Role of glutathione and catalase in H2O2 detoxification in LPS-activated hepatic endothelial and Kupffer cells

The present study investigated the effect of lipopolysaccharide (LPS; from Escherichia coli, 2 mg/kg body wt ip) on selected aspects of the antioxidant status in Kupffer and sinusoidal endothelial cells. Cells were isolated 18 h after the injection of saline or LPS. In fresh suspension cultures, cellular reduced glutathione (GSH) and H2O2 were determined by monochlorobimane, and 2',7'-dichlorofluorescein diacetate, respectively, using a fluorescence plate reader. LPS injection increased GSH content two- to threefold in Kupffer cells compared with cells from control rats. Cellular GSH content was higher in endothelial than Kupffer cells. However, LPS did not increase GSH content in endothelial cells. Addition of H2O2 (40-200 microM) to Kupffer or endothelial cells caused a transient decrease in GSH, which was more pronounced in cells from control rats (approximately 45% drop) than in LPS-exposed cells (approximately 25% drop). Depleted GSH levels were accompanied by a proportional increase in cellular H2O2. After inhibition of catalase by 3-amino-1,2,4-triazole, the presence of 0.2 mM H2O2 depleted GSH content by 75% and 40% in Kupffer cells from saline- or LPS-injected rats, respectively. The same treatments caused a similar 50% decrease in both activated and control endothelial cells. LPS decreased catalase activity by 45% in Kupffer cells, whereas it had no effect on catalase in endothelial cells. Glutathione reductase activity was not altered by LPS in either cell type. These data show that in activated Kupffer cells the elevated level of cellular glutathione plays an augmented role in the protection against reactive oxygen species, whereas the contribution of catalase to H2O2 detoxification is attenuated. In LPS-stimulated endothelial and Kupffer cells, the efficient maintenance of GSH is consistent with upregulated production of reducing power through the hexose phosphate shunt observed previously.

[Effects and mechanism of emodin and sandostatin on pancreatic ischemia in acute haemorrhagic necrotizing pancreatitis]

OBJECTIVE

To investigate pancreatic ischemia and abnormal metabolism of eicosanoids in acute haemorrhagic-necrotizing pancreatits (AHNP) and the effects of emodin or sandostatin on them.

METHODS

Rats with AHNP were triggered with sodium taurocholate; the pancreatic blood flow (PBF) was detected with computerized tissue blood flowmeter, and plasma prostaglandin E2 (PGE2), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane (TXB2) were determined with radioimmunoassay.

RESULTS

There was a significant decrease of PBF in the early stage of AHNP. Compared with that in the untreated group, significant improvement of PBF was demonstrated in emodin as well as in sandostatin group which showed reduced PBF following infusion of sandostatin before triggering AHNP. In untreated group plasma TXB was significantly higher, with an increase of 4.5 times, than that in sham-operated group while 6-keto-PGF1 alpha or PGE2 tended to decrease. The above mentioned abnormal synthesis of eicosanoids was blocked either in emodin or in sandostatin group in which lessened damage of acini cells was shown by pathologic scoring or transmission electron microscope. Both of the two groups shared significantly lower mortalities than the untreated group.

CONCLUSION

Either emodion or sandostatin could partly reverse the decrease of PBF in the early stage of AHNP, which may be ascribed at least in part to inhibition of abnormal synthesis of eicosanoids and improvement of cytoprotection of acini cells, and combined application of the two drugs might promise positively synergetic action as well.

No correlation between side-chain of propranolol oxidation and S-mephenytoin 4'-hydroxylase activity

AIM

To determine if any correlation between the side-chain oxidative capacity for propranolol and S-mephenytoin 4'-hydroxylase (cytochrome P-450 2C19, CYP2C19) activity in healthy Chinese of Han nationality.

METHODS

S-mephenytoin oxidative metabolite 4'-hydroxymephenytoin (4'OH-M), S- and R-mephenytoin, and naphthoxyl-actic acid (NLA) excreted in urine, and propranolol in plasma were measured after 14 healthy extensive metabolizers of S-mephenytoin oxidation were given a single oral dose of racemic mephenytoin 100 mg and racemic propranolol 80 mg, respectively. S/R-mephenytoin in urine was determined by chiral capillary gas chromatography with nitrogen-phosphorus detection, 4'-OH-M in urine by reversed-phase liquid chromatography (RPLC) with ultraviolet detection, and plasma propranolol or urinary NLA by the RPLC with fluorescence detection.

RESULTS

No significant correlations were found between the partial metabolic clearance (Clm) of propranolol to NLA and 8 h urinary S/R ratio of mephenytoin (rs = -0.0484; P = 0.8695), nor between the Clm and log10 of 8 h urinary excretion of 4'-OH-M (rs = -0.1077; P = 0.7140).

