Alteration of heme-oxygenase-carbon monoxide pathway in calcified rat vascular smooth muscle cells

OBJECTIVE

The aim of the present study was to investigate the changes in heme-oxygenase (HO)-carbon monoxide (CO)-cyclic guanosine monophosphate (cGMP) pathway in clacified rat vascular smooth muscle cells (VSMCs).

METHODS

Calcification of cultured rat VSMCs was induced by incubation of VSMCs with beta-glycerophosphate. Cellular calcium content, ALP activities and (45)Ca uptake were measured. HO activity, HbCO formation and content of cGMP in VSMCs were determined. Immunocytochemistry for HO-1 expression was observed.

RESULTS

In comparison of control VSMCs, the cellular calcium content, ALP activity and (45)Ca uptake in calcified VSMCs were obviously increased. Immunocytochemistry showed that HO-1 expression was weak and not well distributed in calcified cells as compared to non-calcified VSMCs, but interestingly, there was stronger staining in calcified nodules than in VSMCs. Compared with VSMCs, HO-1 activity in calcified cells decreased by 42.7% [36.4 +/- 2.8 pmol (mg Pr x h)(-1) vs 63.5 x 5.3 pmol (mg Pr x h)(-1), p < 0.01], and HbCO formation decreased by 39.2% (3.38 x 0.69 micromol/mg Pr vs 5.56 +/- 0.48 micromol/mg Pr, p < 0.05). The cGMP content in calcified VSMCs was 78.1% lower than that of non-calcified VSMCs (4.3 +/- 0.51 vs 19.6 +/- 1.2 pmol/mg, p < 0.01).

CONCLUSION

The results showed that HO-CO-cGMP pathway in calcified vascular cells obviously changed, which might contribute to disturbance of vascular function.

Taurine protected myocardial mitochondria injury induced by hyperhomocysteinemia in rats

Taurine can protect against cardiovascular diseases, whereas elevated levels of plasma homocysteine are associated with atherosclerotic and thromboembolic cardiovascular diseases. To illustrate the effects of taurine on hyperhomocysteinemia, we observed the myocardial mitochondria dysfunction in the rats with hyperhomocysteinemia induced by diet methionine loading, and the therapeutic effect of taurine. A methionine diet increased plasma homocysteine concentration (133.51 +/- 27.91 micromol/L vs 12.31 +/- 2.58 micromol/L in control, P < 0.01), stimulated the production of reactive oxygen species (ROS) in the myocardial mitochondria, and inhibited the activities of mitochondrial Mn-superoxide dismutase and catalase. The 45Ca uptake and Ca2+-ATPase activity in the myocardial mitochondria were significantly lowered in rats with hyperhomocysteinemia. Taurine supplements effectively attenuated the hyperhomocysteinemia-induced ROS production and inhibition of Mn-superoxide dismutase and catalase activities in the myocardial mitochondria, and increased its 45Ca uptake and Ca2+-ATPase activity. Thus, taurine antagonizes the oxidative stress injury in the myocardial mitochondria induced by the hyperhomocysteinemia.

The photocatalytic degradation of reactive black 5 using TiO2/UV in an annular photoreactor

The textile effluent is a major industrial polluter because it is highly colored, containing about 15% unfixed dyes as well as high levels of salts that can potentially be discharged into the environment. Photocatalytic oxidation using an thin gap annular UV reactor with TiO2 was used to break down the colour of a synthetic effluent ranging up to 400 ppm in dye concentration of Reactive Black 5 and up to 80 g/L in NaCl. Results show that the reaction kinetics was dominated by the TiO2 loading, the initial dye concentration, and the dissolved oxygen concentration; with the other parameters showing less significant effects. High rates of decolorization were found, with a linear fit to the Langmuir-Hinshelwood equation yielding a reaction rate constant (k) of 2.45 ppm/min, and an adsorption equilibrium constant (K) of 0.048 ppm(-1) based on color removal. The presence of the combination of high dissolved oxygen (15 ppm) and sodium chloride (up to 80 g/L) was found to enhance the decolorization and mineralization rates of the reactive dye. However, pH was found to not significantly affect the degradation rate. Since textile effluent is strongly alkaline, this result is significant, as no solution neutralisation is required and direct treatment of the effluent is possible.

