The functional ratio of chymase and angiotensin converting enzyme in angiotensin I-induced vascular contraction in monkeys, dogs and rats

Recently, a chymase-dependent angiotensin (Ang) II-forming pathway was found in human cardiovascular tissues, and the significance of this pathway in the pathogenesis of some cardiovascular diseases was suggested. The present study examined the ratio of angiotensin converting enzyme (ACE) to chymase-dependent Ang II formation in various isolated vessels from monkeys, dogs and rats. In all of the examined vessels, the addition of KCl at a concentration of 50 mM could induce a maximal contraction. Except for monkey coronary artery and rat renal and femoral artery, the addition of Ang I could induce transitory contractions, whereas the force of contractions in these vessels was quite different. The sensitivity to Ang II in these vessels was similar to that for Ang I. In monkey gastroepiploic and mesenteric arteries, about 70% of the Ang I-induced contraction was suppressed by chymase inhibition, while it was suppressed about 50% in monkey renal, femoral and carotid arteries. In dog renal arteries, about 65% of the Ang I-induced contraction was suppressed by chymase inhibition, while it was suppressed by about 30% in other dog arteries. In contrast, in all rat arteries, Ang I-induced contractions were completely suppressed by treatment with ACE inhibitor alone. We concluded that regional differences in the response to Ang I exist in vascular tissues, and the ratio of ACE- to chymase-dependent Ang II formation is different in the various vessels.

Characteristics of monkey tryptase purified from cheek pouch vascular tissues

Tryptase purified from rat and dog tissues has been reported, although the characteristics of these enzymes are different from human tryptase. For pathophysiological studies of human tryptase, studies on species that have a similar tryptase to humans is needed. In this study, we purified monkey tryptase from cheek pouch vascular tissues using heparin affinity and gel filtration columns. The monkey tryptase, which had a molecular weight of 130 kDa by gel filtration, consisted of a tetramer of 33 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The N-terminal sequence showed high homology with tryptases from other species. The optimum pH and temperature were 7.5-9.0 and 25-40 degrees C, respectively. The enzyme was labile in high-KCl buffer, and the optimum KCl concentration was 0.1 M. The enzyme activity was completely inhibited by diisopropyl phosphorofluoridate and leupeptin but not by soybean trypsin inhibitor and alpha-antitrypsin. The enzyme hydrolyzed vasoactive intestinal peptide but did not affect angiotensin I, somatostatin and bradykinin. In the present study, we first isolated monkey tryptase from cheek pouch vascular tissues and showed that the characteristics of monkey tryptase are very similar to those of human tryptase.

[Anterior interbody autografting and internal fixation for primary surgical management of thoracolumbar spinal tuberculosis]

OBJECTIVES

To verify the importance of early reconstruction of spinal stability and to evaluate the safety of anterior instrumentation in surgical management of spinal tuberculosis.

METHODS

Eleven cases of thoracolumbar spinal tuberculosis were treated with primary anterior debridement, interbody autografting and Z-plate fixation from October 1997 to January 1999.

RESULTS

All the 11 cases healed without any recurrence after follow-up for an average of 16 months. Spinal fusion occurred in 3.8 months on average after surgery. 18 degrees of kyphosis correction was achieved with no associated complication.

CONCLUSIONS

Early reconstruction of spinal stability plays an important role in surgical management of spinal tuberculosis, and it is safe to implant anterior titanium spinal instrument in tuberculosis foci.

Angiotensin II receptor antagonist, L-158,809, prevents intimal hyperplasia in dog grafted veins

We investigated the levels of the angiotensin II-forming enzymes, chymase and angiotensin converting enzyme (ACE), in dog grafted veins, and studied the effect of an angiotensin II type 1 receptor antagonist, L-158,809, on vascular proliferation in the grafted veins. The right external jugular vein was grafted to the ipsilaterial carotid artery. In the group treated with L-158,809, the drug (10 mg/kg per day, p.o.) were administered orally from 7 days before the operation to 28 days after it, while the others were administrated placebo. In the placebo-treated group, the chymase activity in the grafted veins was increased about 10-fold and the ACE activity was doubled. The areas of intima and media were significantly increased in the grafted veins in the placebo-treated group. L-158,809 significantly reduced the intimal area of the grafted veins. An angiotensin II receptor antagonist, L-158,809, prevented the vascular proliferation in the grafted veins, and the development of the proliferation may depend on activation of local angiotensin II formation.

[Thoracolumbar injuries: pathomorphology of and a new classification]

OBJECTIVE

To introduce a new classification of thoracolumbar injuries.

METHODS

Three modes were used to classify the injuries according to the mechanisms of injuries: Type A, flexion-compression fractures; Type B, vertical compression fractures; Type C, distraction injuries. Two groups were used to distinguish the fractures in one type according to the pathomorphological differences and the clinical incidence: Group A, with a more clinical incidence, and Group B, with a less clinical incidence. Three subgroups were used to divide the injuries in one group in consideration of the severity of the fracture instability and the fracture displacement: fracture, subluxation, and dislocation.

RESULTS

A new classification of thoracolumbar fractures was established.

CONCLUSION

The new classification is more systemic and more convenient.

A new method for simultaneous measurements of mast cell proteases in human vascular tissue

1. Human mast cells contain carboxypeptidase A, chymase and tryptase. In the present study, in order to analyse the mast cell proteases simultaneously, we investigated a method for the measurement of carboxypeptidase A, chymase and tryptase in human vascular tissues. 2. Human vascular tissues were homogenized in 10 mmol/L phosphate buffer containing 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6 or 1.8 mol/L KCl and 0.1% non-idet P-40 and samples were then extracted. Because carboxypeptidase A and chymase convert angiotensin (Ang)I to Ang-(1-9) and AngII, respectively, the extracts were incubated with AngI in the presence of an angiotensin-converting enzyme (ACE) inhibitor. The extract prepared in buffer with over 0.8 mol/L KCl converted AngI to Ang-(1-9) and AngII. Formation of Ang-(1-9) and AngII plateaued in extracts with 1.0 and 1.2 mol/L KCl, respectively. 3. The formation of Ang-(1-9) and AngII in the extract with 1.2 mol/L KCl was inhibited by inhibitors of carboxypeptidase A and chymase, respectively, suggesting that Ang-(1-9) and AngII were generated from AngI by carboxypeptidase A and chymase, respectively. 4. Using a specific tryptase substrate, tryptase activity was detected in extract in buffer with over 0.8 mol/L KCl and reached a plateau at concentrations of KCl over 1.0 mol/L. 5. These findings show that the maximum activity of carboxypeptidase A, chymase and tryptase was detected in extracts of human homogenized vascular tissues in buffer at 1.2 mol/L KCl. The present study demonstrates a new method for the simultaneous measurement of proteases derived from mast cells in humans.

[Mitogenesis of platelet-derived growth factors to human osteoblasts modulated by basic fibroblast growth factor]

OBJECTIVES

To investigate the mechanism by which basic fibroblast growth factor modulates the mitogenesis of platelet-derived growth factor to human osteoblasts.