CONCLUSIONS

CYP2C19 is not a principal P-450 isozyme responsible for the in vivo side-chain oxidation of propranolol in the Chinese.

Variation of nerve fibre layer thickness measurements with age and ethnicity by scanning laser polarimetry

AIMS

Scanning laser polarimetry is a new technique allowing quantitative analysis of the retinal nerve fibre layer in vivo. This technique was employed to investigate the variation of the retinal nerve fibre layer thickness in a group of normal subjects of different ages and ethnic groups.

METHODS

150 normal volunteers of different ages and ethnic groups were recruited for this study. Three consecutive 15-degree polarimetric maps were acquired for each subjects. Nerve fibre layer thickness measurements were obtained at 1.5 disc diameters from the optic nerve. Four 90-degree quadrants were identified.

RESULTS

The mean nerve fibre layer thickness varied from a minimum of 55.4 microns to a maximum of 105.3 microns, with a mean thickness value of 78.2 (SD 10.6) microns. Superior and inferior quadrants showed a comparatively thicker nerve fibre layer than nasal and temporal quadrants. Retinal nerve fibre layer thickness is inversely correlated with age (p < 0.001). White people showed thicker nerve fibre layers than Afro-Caribbeans (p = 0.002).

CONCLUSION

The results indicate a progressive reduction of the nerve fibre layer thickness with increasing age. This may be due to a progressive loss of ganglion axons with age as suggested in postmortem studies. A racial difference in nerve fibre layer thickness is present between whites and Afro-Caribbeans.

Antinociceptive activities of 70% methanol extract of evodiae fructus (fruit of Evodia rutaecarpa var. bodinieri) and its alkaloidal components

The effects of 70% methanol extract (EA-ext) from Evodiae Fructus (EA) consisting of dried fruits of Evodia rutaecarpa var. bodinieri (Rutaceae) on nociceptive responses were investigated. Oral administration of 50 or 200 mg/kg EA-ext had the same antinociceptive effect on writhing responses as induced by acetic acid. Its major alkaloidal constituents, evodiamine and rutaecarpine also had the antinociceptive effect. EA-ext significantly decreased the frequency of licking behavior within a unit of time at the late phase without affecting that of the early phase in the formalin test. EA-ext also increased nociceptive threshold of the inflamed paw without increasing that in the non-inflamed paw in the Randall-Selitto test. Although EA-ext inhibited the rise of vascular permeability induced by acetic acid and the increase of paw edema induced by carrageenin, it was ineffective on nociceptive response in the hot plate test and on locomotor activity. These results suggest that EA possesses antinociceptive effects and its mode of action may be mediated by anti-inflammatory action, and that the antinociceptive constituents are only partially attributable to alkaloidal components mentioned above.

Tumor necrosis factor alpha augments the expression of glucose-6-phosphate dehydrogenase in rat hepatic endothelial and Kupffer cells

Cellular activity of glucose-6-phosphate dehydrogenase (G6PD), the key enzyme of the hexose monophosphate shunt, supports several pathways involved in the nonspecific immune response. In the present study, we investigated the in vivo effects of selected pro-inflammatory cytokines on the expression of G6PD in Kupffer and hepatic endothelial cells. Murine recombinant TNF alpha, IL-1 beta, or IL-6 (1.5 x 10(5) U/kg) was injected and cellular G6PD mRNA level determined using a quantitative reverse transcription and polymerase chain reaction method. G6PD mRNA was elevated two- to threefold seven hours after the injection of TNF alpha in Kupffer and endothelial cells as compared to cells from saline-injected animals. The elevated G6PD mRNA was accompanied by increased cellular enzyme activity in both cells. The cellular activity of 6-phosphogluconate dehydrogenase (6PGD) was also increased seven hours after TNF alpha treatment in these cells. G6PD mRNA and enzyme activity returned to control levels 22h after TNF alpha administration. In contrast to the marked effects of TNF alpha, no significant alterations were found on G6PD expression following IL-1 beta or IL-6 injections in these cells. None of these cytokines caused changes in G6PD or 6PGD expression in parenchymal cells. These data indicate that the proinflammatory cytokine TNF alpha plays an important role in the regulation of cellular G6PD expression in hepatic immune competent cells.