NO-1886 decreases ectopic lipid deposition and protects pancreatic beta cells in diet-induced diabetic swine

The synthetic compound NO-1886 (ibrolipim) is a lipoprotein lipase activator that has been proven to be highly effective in lowering plasma triglycerides. Recently, we found that NO-1886 also reduced plasma free fatty acids and glucose in high-fat/high-sucrose diet-induced diabetic rabbits. In the current study, we investigated the effects of NO-1886 treatment on ectopic lipid deposition and the islet pathology in miniature swine fed a high-fat/high-sucrose diet. Our results showed that feeding this diet to miniature swine caused insulin resistance, increased lipid deposition in non-adipose tissue, such as in the heart, skeletal muscle, liver and pancreas, and also caused pancreatic beta cell damage. However, supplementing 1% NO-1886 (200 mg/kg per day) into the high-fat/high-sucrose diet decreased ectopic lipid deposition, improved insulin resistance, and alleviated the beta cell damage. These results suggest that improvement of lipid disorder, non-adipose tissue steatosis and insulin resistance may be very important for the protection of beta cell damage. Therefore, NO-1886 is potentially beneficial for the treatment of insulin-resistance syndrome.

The disulfide-rich region of platelet glycoprotein (GP) IIIa contains hydrophilic peptide sequences that bind anti-GPIIIa autoantibodies from patients with immune thrombocytopenic purpura (ITP)

Immune thrombocytopenic purpura (ITP) is an autoimmune blood disease caused by autoantibody-mediated destruction of blood platelets. Platelet glycoprotein (GP) IIb/IIIa is a common target for antiplatelet autoantibodies. The present studies were undertaken (1). to confirm whether the disulfide rich repeat region of GPIIIa contains target epitopes for antiplatelet antibodies in patients with ITP; (2). to determine whether these antigens were defined by peptide sequences in the absence of post-translational modification; and (3). to correlate observed immunologic reactivity with the recently solved X-ray crystallographic structure of an analogous integrin complex, the vitronectin receptor, alpha(V)beta(3). Recombinant fusion proteins of four GPIIIa extracellular sequences were prepared and purified. Immunoblotting results with purified recombinant peptides showed potent reactivity of 16 of 24 ITP patient serum anti-GPIIb/IIIa antibodies with the fusion protein containing the GPIIIa sequence of residues from 468 to 691. These results are consistent with a report by Kekomaki et al. that a 50 kDa chymotryptic digestion product of GPIIIa isolated from blood platelets contains target epitopes for serum antiplatelet antibodies in 16 of 33 ITP patients. Smaller peptides including residues 446-501 and residues 593-691 each reacted with only 5 of the 24 patient sera; furthermore all but 3 of these interactions were very weak. Visualization of the conformation of the extracellular portion of alpha(V)beta(3) reveals the location of the 222-residue antigenic GPIIIa (beta(3)) peptide 'B' at the immediately extracellular region of the protein that includes a beta-tail domain and several integrin-EGF domains. In summary, predictions of hydrophilicity, surface accessibility and antigenicity and the three dimensional structure of the beta(3) integrin correlate with autoantibody binding to a recombinant GPIIIa peptide 'B' containing residues 468-691.

Evaluation of novel biodegradable cyclic carbonate polyester copolymers for cytocompatibility using MRC-5 cells

The objective of this work was to synthesize and characterize a novel series of biodegradable cyclic carbonate polyester copolymers based on lactide and 5-methyl-5-benzyloxy-carbonyl-1,3-dioxan-2-one (MBC). Two compositions were selected for characterization. One copolymer was based on a racemic mixture of 1-lactide with 15.4 mole % MBC and the other was based on 1-lactide with 8.2 mole % MBC. These polymers contain carboxylic acid moieties along the backbone that may be used for tethering bioactive agents, forming ionic crosslinks or be reacted with vinyl containing monomers to allow free radical crosslinking. The initial materials evaluated have the carboxylic acid functionalities blocked with benzene. These polymers and the de-blocked versions may have potential applications for hard and soft tissue scaffolds, control drug delivery matrixes or a variety of other applications in medicine. The copolymer samples were pressed into 7.0-mm diameter disk using a KBr press. The disks were then sterilized using U.V radiation under a laminar flow hood. After sterilization, the copolymer disks were submerged in 2 ml of media and placed in a CO2 regulated incubator at 37 degrees C. A total of six groups per phase (n = 7 test tubes per group) were used in this study. Test tubes in groups I and III were plated with MRC-5 and subsequently treated with media alone (controls). Test tubes in groups II and IV were plated with MRC-5 and subsequently treated with media before being introduced to copolymer samples. Cell number, as well as, biochemical markers such as protein and malondialdehyde (MDA) were determined at the end of the 24, 48 and 72-hour time periods. Representative test tubes were subjected to an H&E staining procedure for microscopic morphological evaluation. The results of this evaluation suggest that the exposure of both copolymers produced a non-cytotoxic environment with the MRC-5 cell line. Although both copolymers are non-cytotoxic, the sample having the higher MBC content is the preferred composition based upon MDA levels and morphological evaluations.

