3D-reconstruction and functional properties of GFP-positive and GFP-negative granule cells in the fascia dentata of the Thy1-GFP mouse

Granule cells of the mouse fascia dentata are widely used in studies on neuronal development and plasticity. In contrast to the rat, however, high-resolution morphometric data on these cells are scarce. Thus, we have analyzed granule cells in the fascia dentata of the adult Thy1-GFP mouse (C57BL/6 background). In this mouse line, single neurons in the granule cell layer are GFP-labeled, making them amenable to high-resolution 3D-reconstruction. First, calbindin or parvalbumin-immunofluorescence was used to identify GFP-positive cells as granule cells. Second, the dorsal-ventral distribution of GFP-positive granule cells was studied: In the dorsal part of the fascia dentata 11% and in the ventral part 15% of all granule cells were GFP-positive. Third, GFP-positive and GFP-negative granule cells were compared using intracellular dye-filling (fixed slice technique) and patch-clamp recordings; no differences were observed between the cells. Finally, GFP-positive granule cells (dorsal and ventral fascia dentata) were imaged at high resolution with a confocal microscope, 3D-reconstructed in their entirety and analyzed for soma size, total dendritic length, number of segments, total number of spines and spine density. Sholl analysis revealed that dendritic complexity of granule cells is maximal 150-200 mum from the soma. Granule cells located in the ventral part of the hippocampus revealed a greater degree of dendritic complexity compared to cells in the dorsal part. Taken together, this study provides morphometric data on granule cells of mice bred on a C57BL/6 background and establishes the Thy1-GFP mouse as a tool to study granule cell neurobiology.     

Ein einfacher „Kunstgriff“ zur Erkennung kohlenoxydhaltigen Blutes

Ohne Zusammenfassung     

Das geworfene Werkzeug

Ohne ZusammenfassungHerrn Prof.F. Reuter in Graz in Verehrung zum 60. Geburtstage gewidmet.     

Facing resistance to health advice

This paper examines the possible responses for resistance to health information among women. The data are drawn from a broader qualitative study of how 60 women in Finnmark, a region of Norway, which examined how the participants responded to health information related to coffee, exercise, smoking and diet. This paper focuses on responses to health information about smoking. The study suggests that health information challenges the women's conception of their selves. This may make them take a distance to health information which then makes health information less effective.     

Expression patterns of cell cycle components in sporadic and neurofibromatosis type 1-related malignant peripheral nerve sheath tumors

The molecular biology underlying the development of highly malignant peripheral nerve sheath tumors (MPNSTs) remains mostly unknown. In the present study, the expression pattern of 10 selected cell cycle components is investigated in a series of 15 MPNSTs from patients with (n = 9) or without (n = 5) neurofibromatosis type 1 (NF1). Thirteen tumors did not express the cyclin-dependent kinase inhibitor, p16(INK4A), an observation that was related to homozygote gene deletions in three tumors, heterozygote deletions in five, and gross gene rearrangements in five. The absence of protein expression in the tumors with one seemingly intact allele was not caused by promoter hypermethylation of p16(INK4A) or p14(ARF). All tumor samples expressed normal sized RB1, cyclin D3, CDK2, CDK4, p21(CIP1), and p27(KlP1) proteins, and only a single tumor showed an aberrant protein band for one of these proteins, p21(CIP1). Cyclin D1 was absent in four tumors; all except one tumor showed expression of TP53 protein, and three of nine MPNSTs had expression of normal-sized MDM2. In conclusion, this study shows that the vast majority of MPNSTs had gross rearrangements of the p16(INK4A) gene, explaining the absence of the encoded protein in the same tumors. The level of expression was equally distributed between the familial (NF1) and sporadic cases, although it should be noted that the 2 cases with p16(INK4A) expression were sporadic. The data imply that the complete absence of p16(INK4A) is sufficient for activation of the cell cycle in most MPNSTs; thus, it is not necessary for tumor proliferation to further stimulate the cycle through alteration of other central components.     

Chromosome- and plasmid-encoded beta-lactamases in Capnocytophaga spp

Chromosome- and plasmid-encoded CfxA2 and CfxA3 beta-lactamases were detected in Capnocytophaga spp. from oral sources in France, Norway, and the United States. Unidentified chromosome-encoded beta-lactamases were present in Capnocytophaga sputigena. Nucleotide sequence analysis of the CfxA3-encoding plasmid from C. ochracea revealed an unreported insertion sequence (ISCoc1) upstream of the cfxA gene.     

Infant mortality,low birth weight,and prematurity among Hispanic,white, and African American women in North Carolina

OBJECTIVES: The study was undertaken to compare Hispanic birth outcomes with those of white and African American women in North Carolina and to examine variables associated with adverse birth outcomes among Hispanic women. STUDY DESIGN: Retrospective comparison of birth outcomes by ethnicity/race, from linked birth/infant death certificates in North Carolina (1993-1997) was conducted. Multivariate, binary logistic regression and chi(2) analysis were used to examine relationships between available medical and sociodemographic index values and composite birth outcomes among Hispanic women. RESULTS: Infant mortality rates were lowest among Hispanic women. Low birth weight and prematurity rates were similar to those of white women and lower than those of African American women. Variables significantly related to healthy composite birth outcomes among Hispanic women included higher education, no preterm delivery history, prenatal care, marriage, and no daily tobacco use. CONCLUSION: Hispanic birth outcomes in North Carolina were better than those of African American women and similar to those of white women, despite use of prenatal care and socioeconomic characteristics similar to African American women.