Modifications in lens protein biosynthesis signal the initiation of cataracts induced by buthionine sulfoximine in mice

Cataract induction in preweanling mice by L-buthionine sulfoximine (BSO), an inhibitor of glutathione biosynthesis, was correlated with perturbations in vitro protein biosynthesis. These were detected by incubation of late precataract and early cataract lenses with 35S-labeled amino acids, followed by dissection of lenses into capsule-epithelium and decapsulated fiber fractions, further processing of the fibers into water-soluble, urea-soluble and urea-insoluble fractions, and analysis by 2D electrophoresis and fluorography. Most of the protein labeling in control lenses was in the water-soluble fiber and capsule-epithelium fractions (80% and 14% of total cpm, respectively). Labeling in all three fiber fractions was decreased by cataract induction. The urea-insoluble fraction displayed a transient increase in labeled high molecular weight basic protein, as labeling of polypeptide monomers decreased. Densitometric analysis of fluorograms from the water-soluble and urea-soluble fiber fractions revealed a sharp decrease in fiber gamma-crystallin polypeptide labeling preceding and accompanying early cataract development, a delayed decrease in labeling of alpha A-crystallin and increased relative percentage of several labeled beta-crystallin polypeptides, especially in the urea-soluble fraction. By contrast with diminished labeling of the fiber fractions during cataract initiation, protein labeling of the corresponding capsule-epithelium fraction was stimulated dramatically and persisted at reduced levels during early opacification (stage 3), when nearly all of the protein labeling in the lens was found in capsule-epithelium. Capsule-epithelium polypeptides showing increased labeling during cataract initiation included alpha A-crystallin, several acidic polypeptides of M(r) = 40-50 kDa and a group of neutral to mildly acidic polypeptides of M(r) = 20-28 kDa. this transient activation, which was relatively non-specific, may relate to previously reported observations of polyribosome accumulation in lens epithelium during initial development of BSO cataracts. The labeled capsule-epithelium preparations are known to include newly differentiating fibers near the lens equator as well as epithelial cells. Both of these cell populations survive in mature BSO cataracts. It is suggested that modifications of the normal pattern of gene expression in the lens may be involved in initiation of the mouse BSO cataract and its subsequent pattern of development.

Kinase-negative mutant epidermal growth factor receptor (EGFR) expression during embryonal stem cell differentiation favours EGFR-independent lineages

EGF receptors are expressed on most fetal and adult cells but their precise roles are not well known. We previously reported that, in P19 embryonal carcinoma cells, the expression of kinase-negative EGFR inhibits retinoic acid (RA)-induced differentiation to nervous tissue, suggesting that EGFR plays a role in differentiation (J.-X. Wu and E. D. Adamson (1993) Dev. Biol. 159, 208–222). Embryo stem (ES) cells differentiate into a wide range of tissue types after the removal of the cytokine LIF from the culture medium. We demonstrate here that the induction of some early markers of differentiation, tissue-type plasminogen activator (tPA), AFP and keratins 8 and 19 is inhibited, whilst brachyury and myosin are increased, in clones containing kinase-negative mutant EGFR. After an extended period of differentiation, the cell types present in mutant and control cultures differed. Mutant clones produced frequent cardiac and skeletal muscle as the predominant differentiated cell types in vitro; other cells types were sparse or absent. Teratocarcinomas formed by EGFR-deltakinase-expressing ES cells contained frequent skeletal and cardiac muscle as well as apoptotic nuclei, while normal ES cells produced no detectable muscle and less apoptoses. Since mutant differentiated cultures had slower growth rates and increased levels of cell death, we concluded that: (1) inactive EGFR does not allow some cell types to survive and/or proliferate; (2) tissues that do not require EGFR for their survival, development or function predominate in long-term mutant cultures; (3) EGFR activity is not necessary for cardiac and skeletal muscle or endoderm formation and (4) Impaired survival of EGF-dependent lineages leads to preferential selection of muscle in differentiating ES cells.

UV activates growth factor receptors via reactive oxygen intermediates

Exposure of mammalian cells to UV irradiation induces rapid and transient expression of early growth response-1 gene (Egr-1) encoding a transcription factor that plays a role in cell survival. These signals from the irradiated cell surface are likely to involve more than one pathway, and we show here that an essential pathway involves activation of several growth factor receptors by reactive oxygen intermediates (ROI). UVC irradiation causes the tyrosine phosphorylation of EGF receptor (EGFR) in mouse NIH 3T3 fibroblasts and HC11 mouse mammary cells. EGFR activation by irradiation of cells is abrogated by suramin, by antioxidants, and by the presence of a dominant negative EGFR. UV induces the formation of complexes between activated EGFR and SOS, Grb2, PLC gamma, and SHC that can be precipitated with antibodies to EGFR. The activation of EGFR by UV is mimicked by H2O2, suggesting that ROI may function upstream of EGFR activation. Our observations support the hypothesis that ROI and growth factor receptors operate in the early steps of the UV signal that lead to the enhanced expression and activity of Egr-1.

