Role of radiation therapy in the treatment of stage I/II mucosa-associated lymphoid tissue lymphoma.

BACKGROUND: Few large studies exist on the outcome of patients treated for stage I/II mucosa-associated lymphoid tissue (MALT) lymphoma. PATIENTS AND METHODS: We retrospectively reviewed the records of 77 patients consecutively treated for stage I (n = 66) or II (n = 11) MALT lymphoma at our institution. Progression-free survival (PFS), freedom from treatment failure (FFTF), and overall survival (OS) were calculated using the Kaplan-Meier method. RESULTS: The median follow-up time was 61 months (range 2-177 months). Fifty-two patients (68%) received local radiation therapy (RT) alone, 17 (22%) had surgery followed by adjuvant RT, five (6%) had surgery alone, two (3%) had surgery and chemotherapy, and one patient had chemotherapy alone. The median RT dose was 30 Gy (range 18-40 Gy). The 5-year PFS, FFTF, and OS rates were 76%, 78%, and 91%, respectively. The 5-year PFS (79% versus 50%; P = 0.002) and FFTF (81% versus 50%; P = 0.0004) rates were higher for patients who received RT as compared with patients who did not. CONCLUSIONS: The prognosis following treatment of stage I/II MALT lymphoma is excellent. RT improves PFS and FFTF and has an important role in the curative treatment of patients with localized disease.

Multivalued associative memories based on recurrent networks.

A multivalued neural associative memory model based on a recurrent network structure is proposed. This model adopts the same principle proposed in the authors' previous work, the exponential correlation associative memories (ECAM). The model also has a very high storage capacity and strong error-correction capability. The major components of the new model include a weighted average process and some similarity-measure computation. As in ECAM, in order to enhance the differences among the weights and make the largest weights more overwhelming, the new model incorporates a nonlinear function in the calculation of weights. Several possible similarity measures suitable for this model are suggested. Simulation results of the performance of the new model with different measures show that, loaded with 500 64-component patterns, the model can sustain noise with power about one fifth to three fifths of the average signal power.

The vascular architecture and innervation of the cerebral arteries in Leiothrix lutea.

The vascular architecture and innervation of the cerebral arteries in the robin-billed leiothrix, Leiothrix lutea, were studied using catecholamine fluorescence, acetylcholinesterase active staining, and immunohistochemical techniques. The cerebral arteries in Leiothrix lutea consisted of the cerebral carotid and the basilar systems. The cerebral carotid artery can be divided into the anterior and posterior rami. Due to poor development of the posterior ramus, the posterior cerebral artery originated from the anterior ramus, and an anterior communicating artery between the cerebroethmoidal arteries formed the circle of Willis. The cerebral carotid system was supplied with aminergic nerve fibers (Amn), cholinergic nerve fibers (Chn) and peptides [substance P (SP), neurokinin A (NKA), calcitonin gene related peptide (CGRP) and vasoactive intestinal polypeptide (VIP)]-like immunoreactive (LI) nerve fibers in all regions. These nerve fibers were abundant in the cerebral carotid system, but were few and scattered in the basilar system. Only neuropeptide Y (NPY)-LI nerve fibers were recognized in moderate numbers in the cerebral carotid system, but were not found in the basilar system. Innervation of the small blood vessels of the cerebral parenchyma differed from that of the cerebral superficial arteries, SP-, NKA-, CGRP- and VIP-LI nerve fibers showed a dense distribution, but Amn and NPY-LI nerve fibers showed a sparse distribution, and almost no Chn was observed. Double staining in the cerebral arteries for SP-, NKA- and CGRP-LI nerve fibers demonstrated exactly the same distribution. This suggests that SP, NKA and CGRP co-exist in the same fiber.(ABSTRACT TRUNCATED AT 250 WORDS)