METHODS

The osteoblasts isolated from human fetal calvaria were incubated with PDGF-AB (100 ng/ml) or bFGF(10 ng/ml) combined with PDGF-AB (100 ng/ml); the growth curve was plotted. The(3)H-TdR incorporation of the osteoblasts was measured after the cells were incubated with different combination of bFGF and PDGF-AA or PDGF-BB. After incubated with bFGF (10 ng/ml) for 24 hours, the number of PDGFR-alpha and PDGFR-beta on the membrane of the osteoblasts was detected by fluoroimmunoassay.

RESULTS

Four days after PDGF-AB added into the medium, the population of the osteoblasts was larger than that of the control (P < 0.05). The number of the osteoblasts incubated with PDGF-AB (12.1 x 10(4)) was 1.8 times as large as the control (6.8 x 10(4)) in the 10th day (P < 0.05), and that of the osteoblasts incubated with both bFGF and PDGF-AB increased more quickly than the cells only incubated with PDGF-AB. The incorporation of (3)H-TdR into the osteoblasts cultured with bFGF combined with PDGF-AA (533.6 +/- 13.1) was more than that cultured only with PDGF-AA (435.4 +/- 14.8, P < 0.01), so was the incorporation of (3)H-TdR of those cells cultured with bFGF and then PDGF-AA (633.8 +/- 51.5). bFGF up-regulated PDGFR-alpha and down-regulated PDGFR-beta on the surface of the human osteoblasts.

CONCLUSION

bFGF elevates the mitogenesis of PDGF-AA or -AB to human osteoblasts by up-regulating PDGFR-alpha.

Platelet-derived growth factor (PDGF)-AA: a self-imposed cytokine in the proliferation of human fetal osteoblasts

PDGF, a multiple mitogen, stimulates osteoblast replication and bone collagen degradation, and it has been described as a key factor in bone metabolism. Recently, PDGF was disclosed to be the autocrine cytokine of human osteoblasts. PDGF's effect on human bone development needs elucidation, and the mechanism of PDGF-AA autocrining remains unclear. In this work, osteoblasts were isolated from human fetal calvaria which resemble the cells in developing bone tissue. Using an in vitro model, the effect of PDGF-AA on the cells was investigated with the results showing that (i) after PDGF-AA was added into the medium for 24 h, PCI of the cells increased by 48.2% (P<0.05), and PCI decreased after the removal of PDGF-AA. (ii) 24 h after treatment with PDGF-AA, the percentage of osteoblasts in G(0)/G(1)phase decreased and that in S phase increased. (iii) The expression of PDGF-A mRNA was upregulated by PDGF-AA, PDGF-BB, TGFbeta,and bFGF respectively. These results proved that: (i) PDGF-AA enhances cell replication by accelerating cell recycle and inducing the quiescent cells into the proliferation portion of cell cycle. (ii) PDGF-AA is a self-imposed cytokine in human fetal osteoblast replication.

A topological study of the human gamma-glutamyl carboxylase

gamma-Glutamyl carboxylase (GC), a polytopic membrane protein found in the endoplasmic reticulum (ER), catalyzes vitamin K-dependent posttranslational modification of glutamate to gamma-carboxyl glutamate. In an attempt to delineate the structure of this important enzyme, in vitro translation and in vivo mapping were used to study its membrane topology. Using terminus-tagged full-length carboxylase, expressed in 293 cells, it was demonstrated that the amino-terminus of the GC is on the cytoplasmic side of the ER, while the carboxyl-terminus is on the lumenal side. In addition, a series of fusions were made to encode each predicted transmembrane domain (TMD) followed by a leader peptidase (Lep) reporter tag, as analyzed by the computer algorithm TOPPRED II. Following in vitro translation of each fusion in the presence of canine microsomes, the topological orientation of the Lep tag was determined by proteinase K digestion and endoglycosidase H (Endo H) cleavage. From the topological orientation of the Lep tag in each fusion, the GC spans the ER membrane at least 5 times, with its N-terminus in the cytoplasm and its C-terminus in the lumen.

Modulation of transforming growth factor beta to platelet-derived growth factor receptor-alpha of human osteoblasts

OBJECTIVE

To investigate the mechanism and the significance of TGF beta in modulating the expression of Platelet-Derived Growth Factor Receptor-alpha (PDGFR-alpha) in human osteoblasts.

METHODS

The osteoblasts were isolated from human fetal calvaria. The percentage of cell increase (PCI) in every 4 hours was calculated to demonstrate the proliferation of osteoblasts affected by PDGF-AA and TGF beta. The osteoblasts were cultured with TGF beta for 24 hours and with PDGF-AA for another 24 hours, and the cells proliferation was shown by PCI too. The osteoblasts were cultured with TGF beta for 24 h, and the PDGFR-alpha of the cells were measured by immunofluorescent analysis.

RESULTS

PCI was increased by 48.2% and 22.4% after PDGF-AA and TGF beta were added into the medium for 24 hours respectively (P < 0.05), and PCI decreased after the removal of the two cytokines. Preincubated with TGF beta for 24 hours and then stimulated with PDGF-AA, PCI grew slowly. TGF beta downregulated the expression of the PDGFR-alpha.

CONCLUSION

TGF beta can downregulate the mitogenesis of PDGF-AA by lowering the number of PDGFR-alpha.

Identification of a Drosophila vitamin K-dependent gamma-glutamyl carboxylase

Using reduced vitamin K, oxygen, and carbon dioxide, gamma-glutamyl carboxylase post-translationally modifies certain glutamates by adding carbon dioxide to the gamma position of those amino acids. In vertebrates, the modification of glutamate residues of target proteins is facilitated by an interaction between a propeptide present on target proteins and the gamma-glutamyl carboxylase. Previously, the gastropod Conus was the only known invertebrate with a demonstrated vitamin K-dependent carboxylase. We report here the discovery of a gamma-glutamyl carboxylase in Drosophila. This Drosophila enzyme is remarkably similar in amino acid sequence to the known mammalian carboxylases; it has 33% sequence identity and 45% sequence similarity to human gamma-glutamyl carboxylase. The Drosophila carboxylase is vitamin K-dependent, and it has a K(m) toward a model pentapeptide substrate, FLEEL, of about 4 mm. However, unlike the human gamma-glutamyl carboxylase, it is not stimulated by human blood coagulation factor IX propeptides. We found the mRNA for Drosophila gamma-glutamyl carboxylase in virtually every embryonic and adult stage that we investigated, with the highest concentration evident in the adult head.

[The effects of platelet-derived growth factor-AA on the osteoclasts]

OBJECTIVE

To study the effects of platelet-derived growth factor (PDGF)-AA on the osteoclasts.

METHODS

The PDGF receptor alpha (PDGFR-alpha) was detected on the osteoclastic membrane with immunoelectronmicroscopy. Acid phosphatase (ACP) and tartrate-resistant acid phosphatase (TRAP) activities were measured kinetically and the introcellular hydrogen ions were calculated on the confocal laser scanning microscope (CLSM) stained with SNAFL. Stained by toluidine blue, the area and number of the resorption pits were determined with the Leica Quantimet 500 system.

RESULTS

The colloidal gold precipitated on the cellular membrane, and the TRAP activity had no difference (P > 0.05). Hydrogen ions rose significantly but their release could not be promoted by PDGF-AA. The changes of the resorption pits were not significant.

