Striatal cells containing the Ca2+-binding protein calretinin (protein 10) in ischemia-induced neuronal injury

The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca²⁺-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury.     

Malignant Rhabdoid Tumor of the Breast: A Case Report

A 66-year-old woman time of 10 days. One month after radicalmastectomy, there was local recurrence, followed by multiplepulmonary metastases, and the patient died of respiratory failure5 months after surgery. The gray-white-colored tumor measured13x12x;10 cm, and its border was well defined. The tumor wascomposed of diffusely growing round or polygonal cells withvesicular nuclei, prominent nucleoli, and ample cytoplasm containingeosinophilic inclusions. Lymph node involvement was widespread.Both vimentin and keratin were clearly demonstrated by immunohistochemicalstaining. Ultrastructural studies revealed that the MRT cellscontained cytoplasmic whorls of intermediate filaments.     

GABA affects the glutamate receptor-chloride channel complex in mechanically isolated and internally perfused Aplysia neurons.

The effects of gamma-aminobutyric acid (GABA) on the glutamate receptor chloride ion (Cl-) channel complex were examined in mechanically isolated and internally perfused Aplysia neurons using a concentration clamp technique. GABA at concentrations of 3 x 10(-6) M or more, concentration dependently delayed the recovery of the glutamate response from desensitization. This effect was independent of the GABA response and Cl- redistribution. Muscimol (10(-4) M) mimicked the effect of GABA. However, this was not the case for baclofen (10(-3) M). In some isolated neurons, GABA at concentrations of more than 10(-4) M clearly induced an additional Cl- current, the current kinetics of which were different from those induced by lower concentrations of GABA. Even in the continued presence of 10(-4) M GABA, which desensitized the fast GABA response, higher concentrations of GABA (3 x 10(-4) M to 10(-2) M) elicited the additional current in a concentration-dependent manner. The presence of 10(-4) M glutamate completely abolished this current, indicating cross-desensitization between the glutamate and slow GABA responses. High concentrations of GABA (3 x 10(-2) M) did not activate the glutamate receptor coupled to the large cation channel. The results suggest that, in Aplysia neurons, the glutamate receptor-Cl- channel complex has some similarities to the GABA receptor-Cl- channel complex.     

Peripheral T-cell lymphoma of AILD (angioimmunoblastic lymphadenopathy with dysproteinemia) type involving gastrointestinal tract. A morphologic, phenotypic and genotypic study.

A case of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) which showed widespread involvement of the gastrointestinal tract is reported. A lymph node biopsy specimen showed the characteristic histological features of AILD. During the progression of the illness, lymphomatous lesions developed in the gastrointestinal tract, complicated by cytomegalovirus infection. A double immunoenzymatic study using a combination of Ki-67 antibody and antibodies against surface antigens demonstrated that CD3+, CD4+, and/or T-cell receptor (TCR) beta+ cells were predominant (67-68%) among the population of proliferating Ki-67% cells, rather than CD8+ or CD22+ cells. Clonal rearrangement of the TCR beta chain gene was also detected. These findings provide further evidence for the neoplastic nature of lesions of this type, and the diagnosis of peripheral T-cell lymphoma.