND METHODS: A total of 40 surgically-resected esophageal carcinoma tissues were immunohistochemically stained, and the expression of uPA, PAI-1 and the uPA/PAI-1 ratio, were evaluated. RESULTS: The expression of uPA was significantly stronger in the macroscopically infiltrative type (n = 20: p = 0.0027), whereas PAI-1 was significantly stronger in the localized type (n = 20: p = 0.0005). The uPA/PAI-1 ratio was significantly higher in the infiltrative type (p < 0.0001). A significant correlation was found between the U/P ratio and the depth of tumor invasion (r = 0.511, p = 0.0014). Analysis of tumors of uniform size (4.0-6.0 cm in length), showed that the depth of invasion was significantly greater in the infiltrative type (p = 0.0038). CONCLUSION: The results demonstrated that uPA and PAI-1 play important roles in invasion and formation of macroscopic types of esophageal carcinoma.     

A GDP/GTP exchange protein for the Rab3 small G protein family up-regulates a postdocking step of synaptic exocytosis in central synapses

The Rab3 GDP/GTP exchange protein (Rab3 GEP) activates the Rab3 small GTP-binding protein (G protein) family, including Rab3A that is an important member controlling synaptic vesicle trafficking. Here, we examined the role of Rab3 GEP in regulating neurotransmitter release in autapses of mouse hippocampal neurons in culture. The release probability was markedly reduced in Rab3 GEP-/- neurons, whereas the readily releasable pool size was not different between WT and Rab3 GEP-/- neurons, indicating that Rab3 GEP up-regulates a postdocking step of synaptic exocytosis. Because Rab3A reportedly down-regulates Ca(2+)-triggered fusion of synaptic vesicles, these results provide evidence for a role of Rab3 GEP in the postdocking process distinct from Rab3A activation.     

Abnormal vestibular evoked myogenic potentials in the presence of normal caloric responses.

OBJECTIVE: Combined use of vestibular evoked myogenic potential (VEMP) and caloric response testing has enabled us to examine the function of the inferior and superior vestibular nerves separately. Although results of VEMP testing and caloric response testing have been reported for many diseases, a clinical entity showing abnormal VEMP responses but normal caloric test responses has rarely been reported. The aim of the study was to investigate clinical features of diseases showing abnormal VEMP responses with normal caloric test responses. STUDY DESIGN: Retrospective. SETTING: University hospital. PATIENTS: Eight hundred eleven patients with balance problems who had undergone both caloric response and VEMP testing were included in the study. MAIN OUTCOME MEASURES: The amplitudes and latencies of the first positive-negative peak of the VEMP (p13-n23) were measured. RESULTS: Forty of the 811 patients (5%) were found to have abnormal VEMP responses with normal caloric test responses. Clinical diagnoses of these patients were Ménière's disease (n = 12), acoustic neuroma (n = 8), sudden deafness with vertigo (n = 6), and other diseases (n = 6). Eight patients could not be diagnosed as having a disease already recognized. Clinical manifestations of these eight patients were rotatory vertigo in six patients and non-rotatory dizziness in two. None of these patients showed abnormalities other than VEMP responses on neurologic or neurotologic examinations. CONCLUSION: Apart from Ménière's disease, acoustic neuroma, and sudden deafness with vertigo, which are already known as diseases with abnormal VEMP responses but normal caloric test responses, some patients might be diagnosed as having a disease that involves only the inferior vestibular nerve region.     

Internal carotid artery aneurysm visualized during successful endovascular treatment of carotid embolism

We herein present a case of an internal carotid artery embolism associated with a hidden internal carotid artery aneurysm. The aneurysm was visualized during successful endovascular treatment of the carotid embolism. In retrospect, the aneurysm was at risk of rupture during the procedure. In the endovascular treatment of cerebral embolism, the possibility that aneurysms are hidden by emboli must be borne in mind. Care should be taken not to injure unidentified arterial walls while advancing a catheter blindly.     

Treatment with a metallic endovascular stent in a patient with iliac venous stenosis due to endometrial cancer

There are few cases, to our knowledge, that report the successful treatment of iliac venous stenosis due to gynecologic malignancies with the use of self- expanding metallic endovascular stents. Our patient, who had right lower limb edema, had iliac lymph node metastases which caused iliac vein stenosis by direct invasion from endometrial cancer. The patient was not considered to be a good surgical candidate. A 10-mm diameter self-expanding metallic endovascular stent was placed in the external iliac vein. The patient’s symptoms of right lower limb edema improved dramatically, and she was discharged at 3 weeks after stent placement. The patient had no further symptoms, with continued resolution of the right leg edema during the 10 months following stent placement, at which time she died from the primary disease. The treatment to this patient with a self-expanding metallic endovascular stent proved to be very efficacious and less stressful than direct venous reconstruction or femorofemoral venous bypass grafting. In addition, this procedure dramatically improved the patient’s quality of life. Received: 10 January 2000 / Accepted: 8 February 2000     

A case of recurrent pancreatic carcinoma treated by low-dose rate telecobalt therapy

A 27-year-old female with recurrent pancreatic carcinoma measuring 12 by 12 by 14 cm was treated with protracted (1.5 Gy/day) irradiation and low dose rate (1 Gy/hr, 7 Gy/day)telecobalt therapy. The regression obtained from a total dose of 60 Gy by protracted irradiation was mild; a remarkable reduction in tumor volume was achieved from an additional dose of 14 Gy by low dose rate teletherapy. Although she died of fulminant hepatitis at 45 days after radiotherapy, this treatment method is considered useful in patients with advanced carcinoma.     

Fc receptor targeting in the treatment of allergy, autoimmune diseases and cancer

Immune activation and inhibitory receptors play an important role in the maintenance of an adequate activation threshold of various cells in our immune system. Analyses of murine models show that the inhibitory Fcreceptor, FcgammaRIIB plays an indispensable role in the suppression of anti-body-mediated allergy and autoimmunity. In contrast, the activating-type Fcreceptors (FcRs) are essential for the development of these diseases, suggesting that regulation of inhibitory or activating FcR is an ideal target as a therapeutic agent. In addition, recent crystal structural analyses of FcR-Ig-Fc fragment complexes provide an effective approach for developing FcR-targeting drugs. This review summarises recent advances of FcR, which were mainly obtained by murine studies, and highlights novel antibodies as possible FcR-targeting therapies for allergy, autoimmune diseases and cancer.     

Saccular aneurysm of the aortic cusp associated with discrete subaortic stenosis

A 54-year-old male who experienced a syncopal episode underwent aortic valve replacement for aortic stenosis and regurgitation. The aortic valve was incompetent as a result of thickening of the left coronary cusp and noncoronary cusp. In addition a saccular aneurysm was indicated on the left coronary cusp. A shelf of tissue protruding at right angles from the ventricular septum was particularly prominent below the right coronary cusp, resulting in subvalvular stenosis. The cause of the saccular aneurysm was most likely caused by the long-term effects of the jet stream instigated by discrete subaortic stenosis.