The significance of bile secretion after the transplantation of long-preserved livers in the rat

Although one of the simplest indicators for predicting liver viability is bile secretion, it has never been proven whether it could be a good index for the viability of grafts in liver transplantation after cold ischemia. The present study, conducted on male Wistar rats, was undertaken to determine whether bile secretion reflects the viability of livers which have been preserved long-term. Livers were stored for up to 24 h in Euro-Collins (EC) or University of Wisconsin (UW) solution at 4°C, and transplanted orthotopically. The correlation between 1-week survival, bile flow, and the tissue adenosine triphosphate (ATP) level 4 h after transplantation was then investigated for each subgroup. The survival rates of the animals in the UW subgroups were much higher than those in the EC subgroups. In the rats transplanted with livers preserved for 6h in EC solution (EC-6), in which 100% survival was observed, both bile flow and ATP recovered sufficiently. Conversely, in the EC-12 group, in which only 10% survival was seen, restoration of bile flow, in ml/h per kg body weight, and ATP resynthesis, in pmol/g wet weight, were severely suppressed, with levels of 1.35 ± 1.05 and 0.77 ± 0.34, respectively. Moreover, in the EC-18 group, with 0% survival, neither bile flow nor ATP recovered. In the rats transplanted with livers preserved for 18h in UW solution (UW-18), bile flow and ATP, being 1.03 ± 0.56 and 1.12 ± 0.59, respectively, were much higher than those in the EC-18 group. A good correlation was found between bile flow and ATP (r = 0.84). The results of this study thus led us to conclude that bile secretion is a reliable index for predicting the viability of orthotopically transplanted grafts damaged by cold ischemia.     

Ossifying fibroma vs fibrous dysplasia of the jaw: molecular and immunological characterization.

Ossifying fibroma and fibrous dysplasia of the jaw are maxillofacial fibro-osseous lesions that should be distinguished each other by a pathologist because they show distinct patterns of disease progression. However, both lesions often show similar histological and radiological features, making distinction between the two a diagnostic dilemma. In this study, we performed immunological and molecular analyses of five ossifying fibromas, four cases of extragnathic fibrous dysplasia, and five cases of gnathic fibrous dysplasia with typical histological and radiographic features. First, we examined the difference between fibrous dysplasia and ossifying fibroma in the expression of Runx2 (which determined osteogenic differentiation from mesenchymal stem cells) and other osteogenic markers. Fibroblastic cells in fibrous dysplasia and ossifying fibroma showed strong Runx2 expression in the nucleus. The bone matrices of both lesions showed similar expression patterns for all markers tested except for osteocalcin. Immunoreactivity for osteocalcin was strong throughout calcified regions in fibrous dysplasia, but weak in ossifying fibroma lesions. Second, we performed PCR analysis with peptide nucleic acid (PNA) for mutations at the Arg(201) codon of the alpha subunit of the stimulatory G protein gene (GNAS), which has reported to be a marker for extragnathic fibrous dysplasia. All nine cases of extragnathic or gnathic fibrous dysplasia were positive for this mutation. On the other hand, none of the five cases of ossifying fibroma showed the mutation. These findings indicate that although fibrous dysplasia and ossifying fibroma are similar disease entities, especially in the demonstration of the osteogenic lineage in stromal fibroblast-like cells, they show distinct differences that can be revealed by immunohistochemical detection of osteocalcin expression. Furthermore, PCR analysis with PNA for GNAS mutations at the Arg(201) codon is a useful method to differentiate between fibrous dysplasia and ossifying fibroma.     

Driven shield for multi-barrel electrode

A driven shield for a nine-barrel micropipette containing a carbon fiber recording electrode in the center barrel is described. Two of the nine surrounding micropipettes were used as a driven shield channel to reduce capacitance between the recording electrode and the brain tissue. This method facilitates recording of single neuron activity, even in deep areas of the monkey brain, such as the amygdala and lateral hypothalamic area.     