CONCLUSIONS

The PDGF-AA could promote hydrogen ions yielding but not stimulate osteoclastic bone resorption due to the significant TRAP changes of TRAP activities.

Expression of bone morphogenetic protein receptors type-IA, -IB and -II correlates with tumor grade in human prostate cancer tissues

Bone morphogenetic proteins (BMPs) are potential regulators of prostate cancer cell growth and metastasis that signal through an interaction with BMP membrane receptors (BMPRs) type I and type II. In the present study, Western blot and immunohistochemical analysis of BMPRs were carried out in benign and malignant human prostate tissues to explain the loss of BMP response in human prostate cancer cells. The results demonstrated that the benign prostate specimens expressed high levels of all three BMPRs. In normal prostate, BMPRs were localized predominantly to epithelial cells. Among prostate cancer specimens, well-differentiated cancers were positive for the expression of BMPR-II, BMPR-IA, and BMPR-IB, for the most part. In contrast, only 1 of 10 poorly differentiated prostate cancer cases was positive for each of the three BMPRs (P < 0.005 for all three receptors). Taken together, these results indicate that human prostate cancer cells frequently exhibit loss of expression of BMPRs and suggest that loss of BMPRs may play an important role during the progression of prostate cancer.

Inhibition of chymase reduces vascular proliferation in dog grafted veins

We investigated the effect of a chymase inhibitor Suc-Val-Pro-Phe(P)(OPh)(2) on the proliferation of the grafted vein in dog. By 28 days after the operation, the mean intimal area of the grafted vein in the placebo group was 3.24+/-0.32 mm(2). The intimal area of the grafted vein in the chymase inhibitor-treated group was reduced to 63.9%. In the placebo group, the activities of chymase and angiotensin-converting enzyme in grafted vein were significantly increased 15- and 2-fold, respectively. In the chymase inhibitor-treated group, chymase activity in the grafted veins was decreased significantly. These findings suggest that inhibition of chymase appears useful for preventing vascular proliferation.

Characterization of recombinant human chymase expressed in Escherichia coli

We compared recombinant human chymase expressed in Escherichia coli with human chymase purified from vascular tissues. The recombinant chymase, the structure of which was NH2-enterokinase cleavage site-chymase-COOH, was expressed in Escherichia coli and then was solubilized and renatured. The protein did not have a chymase activity, but gained this activity after the cleavage of the N-terminal site by enterokinase. The enzyme was purified by heparin affinity and gel filtration columns. The N-terminal sequence of the protein was identical to the sequence for human chymase. The molecular weights of the recombinant chymase and chymase purified from human vascular tissues were 26 and 30 kDa, respectively, and the 4 kDa difference was thought to be due to the presence or absence of glycan. The optimum pH of the recombinant enzyme activity was between 7.5 and 9.0. The activity of the recombinant enzyme was inhibited by chymostatin, soybean trypsin inhibitor and phenylmethylsulfonyl fluoride, but not by ethylenediaminetetraacetic acid and aprotinin. This enzyme cleaved specifically the Phe8-His9 bond of angiotensin (Ang) I to form Ang II and that of big endothelin (ET)-1 to form ET-1-(1-31). These findings demonstrated that the enzymatic characteristics of the recombinant enzyme were identical to that of native human chymase.

[Biocompatibility studies on bioactive glass ceramics and polylactic acid combined with cultured bone marrow stromal cells in vitro]

OBJECTIVE

To study the biocompatibility on bioactive glass ceramics (BGC) and polylactic acid (PLA) combined with cultured bone marrow stromal cells (BMSCs) in bone tissue engineering.

METHODS

BMSCs were cultured combined with BGC and PLA in vitro, and the morphological characters, cell proliferation, protein content, and alkaline phosphatase activity were detected.

RESULTS

BMSCs could be attached to and extended on both BGC and PLA, and normally grown, proliferated, had active function. BGC could promote cell proliferation.

CONCLUSION

The results show that both BGC and PLA have good biocompatibility with BMSCs, they can be used as biomaterials for cell transplantation in tissue engineering.

Construction and characterization of a bacterial artificial chromosome library of thermo-sensitive genic male-sterile rice 5460S

In order to develop a detailed physical map of the thermo-sensitive genic male-sterile (TGMS) gene-encompassing region and finally clone the TGMS gene, a high-quality rice bacterial artificial chromosome (BAC) library from TGMS rice 5460S was constructed. The method of constructing BAC library was examined and optimized. The 5460S library consists of 19 584 BAC clones with an average insert size of 110 kb, which represents about 5 times rice haploid genome equivalents. Rice inserts of up to 140 kb and 250 kb were isolated and appeared stable after 100 generations of serial growth. Hybridization of BAC clones with mitochondrial and chloroplastic genes as probes demonstrated that this library has no organellar contamination. The 5460S library was screened with 3 molecular markers linked to tms 1 gene as probes and at least 1 BAC clone was identified with each probe. The insert ends of positive clones were successfully isolated using thermal asymmetric interlaced PCR (TAIL-PCR) technique.

[Human motion analysis system based on common video-camera]

A new human motion analysis system based on common video-camera is introduced in this paper. The image processing technique is used to recognize and track anatomic landmarks, which makes data processing more quickly and accurately. The system is cost-effective and can be easily operated because the common video-cameras instead of special instruments are used. Furthermore, the system can also be used for detection and analysis of other low-speed moving objects.

[Nosocomial catheter-related sepsis secondary to central venous catheters]

OBJECTIVE

To study bacteria and drug sensitivity of catheter-related sepsis (CRS).

METHODS

Between February 1993 and December 1997, 52 patients with central venous catheter-related sepsis were studied retrospectively.

RESULTS

The most common organisms were staphylococcus aureus and staphylococcus epidermis. The bacterial pathogens isolated demonstrated a marked pattern of antibiotic resistance. Gram-positive cocci were sensitive to vancomycin with a sensitivity of 93.3%, and gram-negative bacilli were sensitive to amikacin and ceftazidine with a sensitivity of 51.7%.

CONCLUSIONS

The effective treatment of catheter-related sepsis is removal of infected catheters. Vancomycin and (or) amikacin may be first chosen to treat CRS.

[Pathophysiological roles of chymase and effects of chymase inhibitor]

Human chymase forms angiotenin (ANG) I to ANG II, whereas the roles of ANG II generated by chymase and the effects of chymase inhibitors have been unclear. On the other hand, rat chymase could not convert ANG I to ANG II. In isolated rat arteries, the ANG I-induced vascular contraction was completely suppressed by angiotensin-converting enzyme (ACE) inhibitor only. However, 30% of ANG I-induced vascular contraction in isolated human arteries was suppressed by an ACE inhibitor, but the remainder was blocked by chymostatin. In hamster hypertensive models, ANG II formation by ACE, but not by chymase, in vascular tissues plays an important role in maintaining hypertension. ANG II formation also induces vascular remodeling such as neointima formation. After balloon injury of vessels in dog, chymase and ACE activities were significantly increased in the injured vessels. In this model, an ANG II receptor antagonist was effective in preventing neointimal formation after balloon injury of vessels in dog, but an ACE inhibitor was ineffective. In dog grafted veins, the activities of chymase and ACEmin the grafted vein were significantly increased 15- and 2-fold, respectively, compared with those in the symmetrical veins. The intimal area of the grafted vein was reduced by a chymase inhibitor. Therefore, chymase-dependent ANG II formation plays an important role in the proliferative response, and chymase inhibitors may appear useful for preventing vascular proliferation.