Effect of intermittent radiant warming on proliferation of human dermal endothelial cells in vitro

OBJECTIVE

This study investigated the effect of Warm-Up therapy on the proliferation of human microvascular dermal endothelial cells.

METHOD

Endothelial cells from an adult subject were seeded in six-well plates and placed in an incubator at 32.5 degrees C. The following day Warm-Up dressings were placed over the plates, with or without warming cards. Cards set at 38 degrees C or 42 degrees C raised the temperature in the medium to maxima of 34.5 degrees C and 37.5 degrees C respectively. Units were switched on daily for three one-hour periods. Cell numbers were counted by haemocytometer.

RESULTS

Maximum stimulation of endothelial cell proliferation occurred under the 38 degrees C card, with cells numbering 135-158% of the controls (p < 0.05). the 42 degrees C card also stimulated cells (110-155%) but this did not reach statistical significance.

CONCLUSION

The accelerated proliferation of microvascular dermal endothelial cells achieved by intermittent radiant warming may have contributed to the increase in granulation tissue reported previously in our clinic.

Screening wheat genotypes for tolerance of soil acidity

A soil-based screening method was used to test tolerance of wheat genotypes to acidity. Plants were grown for 6 days in an acid soil with the pH adjusted to 3.9–5.8. The number and length of roots were measured. To validate the method, 12 wheat cultivars of known acidity tolerance and one acid-sensitive barley cultivar were grown on an acid soil in the field with or without amelioration of subsoil acidity. The relative yields of these wheat genotypes on the soil with subsoil acidity ranged from 50 to 89% of yields on soil without subsoil acidity, and were correlated with root growth parameters obtained in the glasshouse. The best correlation was obtained between relative yields in the field (y) and root length per plant (x) at pH 3.9 in the glasshouse (y = –43 + 52*log x, r = 0.95) or root length per plant at pH 3.9 as a percentage of root length at pH 4.8 (y = 1.2 + 46*log x, r = 0.94). Following validation of the glasshouse screening method in the field, 115 wheat genotypes, including cultivars and breeding lines, were screened in the glasshouse. A substantial genotypic variation in acidity tolerance was found, with root length per plant at pH 3.9 ranging from 66 to > 350 mm. Many Western Australian breeding lines displayed better tolerance than existing tolerant wheat cultivars. The screening system can be instrumental in breeding wheat for increased tolerance to acid soils.

Effects of adrenomedullin on vascular calcification in rats

OBJECTIVE

The aim of the present study was to investigate the effect of adrenomedullin (ADM) on vascular calcification.

METHODS

The vascular calcification model was established in rats (VND group) by using vitamin D3 (300,000 IU/kg) and nicotine (25 mg/kg, two doses). The effect of liposome-encapsulated ADM was observed. Vascular calcium content, alkaline phosphatase (ALP) activity, ADM in aortic tissue and plasma, binding ability of 125I-ADM for ADM receptor on vascular plasma membrane and content of cAMP in vessels were measured.

RESULTS

Compared with control rats, the aortic calcium content and vascular ALP activity in rats of the VDN group was obviously increased; in addition ADM concentrations in plasma and vessels of rats in VDN group were increased. But the maximum binding sites of 125I-ADM for ADM receptor (Bmax) on vascular plasma membrane in rats of VDN group were significantly decreased compared with control rats. The affinity of 125I-ADM for the ADM receptor was reduced, as shown by the Kd value and vascular cAMP content being reduced in rats of the VDN group compared to the control group. The in vitro response of isolated vessels to ADM incubation was weakened. Administration of empty liposome had no effect on vascular calcification. But administration of ADM significantly decreased vascular calcium content and ALP activity. The Bmax of 125I-ADM for ADM receptors on vascular plasma membrane increased by 17.7% (p < 0.01), and the value of Kd decreased by 36.2% (P < 0.01) in rats treated with ADM as compared with rats of the VDN group. In addition, the vascular cAMP content and the response to ADM in isolated aorta were markedly increased.