VCP (p97) Regulates NFKB Signaling Pathway, Which Is Important for Metastasis of Osteosarcoma Cell Line

In order to identify genes associated with metastasis, suppression subtractive hybridization (SSH) was performed using murine osteosarcoma cell line Dunn and its subline with higher metastatic potential, LM8. SSH revealed expression of the gene encoding valosin-containing protein (VCP; also known as p97) to be constitutively activated in LM8 cells, but it declined in Dunn cells when the cells became confluent. Because VCP is known to be involved in the ubiquitination process of Inhibitor-αBα (IαBα), an inhibitor of nuclear factor-αB (NFαB), whether VCP influences NFαB activation or not was examined by using VCP-transfected Dunn cells (Dunn/VCPs). When stimulated with tumor necrosis factor-α (TNFα), Dunn/VCPs showed constantly activated NFαB, although in the original Dunn cells and control vector transfectant (Dunn/Dunn-c) NFαB activation ceased when the cells became confluent. Western immunoblot analysis showed an increase of phosphorylated IαBα (p-IKBα) in the cytoplasm of confluent Dunn/Dunn-c cells compared to that of Dunn/VCPs. Therefore, decrease of p-IKBα degrading activity might be responsible for the decrease in NFKB activation. In vitro apoptosis assay demonstrated increased apoptosis rates of Dunn/Dunn-c cells after TNFα stimulation compared to those of Dunn/VCPs and LM8 cells. In vivo metastasis assay showed increased incidences of metastatic events in Dunn/VCP-1 inoculated male C3H mice compared to those in Dunn/Dunn-c inoculated mice. These findings suggested that VCP expression plays an important role in the metastatic process. Anti-apoptotic potential in these cells owing to constant NFKB activation via efficient cytoplasmic p-IKBα degrading activity may explain the increased metastatic potential of these cells.     

Effects of acute and chronic parathyroidectomy on phosphate transport in brush border membrane vesicles

Acute parathyroidectomy (PTX) is associated with an increase in phosphate (Pi) uptake by renal cortical brush border membrane (BBM). We investigated the response to acute and chronic PTX in the renal BBM. Kinetic studies of Pi uptake were carried out in 5 groups of rats as follows; control, acute PTX (1h), chronic PTX (20h and 72h), and chronic PTX (20h) treated with 10 IU of parathyroid hormone (PTH). The Na⁺-dependent Pi transport in BBMV was significantly increased 1h after PTX. However, this increase was not retained 72h after PTX. The V_max of Pi uptake was significantly increased and the apparent Km was significantly decreased in acute PTX. In chronic PTX, the V_max and the apparent Km returned to control leyels. The treatment with PTH increased the apparent Km and decreased V_max significantly 20h after PTX. These results suggested an adaptive response to hyperphosphatemia in chronic PTX rats.     

Risk assessment of adverse pulmonary effects induced by adrenaline β-receptor antagonists and rational drug dosage regimen based on receptor occupancy

To clarify the β-1 selectivity of β-adrenergic receptor blocking agents (β-blocking agents) after typical oral doses, the relationships between the effects on exercise heart rate or FEV₁ and β-1 or β-2 receptor occupancies (Φ ₁ ,Φ ₂ ) of seven β-blocking agents, acebutolol, atenolol, metoprolol, oxprenolol, timolol, propranolol, and pindolol were analyzed retrospectively. Nonlinear relationships between the pharmacologic effect andΦ ₁ and between the pulmonary adverse effect andΦ ₂ were obtained. Based on these findings, a new index of cardiovascular selectivity is proposed, given by the ratio of β-1 receptor occupancy to β-2 receptor occupancy (Φ ₁ /Φ ₂ ). Using this new index, there was a little difference in β-1 selectivity between acebutolol and pindolol (3.1:1.0), in contrast to a marked difference in β-1 selectivity (320:1) as a conventional index between these two drugs. This finding indicates that even β-1 selective drugs must be administered carefully to patients with pulmonary disease. Furthermore, the relationship between the pharmacologic or pulmonary effects andΦ ₁ orΦ ₂ has been analyzed quantitatively with a ternary complex model and used to develop rational dosage regimens for β-1 selective β-blocking agents, such as atenolol, to obtain the desired pharmacologic effects with minimum adverse pulmonary effects.