Establishing a reliable visual function test and applying it to screening optic nerve disease in onchocercal communities

The computer Controlled Video Perimetry (CCVP) is a computer screening test for detecting visual function loss caused by onchocerciasis, glaucoma, etc. Installed on portable computers, the CCVP has been shown to be high acceptability in field community investigation. However, it is regarded to be difficult in obtaining reliable results from portable computer screening tests because of human behavioural variants and the lack of standard testing environment. In this paper, we propose an architecture for implementing a more reliable CCVP system. In particular, a self-organising neural network is applied to manage measurement noise caused by behavioural factors. A control unit is introduced to manage the overall behaviour of the system. The integrated test system has been used to screen optic nerve disease in onchocercal communities of rural Nigeria and the experimental results obtained from a large number of test records are very encouraging: reliable results from volatile test environments may be obtained using the proposed method.

Detection and location of amphiregulin and Cripto-1 expression in the developing postnatal mouse mammary gland

Amphiregulin (Ar) and Cripto-1 (Cr-1) are growth promoting peptides that share amino acid sequence homology with epidermal growth factor (EGF). The present study examined Ar and Cr-1 mRNA and protein expression during various stages of C57BL/6 mouse mammary morphogenesis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect transcripts for Ar and Cr-1 at all stages of mammary development. Immunocytochemical (ICC) localization demonstrated that in virgin 4-week to mature 12-week-old mouse fourth inguinal mammary gland, Ar and Cr-1 are expressed in the stromal cells, luminal epithelial cells, and myoepithelial cells of the branching ducts. Ar, and to lesser extent Cr-1, were also found in the epithelial cap cells and in the luminal epithelial cells of the advancing terminal end bud (TEB) from virgin 4-week and 6-week-old mice. Western blot analysis demonstrated that both Ar (28 and 26 kDa) and Cr-1 (90, 67, 56, and 21 kDa) proteins are expressed in virgin, 13.5 day midpregnant and in the 14 day lactating mammary gland. In addition, Ar and Cr-1 are associated with developing alveolar structures as determined by ICC. These results imply that together with EGF and transforming growth factor alpha (TGF alpha), Ar and Cr-1 may play salient roles as modifiers in the morphogenesis and differentiation of the mammary gland.

Identifying the measurement noise in glaucomatous testing: an artificial neural network approach

Diagnosis of visual function losses in glaucomatous patients depends to a large extent on the analysis of the data collected from corresponding psychophysical tests. One of the main difficulties in obtaining reliable data from patients in these tests is the measurement noise caused by the learning effect, inattention, failure of fixation, fatigue etc. Using Kohonen's self-organising feature map, we have developed a computational method to distinguish between the noise and true measurement and to provide an instant assessment of reliability of the computer-based visual function test. In particular we have experimented with 270 test records from glaucoma patients and glaucoma suspects and found that this method provides a satisfactory way of locating and rejecting noise in the test data, an improvement over conventional statistical methods. This method can also provide doctors with a clear view of the patient's behaviour during the test, thus assisting in their diagnostic decision making process.

Perforated amebic liver abscess: clinical analysis of 110 cases

In this study of 503 consecutive cases of amebic liver abscess documented during a 21-year period, 110 (22%) were complicated by perforation. Perforation sites included pleuropulmonary structures (79 cases, 72%) subphrenic space (15 cases, 14%); and peritoneal cavity (11 cases, 10%). The less common sites were the thoracic and abdominal wall, pericardial sac, bile duct, kidney, mediastinum, colon, and right flank. Trophozoites were recovered in 29% of cases. For the rest of the cases, diagnosis was based on the clinical manifestations and the dramatic response to a therapeutic trial of amebicides. Open surgical drainage was done in 10 of 11 patients who had peritoneal perforation; 6 of them were cured and 5 died. Of 97 patients with perforation sites other than the peritoneal cavity, 64 were treated with metronidazole in addition to needle aspiration and/or percutaneous catheter drainage, and all achieved complete remission without relapse during subsequent follow-up. Of the 36 cases treated with metronidazole alone, 22 (61%) were cured. The mortality rate in the group with perforated abscess was 17% (19/110), compared with 5% (25/503) in the whole series. The results suggested that (1) amebic liver abscess can be difficult to diagnose, especially when the pathogen is not isolated; and (2) metronidazole combined with needle aspiration and/or percutaneous catheter drainage is the treatment of choice for amebic liver abscess with perforation.

Protective effect of tetramethylpyrazine against damages of aortic endothelial cells elicited by low-density lipoproteins

Effects of tetramethylpyrazine (TMP) on endothelial cells damaged by low-density lipoproteins (LDL) were investigated. When endothelial cells were incubated with LDL (1.5 mg protein.ml-1) the level of malondialdehyde (MDA) was increased and the activity of superoxide dismutase (SOD) was inhibited, and levels of cGMP and epoprostenol were decreased. TMP at concentrations of both 20 and 150 mg.L-1 nullified the inhibition of SOD activity and the reduction of cGMP and epoprostenol content elicited by LDL. However, the elevation of MDA content induced by LDL was negated by TMP only at 150 mg.L-1. TMP also caused a reduction in MDA content and an increase of epoprostenol level in normal endothelial cells. This study suggests that TMP protects endothelial cells against damages elicited by LDL and that the protection of TMP might be due to reduction in lipid peroxidation through stimulation of production and/or release of epoprostenol.

