Dendritic changes of the pyramidal neurons in layer V of sensory-motor cortex of the rat brain during the postresuscitation period

The present study examined the temporal pattern and cellular localisation of nitric oxide synthase in Endotoxin-Induced Uveitis (EIU). Lewis rats (n=40) received a single footpad injection of 200 microg of bacterial lipopolysaccharide. Animals were killed at 0, 2, 4, 6, 12, 24, 48 and 72 hr after injection and ocular tissues prepared as iris-ciliary body wholemounts or frozen sections of the anterior segment. The expression of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) was investigated at all time points by immunohistochemistry. A further group of animals (n=6) were killed at the peak of the disease (12 hr) and the cellular co-localisation of iNOS on resident and infiltrating immune cells was investigated by double immunohistochemistry utilising the biotinylated monoclonal antibodies ED1, ED2 and Ox6. Expression of cNOS on iris vessels did not alter during the course of EIU. Quantitative analysis of iris-ciliary body wholemounts revealed the first evidence of iNOS+ at 2 hr which increased dramatically at 4 and 6 hr with a peak at 12 hr. The expression of iNOS in the early phase of the disease (2-6 hr) was associated with small round marginating and newly extravasated cells that on morphological criteria were most likely neutrophils and monocytes. At 12 hr, cells of more mixed morphologies began to express iNOS and double labelling revealed 70% of these cells were also ED1(+) (a lysosomal antigen present in monocytes/macrophages and dendritic cells), 52% were Ox6(+) (MHC class II) (dendritic cells, activated macrophages and some T-cells) and 19% were ED2(+) (pan-specific resident tissue macrophages). Expressed in an alternative manner, 10% of the total ED1(+) cell population, 11% of the ED2(+) cells and 44% of Ox6(+) cells co-expressed iNOS. Expression of iNOS decreased significantly by 24 hr to near baseline levels and was absent by 48 and 72 hr. Within the ciliary processes iNOS+ dendriform cells were noted at 6 hr and accumulations of many small round iNOS+ cells were present at 12 hr. The ciliary epithelium did not at any time express iNOS at the protein level detectable by immunohistochemistry. The results of this study suggest that iNOS expression early in EIU is associated with infiltrating or newly recruited neutrophils and monocytes/macrophages in the iris whereas later in the disease resident tissue macrophages and MHC class II+ cells (activated macrophages and putative dendritic cells) in the iris and ciliary body may synthesise nitric oxide. The role of this late phase of nitric oxide synthesis may include lymphocytostasis and immunosuppression as proposed in other tissue sites. The outcome of the present study may help in planning therapeutic strategies using NOS inhibitors.     

Insulin-like growth factor-binding protein (IGFBP-3) predisposes breast cancer cells to programmed cell death in a non-IGF-dependent manner

Insulin-like growth factor (IGF) -independent growth inhibition of human breast cancer cells, Hs578T, by IGF-binding protein-3 (IGFBP-3) has previously been demonstrated. Cell growth is a balance between proliferation and programmed cell death (apoptosis). We have investigated whether IGFBP-3 can affect apoptosis of Hs578T cells. As no induction of apoptosis was found, we also investigated its effect on the response to ceramide, an intracellular second messenger that mediates the signal for apoptosis. Using the cell permeable ceramide analogue, C2, induction of apoptosis was established by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide) assay, trypan blue uptake, morphological criteria, and flow cytometry. Incubation of cells with non-glycosylated IGFBP-3 (ngIGFBP-3; 0.5-100 ng/ml) resulted in no growth inhibition or increase in apoptosis; whereas, C2 (1-30 microM) resulted in a dose-dependent induction of apoptosis. Addition of IGFs to the cells, alone or with C2, elicited no response in terms of proliferation or survival, respectively. When the cells were preincubated with ngIGFBP-3 before addition of C2 (2-5 microM), apoptosis was accentuated in a dose-dependent manner (at 100 ng/ml IGFBP-3, apoptosis increased from 11 to 88%). In conclusion, we found that IGFBP-3 had no direct inhibitory effect on Hs578T cells but could accentuate apoptosis induced by the physiological trigger ceramide in an IGF-independent manner.     

Ossified lipoma of the interpeduncular fossa: a case report and review of the literature

We report two cases of Creutzfeld-Jakob disease with clusters of giant collagen fibers. To our knowledge, these abnormally large collagen fibers have never been described in patients with degenerative diseases of the central nervous system. The significance of the formation of such plaque-like large collagen fibers has as yet not been elucidated. It is felt that these represent a product of the degenerative process.     

Prospective evaluation for pneumonectomy using the 99mtechnetium quantitative perfusion lung scan

We evaluated 33 high-risk patients before pneumonectomy, all of whom had a forced expiratory volume in one second (FEV1) of less than 2.0 L before surgery. A quantitative perfusion lung scan was used to assess the right-left distribution of blood flow. A predicted postoperative FEV1 was calculated from the information on the lung scan and the preoperative FEV1. If this calculated value exceeded 800 ml, the patient was physiologically cleared for surgery up to and including a pneumonectomy. Surgery was otherwise believed to be contraindicated in the absence of studies using balloon occlusion. Perioperative mortality (less than or equal to 30 days after surgery) was found to be 15 percent (5/33). In surgery of this magnitude, we find this to be an acceptable percentage of mortality and have continued to use these simple physiologic criteria to determine whether a patient can tolerate pneumonectomy.     

Chemical constituents of Gentianaceae XIX: CNS-depressant effects of swertiamarin

CNS activity of swertiamarin, a secoiridoid glucoside from Swertia chirata, was evaluated. An apparent anomaly, associated with the unanticipated finding that the alcoholic extracts (excluding mangiferin) of S. chirata significantly reversed the mangiferin-induced CNS-stimulating effects in albino mice and rats, was resolved. The results indicate that swertiamarin and mangiferin antagonize each other in vivo and thereby reverse their CNS effects.     

Ultrastructural differences induced by heat in red and white avian muscles in rigor mortis

A species difference in the intercellular adhesive selectivity of mixtures of embryonic liver cells is reported. This is first quantitative assessment of species differences in the intercellular adhesive properties of embryonic cells. A collecting aggregate assay, a new double-label assay procedure, and histological and autoradiographic procedures were used to elucidate the intercellular adhesive selectivity of developing mammalian and avian liver cells. Evidence is presented that the reported adhesive differences are not due to the different cell types composing the respective embryonic mammalian and avian livers. Finally, such heterolgous-homotypic selectivity of adhesion is not a property of all tissues, since it is shown that developing brain cells (mesencephalon) do not exhibit the avove intercellular adhesive selectivity (mammalian vs. avian). These findings provide further support for the hypothesis that generic identity as well as cell type may play an important part in determining the intercellular adhesive behavior of heterologous-homotypic mixtures of embryonic cells. A possible evolutionary divergence of morphogenetic mechanisms is discussed.