A rifampicin-induced hepatic microsomal enzyme system for the generation of cyclosporine metabolites

A drug-induced rabbit hepatic microsomal enzyme system has been developed to produce milligram quantities of cyclosporine metabolites (CMs). Using a rifampicin-induced microsomal preparation in the presence of a NADPH regenerating system, 60% of the cyclosporine (CsA) was converted to CMs in 2 h. The CMs were recovered by solid phase extraction, and separated by gradient high performance liquid chromatography with two Ultrasphere Ocyl (C8) columns connected in tandem. More than 20 CMs were resolved. The quantities of major CMs produced by 45 mg of microsomal proteins were established by comparing peak areas with known concentrations of authentic CM standards. These major CMs included AM1, AM9, AM19, AM4N, AM1c and the aldehydic isomers (AM1cAL plus AM1AL). Other CMs that were not quantified included AM14N, AM4N9, AM1A, AM1c9, and AM1D1. Several CMs remained to be identified. All CMs were detected by radioimmunoassay using a non-specific CsA antiserum. The purity of the CMs were confirmed by fast atomic bombardment mass spectrometry. Similar findings were observed when erythromycin or trolandomycin was used to induce the hepatic microsomal enzymes. The procedure used to generate CMs was simple. With the enzyme fraction derived from one rabbit liver, 90 to 100 mg of CMs can be obtained. In this study, the metabolite patterns of CsA produced by rabbit liver microsomes were shown to resemble those observed for humans. These results indicate the possibility of using rabbit models to predict CsA biotransformation in man. The CMs generated by this enzyme system can be used to acquire information relevant to the situation in man.

[Study of anti-cerebral thromboembolism injection's activity on experimental arterial thrombosis and its therapeutical mechanism]

Anti-Cerebral Thromboembolism Injection (ACTI), applied intravenously in Cattaneo's animal model of arterial thrombosis, could significantly reduce the weight of thrombus, blood viscosities, plasma TXB2 level and delay the prothrombin time, compared to control group (P < 0.05). From this trial, it was indicated that ACTI's reducing thrombosis action was the result of inhibiting aggregation and releasing of platelets through reducing whole blood viscosities and TXB2 level.

[Effects of 3 kinds of decoction on serum gastrin, gastrin cell density and the content of PGE2 of gastric antral mucosa in experimental chronic gastritis in rats]

Experimental chronic gastritis (ECG) models were established in rats by inserting a spring into pyloric canal as well as feeding sodium deoxycholate. An experiment was undertaken to observe the therapeutic effects of three formulas of traditional Chinese medicine "Shipitong" (SPT), "Ganpingyangwei" (GPYW) and "Weile" (WL). The experimental results show that all of the three decoctions can make serum gastrin, gastrin cell density and amount of antral mucosal PGE2 of the ECG rats return to normal levels.

CD36 gene transfer confers capacity for phagocytosis of cells undergoing apoptosis

Phagocyte recognition and ingestion of intact cells undergoing apoptosis are key events in this generally important program of cell death. Insufficient phagocyte capacity for apoptotic cells can result in failure to clear dying cells before membrane integrity is lost, resulting in leakage of noxious cell contents and severe tissue damage. However, no means has been available to increase phagocytic clearance of apoptotic cells. We now report that transfection of the macrophage adhesion molecule CD36 into human Bowes melanoma cells specifically conferred greatly increased capacity to ingest apoptotic neutrophils, lymphocytes, and fibroblasts, comparable to that exhibited by macrophages. Furthermore, when CD36 was transfected into another cell type with limited capacity to take up apoptotic bodies, the monkey COS-7 cell, similar effects were observed. Therefore, CD36 gene transfer can confer "professional" capacity to ingest apoptotic cells upon "amateur" phagocytes.