[Experimental study on cellular electrophysiology of Viscum coloratum flavonoid in treating tachyarrhythmias]

Viscum Coloratum Flavonoid (VCF) is one of the dihydro-flavonoids isolated and purified from the stem and leaf of Viscum Coloratum. It was proved both experimentally and clinically to have the effects of anti-tachyarrhythmias. The mechanism of this effect, however, was unclear. In this study, the effects of the drug on the fast response action potentials (FAP) in canine Purkinje fibers and guinea pig ventricular myocardial cells were investigated by glass-microelectrode technique. The results indicated that 0.1 mg/ml VCF accelerated the repolarizations of 2nd and 3rd phase of FAP, shortened action potential duration (APD), and slightly shortened effective refractory period (ERP) (canine) or unchanged (guinea pig). delta ERP/delta APD ratio was increased, therefore, ERP was relatively prolonged. All effects appeared after using the drug for 2 minutes, reached stable status after 10 minutes, and disappeared after washing off the drug for 15 minutes. It was suggested that VCF was the drug which exerted effects rapidly, maintained effects shortly, and had effects reversibly. The cellular electrophysiologic mechanisms of VCF on anti-tachyarrhythmias should be attributed to prolong the ERP relatively and abolish the reentry. This drug is particularly applicable to the tachyarrhythmias due to reentry.

[Effects of Viscum coloratum flavonoids on fast response action potentials of hearts]

The effects of the total flavonoids of Viscum coloratum (VCF) on the fast response action potentials (FAP) of canine Purkinje fibers and guinea pig ventricular papillary muscles were studied by glass-microelectrode technique. The effects of VCF on the ionic currents through cellular membrane were analysed with selective ion blockers (CsCl, verapamil, and TEA+), respectively. VCF (100 micrograms.ml-1) accelerated the repolarization of FAP and increased delta ERP/delta APD ratio, which were related to decreasing Isi and increasing Ix. It was suggested that the anti-tachyarrhythmic mechanism of VCF was attributed to prolonging ERP relatively and to abolishing reentrant excitation.

[The preventive and curative action of fish oil compound on early atherosclerotic lesions in the aortic of diabetic rats]

250-320g male Wistar rats were divided randomly into three groups: normal control, diabetes mellitus (DM) control and fish oil compound (FOC) treatment groups. The latter two groups were induced diabetic by streptozotocin injection. At the end of the third week after injection, the treatment group was fed FOC for 9 weeks. The results showed that FOC could decrease the plasma total cholesterol, triglycerides, low density lipoprotein-cholesterol and very low density lipoprotein cholesterol levels significantly; restrain platelet aggregation; decrease blood pressure and increase atrial natriuretic polypeptide-mRNA content. It was found that the aorta in DM rats had more serious lesions than those in the FOC group. Our study found that FOC could prevent the development of atherosclerosis in DM rats.

Inhibition of differentiation in P19 embryonal carcinoma cells by the expression of vectors encoding truncated or antisense EGF receptor

Murine embryonal carcinoma cells do not express detectable cell-surface epidermal growth factor receptors (EGF-R) but after 2 days of differentiation induced by retinoic acid (RA) increasingly express mRNA and protein encoded by the EGF receptor gene (Joh et al., Cell Growth and Differentiation 3, 315, 1992). The effect on morphology, growth, and differentiation of the introduction of expression vectors that produce either a truncated, kinase-negative mouse EGF receptor or an antisense mRNA was studied in P19 embryonal carcinoma (EC) cells before and after differentiation. The presence of either construct should lead to the reduction of EGF-R expression by either the dominant negative effects of a truncated protein or the inhibition of endogenous EGF-R mRNA production/translation by complementary RNA, respectively. Cells were cotransfected with the bacterial neomycin resistance gene and constitutively expressing clones were selected with G418. The cytomegalovirus LTR promoter/enhancer was found to be very inefficiently activated in P19 EC cells. After RA addition, changes in gene expression included induction of both the exogenous truncated constructs and endogenous EGF-R. Differentiation was gauged by the expression of tissue-type plasminogen activator and intermediate filament protein markers of neural tissues, as well as EGF-R. The expression of 120-kDa truncated EGF-Rs was high in four clones, but all 10 clones examined had diminished abilities to differentiate after RA induction compared to four control cell lines. Similarly, the majority of antisense transfected clones was unable to differentiate normally. The results indicate that the reduced expression of EGF-Rs in differentiating EC cells inhibits the rate, frequency, and extent of differentiation after RA induction. We conclude that the expression of EGF-Rs plays a role in the stimulation of differentiation and we speculate that the mechanism involves the tyrosine kinase activity of the receptor.

