Internal excitation of intermediate mass fragments from collisions of 36Ar+Ag nuclei at 35 MeV/nucleon

An extruding wire knife was used to give adult male CFHB rats a minimally traumatic unilateral mechanical lesion of the medial forebrain bundle. In addition, some rats received bilateral intrastriatal injections of one of three fluorescent retrograde tracers either eight days before or eight days after the lesion. Injections made after the lesion revealed that about half of the animals had complete lesions of the nigrostriatal tract, while the other half were incompletely lesioned, the mean proportion of non-axotomized neurons being 23%. Over the 10 weeks following the lesions, the number of tyrosine hydroxylase-immunoreactive cells in the lesioned substantia nigra fell linearly, reaching a mean of 29% of that of the control substantia nigra. In the animals which were completely lesioned, neuronal survival at 10 weeks varied between 6 and 12%. That the disappearance of tyrosine hydroxylase-immunoreactive neurons was due to cell death rather than the loss of tyrosine hydroxylase itself was confirmed by labelling the cells with Fluoro Gold before axotomy; the tracer was seen in survival neurons, microglia and in a few involuted neurons which continued to be tyrosine hydroxylase-immunoreactive. This percentage of neurons surviving axotomy corresponds to the proportion of substantia nigra neurons which project to the contralateral striatum, and these neurons were in the region of the substantia nigra from which the contralateral projection originated. It is concluded that following mechanical transection of the nigrostriatal tract, all truly axotomized substantia nigra neurons die over a period of about 10 weeks.     

V beta specificity of superantigen TSST-1 plus CD28 costimulation without APCs

Little has so far been known about the role of antigen-presenting cells (APCs) in the activation of T cells by superantigens. Recently several studies showed that superantigens could directly activate purified T cells in the presence of CD28 costimulation. Here we investigate V beta expression of T cells activated by the superantigen toxic shock syndrome toxin-1 (TSST-1), plus CD28 costimulation, in the absence of APCs. The aim of this study was to ask if TSST-1 activated purified T cells in the presence of CD28 costimulation with the same specificity as in the presence of APCs. We provide evidence that the specificity of TSST-1 to human V beta, in the presence of CD28 costimulation, is identical to that in the presence of APCs, with V beta 2 being significantly expanded. The results indicate that the main role of APCs in the superantigen-mediated T cell activation may be to provide T cells with CD28 costimulation.     

Survival of patients with carcinoma of the esophagus treated with combined-modality therapy

Since 1985, 229 cases of carcinoma of the esophagus have been considered for entry into a protocol with the use of preoperative chemotherapy and radiation therapy followed by surgical intervention as the primary element of treatment. One hundred sixty-five patients (93 with adenocarcinoma and 72 with squamous cell carcinoma) had esophagogastrectomy. The 5-year survival of the protocol patients who underwent resection was 25% for both groups--squamous cell carcinoma and adenocarcinoma. Of the protocol patients with squamous cell carcinoma who underwent resection, 40% had a sterilized specimen, whereas of those with adenocarcinoma, 20% had a sterilized specimen. If the patient had a sterilized specimen, the 5-year survival was approximately 60% for adenocarcinoma and 40% for squamous cell carcinoma. Those patients with adenocarcinoma and Barrett's esophagus had a 5-year survival of 55%. Of the patients who underwent only esophagectomy and esophagogastrectomy and had not been entered into the protocol, none lived beyond 3 years. The operative mortality rate for those who had esophagogastrectomy was 5%. Sixty-four patients completed the radiation therapy and chemotherapy but did not undergo surgical procedures because of progressive disease or refusal. Of those patients who completed chemotherapy and radiation therapy without surgical intervention, 5-year survival was 18% in patients with squamous cell carcinoma, whereas no patients with adenocarcinoma survived beyond 3 years. The finding of a sterilized specimen after esophagectomy is a favorable prognostic factor in patients with adenocarcinoma or squamous cell carcinoma. The finding that patients with Barrett's esophagus and adenocarcinoma have an improved chance for survival is perhaps related to an earlier diagnosis. It is clear that some patients with squamous cell carcinoma who did not undergo surgical procedures did have a sterilized specimen, because the survival in this group approached 20% at 5 years.     

The impact of treatment of eye disease on optometric practice in Missouri

In an attempt to validate the use of topographical mapping of EEG as a method of localising cerebral function, EEG was recorded during a simple motor task. A minimum of 20 sec artifact-free EEG was recorded from 24 healthy right handed subjects in each of 4 conditions: eyes open 1, motor task (left/right, order randomized), eyes open 2. EEG amplitude maps were computed in delta, theta, alpha, and beta (1 and 2). Differences were seen between the eyes open and the motor conditions in alpha, beta 1 and beta 2 localised to the motor and supplementary motor areas. It is argued that topographical mapping of EEG is a valid method of localising cognitive function in healthy individuals for the Luria task.