[Application study of yangkang biological fertilizer on Panax notoginseng cultivation]

Yangkang Biological Fertilizer was sprayed on Panax notoginseng. The result indicated that the yield and the surviving rate can be raised 25.2% and 15.2% respectively. The best spraying practice were: in the unfolding stage of leaves (April) and bloom stage (July), with Yangkang Biological Fertilizer plus water (1:400), at four times every stage.

[An analysis of nutritional and harmful components of vegetables grown in plastic greenhouses]

OBJECTIVE

To study the changes in nutritional and harmful components of vegetables grown in plastic greenhouses.

METHODS

In plastic greenhouses, microclimate and air concentrations of carbon monoxide, carbon dioxide, fluoride and respirable particulate were measured, and chlorophyll, total sugar, crude fiber, nitrite, fluoride, arsenic and some mineral elements in vegetables were determined as compared with those grown in the open-air fields.

RESULTS

Greenhouse appeared a lower wind speed and darker illumination. Contents of chlorophyll a an b, total chlorophyll, reduced vitamin C, crude fiber in vegetables grown in greenhouse all were lower than those grown in open-air fields. Contents of potassium, calcium, magnesium, iron, zinc, copper and phosphorous were all lower in the vegetables grown in greenhouse than those grown in open-air fields. The contents of chlorophyll reducing Vitamin C.

CONCLUSION

Lower wind speed and inadequate illumination in greenhouse affected photosynthesis and uptake of water in vegetables causing changes in their nutritional components. But, no contamination of burning coal was found in vegetables grown in greenhouse.

Chymase-dependent angiotensin II formation in human vascular tissue

BACKGROUND

Some reports have suggested that, in vitro, human heart chymase in homogenates contributes little to angiotensin (Ang) II formation in the presence of natural protease inhibitors such as alpha-antitrypsin. We studied whether chymase bound to heparin, resembling an in vivo form, could contribute to Ang II formation in the presence of natural protease inhibitors.

METHODS AND RESULTS

The Ang II formation was increased time-dependently after incubation in an extract (1 mg of protein/mL) of human vascular tissues containing Ang I. The concentration of Ang II in the extract after incubation for 30 minutes was 1.67+/-0.06 nmol/mL, and we regarded this quantity of Ang II as 100%. The Ang II formation was inhibited 10%, 95%, and 96% by 1 micromol/L lisinopril, 100 micromol/L chymostatin, and 0.1 g/L alpha-antitrypsin, respectively. The extract was applied to a heparin affinity column. After the column was washed with PBS, the eluted PBS contained a weak Ang II-forming activity, which was completely inhibited by lisinopril. The eluted PBS, to which >0.8 mol/L NaCl had been added, showed a strong Ang II-forming activity which was inhibited by chymostatin and alpha-antitrypsin. After the application of the extract, the column was washed with PBS and then an Ang I solution in PBS was applied to the column. The Ang II formation in the PBS eluted from the incubated column was increased time-dependently. The concentration of Ang II in the PBS (1 mL) eluted from the column after incubation for 30 minutes was 2.56+/-0.28 nmol/mL, and we regarded this quantity of Ang II as 100%. To study the effects of inhibitors, the extract (1 mg of protein/mL) was applied to a heparin affinity column (1 mL) which was preequilibrated with PBS (3 mL); 100 micromol/L chymostatin or 0.1 g/L alpha-antitrypsin in PBS (1 mL) was then applied to the column. After the column was washed with PBS (3 mL), Ang I solution (1 mg/mL) in PBS was applied to the column, and the column was incubated for 30 minutes. The Ang II formation in the PBS eluted from the column was suppressed up to 5% by application of chymostatin, although this was not affected by application of alpha-antitrypsin.

CONCLUSIONS

These findings suggest that human chymase bound to heparin plays a functional role in Ang II formation in the presence of natural protease inhibitors such as alpha-antitrypsin.

Osteocalcin binds tightly to the gamma-glutamylcarboxylase at a site distinct from that of the other known vitamin K-dependent proteins

Vitamin K-dependent proteins contain a propeptide that is required for recognition by the enzyme gamma-glutamylcarboxylase. Substrates used in vitro for carboxylation studies lacking a prosequence are characterized by Km values in the millimolar range, whereas the Km for peptides containing a prosequence is three or four orders of magnitude smaller. Here we report that descarboxy-osteocalcin is an exception in this respect. With descarboxy-osteocalcin in purified propeptide-free recombinant carboxylase, the Km was 1.8 microM. Furthermore, osteocalcin was an inhibitor of descarboxy-osteocalcin carboxylation with a Ki of 76 microM. In contrast with the other vitamin K-dependent proteins, free propeptides do not inhibit descarboxy-osteocalcin carboxylation. Moreover, propeptide-containing substrates were inhibited neither by osteocalcin nor by its propeptide. From our studies we conclude that descarboxy-osteocalcin must have an internal recognition sequence that binds to gamma-glutamylcarboxylase at a site different from the propeptide-recognition site.

[The effects of platelet-derived growth factor on rat osteoblastic DNA contents]

OBJECTIVE

To study the effects of platelet-derived growth factor (PDGF) on the DNA content of the isolated osteoblast-like cells and the cellular period changes, and further study the effect of PDGF on bone fracture healing.

METHODS

The cultured osteoblast-like cells in vitro were isolated from fetal rat calvaria and the effects of PDGF on cellular DNA contents were observed under flow cytometer. The changes of osteoblastic surface structure and ultrastructure were observed under electron microscope.

RESULTS

PDGF could increase the DNA contents of cellular S period by promoting osteoblast from G0/G1 period into S period. The effects of PDGF on increasing cellular DNA contents were most significant at 24th culture hour (DNA content: 17.6% at the 24th hour, 9.0% at the 48th hour, 10.2% at the 72nd hour). PDGF could increase osteoblastic surface granules, reticular fibers and intracellular calcium salt crystals, and calcium granule mitochondria.

CONCLUSIONS

PDGF could promote bone fracture healing by stimulating osteoblastic DNA synthesis and cell proliferation. The flow cytometer is a better instrument to analyze cell DNA content for a large number of cells.

Effects of parenteral nutrition support and chemotherapy on the phasic composition of tumor cells in gastrointestinal cancer

BACKGROUND

Some clinical studies report the effects of parenteral nutrition in malnourished cancer patients, but few discuss the tumor response to parenteral nutrition plus chemotherapy. If used in combination, the antitumor activity of chemotherapeutic agents may compensate for the tumor stimulation of parenteral nutrition.