Modulation of mouse preimplantation development by epidermal growth factor receptor antibodies, antisense RNA, and deoxyoligonucleotides

Two-cell mouse preimplantation embryos were cultured for 48 h in four different reagents to modulate epidermal growth factor (EGF) receptor function. These were rabbit polyclonal and mouse monoclonal antibodies to EGF receptor, EGF receptor antisense RNA, and EGF receptor antisense deoxyoligonucleotides. Embryos were scored for two endpoints: onset of cavitation as a measure of trophectoderm differentiation and mean embryo cell number as a measure of cell proliferation. The consistent observations were that cavitation was significantly accelerated by antibodies and delayed by antisense RNA and antisense deoxyoligonucleotides. None of these reagents exerted a significant effect on mean embryo cell number, with one exception, the polyclonal antibody. Our interpretation of these observations is that the antibody binding facilitated cavitation by mimicking natural ligand-receptor binding and inducing the signal transduction cascade that is typical for the EGF receptor. In the case of antisense RNA or deoxyoligonucleotide, we propose that they delayed onset of cavitation by interfering with EGF receptor production. We hypothesize that during this period of development, EGF receptor is concerned predominantly with the regulation of differentiation more than with cell proliferation.

[Comparative effects of Panax notoginseng saponins, verapamil, and norepinephrine on cerebral circulation in anesthetized rats and rabbits]

In urethane-anesthetized New Zealand rabbits, mean blood pressure (MBP) and cerebrovascular resistance (CVR) fell by 27-47% and 11-17% (P < 0.05), respectively after Panax notoginseng saponins (PNS) 20-80 mg.kg-1 i.v. Verapamil (Ver) 30 micrograms.kg-1 i.v. showed similar effects, but norepinephrine (NE) 30 micrograms.kg-1 i.v. showed opposite effects. PNS and Ver reduced the MBP and CVR in sodium pentobarbital-anesthetized Wistar rats. The actions of PNS and Ver on cerebral blood flow (CBF) were related to the animal species, i.e. PNS increased CBF in rats but reduced that in rabbits, Ver increased CBF in rabbits but had no effects on that in rats. In isolated ring segments of New Zealand rabbit basilar arteries, PNS 1 and 3 mg.ml-1 non-competitively inhibited the contractions induced by KCl with the pD2' value 2.69 +/- 0.20 (-lg g.ml-1). The results indicate that PNS and Ver are vasodilators of brain blood vessel, which would be beneficial to cerebral circulation, while NE is a vasoconstrictor of brain blood vessel.

Regulation of epidermal growth factor receptor gene expression in murine embryonal carcinoma cells

The protooncogene c-erbB1 [epidermal growth factor receptor (EGF-R)] is expressed in a wide variety of cell types and in most adult tissues. The precise roles of the EGF-R in vivo are largely unknown, especially their role in growth and development of embryonic tissues. We reported earlier that EGF-Rs are not expressed on the cell surface of undifferentiated embryonal carcinoma (EC) cells, but intracellular receptor protein is detectable (A. Weller, J. Meek, and E. D. Adamson, Development, 100: 351-363, 1987). We document here that in embryonal carcinoma cells, low levels of both receptor mRNA and protein are observed, but after 4 days of retinoic acid-induced differentiation, large increases are seen. Most notable is the 35-70-fold rise in the levels of EGF-R transcripts during the differentiation of P19 embryonal carcinoma cells to neural and glial cells, and this is paralleled by a 10-fold rise in protein. Measurements of the degradation rates of EGF-R mRNA and receptor protein show that both are rather stable and may partially explain the steady-state increases during differentiation. Run-on transcription assays of the EGF-R gene show very low rates of transcriptional activity at all stages: about 2-fold changes in transcription rate can be detected. It is concluded that transcriptional mechanisms may also partially account for increased levels of gene products. We hypothesize that the appearance of EGF-Rs at the cell surface leads to the slow induction of further receptor levels by EGF/transforming growth factor alpha stimulation, and this contributes to the driving force of differentiation and to the stability of the differentiated state.