[An experimental study on the integrated effects of heat-cleaning and detoxifying drugs and fire-purging drugs used in combination]

Heat-cleaning and detoxifying drugs and fire-purging drugs used in combination have been proved able to restore the endotoxin-induced deviant of HCT, blood viscositites, PTT and fibrinolytic activity, and reduce the blood content of both endotoxin and PGE2 in rabbits. In addition, the combination can also decrease the pes swelling percentage in rats as well as evans blue extravasation volume in mice. In practice, however, it should be noted that the bitter and cold qualities of these two kinds of drugs may be harmful to health.

The orphan receptor hepatic nuclear factor 4 functions as a transcriptional activator for tissue-specific and hypoxia-specific erythropoietin gene expression and is antagonized by EAR3/COUP-TF1

The erythropoietin (Epo) gene is regulated by hypoxia-inducible cis-acting elements in the promoter and in a 3' enhancer, both of which contain consensus hexanucleotide hormone receptor response elements which are important for function. A group of 11 orphan nuclear receptors, transcribed and translated in vitro, were screened by the electrophoretic mobility shift assay. Of these, hepatic nuclear factor 4 (HNF-4), TR2-11, ROR alpha 1, and EAR3/COUP-TF1 bound specifically to the response elements in the Epo promoter and enhancer and, except for ROR alpha 1, formed DNA-protein complexes that had mobilities similar to those observed in nuclear extracts of the Epo-producing cell line Hep3B. Moreover, both anti-HNF-4 and anti-COUP antibodies were able to supershift complexes in Hep3B nuclear extracts. Like Epo, HNF-4 is expressed in kidney, liver, and Hep3B cells but not in HeLa cells. Transfection of a plasmid expressing HNF-4 into HeLa cells enabled an eightfold increase in the hypoxic induction of a luciferase reporter construct which contains the minimal Epo enhancer and Epo promoter, provided that the nuclear hormone receptor consensus DNA elements in both the promoter and the enhancer were intact. The augmentation by HNF-4 in HeLa cells could be abrogated by cotransfection with HNF-4 delta C, which retains the DNA binding domain of HNF-4 but lacks the C-terminal activation domain. Moreover, the hypoxia-induced expression of the endogenous Epo gene was significantly inhibited in Hep3B cells stably transfected with HNF-4 delta C. On the other hand, cotransfection of EAR3/COUP-TF1 and the Epo reporter either with HNF-4 into HeLa cells or alone into Hep3B cells suppressed the hypoxia induction of the Epo reporter. These electrophoretic mobility shift assay and functional experiments indicate that HNF-4 plays a critical positive role in the tissue-specific and hypoxia-inducible expression of the Epo gene, whereas the COUP family has a negative modulatory role.

Proinflammatory cytokines potentiate thrombospondin-mediated phagocytosis of neutrophils undergoing apoptosis

Apoptosis leads to swift recognition, ingestion, and degradation of intact senescent neutrophils by macrophages. This protects tissues from leakage of noxious contents from dying cells and may promote resolution of inflammation. However, little has been known of the mechanisms that regulate macrophage capacity for apoptotic cells during an inflammatory response. We examined whether proinflammatory cytokines modulated phagocytosis of senescent neutrophils undergoing apoptosis by human monocyte-derived macrophages at 4 days maturity (4d M phi), an in vitro model of neutrophil "disposal" by apoptosis. Pretreatment of 4d M phi with granulocyte-macrophage-CSF increased the proportion of 4d M phi taking up apoptotic PMN in a concentration-dependent fashion by up to approximately 240%. This was by a rapid effect detectable by 4 h and exerted on the M phi, not the PMN. Granulocyte-macrophage-CSF also increased the number of apoptotic PMN taken up by each M phi. IFN-gamma, IL-1 beta, TNF-alpha, and TGF-beta 1 also enhanced phagocytosis, but IL-4 and IL-6 had no effect. In each case, the cytokine-expanded phagocytic subpopulation employed the thrombospondin (TSP)-dependent recognition mechanism defined for mature M phi, in which M phi vitronectin receptor and CD36 cooperate. However, commensurate increases in M phi expression of VnR, TSP, or CD36 were not detectable, indicating that TSP-mediated recognition can be recruited by other mechanisms. Cytokines did not recruit phosphatidylserine-dependent recognition, the other major mechanism by which some macrophage populations ingest apoptotic cells. Thus, M phi phagocytosis of apoptotic neutrophils can be potentiated by proinflammatory cytokines, suggesting a mechanism for negative feedback control of neutrophil number at inflamed sites.