METHODS

Ninety-two patients with operable gastrointestinal cancer and malnutrition were randomly assigned to four interventions that were administered for 7 days preoperatively: parenteral nutrition alone, parenteral nutrition plus chemotherapy, chemotherapy alone, or no treatment (control). The preintervention and postintervention DNA content, DNA index, percentage of cells in S phase, and tumor cell sensitivity to chemotherapy were measured using image cytometry.

RESULTS

Parenteral nutrition resulted in a significant proliferation of tumor cells and a significant increase in the sensitivity of tumor cells to chemotherapy; these effects were not seen in tumors of patients receiving parenteral nutrition plus chemotherapy. There was, however, a nonsignificant increase in tumor cell proliferation and sensitivity to chemotherapy in the tumors of subjects receiving combined therapy compared with those of subjects who received chemotherapy alone. The postintervention nutritional status of both the parenteral nutrition group and the parenteral nutrition plus chemotherapy group were significantly better than that of the control group and the chemotherapy group. The short-term, postoperative clinical outcomes in the chemotherapy group were significantly worse than those in the other three groups.

CONCLUSIONS

These results indicate that combining chemotherapy and nutrition support preoperatively for malnourished patients with gastrointestinal cancer improves short-term nutritional status without increasing the proliferation of tumor cells and prevents the postoperative complications that occur when such patients are given chemotherapy without nutrition support. The results also suggest--but do not prove--that parenteral nutrition may increase the effectiveness of chemotherapy in malnourished patients.

Effects of daphnodorin A, daphnodorin B and daphnodorin C on human chymase-dependent angiotensin II formation

We investigated whether daphnodorin A, daphnodorin B and daphnodorin C inhibited human chymase-dependent angiotensin II-forming activity. Although the structures of these compounds are very similar, daphnodorin A completely inhibited angiotensin II formation generated by chymase, while daphnodorin B partially inhibited and daphnodorin C did not. On the other hand, these daphnodorins did not affect angiotensin converting enzyme-dependent angiotensin II formation. Furthermore, these daphnodorins did not inhibit purified human tryptase, which, like chymase, is contained in mast cells. Therefore, daphnodorin A, but not daphnodorin B and daphnodorin C, may specifically inhibit the chymase-dependent angiotensin II formation, and such differences between inhibitory effects of these compounds to human chymase may be useful for the development of human chymase inhibitor.

Effects of a lipoxygenase inhibitor, panaxynol, on vascular contraction induced by angiotensin II

We investigated whether a lipoxygenase inhibitor, panaxynol, affected the vascular contraction induced by angiotensin (Ang) II and the mean arterial pressure in spontaneously hypertensive rats (SHR). Panaxynol suppressed dose-dependently the contractile responses induced by 30 nM Ang II in isolated intact and endothelial cell-denuded aorta in the hamster. IC50 values in the intact and endothelial cell-denuded aorta were 23 and 20 microM, respectively. In SHR, the mean arterial pressure after injection of 30 and 60 mg/kg panaxynol was reduced, and the maximum hypotensive values were 23 and 48 mmHg, respectively. Thus, lipoxygenase products may affect the renin-angiotensin system.

Determination of D-amino acids labeled with fluorescent chiral reagents, R(-)- and S(+)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazoles, in biological and food samples by liquid chromatography

D-Amino acids in food and biological samples labeled with R(-)- and S(+)-4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazoles (DBD-PyNCS) were separated by reversed-phase chromatography and detected fluorometrically at 550 nm (excitation at 460 nm). DL-Amino acids were efficiently labeled at 55 degrees C for 20 min in basic medium. The resulting thiocarbamoyl-amino acids were resolved by an isocratic elution using water:30% methanol in acetonitrile (72:28) containing 0.1% trifluoracetic acid as mobile phase for hydrophilic amino acids and gradient elutions using sodium acetate buffer (pH 5. 2)/acetonitrile as gradient solvent mixture for hydrophobic amino acids, respectively. The detection limits (S/N = 3) of DL-amino acids tested were in the range of 0.16-0.75 pmol. The proposed method was applied to determine the D-amino acid(s) in milk, cream, fermented dairy products (yogurt and yakult), tomato products (juice, puree, and catchup), fermented beverages (beer and red wine), and human urine. The existence of D-amino acid(s) was demonstrated in all the samples tested. Furthermore, the identification of the D-amino acid(s) was performed using both isomers of DBD-PyNCS and by on-line HPLC-electrospray ionization-MS.

Chromosomal localization of three human genes encoding bone morphogenetic protein receptors

Bone morphogenetic proteins (BMPs) are members of the TGF-beta superfamily that play a pivotal role in bone formation during embryogenesis and fracture repair. BMP signaling occurs via hetero-oligomeric serine/threonine kinase complexes of BMP type I (BMPR-IA or BMPR-IB) and type II receptors (BMPR-II). BMPR-IA and IB are closely related receptors, with sequence differences conserved between different species, suggesting that they serve distinct functions. Here we report the cDNA cloning of human BMPR1B and the chromosomal localization of all three BMPR genes. Using somatic cell hybrid and FISH analyses, the BMPR1A, BMPR1B, and BMPR2 genes were assigned to 10q23, 4q22-24, and 2q33-34, respectively. A processed BMPR1A pseudogene was mapped to 6q23.

Effects of a new 12-lipoxygenase inhibitor, daphnodorin A, on angiotensin II-induced vascular contraction in hamster

We studied whether lipoxygenase inhibition suppressed angiotensin II-induced vascular contraction. In the present study, we used a new 12-lipoxygenase inhibitor, daphnodorin A, and an analogue of daphnodorin A, daphnodorin B, which has no inhibitory effects on 12-lipoxygenase. Daphnodorin A at 30 microM and 100 microM significantly suppressed the contractile responses induced by angiotensin 11 (3 x 10(-8) M) in isolated hamster aorta, while daphnodorin B up to 100 microM did not affect the responses. These results suggest that daphnodorin A, but not daphnodorin B, may suppress angiotensin II-induced vascular contractile responses through the inhibition of 12-lipoxygenase.

Tranilast, an anti-allergic drug, possesses antagonistic potency to angiotensin II

N-(3',4'-dimethoxycinnamoyl) anthranilic acid (tranilast), an effective anti-allergic drug, has successfully prevented restenosis in patients who have undergone percutaneous transluminal coronary angioplasty. To elucidate the mechanism of tranilast, we investigated its antagonistic effect to angiotensin II, which plays a pivotal role in the proliferation of vascular smooth muscle cells, using angiotensin II-induced contractions in human gastroepiploic artery and rabbit aorta. The possible antagonistic effects of other anti-allergic agents such as 4-( p-chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4-yl)-1(2H)-phthal azinone hydrochloride (azelastine), 9-methyl-3-( 1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyramidin-4-one potassium salt (pemirolast) and disodium cromoglycate were also compared. Tranilast dose-dependently inhibited the angiotensin II-induced contractions in human and rabbit arteries (IC50 = 3.6x10(-5) M and pD'2 = 3.69, respectively). Pemirolast showed a weak antagonistic effect to angiotensin II, but the effective concentration cannot be administered in clinical dosage. Tranilast and pemirolast had no effect on the concentration-contractile response curves for KCI and norepinephrine. Azelastine inhibited angiotensin II-, KCl- and norepinephrine-induced contractions non-specifically, while disodium cromoglycate did not affect these contractile responses. Tranilast but not azelastine showed synergistic action with 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimi dazole-7-carboxylic acid (CV- 11974) in antagonizing angiotensin II-induced contraction and the inhibitory pattern was similar to that of the non-peptide angiotensin II AT1 receptor antagonist CV-11974. These findings indicate that only tranilast possesses the unique ability to antagonize angiotensin II in clinical dosage, which may contribute at least in part to prevention of restenosis after percutaneous transluminal coronary angioplasty.