Hemodynamic actions of guan-fu base A in anesthetized rats

Guan-fu base A (GFA) is a terpenoid alkaloid isolated from the tuber of Aconitum coreanum in this institute. GFA exhibited anti-arrhythmic effects in various experimental arrhythmia animal models, and bradycardic actions. In this paper, the hemodynamic action of GFA was investigated. GFA 20 mg.kg-1 iv decreased in heart rate from 420 +/- 51 to 305 +/- 60 bpm (P less than 0.05). The changes of SBP, DBP, LVSP, +/- dP/dtmax, and LVEDP were much smaller or insignificant. GFA (1, 3, 10, 30, 60 mg.kg-1 cumulative iv) increased the heart periods (HP) and QT-intervals in a dose-dependent manner, accompanied by a small increase in PQ-interval, but did not affect QRS complex. The increase in HP from 138 +/- 11 to 321 +/- 48 ms (P less than 0.01) was mainly due to a prolongation of the diastolic period from 22 +/- 12 ms to 156 +/- 46 ms (P less than 0.01). The triple product of HR x LVET x SBP was also decreased with every dose of GFA. This hemodynamic profile suggests that the bradycardic action of GFA can reduce myocardial oxygen consumption and improve myocardial blood supply, which may be of use in certain cardiac patients.

Epidermal growth factor receptor mRNA and protein increase after the four-cell preimplantation stage in murine development

Epidermal growth factor receptors (EGF-Rs) are expressed at increasing levels on mouse preimplantation embryos. Immunofluorescence assays were used to show that unfertilized eggs and 2-cell embryos have a very low level of reactivity to antimouse EGF-R antibodies, but by the 4-cell stage and later the reactivity increases. The synthesis of EGF-R protein was verified at the blastocyst stage by immunoprecipitation of a 170-kDa metabolically labeled protein. The EGF-R protein is expressed on cell plasma membrane surfaces, but after compaction at the 8-cell stage concentrates on the apical cell surfaces. We also find a low level of expression of EGF-R protein on inner cell mass cells; thus, all cell lineages express receptors from the beginning of gestation. The receptor protein synthesized by the 8-cell embryo and later is probably translated from embryonic transcription, since reverse transcription-polymerase chain reaction indicates increasing levels of mRNA starting after the 4-cell stage. However, we also detected maternal mRNA in zygotes and 2-cell embryos. The pervasive nature of EGF-R expression throughout development suggests important roles for these receptors which could include autocrine and paracrine stimulation.

The effects of streptozotocin induced diabetes mellitus and fish oil compound on gene expression of atrial natriuretic peptide in rat

1. Adult male Wistar rats were injected with streptozotocin (STZ: 55 mg/kg) for inducing diabetes. Then blood and atria for RNA extraction were withdrawn from rats treated 3 and 11 weeks previously with STZ respectively. Atrial total RNA were extracted with cold phenol method. The ANP mRNA contents were determined using Dot blot hybridization technique with alpha-32-P-labelled r-prepro ANP cDNA probe. 2. Plasma glucose was increased and plasma immunoreactive insulin was lowered in rats at 3 and 11 weeks after injection of STZ. ANP gene expression in diabetic rats was depressed. ANP mRNA contents in rats treated 3 and 11 weeks with STZ were 86.4% and 31.7% of that of control rats. 3. Three weeks after treatment of STZ, the rats were gastrically perfused with FOC (Fish Oil Compound) (0.355 ml/kg) once a day successively until 11 weeks. This treatment induces lower blood pressure in rats. ANP gene expression in FOC group was apparently recovered which had been decreased because of the effect of diabetes mellitus.

The proto-oncogene c-fos is over-expressed in the majority of human osteosarcomas

The expression of fos protein was examined in 30 cases of human osteosarcoma as formalin-fixed and paraffin-embedded tissue sections using two monoclonal antibodies and, for five cases, as frozen sections using 3 polyclonal antibodies. Nuclear antibody labeling intensities were determined either by visual scoring (3 pathologists) or by microdensitometry and included over 700 tumor, 350 normal and 150 benign tissue observations. Visual scores were shown to be linear with optical density with a correlation coefficient of 0.97. Analysis of the osteosarcoma cases at one antibody concentration revealed two groups: a minority (39%) with a low average visual score of 2 +/- 0.2 which was very similar to benign and normal tissues, and a majority (61%) with an average score of 3.1 +/- 0.3. The difference is highly significant (t-test), P less than or equal to 0.01. The results were supported by an analysis of partial immunotitration curves using a curve-fitting procedure which yielded estimates of FOSo (maximum relative fos protein concentration) which were ca. 150% increased for the majority tumor group compared to the minority group or benign or normal tissues. In previous studies of v-sis transformed cells, which exhibit ca. 300% over-expression of c-fos protein as observed here, antisense techniques were used to show that over-expression leads to increased growth and loss of contact inhibition. Thus the combined results suggest that steady state c-fos protein is significantly elevated in, and may contribute to, the aggressive growth properties of a majority of human osteosarcomas.

[A study on the literature on sheng mai powder of past dynasties]

Our study reveals that the earliest historical records of Sheng Mai Powder are found in "Yixue qiyuan" ("Origins of Medicine"), a medical book written by Zhang Yuansu and published in the beginning of 1186, 45 years earlier than the latest edition of "Neiwai shangbian huolun" ("Treaties on the identification of Internal Diseases and External Damages"), written by Li Gao in 1231. The study also suggests that the assertion of Sheng Mai Powder to be inaugurated by Sun Simiao is groundless.

