Selected markers of proliferation and apoptosis in the parathyroid lesions: a spatial visualization and quantification.

The aim of the paper was to apply a method for quantitative assessment of proliferation and apoptosis markers, based on their 3D visualization, in cases of parathyroid adenoma and hyperplasia. Material was obtained from 49 patients (32 females and 17 males) with primary hyperparahyroidism. Quantitative immunohistochemistry studies of Ki-67, proliferating cell nuclear antigen (PCNA) and bcl-2 were performed on digital microscopy images with the use of 3D visualization. The use of spatial visualization method allowed us to perform objective quantitative assessment of the studied immunohistochemical markers. The average cell nuclear fraction of Ki67+ was 1.8% in hyperplasia and 1.9% in adenoma cases while 3.5% in the controls. The highest expression of PCNA was found in parathyroid hyperplasia (22.9%) and significantly decreased in adenoma (12.5%) and in the control group (16.8%). The lower expression of bcl-2 in hyperplasia cases (mean area fraction of 0.172 per 1 mum(2), in contrast to 0.643 in adenomas and 0.648 in control) suggested that principal cells can be ready for apoptosis and may confirm the important role of bcl-2 protein in etiopathogenesis of hyperplasia of the parathyroid gland while PCNA might be a useful marker for differentiating adenoma from early hyperplasia in primary hyperparahyroidism cases.

Erythropoietin is neuroprotective against NMDA-receptor-mediated excitotoxic brain injury in newborn mice.

Using an established mouse model of human periventricular leukomalacia, we investigated whether EPO could reduce excitotoxic damage. When administered 1 h following intracerebral injection of 10 microg ibotenic acid at day 5 of life, both a single injection of EPO (5000 IU/kg bw) and repetitive administrations of EPO reduced white and gray matter lesion size. The therapeutic window for protection was small as the protective effect of EPO was lost when EPO administration was delayed to 4 h post-insult. EPO-mediated upregulation of EPO-R, but not EPO, mRNA was observed within 4 h of the excitotoxic insult. The EPO effect was gender independent. Minor hematopoetic effects were observed following EPO treatment. We conclude that a single dose of EPO is sufficient to reduce excitotoxic brain injury and may therefore possess therapeutic relevance in the clinical setting.

Systemic application of granulocyte-colony stimulating factor and stem cell factor exacerbates excitotoxic brain injury in newborn mice.

Granulocyte-colony stimulating factor (G-CSF) has been shown to reduce brain lesion size and mortality in adult mice after hypoxic-ischemic injury. Another hematopoietic growth factor, stem cell factor (SCF), has been shown to be up-regulated in the brains of adult rodents following brain damage, where it stimulates postlesional neurogenesis. Injection of the excitotoxic agent ibotenate into the brain of newborn mice produces a brain lesion characterized by neuronal death and white matter cysts, which is similar to periventricular leucomalacia. The aim of the present study was to investigate whether administration of SCF and G-CSF is neuroprotective against ibotenate lesions in neonatal mice. Contrary to our expectations, cortical and white matter brain lesions induced by ibotenate were enhanced following the administration of 50 microg/kg SCF or 200 microg/kg G-CSF. Dose-response studies indicated that G-CSF could increase grey matter lesions even at lower dosages (22 and 66 microg/kg). Administration of SCF and G-CSF in combination also increased cortical and white matter lesions, to 133 +/- 8% and 187 +/- 12%. In the undamaged brain, G-CSF or G-CSF+SCF treatment had no effect on apoptosis in the grey or white matter; however, these treatments significantly increased apoptosis in the damaged brain. Our data clearly demonstrate that G-CSF and SCF are not neuroprotective and result in deleterious enhancement of excitotoxic brain damage in newborn mice. We conclude that G-CSF and SCF should be used cautiously in newborn infants with brain lesions; if they are used, long term neurologic and neurodevelopmental follow-up is warranted.