Functional role of chymase in angiotensin II formation in human vascular tissue

Recent reports suggested that human heart chymase contributed little to angiotensin (Ang) II formation in the presence of natural protease inhibitors such as alpha-antitrypsin. We studied whether chymase could contribute to Ang II formation in the presence of natural protease inhibitors in the homogenate, the extract, and slices of human vascular tissue, and whether these inhibitors affect Ang I-induced vasocontractile responses due to chymase. In the homogenate, lisinopril, chymostatin, and alpha-antitrypsin inhibited the formation of Ang II by 14, 92, and 74%, respectively. In the extract, the inhibition of Ang II formation by lisinopril, chymostatin, and alpha-antitrypsin was 18, 94, and 93%, respectively. In the slices, lisinopril and chymostatin inhibited Ang II formation by 5 and 90%, respectively. However, unlike the homogenate and the extract experiments, only 8% of the Ang II formation was suppressed by alpha-antitrypsin. In isolated human gastroepiploic artery, 30% of Ang I-induced vasoconstriction was blocked by lisinopril, and the rest was completely eliminated by a combination of lisinopril and chymostatin. On the other hand, alpha-antitrypsin was ineffective in blocking Ang I-induced vasoconstriction in the presence of lisinopril, which demonstrates that Ang II formation is dependent on chymase. These findings suggest that chymase in human vascular tissue plays a functional role in Ang II formation in the presence of natural protease inhibitors such as alpha-antitrypsin.

Propagation of experimental uncertainties using the Lipari-Szabo model-free analysis of protein dynamics

In this paper we make use of the graphical procedure previously described [Jin, D. et al. (1997) J. Am. Chem. Soc., 119, 6923-6924] to analyze NMR relaxation data using the Lipari-Szabo model-free formalism. The graphical approach is advantageous in that it allows the direct visualization of the experimental uncertainties in the motional parameter space. Some general 'rules' describing the relationship between the precision of the relaxation measurements and the precision of the model-free parameters and how this relationship changes with the overall tumbling time (tau m) are summarized. The effect of the precision in the relaxation measurements on the detection of internal motions not close to the extreme narrowing limit is analyzed. We also show that multiple timescale internal motions may be obscured by experimental uncertainty, and that the collection of relaxation data at very high field strength can improve the ability to detect such deviations from the simple Lipari-Szabo model.

Chymase processes big-endothelin-2 to endothelin-2-(1-31) that induces contractile responses in the isolated monkey trachea

Purified monkey chymase cleaved the Tyr31-Gly32 bond of big-endothelin-1 and big-endothelin-2 to yield endothelin-1-(1-31) and endothelin-2-(1-31), respectively. In the isolated monkey trachea, endothelin-1-(1-31) and endothelin-2-(1-31), as well as big-endothelin-1 and big-endothelin-2, induced contractile responses. Chymostatin, which inhibits chymase, suppressed the contractile response induced by big-endothelin-2 to 16.6% but not the responses induced by big-endothelin-1, endothelin-1-(1-31) and endothelin-2-(1-31). These results suggest that the contractile response of big-endothelin-2 is predominantly dependent on the conversion of big-endothelin-2 to endothelin-2-(1-31) by chymase.

Platelet-derived growth factor (PDGF)-BB stimulates osteoclastic bone resorption directly: the role of receptor beta

The growth-promoting activity of PDGF-BB was studied on the adult osteoclasts in the present study. The PDGF receptor beta was detected on the osteoclast membrane through immunohistochemistry (LSAB method) and immunomicroscopy. The PDGF-BB was exerted on the osteoclasts that adhered to the bone slice at concentrations of 0, 10, 20, 30, and 40 ng/ml. The volume of Howship's lacuna augmented significantly and the number of resorption pits also increased with its dose (p < 0.01). The activity of both total acid phosphatase (ACP) and tartrate-resistant acid phosphatase (TRAP) increased significantly. These results suggest that PDGF-BB promotes adult osteoclastic bone resorption directly through PDGF receptor beta and is believed to play important roles in the bone healing process and reconstruction.

Total resolution of 17 DL-amino acids labelled with a fluorescent chiral reagent, R(-)-4-(3-isothiocyanatopyrrolidin-1-y1)-7-(N,N-dimethylaminosulfonyl)- 2,1,3-benzoxadiazole, by high-performance liquid chromatography

Total resolution of 17 DL-amino acids after derivatization with a fluorescent chiral tagging reagent, 4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfony l)-2,1,3- benzoxadiazole [R(-)-DBD-PyNCS], was studied by reversed-phase liquid chromatography. The reaction of the reagent with amino acids proceeds effectively at 55 degrees C for 20 min in the presence of 1% TEA to produce the corresponding fluorescent diastereomers (excitation at 460 nm, emission at 550 nm). Each pair of the resulting derivatives was efficiently separated with water-acetonitrile containing 1% acetic acid as the mobile phase. Peak resolution was in the range of 0.92 (DL-Arg)-9.8 (DL-Cys). Although mutual separation of some DL-amino acids was possible using the elution solvent, simultaneous resolution of 17 DL-amino acids was difficult with a single chromatographic run, even if some gradient elutions were adopted. Therefore, both gradient and isocratic elution systems were used for total resolution of the DL-amino acids. Thus, 17 DL-amino acids were well resolved by a gradient and an isocratic elution systems. The proposed derivatization and elution methods were applied to the determination of DL-amino acids in yogurt. The results showed that some of the L-amino acids, i.e., Glu, Asp, Ser, Gly, Ala, Thr, Pro, Lys, Phe and Met, were found in the methanol extracts of yogurt. On the other hand, the D-amino acids that were identified in the extracts were D-Glu, D-Asp and D-Ala, and the mean % to each L-amino acid were 11.9% (D-Glu), 27.6% (D-Asp) and 56.7% (D-Ala), respectively.

12-Hydroxyeicosatetraenoic acid directly potentiates angiotensin II-induced vascular contraction

We studied whether 12-hydroxyeicosatetraenoic acid (HETE) affected the angiotensin II-induced contractile response in isolated hamster aorta. After preincubation with 10 nM 12-HETE for 1, 3, 5, 10 and 30 min, the angiotensin II-induced contractions were increased to 101%, 109%, 114%, 109% and 98%, respectively. The optimum preincubation time for the maximum effect of 12-HETE was 5 min. Under these conditions, 12-HETE increased dose dependently the contraction induced by 10 nM angiotensin II, and the concentration needed for the maximum effect was 30 nM, which increased contraction to 118% compared to the control angiotensin II-induced contraction. We demonstrated clearly that 12-HETE directly potentiates the angiotensin II-induced contraction.

