Spatio-temporal course of macrophage-like cell accumulation after experimental embolic stroke depending on treatment with tissue plasminogen activator and its combination with hyperbaric oxygenation.

Inflammation following ischaemic stroke attracts high priority in current research, particularly using human-like models and long-term observation periods considering translational aspects. The present study aimed on the spatio-temporal course of macrophage-like cell accumulation after experimental thromboembolic stroke and addressed microglial and astroglial reactions in the ischaemic border zone. Further, effects of tissue plasminogen activator (tPA) as currently best treatment for stroke and the potentially neuroprotective co-administration of hyperbaric oxygen (HBO) were investigated. Rats underwent middle cerebral artery occlusion and were assigned to control, tPA or tPA+HBO. Twenty-four hours, 7, 14 and 28 days were determined as observation time points. The accumulation of macrophage-like cells was semiquantitatively assessed by CD68 staining in the ischaemic area and ischaemic border zone, and linked to the clinical course. CD11b, ionized calcium binding adaptor molecule 1 (Iba), glial fibrillary acidic protein (GFAP) and Neuronal Nuclei (NeuN) were applied to reveal delayed glial and neuronal alterations. In all groups, the accumulation of macrophage-like cells increased distinctly from 24 hours to 7 days post ischaemia. tPA+HBO tended to decrease macrophage-like cell accumulation at day 14 and 28. Overall, a trend towards an association of increased accumulation and pronounced reduction of the neurological deficit was found. Concerning delayed inflammatory reactions, an activation of microglia and astrocytes with co-occurring neuronal loss was observed on day 28. Thereby, astrogliosis was found circularly in contrast to microglial activation directly in the ischaemic area. This study supports previous data on long-lasting inflammatory processes following experimental stroke, and additionally provides region-specific details on glial reactions. The tendency towards a decreasing macrophage-like cell accumulation after tPA+HBO needs to be discussed critically since neuroprotective properties were recently ascribed to long-term inflammatory processes.

Cell-cell-neighborhood relations in tissue sections--a quantitative model for tissue cytometry.

Physical interactions between different cell types are a requirement for the initiation and maintenance of immune responses. The distribution pattern of cells within a tissue may result from specific cell-cell-interactions or random distribution. Tissue architecture, degree of inflammation, frequencies of cells, number of contact partners, cell type, and size as well as cell movement and contact time determine the distribution of cells within tissues. We developed a matrix model to determine the degree of expected random distribution of two cell types (A and B) and cell-cell-contacts within tissue sections. The model predictions were compared with experimental data derived from immunofluorescence microscopy. We implemented a computer algorithm for automatic image analysis to visualize and quantify cell-cell-neighborhood relations. Using the number of cells type A (a), the total cell number (t) and the mean number of cells that are in contact with cells type B (c(B)), the ratio of cells type B in contact with cells type A can be described by b(A)/b = 1- (1- (a/t))[symbol: see text]c(B). We applied the model system to investigate the distribution of Foxp3(+) regulatory T cells with Ki-67(+) proliferating cells within mouse tissue sections. The matrix model provides a tool to describe the expected distribution of two different cell types and their cell-cell-contacts within tissues. Comparing the degree of expected random distribution with experimental data might help to propose functional cell-cell-interactions in tissue sections.

Dealing with feelings: who is the victim?

The nurse is an essential member of the child abuse team. Provision of care to identified abusive families requires intense, long-term intervention. Without a clear understanding of the emotions being experienced by family unit and the professionals involved in their care, progress will be limited. It is the responsibility of the nurse to identify and work through feelings, to recognize factors contributing to the family's behavior, and to provide quality care. Anger, shock, or pity inhibit effective treatment. The nurse is not expected to feel positively about injury of a child, but is required to take the steps necessary to understand the dynamics of abuse.

Circular dichroism comparative studies of two bacterial collagenases and thermolysin.

The recently isolated and purified collagenase produced by Achromobacter iophagus, the collagenase from Clostridium histolyticum, and thermolysin, three enzymes having common properties, were studied by circular dichroism. From the spectra of the aqueous solutions obtained in the peptide region, the fraction of alpha helix, beta sheet and aperiodic segments in the three proteins could be estimated. Good similarity was found between Achromobacter collagenase and thermolysin, which both contain a high fraction of alpha helix. Side-chain contributions were analyzed in the aromatic region of thespectra: effects of pH and of organic solvents were observed, showing the strong influence of surroundings on the stabilization of the proteins.