CONCLUSION

Vascular calcification induced an alteration of the vascular ADM-ADM receptor-cAMP pathway. Treatment with exogenous ADM inhibited vascular calcification by improving the vascular ADM-ADM receptor-cAMP pathway.

Improved tolerance of maize plants to salt stress by arbuscular mycorrhiza is related to higher accumulation of soluble sugars in roots

The effect of colonization with the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe on the growth and physiology of NaCl-stressed maize plants ( Zea mays L. cv. Yedan 13) was examined in the greenhouse. Maize plants were grown in sand with 0 or 100 mM NaCl and at two phosphorus (P) (0.05 and 0.1 mM) levels for 34 days, following 34 days of non-saline pre-treatment. Mycorrhizal plants maintained higher root and shoot dry weights. Concentrations of chlorophyll, P and soluble sugars were higher than in non-mycorrhizal plants under given NaCl and P levels. Sodium concentration in roots or shoots was similar in mycorrhizal and non-mycorrhizal plants. Mycorrhizal plants had higher electrolyte concentrations in roots and lower electrolyte leakage from roots than non-mycorrhizal plants under given NaCl and P levels. Although plants in the low P plus AM fungus treatment and those with high P minus AM fungus had similar P concentrations, the mycorrhizal plants still had higher dry weights, soluble sugars and electrolyte concentrations in roots. Similar relationships were observed regardless of the presence or absence of salt stress. Higher soluble sugars and electrolyte concentrations in mycorrhizal plants suggested a higher osmoregulating capacity of these plants. Alleviation of salt stress of a host plant by AM colonization appears not to be a specific effect. Furthermore, higher requirement for carbohydrates by AM fungi induces higher soluble sugar accumulation in host root tissues, which is independent of improvement in plant P status and enhances resistance to salt-induced osmotic stress in the mycorrhizal plant.

[Discrimination of black inks by FT-Raman spectrometry]

Six brands of black inks on paper were examined by FT-Raman spectrometry. The results showed that the black inks could be discriminated by FT-Raman spectrometry. As the method is easy, quick and undestructive to samples, it is useful in black ink examination.

The first clinical results of "wide-focus and low-pressure" ESWL

A clinical study of the concept "wide-focus and low-pressure" extracorporal shock-wave lithotripsy (ESWL) was performed in a scientific cooperation between the Physical Institute of the University of Stuttgart and the Xixin Medical Instruments Co. Ltd. in Wuxian-Suzhou, China. In this cooperation, self-focusing electromagnetic shock-wave generator systems from the University of Stuttgart were integrated into Xixin lithotripters and installed in seven hospitals in China. A total of 297 detailed patient protocols revealed an average of 1532 shock pulses for successful treatment with no necessity for pain medication and auxiliary measures, and a stone-free rate of 86% after a follow-up of 3 months. These results are discussed in terms of the wide-focus low-pressure conditions and the mechanism of binary fragmentation by squeezing.

Differences in the absorption, metabolism and biliary excretion of a diastereomeric pair of alphavbeta3-antagonists in rat: limited role of P-glycoprotein

1. The study investigated mechanisms underlying the pharmacokinetic differences of two zwitterionic diastereomers ((3S)-3-[(3R or 3S)-2-oxo-3-[3-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)propyl]pyrrolidin-1-yl]-3-quinolin-3-ylpropanoic acid) with different lipophilicities using a combination of in vivo and in vitro approaches. 2. In rat, both isomers possessed comparable plasma clearances (CL). However, the more lipophilic diastereomer I exhibited a higher metabolic clearance (>2-fold higher than II), whereas the hydrophilic zwitterion II exhibited a higher biliary clearance (approximately 5-fold higher than I). Following oral administration, the bioavailability (F) of I (17%) was much higher than that of II (1%). 3. Consistent with these in vivo observations and the expectation based on their lipophilicity differences, the metabolism in rat liver microsomes was faster and the permeability in Caco-2 and LLC-PK1 cells and in situ rat intestinal loop was better for I than for II. 4. Only the absorption of the more lipophilic diastereomer I was subjected to an efflux system in the Caco-2 and in situ rat intestinal loop models. I was a good substrate for P-glycoprotein (P-gp) in both the human MDR1 and mouse mdr1a transfected cell lines, and in the wild-type mdr1a (-/-) mouse when compared with the P-gp-deficient mdr1a (-/-) mouse. Concomitant administration of I with verapamil in rat caused significant increases in oral AUC, F and Cmax of I without affecting its CL, further supporting the effect of P-gp in limiting the intestinal absorption of I in vivo in this animal model. 5. Since the findings that the lipophilic diastereomer I, but not II, was a good P-gp substrate were not in line with the observations that I was excreted to bile much slower than II and that I was absorbed better than II, the results suggested that P-gp played a minor role to the observed differences in the biliary excretion and intestinal absorption of the diastereomers I and II in rat.