[Apoptosis in multiple organs of rats in early stage of polytrauma combined with shock]

OBJECTIVE

To discuss Apoptosis in multiple organs of rats in early stage of polytrauma combined with shock.

METHODS

DNA agarose gel electrophoresis, in situ end labeling (ISEL), light microscope and electron microscope were used and DNA fragmentation percentage (ap%) was detected.

RESULTS

The special ladder pattern for apoptosis was seen in thymus, spleen, liver, lung and intestine, but not in heart, kidney and brain. At 6 hours after resuscitation, the ap% of thymus, spleen, liver, lung and intestine increased together with the severity of trauma. In six-site trauma combined with hemorrhagic shock group, the ap% of these five organs increased significantly at 1 hour after resuscitation and most significantly at 3 hours. At this point, the ap% of spleen, liver, lung and intestine reached peak, and declined gradually afterward. But the ap% of thymus continued to increase after 3 hours and kept stable from 6 hours to 24 hours ISEL showed that there were positive responses of different degrees in these eight organs. It was feand Morphologically most apoptotic cells in the thymus were positioned in the cortex, and those in spleen in the growing center of white pulp, and those in liver in the border area of hepatic lobule and portal area, and apoptosis of multiple kinds of cells including alveolar epithelial cells, vascular endothelial cells and polymorphonuclear neutrophils was induced in lung, and intestinal apoptotic cells laid in the epithelium and lamina propria of mucosa.

CONCLUSION

Apoptosis was really induced in thymus, spleen, liver, lung and intestine in early stage of polytrauma combined with shock, which may play a role in early organ injury and late multiple organ failure.

Osteogenic protein-1 (bone morphogenetic protein-7) reduces severity of injury after ischemic acute renal failure in rat

We have shown that osteogenic protein-1 (OP-1) (bone morphogenetic protein-7) is responsible for the induction of nephrogenic mesenchyme during embryonic kidney development. Gene knock-out studies showed that OP-1 null mutant mice die of renal failure within the first day of postnatal life. In the present study, we evaluated the effect of recombinant human OP-1 for the treatment of acute renal failure after 60 min bilateral renal artery occlusion in rats. Bioavailability studies in normal rats indicate that approximately 1.4 microg OP-1/ml is available in the circulation 1 min after intravenous administration of 250 microg/kg, which then declines steadily with a half life of 30 min. About 0.5% of the administered OP-1 dose/g tissue is targeted for OP-1 receptors in the kidney. We show that OP-1 preserves kidney function, as determined by reduced blood urea nitrogen and serum creatinine, and increased survival rate when administered 10 min before or 1 or 16 h after ischemia, and then at 24-h intervals up to 72 h after reperfusion. Histochemical and molecular analyses demonstrate that OP-1: (a) minimizes infarction and cell necrosis, and decreases the number of plugged tubules; (b) suppresses inflammation by downregulating the expression of intercellular adhesive molecule, and prevents the accumulation and activity of neutrophils; (c) maintains the expression of the vascular smooth muscle cell phenotype in pericellular capillaries; and (d) reduces programmed cell death during the recovery. Collectively, these data suggest that OP-1 prevents the loss of kidney function associated with ischemic injury and may provide a basis for the treatment of acute renal failure.

[Research and development of the surface EMG detection and analysis system]

To meet the requirement of developing myoelectric controller for a man-machine systems, a surface electromyography (EMG) detection and analysis system is discussed in this paper. This system consists of two parts--data acquisition hardware and signal processing software. In the surface EMG acquisition system both wire and wireless TELEMG are available. In the surface EMG processing system various methods are integrated such as the methods in time domain, the methods for frequency analysis, and also including some newly developed methods, e.g., wavelet transform and fractal analysis. This system provides a useful platform for research and development of the myoelectric controller that is widely used in rehabilitation engineering products.

Roles of vascular angiotensin converting enzyme and chymase in two-kidney, one clip hypertensive hamsters

BACKGROUND

A chymase-dependent angiotensin II-forming pathway is present in human vascular tissues; however, the role, if it plays any, of chymase in the pathogenesis of hypertension is not known. When investigating the role of chymase, it is important to recognize marked differences in vascular angiotensin II-forming systems among species. We found recently that hamsters, like humans, possess the dual angiotensin II-forming system.

OBJECTIVE

To analyze the potential involvement of angiotensin converting enzyme and chymase in the pathogenesis of hypertension, and to further characterize the efficiency of angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists for the treatment of hypertension.

METHODS AND RESULTS

The mean arterial pressure in the two-kidney, one clip hamster model had increased significantly 2 weeks after clipping (acute stage), reached a peak after 4 weeks, and was sustained at the high level until 32 weeks after clipping (chronic stage). Plasma renin activity increased markedly during the acute stage, but returned to the normal level during the chronic stage. Vascular angiotensin converting enzyme activity during 4-32 weeks after clipping was significantly higher than that in the control hamsters. By contrast, vascular chymase was not activated throughout the experimental period. Administrations of an angiotensin converting enzyme inhibitor, trandolapril, and an angiotensin II receptor antagonist, CV-11974, equally lowered the mean arterial pressure during the acute and chronic stages.

CONCLUSIONS

Vascular angiotensin converting enzyme plays a predominant role in the maintenance of two-kidney, one clip hypertension in hamsters, which, like humans, possess a dual system of formation of angiotensin II. Vascular chymase was not involved in the pathogenesis of two-kidney, one clip hypertension in the hamster.

[Study on the surface EMG pattern classification with BP neural networks]

This paper presents a surface electromyography (EMG) motion pattern classifier which combines Neural Network (NN) with parametric model such as autoregressive (AR) model. This motion pattern classifier can successfully identify four types of movement of human hand, wrist flexion, wrist extension, forearm pronation and forearm supination, by using of the surface EMG detected from the flexor carpi radialis and the extensor carpi ulnaris. The result shows that it has a great potential application to the control of bionic man-machine systems such as prostheses because of its fast calculating speed, high recognition ability, and good robust.

Pharmacological profiles of a novel non-peptide angiotensin II type I receptor antagonist HR720 in vitro and in vivo

The pharmacological properties of 2-butyl-4-(methylthio)-1-[[2'-[[[(propylamino)carbonyl] amino]sulfonyl](1,1'-biphenyl)-4-yl]methyl]-1H-imidazole-5-carboxylate (HR720), a novel non-peptide angiotensin (Ang) II type I (AT1) receptor antagonist, were characterized in both in vitro and in vivo systems. In vitro autoradiography using 125I-[Sar1,Ile8]Ang II as a ligand revealed that HR720 competitively inhibited the specific binding of the ligand to the adrenal cortex. The IC50 value for the adrenal cortex was 1.5 x 10(-8) M, and the IC50 for medulla was 1.4 x 10(-6) M. Similar results were obtained in the adrenal cortex with CV-11974, a known potent AT1-receptor antagonist. Since AT1 receptors are known to predominate in the adrenal cortex and AT2-receptors in the adrenal medulla, it is considered that HR720 is highly selective for AT1 receptors. HR720 inhibited the Ang II-induced contraction of isolated rabbit aortic strips and human gastroepiploic arteries in a noncompetitive manner, pD'2=9.40 and 9.62 for rabbit aorta and human artery, respectively. With CV-11974, pD'2 values of 9.84 in isolated rabbit aorta and 10.00 in human artery were obtained. HR720 did not affect the norepinephrine-, serotonin- or KCl-induced contraction even at a concentration of 1 x 10(-5) M. In anesthetized hamsters, HR720 induced a dose-dependent inhibition of the pressure response to Ang II. The potency of HR720 to antagonize the Ang II-induced pressure response was similar to that of CV-11974. These results demonstrate that HR720 is a potent and selective AT1-receptor antagonist.

