Angiostatin overexpression in Morris hepatoma results in decreased tumor growth but increased perfusion and vascularization.

Growth of malignant tumors is dependent on sufficient blood supply. Thus, inhibition of tumor angiogenesis is emerging as a promising target in the treatment of malignancies. Human angiostatin (hANG) is one of the most potent inhibitors of endothelial cell proliferation, angiogenesis, and tumor growth in vivo. However, its mechanisms operating in vivo are not well understood. METHODS: To obtain more information about functional changes in the angiogenic process, we established Morris hepatoma (MH3924A) cell lines expressing hANG (hANG-MH3924A). The effects of hANG expression on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) were measured in coculture experiments in vitro. To evaluate changes in tumor perfusion and blood volume, H2 15O and 68Ga-DOTA-albumin (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N',N'-tetraacetic acid) were used for PET studies in vivo. Additionally, immunohistologic quantification of vascularization, apoptosis, and proliferation as well as gene array analyses were performed. RESULTS: Our in vitro experiments demonstrate reduced proliferation and increased apoptosis in HUVECs when being cocultured with hANG-MH3924A. In support, tumor growth of hANG-MH3924A is diminished by 95% in vivo. However, tumor perfusion and blood volume are increased in hANG-MH3924A corresponding to an increased microvessel density. Furthermore, hANG-transfected tumors show changes in expression of genes related to apoptosis, stress, signal transduction, and metabolism. CONCLUSION: hANG expression leads to inhibition of tumor growth, increased apoptosis, and changes in the expression of multiple genes involved in stress reactions, signal transduction, and apoptosis, which indicates a multifactorial reaction of tumors. An enhanced microvessel density is seen as part of these reactions and is associated with increased perfusion as measured by PET.     

Brain tissue microarrays in dementia research: White matter microvascular pathology in Alzheimer's disease

Tissue microarrays (TMA) consist of up to 1000 cylindrical tissue cores from different donor paraffin blocks relocated into one recipient block, allowing for efficient histopathological studies by fluorescence in situ hybridization, RNA in situ hybridization or immunohistochemistry. On the background of the increasing interest of the TMA technique in cancer research and the suggestion of its application also in studies of non‐neoplastic intracranial disorders, the technique was applied to pathologic white matter in AD brains. Eight cases with AD and concomitant white matter pathology were neuropathologically diagnosed on whole brain coronal slides. The TMA technique was used to grade severity of white matter pathology and to quantify small vessels with traditional staining and immunohistochemical markers. These measurements were compared with the whole brain neuropathological assessment. The technique produced good results with preserved tissue structures as confirmed by the whole brain evaluation. Severity of white matter pathology evaluated on the TMA cores correlated negatively with small vessel quantities, and statistically significant differences in vessel quantities paralleled different grades of white matter pathology. It is concluded that the TMA technique could be further utilized in studies of dementing disorders, and may have its advantages in large, clinically well‐characterized materials (e.g. in quantitative mapping of white matter changes).     

The effect of major railway accidents on the psychological health of train drivers—I. Acute psychological responses to accident

The acute psychological reactions of 101 train drivers to on-the-track accidents were studied by means of clinical interviews and questionnaires (Impact of Event Scale, GHQ-20 and a questionnaire addressing stress symptoms, pre-accident expectancies and worries). More than half of the train drivers reported moderate to high intrusive distress (mean 11.3) within hours to days after the accident but only 1/3 reported symptoms of acute psychophysiological arousal. Intrusive symptoms related to visual impressions were most frequently reported. Avoidance was less prevalent (mean 8.8).

Clinical interviews, relationship between pre-accident worries and severity of the acute responses and positive correlation between GHQ-scores relating to the fortnight preceding the accident and IES-intrusion scores, suggest that premorbid variables may influence the stress response. Involvement in more than two previous accidents invoked a feeling of vulnerability and produced stronger acute responses. Post-accident experiences involving various personal contacts did not correlate with the stress responses in this study and only a few drivers experienced such events in a negative way. Denial of the possibility of being involved in accidents was not associated with increased risk of strong acute responses, indicating that denial does not predict poor outcome in healthy persons exposed to situations where possibility of avoiding the event is outside the control of the person.     