Proinflammatory cytokines potentiate thrombospondin-mediated phagocytosis of neutrophils undergoing apoptosis

Apoptosis leads to swift recognition, ingestion, and degradation of intact senescent neutrophils by macrophages. This protects tissues from leakage of noxious contents from dying cells and may promote resolution of inflammation. However, little has been known of the mechanisms that regulate macrophage capacity for apoptotic cells during an inflammatory response. We examined whether proinflammatory cytokines modulated phagocytosis of senescent neutrophils undergoing apoptosis by human monocyte-derived macrophages at 4 days maturity (4d M phi), an in vitro model of neutrophil "disposal" by apoptosis. Pretreatment of 4d M phi with granulocyte-macrophage-CSF increased the proportion of 4d M phi taking up apoptotic PMN in a concentration-dependent fashion by up to approximately 240%. This was by a rapid effect detectable by 4 h and exerted on the M phi, not the PMN. Granulocyte-macrophage-CSF also increased the number of apoptotic PMN taken up by each M phi. IFN-gamma, IL-1 beta, TNF-alpha, and TGF-beta 1 also enhanced phagocytosis, but IL-4 and IL-6 had no effect. In each case, the cytokine-expanded phagocytic subpopulation employed the thrombospondin (TSP)-dependent recognition mechanism defined for mature M phi, in which M phi vitronectin receptor and CD36 cooperate. However, commensurate increases in M phi expression of VnR, TSP, or CD36 were not detectable, indicating that TSP-mediated recognition can be recruited by other mechanisms. Cytokines did not recruit phosphatidylserine-dependent recognition, the other major mechanism by which some macrophage populations ingest apoptotic cells. Thus, M phi phagocytosis of apoptotic neutrophils can be potentiated by proinflammatory cytokines, suggesting a mechanism for negative feedback control of neutrophil number at inflamed sites.

[The effects of progestin on the bone metabolism in postmenopausal women]

Thirty postmenopausal women, including 26 with history of hysterectomy and bilateral salpingooophorectomy due to uterine myoma and 4 with natural menopause without any diseases were randomly allocated into two groups. Fifteen subjects received medroxyprogesterone acetate (MPA) 10 mg twice daily for three months, the other 15 received both MPA 10 mg twice daily and cyclopentylethinyl estriol (CEE3) 5 mg once a month for three months. Fasting urinary calcium/creatinine (Ca/Cr) and hydroxyproline/creatinine (OHpr/Cr) ratio, serum calcitonon (CT) and alkaline phosphatase (AKP) concentrations were measured before and after treatment in all subjects. The results showed that in both groups, the fasting urinary Ca/Cr and OHpr/Cr ratio reduced significantly, while serum CT and AKP increased significantly after treatment. The changes of these parameters were not significantly different between these two groups. These data indicated that progestin alone appeared effective in preventing postmenopausal osteoporosis.