Determination of p-hydroxymandelic acid enantiomers in urine by high-performance liquid chromatography with electrochemical detection

High-performance liquid chromatography (HPLC) with electrochemical detection using a chiral ligand-exchange column was developed for the enantioselective determination of p-hydroxymandelic acid (HMA), a metabolite of synephrine, with high sensitivity. A good linear relationship between current ratio and amount was noted for 0.5-500 pmol HMA, with a correlation coefficient of 0.999 for each HMA enantiomer. The relative standard deviation (R.S.D.) was 1.6% at 100 pmol d-HMA and 2.2% at 100 pmol l-HMA. The detection limit of each HMA enantiomer was 0.5 pmol (signal to noise ratio, S/N = 3). By this method, HMA in Citrus unshiu and in urine following the ingestion of C. unshiu was determined. Although no HMA was found in c. unshiu, d- and l-HMA were present in urine after the ingestion of C. unshiu. The time courses of HMA and conjugated synephrine enantiomers excreted in urine following the ingestion of C. unshiu for 24 h could be monitored. This method should prove applicable to the study of synephrine metabolism.

Chymase is activated in the hamster heart following ventricular fibrosis during the chronic stage of hypertension

Chronic pressure overload induces cardiac tissue remodeling. Chymase is known to regulate matrix metabolism and angiotensin II formation. In the present study, we investigated the pathophysiological functions of chymase in the pressure-overloaded hamster heart induced by a two-kidney, one-clip (2K1C) hypertension procedure. Fibrosis and apoptosis were observed in the pressure-overloaded hearts of 2K1C hamsters 32 weeks after clipping, but these histological changes were not detected at 16 weeks. Heart chymase-like activity of 2K1C hamsters at 32 weeks increased 5.2-fold compared with that at 16 weeks, while angiotensin-converting enzyme was not activated. Chymase might be involved in cardiac tissue remodeling during the chronic stage of hypertension.

Targeting c-erbB-2 expressing tumors using single-chain Fv monomers and dimers

Single-chain Fv proteins containing a COOH-terminal cysteine (sFv') were constructed by using an antidigoxin 26.10 sFv and an anti-c-erbB-2 741F8 sFv. The fully active sFv' proteins were prepared by expression in Escherichia coli as insoluble inclusion bodies, followed by in vitro refolding using glutathione redox buffers and purification. The COOH-terminal cysteines of the refolded sFv' proteins were protected by a blocking group presumed to be the glutathionyl peptide, which was easily and selectively removed by gentle reduction. Air oxidation of the reduced sFv' monomers resulted in the efficient formation of disulfide-linked sFv' homodimers, designated (sFv')2, which were stable under oxidizing conditions and relatively slow to be disrupted under reducing conditions. The (26-10-1 sFv')-(741F8-1 sFv') heterodimer was prepared and possessed dual-antigen specificity; the active bispecific (sFv')2 dimerized under native conditions, apparently as a manifestation of self-association by the 741F8 sFv' subunit. Biodistribution and imaging studies that were performed on mice bearing human SK-OV-3 tumor xenografts that express the c-erbB-2 as a cell surface antigen were reviewed. Radioiodinated 741F8-2 (sFv')2 homodimer localized to the tumors with high specificity, as evidenced by excellent tumor:normal tissue ratios. Sagittal section autoradiography of whole animals 24 h after administration of antibody species revealed that 741F8 (sFv')2 produced a stronger tumor image than comparable doses of the 741F8 Fab, monomeric sFv', and the 26-10 (sFv')2 control without the high nonspecific background distribution of the 741F8 IgG.

Engineering disulfide-linked single-chain Fv dimers [(sFv')2] with improved solution and targeting properties: anti-digoxin 26-10 (sFv')2 and anti-c-erbB-2 741F8 (sFv')2 made by protein folding and bonded through C-terminal cysteinyl peptides

Single-chain Fv fusions with C-terminal cysteinyl peptides (sFv') have been engineered using model sFv proteins based upon the 26-10 anti-digoxin IgG and 741F8 anti-c-erbB-2 IgG monoclonal antibodies. As part of the 741F8 sFv construction process, the PCR-amplified 741F8 VH gene was modified in an effort to correct possible primer-induced errors. Genetic replacement of the N-terminal beta-strand sequence of 741F8 VH with that from the FR1 of anti-c-erbB-2 520C9 VH resulted in a dramatic improvement of sFv folding yields. Folding in urea-glutathione redox buffers produced active sFv' with a protected C-terminal sulfhydryl, presumably as the mixed disulfide with glutathione. Disulfide-bonded (sFv')2 homodimers were made by disulfide interchange or oxidation after reductive elimination of the blocking group. Both 26-10 (sFv')2 and 741F8 (sFv')2 existed as stable dimers that were well behaved in solution, whereas 741F8 sFv and sFv' exhibited considerable self-association. The 741F8 sFv binds to the extracellular domain (ECD) of the c-erbB-2 oncogene protein, which is often overexpressed in breast cancer and other adenocarcinomas. The recombinant ECD was prepared to facilitate the analysis of 741F8 binding site properties; the cloned ECD gene, modified to encode a C-terminal Ser-Gly-His6 peptide, was transfected into Chinese hamster ovary cells using a vector that also expressed dihydrofolate reductase to facilitate methotrexate amplification. Optimized cell lines expressed ECD-His6 at high levels in a cell bioreactor; after isolation by immobilized metal affinity chromatography, final ECD yields were as high as 47 mg/l. An animal tumor model complemented physicochemical studies of 741F8 species and indicated increased tumor localization of the targeted 741F8 (sFv')2 over other monovalent 741F8 species.

A rating instrument for the evaluation of in-patient rehabilitation programmes in China. Results of reliability and validity testing

To objectively evaluate in-patient rehabilitation programmes in China, we developed a new rating scale: the Inpatient Psychiatric Rehabilitation Outcome Scale (IPROS). The scale has five subscales: performance in occupational therapy, daily activities, socialisation, personal hygiene, and level of interest in external events. Evaluators (physicians or nurses) observe patients for one week before coding items on a five-point scale. Comparison of four independent evaluators' results for 32 schizophrenic patients assessed on two separate occasions indicated that the inter-rater and test-retest reliability for the overall IPROS score and for the five subscale scores was excellent (all ICC values > or = 0.973). Validity was evaluated by comparing IPROS results with those of five other independently assessed clinical measures for 101 chronic schizophrenic patients before and after a six-month rehabilitation programme; concurrent validity and longitudinal validity were satisfactory (correlation coefficients 0.37-0.81, all P values < 0.01).