The designability of protein structures

It has been noted that natural proteins adapt only a limited number of folds. Several researchers have investigated why and how nature has selected this small number of folds. Using simple models of protein folding, we demonstrate systematically that there is a "designability principle" behind nature's selection of protein folds. The designability of a structure (fold) is measured by the number of sequences that can design the structure--that is, sequences that possess the structure as their unique ground state. Structures differ drastically in terms of their designability. A small number of highly designable structures emerge with a number of associated sequences much larger than the average. These highly designable structures possess proteinlike secondary structures, motifs, and even tertiary symmetries. In addition, they are thermodynamically more stable and fold faster than other structures. These results suggest that protein structures are selected in nature because they are readily designed and stable against mutations, and that such a selection simultaneously leads to thermodynamic stability.

Urotensin II receptor in the rat airway smooth muscle and its effect on the rat airway smooth muscle cells proliferation

OBJECTIVE

To investigate the characteristics of urotensin II (U-II) receptor in the rat airway smooth muscle and the effect and signal transduction pathway of U-II on the proliferation of airway smooth muscle cells.

METHODS

Using 125I-UII binding assay to measure the Bmax and Kd of U-II receptor. Using the 3H-TdR incorporation to determine the effect of U-II on the proliferation of airway smooth muscle cells and its signal transduction pathway. Using Fura-2/AM to measure the effect of U-1I on the cytosolic free calcium concentration.

RESULTS

1. 125I-UII binding increased with the time and reached saturation at 45 min. The B(max0 was (11.36 +/- 0.37)fmol/mg pr and Kd was (4.46 +/- 0.61) nmol/L. 2. U-II increased 3H-TdR incorporation of the airway smooth muscle cells in a dose-dependent manner. 3. H7, PD98059 and nicardipine, inhibitors of PKC, MAPK, calcium channel, respectively, significantly inhibited U-II-stimulated 3H-TdR incorporation of airway smooth muscle cells. W7, inhibitor of CaM-PK, had no effect. 4. Cyclosporin A, inhibitor of CaN, inhibited 3H-TdR incorporation of the airway smooth muscle cells induced by U-II in a dose-dependent manner. 5. U-II promoted cytosolic free calcium concentration increase by 18%.

CONCLUSIONS

1. There was U-II receptor in the rat airway smooth muscle. 2. The effect of U-II-stimulated 3H-TdR incorporation of airway smooth muscle cells was mediated by such signal transduction pathway as Ca2+, PKC, MAPK and CaN, etc.

The effect of simulated elbow arthrodesis on the ability to perform activities of daily living

The dominant elbow joint of 24 healthy volunteers was immobilized with a functional brace in increments of 20 degrees (6 positions ranging from 30 degrees to 130 degrees ). Average scores were obtained for personal care hygiene tasks (PCH), activity of daily living (ADL), and total functional scores (PCH + ADL) for each elbow flexion position. Functional scores increased with increasing elbow flexion, peaking at 110 degrees and then tapering down. Repeated-measures analysis of variance showed statistical significance, with functional scores improving with increasing elbow flexion for PCH, ADL, and PCH + ADL scores. Further pairwise comparisons for elbow position between 90 degrees and 110 degrees flexion groups demonstrated significant higher mean functional scores for ADL and combined PCH + ADL for the 110 degrees group. The results of this study support a clear advantage in subjects' upper-extremity functional abilities with the elbow immobilized at 110 degrees of flexion when dealing with normal upper-extremity joints. This angle of flexion should be considered in patients undergoing trial immobilization before an elbow arthrodesis.

Intravascular local gene transfer mediated by protein-coated metallic stent

OBJECTIVE

To assess the feasibility, efficiency and selectivity of adenovirus-mediated gene transfer to local arterial wall by protein-coated metallic stent.