Prostaglandin H synthase-1: evaluation of C-terminus function

The first committed step in prostaglandin biosynthesis is catalyzed by prostaglandin H synthase, an enzyme localized to the endoplasmic reticulum (ER) membrane in a variety of cells. Several types of C-terminal region peptide sequence motifs have been found to lead to ER retention of other proteins. We have tested the potential role for such signals in the ER localization and catalytic activity of human isoform-1 of the synthase (PGHS-1). PGHS-1 mutants with alterations in the C-terminus designed to disrupt potential retention signals were expressed in transfected COS-1 cells. The mutations included: substitution of valine for the ultimate leucine residue (position 600) to disrupt a KDEL-type signal, substitution of a neutral glutamine for arginine at position 595 to disrupt signals based on positive charge, and deletion of the last six residues, to remove all of the wild-type extreme C-terminus. The subcellular localization of each recombinant PGHS-1 was assessed by differential centrifugation and by immunofluorescence microscopy. None of the mutations led to a significant change in the distribution of PGHS-1 between microsomes and other cellular fractions. Immunostaining of wild-type PGHS-1 and all of the mutants colocalized with that of protein disulfide isomerase, an ER marker protein. However, mutation of the terminal leucine or deletion of the last six residues did lead to loss of cyclooxygenase activity. Mutation of the terminal leucine also altered the pattern of fragments produced by limited proteolysis, indicating that this mutation led to changes in the polypeptide folding which might account for the loss of activity. The results indicate that the extreme C-terminal region is important to the functional integrity of PGHS-1, but it is not an essential part of the intracellular targeting mechanism.

[Experimental study on compatible application of heat-clearing and detoxifying drugs with blood circulation improving drugs]

The article describes the effectiveness of compatible application of heat-clearing and detoxifying drugs with blood circulation improving drugs to the animal model with endotoxemia and nonspecific inflammation. The compatible application reduces PGE2, endotoxin blood concentration and reduced viscosity of whole blood, decreases Evans blue extravasation volume and pes swelling percentage, increases serum cortisol content and enhances fibrinolytic activity. The experimental result shows that in most cases these two drugs work better when used in combination which implies that compatible application is more effective in detoxification, antiinflammation and inflammation recovery.

Epidural versus subcutaneous administration of alfentanil for the management of postoperative pain

This study was designed to compare the efficacy and serum concentrations of alfentanil given subcutaneously (SQ) or epidurally (EPID) for treatment of postoperative pain. Following abdominal surgery, patients (n = 12) were randomly assigned to receive double-blind SQ or EPID alfentanil over 24 h via the allocated route (1 mg along with 0.2 mg/h and 0.2-mg boluses on demand) and saline via the other route of administration using a patient-controlled analgesic (PCA) delivery system. Significantly less EPID alfentanil produced better quality analgesia and fewer side effects than SQ alfentanil. The fact that EPID analgesia was maintained with serum alfentanil concentrations less than those producing systemic analgesia confirms the spinal site of the EPID alfentanil action.

Overexpression and characterization of recombinant human fusion protein IL-6/IL-2 (CH925)

An expression vector encoding the human recombinant fusion protein interleukin 6/interleukin 2 (IL-6/IL-2) was constructed. When a flexible linker had been synthesized and ligated with the IL-2 gene fragment by polymerase chain reaction (PCR) amplification, the IL-6 gene fragment was unidirectionally inserted into the upstream of the linker-IL-2 sequence. The molecule of the IL-6-linker-IL-2 fusion gene named E. coli DH5 alpha/pfIL-6/2 was cloned and identified by DNA sequencing. The expressed protein named as CH925 showed a strong band on SDS-PAGE and amounted to 32% of total cell protein, and its estimated molecular weight was about 37 kDa. The fusion protein purified by gel filtration and reversed-phase HPLC showed as almost homogeneous. CH925 possesses both IL-2 and IL-6 activities when assayed by CTLL2- and 7TD1-dependent cell lines, respectively. The specific activity of IL-2 was 2.1 x 10(6) U/mg while that of IL-6 was 2.3 x 10(8) U/mg. Our studies exhibited that CH925 exerted a significant augmentative effect on the growth of erythroid colony forming units (CFU-E), and synergized with erythropoietin (EPO) and/or IL-3 in a dose-dependent way. Our experimental results also showed CH925 at a low dose causing active lymphokine-activated killer (LAK) cell proliferation more vigorous than IL-2 and/or IL-6 (p < 0.001). CH925 is a novel fusion protein, being neither IL-6 nor IL-2, more potent than IL-2 and/or IL-6 and causing non-IL-2 and non-IL-6 functions of strong EPO-like and mild IL-3-like effects on erythroid progenitor cell growth. There is a potential for efficacious clinical application of CH925.

