Do fibrinolytic proteins of human bile derive exclusively from gall bladder?

BACKGROUND

In this study we addressed the issue of whether fibrinolytic proteins are presented in gall bladder bile only or in choledochus bile as well.

MATERIAL AND METHODS

Gall bladder bile was obtained from 20 patients (Group I) undergoing laparoscopic cholecystectomy. Bile from common bile duct was aspirated after insertion Kehr drainage from 9 patients (Group II). The concentrations of t-PA, u-PA, PAI-1 and PAI-2 were measured by ELISA.

RESULTS

We have shown that in cholecystectomized patients fibrinolytic proteins can be detected in bile both from gall bladder and from choledochus. Mean concentrations of t-PA, u-PA, PAI-1 were lower in Group II (5.69 ng/ml vs 15.7; 0.46 ng/ml vs 0.7; 16.82 ng/ml vs 26.16 ng/ml) or nearly equal for PAI-2 (343.53 ng/ml vs 341.02). All differences were insignificant (p > 0.05).

CONCLUSIONS

Based on these results we concluded that the entire biliary tree produces the fibrinolytic proteins thus this production is not restricted to the gall bladder as it was earlier reported [1].

Accuracy of t-PA, u-PA, PAI-1 and PAI-2 estimation in human bile by ELISA kits

The aim of this study was to establish the accuracy of determination of fibrinolytic proteins in human bile using commercial kits.

MATERIAL AND METHOD

Gall bladder bile was obtained from patient undergoing laparoscopic cholecystectomy. The concentrations of tissue plasminogen activator (tPA), urokinase (uPA) and plasminogen activator inhibitor-1 (PAI-1) and inhibitor-2 (PAI-2) in bile were measured by enzyme linked immunoassay. Afterwards we conducted so called 'recovery test'.

RESULTS

Recovery percents of t-PA, u-PA, PAI-1, PAI 2 were very high i.e. 91.94, 94.07, 93.95, 91.2. We concluded that human fibrinolytic proteins in bile could be detected very accurately using commercial kits.

Phase I-II trial of intensification of the MAID regimen with support of lenograstim (rHuG-CSF) in patients with advanced soft-tissue sarcoma (STS)

This study was conducted to determine the maximum tolerated dose of an intensified MAID (mesna, adriamycin, ifosfamide, dacarbazine) regimen with the support of lenograstim in patients with advanced soft tissue sarcomas. Following 1 cycle of MAID at the standard dose, four patients were to be treated at each of five dosage levels: +25%, +45%, +65%, +85%, +100%. Sixteen patients were treated. Because there were no significant differences in hematologic toxicity between patients receiving lenograstim 5 or 10 microg/kg/day (levels 1-5 and 1-10), the data were pooled for comparison with level 2. The median duration of absolute neutrophil count < 0.5 x 10(9)/l was 3 days at level 1 and 7 days at level 2 (p < 0.01). The median platelet nadir was 25 x 10(9)/l at level 1 and 10 x 10(9)/l at level 2 (p < 0.01). The median duration of toxicity-related hospitalization was 3.5 days and 11 days at levels 1 and 2, respectively, (p < 0.001). Mucositis > or = grade III occurred after 3/29 cycles at level 1 and 10/15 cycles at level 2 (p < 0.001). After 4 cycles at level 1, 8/8 patients still had performance status scores < or = 2, and only 4/8 had performance status scores < or = 2 after the second cycle at level 2. Lenograstim enabled an increase of 25% of the MAID regimen. At higher dose levels, severe mucositis and deterioration in performance status were dose limiting.

Morelloflavone, a novel biflavonoid inhibitor of human secretory phospholipase A2 with anti-inflammatory activity

The flavanonylflavone morelloflavone inhibited secretory phospholipase A2 (PLA2) in vitro, with a high potency on the human recombinant synovial and bee venom enzymes (IC50 = 0.9 and 0.6 microM, respectively). The inhibition was apparently irreversible. In contrast, the compound was inactive on cytosolic PLA2 activity from human monocytes. Morelloflavone scavenged reactive oxygen species generated by human neutrophils (IC50 = 2.7 and 1.8 microM for luminol and lucigenin, respectively) but did not modify cellular responses such as degranulation or eicosanoid release. This biflavonoid exerted anti-inflammatory effects in animal models, with a potent inhibition of 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear inflammation in mice after topical administration. In this test, morelloflavone was found to decrease oedema and myeloperoxidase levels in ear homogenates ID50 = 58.5 and 74.3 micrograms/ear, respectively). In contrast, this biflavonoid failed to modify arachidonic acid-induced ear inflammation or eicosanoid levels in ear homogenates. A significant anti-inflammatory effect was also observed in the mouse paw carrageenan edema after oral administration, with the highest inhibition at 3 hr after induction of inflammation. Morelloflavone is an inhibitor of secretory PLA2 with selectivity for groups II and III enzymes and may be a pharmacological tool. In addition, it shows anti-inflammatory activity apparently not related to the synthesis of eicosanoids, but likely dependent on other mechanisms such as scavenging of reactive oxygen species.