METHODS

A replication-defective recombinant adenovirus carrying the Lac Z reporter gene for nuclear-specific beta-galactosidase (Ad-beta gal) was used in this study. The coating for metallic stent was made by immersing it in a gelatin solution containing crosslinker. The coated stents were mounted on a 4.0 or 3.0 mm percutaneous transluminal coronary angioplasty (PTCA) balloon and submersed into a high-titer Ad-beta gal viral stock (2 x 10(10) pfu/ml) for 3 min, and then implanted into the carotid arteries in 4 mini-swines and into the left anterior descending branch of the coronary artery in 2 mini-swines via 8F large lumen guiding catheters. The animals were sacrificed 7 (n = 4), 14 (n = 1) and 21 (n = 1) days after implantation, respectively. The beta-galactosidase expression was assessed by X-gal staining.

RESULTS

The results showed that the expression of transgene was detected in all animal. In 1 of carotid artery with an intact intima, the beta-gal expression was limited to endothelial cells. In vessels with denuded endothelium, gene expression was found in the sub-intima, media and adventitia. The transfection efficiency of medial smooth muscle cells was 38.6%. In 2 animals sacrificed 7 days after transfection, a microscopic examination of X-gal-stained samples did not show evidence of transfection in remote organs and arterial segments adjacent to the treated arterial site.

CONCLUSIONS

Adenovirus-mediated arterial gene transfer to endothelial, smooth muscle cells and adventitia by protein-coated metallic stent is feasible. The transfection efficiency is higher. The coated stent may act as a good carrier of adenovirus-mediated gene transfer and have a potential to prevent restenosis following PTCA.

[The 5-year death analysis in patients with nasopharyngeal carcinoma treated with radiotherapy]

OBJECTIVE

To study the main death cause of nasopharyngeal carcinoma (NPC) treated with radiotherapy for 5 years.

METHOD

An analysis had been made to evaluated the 5-year death in 165 patients with NPC treated with radiotherapy.

RESULT

The death correlates strongly with the clinical stage, type and radiation dose (P < 0.05).

CONCLUSION

The distant metastasis and local recurrence are the main death cause of NPC.

[Inhibition effects of octreotide on the growth of hepatocellular carcinoma in vitro and in vivo]

OBJECTIVE

To investigate the effects of somatostatin analogue octreotide on the proliferation and apoptosis of human hepatocellular carcinoma (HCC) cell line as well as the growth of HCC xenografts in nude mice.

METHODS

The effects of octreotide on the proliferation and apoptosis of SMMC-7721 HCC cells was measured by 3H-thymidine incorporation into DNA and the TdT-mediated dUTP nick end labeling assay (TUNEL) or flow cytometric assay separately. Nude mice bearing xenografts of the cell line were treated with octreotide or saline as a control daily until eight weeks after tumor implantation.

RESULTS

Incubation with octreotide decreased 3H-thymidine incorporation into DNA of SMMC-7721 cells by approximately 50% at a concentration of 1 mumol/L. The inhibit effect of octreotide showed a concentration dependence. After 96 h incubation, total cell count was decreased 52.2% compared with control. When cells were treated by octreotide at 1 x 10(-6) mol/L for 24 hours, the apoptosis rates was (15.2 +/- 2.4)%. At necropsy, in mice given octreotide, the mean tumor weight were significantly lower than that of control group (0.27 +/- 0.05 vs 0.85 +/- 0.37, P < 0.01). The inhibition rate of tumor in vivo at 2 months was 68.2%.

CONCLUSION

Octreotide is effective in inhibiting growth of HCC both in vivo and in vitro significantly. The mechanisms of antineoplastic effect action may involved in inhibiting DNA synthesize and inducing apoptosis of tumor cells.

P450 interaction with farnesyl-protein transferase inhibitors metabolic stability, inhibitory potency, and P450 binding spectra in human liver microsomes

Methyl substitution at the 2-position of the imidazole ring greatly improved drug metabolism profiles, in human liver microsomes, of ras farnesyl-protein transferase inhibitor (FTI) candidates for drug development. Methyl substitution markedly reduced the P450 inhibitory potency of non-substituted FTIs for CYP3A4 (by a factor of 12-403) and 2C9 (by a factor of 4.2-28), while it had little effect on the CYP2D6 enzyme. An immunochemical inhibition study demonstrated that CYP3A4 plays a predominant role in the metabolism of both non-substituted and 2-methyl-substituted imidazole-containing FTI candidates. Very strong type II binding spectra with human liver microsomes were observed for all non-substituted FTIs, while methyl substitution markedly weakened type II spectra or shifted the type of spectra from II to I. This indicated that methyl substitution on the imidazole moiety interfered with the substrate-P450 heme interaction, likely due to a steric effect caused by the methyl group. A kinetics study revealed that the methyl substitution increased V(max) and K(m) values to the same extent. These studies suggested that the 2-methyl substitution on the imidazole ring improved its drug metabolism profile by reducing the potential to inhibit CYP3A4-mediated metabolism without affecting intrinsic metabolic clearance (V(max)/K(m)).