The meaning of work after acquired brain injury.

PURPOSE: Research in the field of brain injury rehabilitation has tended to regard return to work as a measure of outcome. Researchers have not paid particular attention to the experiences of people living with a brain injury. The aim of the phenomenological study reported here was to identify and describe what characterizes the meaning of work to those with acquired brain injury. METHODS: Ten participants of working age were interviewed about the meaning of work 1-5 years after being inflicted with a brain injury. Data were analyzed and interpreted using the Empirical Phenomenological Psychological method. RESULTS: The findings revealed a meaning structure consisting of four main characteristics. Work was no longer experienced as the primary event in life and the social dimension had become more important. The perceived competence and work identity were threatened after the injury. A common theme across all interviews was the struggle to return to a state of normality, and working was considered to be evidence of success. CONCLUSION: The findings described the altered meaning of work 1-5 years after brain injury. This knowledge should lead to an increased understanding among occupational therapists engaged in work rehabilitation after brain injury and can serve as a basis for individualized intervention strategies.     

Missense mutations and evolutionary conserved amino acids at the human hypoxanthine phosphoribosyl-transferase locus.

Molecular characterization of in vivo mutation at the human hypoxanthine phosphoribosyltransferase (hprt) locus has revealed a broad spectrum of mutation, both with regard to germ-line mutation in Lesch-Nyhan and gout patients, and somatic mutation in 6-thioguanine resistant T-lymphocytes from healthy individuals. The pattern of missense mutation shows a non-random distribution with a preferential location to codons for amino acids which are identical in human and the two parasites Schistosoma mansoni and Plasmodium falciparum. Although these 'evolutionary conserved' amino acids account for only 32% of the amino acids in the human hprt protein, they are involved in 76% of the missense mutations at the hprt locus in human T-lymphocytes, 67% in Lesch-Nyhan patients (with severe hprt-deficiency), but only 43% in gout patients (with partial hprt deficiency). This observation supports the notion that evolutionary conserved amino acids constitute functionally important sites in the hprt enzyme, and missense mutations affecting these amino acids will often lead to complete loss of enzyme activity. Substitutions of 'non-conserved' amino acids cause less severe hprt-deficiency (as seen in the gout patients), or may even escape clinical diagnosis. These considerations are important for the understanding of structure-activity relationships in the hprt protein, possible differences between hprt mutational spectra in germ-line and somatic cells, and the mutational spectra induced by specific exogeneous mutagens.     

Children with deficits in attention,motor control and perception (DAMP) almost grown up: The contribution of various background factors to outcome at age 16 years

Fifty-six children with and forty-five children without deficits in attention, motor control and perception (DAMP) had been recruited from the general population at age 7 years. They were followed up neuropsychiatrically at age 16 years after intermediate term follow up at age 10 and 13 years. Cases were subdivided into those with good and not good outcome on the basis of absence or presence of psychiatric and personality disorders, multiple traumatic accidents and speech and language problems at age 16 years. The presence of DAMP in itself was the strongest predictor of poor outcome. High scores for minor neurological dysfunction, low performance IQ, autistic features at age 7 years and poor reading skills at age 10 and/or 13 years were important background factors in cases with poor outcome. In the small subgroup with poor outcome among those without DAMP at age 7 years, major life events was the most important background factor.