Glomerular prostaglandins modulate vascular reactivity of the downstream efferent arterioles

The balance of vascular resistance in afferent (Af-) and efferent arterioles (Ef-Arts) is a crucial factor that determines glomerular hemodynamics. We have recently reported that when Ef-Arts were perfused from the distal end of the Af-Art through the glomerulus (orthograde perfusion; OP), both angiotensin II (Ang II) and norepinephrine (NE) induced much weaker constriction than they did when Ef-Arts were perfused from the distal end (retrograde perfusion; RP). This difference was not affected by inhibiting synthesis of nitric oxide. In the present study, we tested the hypothesis that glomerular prostaglandins (PGs) may modulate vascular reactivity of the downstream Ef-Art. In addition, we examined the possible modulatory role of PGs in the Af-Art responses to Ang II or NE. Both Ang II and NE caused dose-dependent constriction of Ef-Arts with either OP or RP; however, the constriction was stronger in RP. At 10(-8) M, Ang II decreased Ef-Art diameter by 35 +/- 3.5% in OP (N = 9) compared to 73 +/- 3.9% in RP (N = 5), while 10(-6) M NE decreased the diameter by 25 +/- 3.6% in OP (N = 9) compared to 62 +/- 7.2% in RP (N = 5). Pretreatment with 5 x 10(-5) M indomethacin (Indo) did not alter basal diameter with either method of perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Dielectric properties of human red blood cells in suspension at radio frequencies

Dielectric properties of human red blood cells (RBCs) in suspension (hematocrit 50%) from 243 healthy persons (120 males, 123 females) were measured at 25 degrees C in a frequency range of 1-500 MHz, with a coaxial transmission line reflection method (one-side measurement). The measuring system, controlled by an IBM-PC computer, was composed of a network analyzer (HP4195A), an impedance test adapter (HP41951-61001), a coaxial line sensor, and a temperature-controlling set. The data measured revealed a statistically significant age dependence, with a critical age of about 49 years, above which permittivity and conductivity of human RBCs in suspension decreased significantly.

Evidence for the role of nitric oxide in macula densa control of glomerular hemodynamics

There is evidence that nitric oxide, an endothelium-derived relaxing factor, may be produced by the macula densa, as well as by blood vessels, within the kidney. To examine the role of nitric oxide in macula densa control of glomerular hemodynamics directly, we performed in vitro microperfusions of both rabbit afferent arterioles (with the glomerulus intact) and adherent tubular segments consisting of portions of the thick ascending limb, macula densa, and early distal tubule. While keeping afferent arteriolar pressure constant at 60 mmHg, we examined the effect of Nw-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis, added to a macula densa perfusate. When the macula densa perfusate was changed from low to high NaCl, the diameter of the arterioles decreased from 16.3 +/- 1.0 to 14.0 +/- 1.1 microns (n = 10; P < 0.001). Addition of 10(-5) M L-NAME to the high NaCl solution further decreased the diameter to 11.9 +/- 1.1 microns (P < 0.001). In contrast, when macula densa perfusion was maintained with the low NaCl solution, addition of L-NAME had no effect. L-NAME-induced constriction was completely reversed by adding 10(-3) M L-arginine (the precursor of nitric oxide) but not D-arginine (an inactive isomer) to the macula densa perfusate. We confirmed that perfusing the macula densa with L-NAME did not affect the vasodilator action of acetylcholine added to the lumen of the afferent arteriole, indicating that NO synthesis by the arteriole was not altered. Thus, our findings suggest that the macula densa may produce nitric oxide, which in turn modulates the afferent arteriolar constriction induced by high concentrations of NaCl at the macula densa.