Glucocorticoid regulation of hepatic S-adenosylmethionine synthetase gene expression

The effects of glucocorticoids on the regulation of rat liver S-adenosylmethionine synthetase were studied in vivo and in two culture systems. Livers from adrenalectomized animals were examined for enzyme activity, immunoreactive protein, and messenger RNA (mRNA) content. All three parameters showed a similar trend, i.e. they decreased 3-fold after adrenalectomy and increased over the control values upon triamcinolone replacement. These results suggested that glucocorticoid regulation of hepatic S-adenosylmethionine synthetase was mediated at the mRNA level. Triamcinolone and dexamethasone increased S-adenosylmethionine synthetase mRNA content in a time- and dose-dependent manner in both rat hepatoma H35 cells and primary cultures of adult rat hepatocytes. The kinetics of mRNA induction were identical in both culture systems, indicating that the hormone-mediated response is independent of the differentiated state of the cell. Insulin blocked the inducing effect of glucocorticoids on S-adenosylmethionine synthetase mRNA in a dose-dependent manner. On the other hand, the triamcinolone-dependent increase in mRNA levels was completely abolished by treatment with actinomycin D, whereas cycloheximide did not affect this response. The transcription rate of the gene, as measured by run-on assay, increased 3-fold after hormone addition. Transient transfections of H35 cells with 1.4 kilobases of the 5'-flanking region of the hepatic S-adenosylmethionine synthetase gene fused to a luciferase reporter gene showed that promoter activity is also increased 3-fold after triamcinolone treatment, suggesting that this promoter region contains the sequence elements necessary to confer glucocorticoid responsiveness. In addition to the transcriptional control of the hepatic S-adenosylmethionine synthetase gene, our results suggest that glucocorticoids may be acting at a posttranscriptional level.

Inositol-phosphoglycan inhibits calcium oscillations in hepatocytes by reducing calcium entry

Inositol-phosphoglycan (IPG) is a putative mediator of insulin action that has been shown to affect numerous biochemical processes. IPG, prepared from liver membranes, promptly inhibited phenylephrine- or vasopressin-induced [Ca2+]i oscillations when perfused over Fura-2-dextran injected rat hepatocytes. An antibody to IPG suppressed the inhibitory effect of insulin on the [Ca2+]i oscillations. Measurement of the rate of quench of cytoplasmic Fura-2 by extracellular Mn2+ showed that Ca2+ entry occurred continuously in the unstimulated cell and was not affected by phenylephrine or vasopressin. IPG, specifically, almost completely abolished the Mn2+ quench rate. Elevated extracellular [Ca2+] reversed the inhibitory effect of IPG on [Ca2+]i oscillations. We conclude that IPG inhibits the hepatocyte Ca2+ oscillatory by reducing the continuous Ca2+ influx that is required to sustain oscillations in [Ca2+]i.

Differential expression pattern of S-adenosylmethionine synthetase isoenzymes during rat liver development

The pattern of expression of liver-specific and extrahepatic S-adenosylmethionine (SAM) synthetase in developing rat liver was established by determining steady-state levels of the respective messenger RNAs (mRNAs) and protein content. Levels of liver-specific SAM synthetase mRNA increased progressively from day 20 of gestation, increased 10-fold immediately after birth, and reached a peak at 10 days of age, decreasing slightly by adulthood. Conversely, mRNA levels of extrahepatic isoenzyme decreased toward birth, increased threefold in the newborn, and decreased further in the postnatal life, reaching a minimum in the adult. Similar expression profiles were observed in isolated hepatocytes, indicating that both mRNAs are differentially regulated in the same cell type. Western blot analysis showed that levels of immunoreactive liver-specific isoenzyme followed a trend similar to the mRNA, indicating that developmental regulation of this enzyme is mediated at the mRNA level. Developmental patterns of expression of albumin and alpha-fetoprotein (AFP) mRNAs were closely related to those for liver-specific and extrahepatic isoenzymes, respectively. Therefore, it is suggested that liver-specific SAM synthetase may be a marker for hepatocyte differentiation. Incubation of primary cultures of hepatocytes from 21-day-old fetuses with permeant cyclic adenosine monophosphate (cAMP) analogues elicited an up-regulation of the mRNA for the liver-specific isoenzyme with a concomitant down-regulation of the extrahepatic message, suggesting a physiological role for the increased postnatal glucagonemia in the control of this isoenzyme switching. In contrast with the isoenzyme expression profiles, the levels of SAM, the product of SAM synthetase reaction, were determined to be greater during gestation than in immediate postnatal periods. These results indicate that synthesis and utilization of SAM may be regulated differentially in fetal and adult hepatocytes.

Effect of bakuchiol on leukocyte functions and some inflammatory responses in mice

The effects of bakuchiol, a meroterpenoid isolated from the leaves of Psoralea glandulosa L., on phospholipase A2 (PLA2) activity from different sources, human neutrophil responses, zymosan air pouch and topical inflammation in mice, were investigated. This natural product was a weak inhibitor of secretory and intracellular PLA2 but dose-dependently reduced the formation of LTB4 and TXB2 by human neutrophils and platelet microsomes, respectively. In addition, bakuchiol inhibited degranulation in human neutrophils, whereas superoxide generation was not affected. In mice, bakuchiol decreased cell migration, myeloperoxidase activity and eicosanoid levels in the air pouch inflammation induced by zymosan. After topical administration, this compound was effective as an inhibitor of oedema and myeloperoxidase activity in the 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear oedema and significantly reduced the PGE2 content and ear oedema in the arachidonic acid-induced response. Bakuchiol is a natural anti-inflammatory agent able to control leukocytic functions such as eicosanoid production, migration and degranulation in the inflammatory site.