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Zusammenfassung 56 Kinder mit und 45 Kinder ohne Störungen der Aufmerksamkeit, der motorischen Kontrolle und der Wahrnehmung (DAMP) waren aus einer Gesamtpopulation 7jÄhriger rekrutiert worden. Sie wurden neuropsychiatrisch im Alter von 16 jahren nachuntersucht, nachdem zwischenzeitliche Untersuchungen im Alter von 10 und 13 Jahren erfolgt waren. Die Probanden wurden in solche mit gutem und nicht gutem Ausgang unterteilt, in AbhÄngigkeit vom Vorliegen psychiatrischer AuffÄlligkeiten, Persönlichkeitsstörungen, multiplen Traumata und Sprech- und Sprachproblemen im Alter von 16 Jahren. Das Vorhandensein von DAMP war der stÄrkste PrÄdiktor für einen schlechten Ausgang. Hohe Werte für leichte neurologische AuffÄlligkeiten, ein niedriger Handlungs-IQ, autistische Züge im Alter von 7 Jahren und schlechte LesefÄhigkeiten im Alter von 10 und/oder 13 Jahren waren wichtige Hintergrundfaktoren bei den Probanden mit einem schlechten Ausgang. In der kleinen Untergruppe mit einem schlechten Ausgang bei den Kindern, die im Alter von 7 Jahren kein DAMP ausgewiesen hatten, bildeten schwerwiegende Lebensereignisse den wichtigsten Hintergrundfaktor.

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Résumé Cinquante-six enfants atteints et quarante-cinq enfants non atteints de déficits de l'attention, du contrÔle moteur et de la perception (DAMP), ont été recrutés en population générale à l'âge de 7 ans. Ils ont été évalués sur la plan neuropsychiatrique à l'âge de 16 ans, après des évaluations intermédiaires à l'âge de 10 et 13 ans. Les cas ont été subdivisés entre bons et mauvais devenir sur la base de la présence ou de l'absence de troubles de la personnalité, l'importance du nombre d'accidents traumatiques, les difficultés d'élocution et de langage à 16 ans. La présence de DAMP était en soi, le facteur prédictif le plus important de mauvais devenir. Des scores élevés à des dysfonctionnements neurologiques mineurs, un QI bas, des traits autistiques à l'âge de 7 ans, et de mauvaises capacités en lecture à l'âge de 10 ou 13 ans ont été des facteurs importants dans les cas de mauvais devenir. Dans le petit sous-groupe à mauvais devenir caractérisé par une absence de DAMP à l'âge de 7 ans, des événements de vie marquants ont semblé Être des antécédents importants.

     

Local interaction of apoptotic hepatocytes and Kupffer cells in a rat model of systemic endotoxemia

Aim: There is strong evidence that hepatocellular apoptosis is not only initiated by circulating blood cells which become adherent within the endotoxemic liver, but also contributes to further sustain the inflammatory cell-cell response. Methods: Because previous studies assumed the importance of the role of cellular cross-talk in mediating inflammatory liver injury, we herein examined the activation of Kupffer cells (KCs) and their spatial coincidence with intrahepatic leukocyte adherence and hepatocellular apoptosis at 6 h after intraperitoneal exposure of rats with lipopolysaccharide (10 mg/kg). Results: In vivo multifluorescence microscopy revealed liver injury including nutritive perfusion failure, tissue hypoxia, leukocyte accumulation, as well as KC activation and parenchymal apoptotic cell death. Detailed spatial analysis revealed frequent colocalization of activated KCs with apoptotic hepatocytes. Colocalization was absent in saline-treated controls.Colocalization was confirmed by histochemistry, which showed ED1-positive KCs neighboring and engulfing TUNEL-positive hepatocytes. Colocalization of KCs with leukocytes ranged between 4% and 5% and did not increase in endotoxemic animals. Taken together, the present results indicate that apoptotic cell death of hepatocytes may stimulate phagocytosis by neighboring KCs. Direct KC-leukocyte contact seems not to be mandatory for cellular communication in the process of hepatocellular apoptosis. Conclusion: With respect to the fundamental importance of cell apoptosis, improved knowledge of these cell-cell interactions might allow the development of new therapeutic strategies through the regulation of apoptotic cell death.