[Low-dose cytosine arabinoside in treatment of 17 patients with acute nonlymphocytic leukemia]

Low dose Ara-C (LDAra-C, Ara-C 10-15 mg/12 h, i.m. x 14-21 days) was used in the treatment of 17 patients with ANLL, and from 14 patients blast cells were isolated before chemotherapy and cultured in the presence of Ara-C (10(-8) and 10(-7) mol/L), no definite induction of differentiation of leukemic cells was found. Of the 17 cases, 5 obtained CR, only one of them with M4 entered CR without pancytopenia or bone marrow aplasia during the LDAra-C treatment. For the rest, 4 with M2 obtained PR, and 8 did not respond. Toxic effects, including pancytopenia and bone marrow aplasia, were observed in most of the patients. Laboratory results showed that differentiation was not induced by Ara-C in low concentration in in vitro culture. LDAra-C is thought to be effective in the treatment of ANLL, and the mechanism may involve both the cytotoxicity and the induction of differentiation of leukemic cells, but the former is far more important.

[Hemihepatectomy under hepato-portal interruption at normal temperature for liver malignancies--a report of 20 patients]

From July 1984 to December 1985, hemihepatectomy was done in 20 liver cancer patients under normothermic interruption of porta hepatis. There were 19 primary and 1 secondary liver carcinomas. Of the former, 17 (89%) were associated with mild or moderate cirrhosis. The peak age ranged 36-60 years. Right hemihepatectomy was performed in 18 and left hemihepatectomy in 2 with an operative mortality of 0%. Hepatic failure or secondary bleeding was not found. In the specimens resected, the largest weight was 2,500 gm. The normothermic interruption of porta hepatis usually lasted 15-25 minutes, a time long enough for hemihepatectomy. This procedure, being simple in manipulation and less detrimental to physiologic and biochemical balance in the human body, is relatively practical and beneficial to hepatectomy.

Regeneration of the femoral artery following experimental end-to-end anastomosis in the rat. An ultrastructural follow-up

An experimental end-to-end anastomosis of the common femoral artery was performed in 45 adult Wistar rats. The vessel wall condition was assessed at 10 min, 3 days, 1, 2, 4, and 8 weeks following surgery by scanning and transmission electron microscopy. The microsurgical procedure inflicts extensive trauma in all layers of the arterial wall, with a desendothelialization largely surpassing the surgical field. Reendothelialization was completed at 2 weeks. Apparently, and as compared to less damaging vessel wall manipulations, such deep medial and wide endothelial lesions do not retard vessel wall healing to normal functionality. Moreover, the formation of primary atherogenic structures by smooth muscle cell migration to the intima seems restricted.

Early morphologic changes in coronary arteries of experimental diabetic rats

Diabetes was induced in 24 adult male Wistar rats by a single intravenous injection of streptozotocin. The ultramorphology of the coronary arterial wall was studied by scanning and transmission electron microscopy up to 10 weeks following this diabetes induction. At that moment, several ultrastructural characteristics of primary atherogenesis could be observed, i.e. important myointimal thickening with extensive medial smooth muscle cell migration towards and into the intima, and synthesis of an abundant mass of intercellular ground substance in the media and in subendothelial areas. Lipid deposition or foam cell formation was not observed. These results confirm that experimental diabetes is a risk factor for the coronary arterial wall as it induces typical atherogenic phenomena.

In vivo arterial platelet-vessel wall interaction and thrombosis: induction, on-line registration and ultrastructural control

A technique for induction and on-line quantification of local platelet thrombi in mesenteric arteries of small laboratory animals was developed and standardized in our laboratory. In the past, this model was used to study the nature of platelet-vessel wall interaction in the living animal. The ultrastructure of the experimental intimal lesion and the vessel wall regeneration were assessed by transmission electron microscopy (TEM), both in normal and pathologic conditions. Scanning electron microscopy (SEM) now shows the ultramorphology of platelet thrombi on the experimentally injured arterial segment following topical superfusion with ADP, mepacrine or platelet-activating factor (PAF). The application of these substances, each with proper bio-activity, leads to distinct types of platelet thrombi. Mepacrine or PAF superfusion causes large thrombotic masses, as compared to control, ADP induced thrombi, and seems toxic for the endothelial cells. Mepacrine thrombi differ significantly from PAF thrombi in their platelet density, degree of platelet activation and in their relation to the endothelium that surrounds the experimental lesion. Furthermore, PAF superfusion induces a phenomenon of spontaneous regeneration of the thrombus after its forced embolization. This is probably due to some unknown bio-action of PAF in the vessel wall.