Inhibition of p53 transcriptional activity by the S100B calcium-binding protein

The levels of S100 Ca(2+)-binding proteins correlate with the progression of certain tumors, but their role, if any, in carcinogenesis is still poorly understood. S100B protein associates with both the p53 oligomerization domain (residues 325-355) and the extreme C terminus of the tumor suppressor p53 (residues 367-392). Consequently, S100B inhibits p53 tetramer formation and p53 phosphorylation mediated by protein kinase C, on p53 C-terminal end. In this report, we show that the S100B protein decreases p53 DNA binding and transcriptional activity. The effect of S100B is reflected in vivo by a reduced accumulation of p53, p21, and MDM2 protein levels in co-transfection assays and in response to bleomycin. The S100B can still interact with p53 in the absence of p53 extreme C-terminal end and reduce the expression of p53 downstream effector genes. These data indicate that S100B does not require p53 extreme C-terminal end to inhibit p53 activity. Collectively, these findings imply that elevated levels of S100B in tumors such as astrocytomas and gliomas could inhibit p53 functions and contribute to cancer progression.

Interleukin 10 inhibits the rat VSMC proliferation and collagen secretion stimulated by angiotensin II

OBJECTIVE

To study the effect of interleukin 10 (IL-10) on the angiotensin II (AngII) stimulated rat VSMC proliferation and collagen secretion, and furthermore, explore its mechanism.

METHODS

On cultured VSMC of rat, 3H-thymine (3H-TdR) and 3H-proline incorporations were used to evaluate the DNA and collagen synthesis, respectively. Western blot and immunoprecipitation were applied to assay the expression and activity of focal adhesion kinase (FAK), respectively.

RESULTS

IL-10 (10(-8) approximately 10(-10) g/ml) inhibited the increase of 3H-TdR and 3H-proline incorporation as well as FAK activity, which was induced by 10(-7) mol/L AngII (P < 0.05 or P < 0.01). IL-10 also obviously downregulated the synthesis and secretion of collagen by AngII stimulated VSMC. But there was no difference in the protein expression of FAK among all the groups (P > 0.05).

CONCLUSION

IL-10 antagonizes the VSMC proliferation and collagen synthesis by regulating FAK activity stimulated by AngII.

Striatal size and relative glucose metabolic rate in schizotypal personality disorder and schizophrenia

BACKGROUND

Schizotypal personality disorder (SPD) shares social deficits and cognitive impairment with schizophrenia, but is not typically characterized by frank psychosis. Because striatal size and functional activity have both been shown to be associated with psychotic symptoms, we carried out the first study of SPD to assess the caudate and putamen for comparison with findings in schizophrenia.

METHODS

Patients with SPD (n = 16), schizophrenic patients (n = 42), and age- and sex-matched normal control subjects (n = 47) were assessed with magnetic resonance imaging. All of the patients with SPD and subsamples of the schizophrenic patients (n = 27) and control subjects (n = 32) were also assessed with positron emission tomography using fluorodeoxyglucose F-18.

RESULTS

The relative size of the putamen in controls was significantly larger than in patients with SPD and significantly smaller than in schizophrenic patients, while the relative size of the caudate was similar in all 3 groups. Compared with control values, relative glucose metabolic rate in the ventral putamen was significantly elevated in patients with SPD and reduced in schizophrenic patients. When subsamples of schizophrenic patients (n = 10) and patients with SPD (n = 10) both of whom never received medication were compared, this pattern was more marked, with the highest value for the putamen being found in patients with SPD for the ventral slice and the lowest value for the right dorsal putamen.

CONCLUSIONS

Patients with SPD showed reduced volume and elevated relative glucose metabolic rate of the putamen compared with both schizophrenic patients and controls. These alterations in volume and activity may be related to the sparing of patients with SPD from frank psychosis.