Development of a new model of transvenous thrombosis in the pig superior sagittal sinus using thrombin injection and balloon occlusion

PURPOSE

To establish an experimental model of superior sagittal sinus (SSS) thrombosis using a transvenous route, and thrombin and balloon occlusion, in pigs.

METHODS

The SSS was catheterized transvenously in six pigs. Thrombin was injected into the pigs' SSS to induce thrombosis. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) confirmed successful SSS thrombosis. MRI and MRV were also used to observe the evolution of thrombus and accompanying brain parenchymal changes before thrombus induction postoperatively on Days 1, 3, and 7. The pigs were sacrificed for histological examination at the follow-up.

RESULTS

SSS thrombosis was successfully achieved in all six pigs. On Day 1 postoperatively, MRV confirmed SSS thrombosis and MRI revealed brain edema in each animal. On Day 3, venous infarction was noted in two cases, one of which appeared to be hemorrhagic. On Day 7, MRV showed partial recanalization of the SSS in one pig. Brain edema was significantly relieved in four cases while, in two other cases, the extent of venous infarction was reduced. Histological examination confirmed SSS thrombosis in all animals, with recanalization in only one case. In two of the animals, bilateral parasagittal infarction was seen, including one with petechial hemorrhage. In the other four animals, bilateral parasagittal edema was observed.

CONCLUSION

The development of an experimental model of SSS via the transvenous route is feasible in pigs using thrombin and balloon occlusion. This model closely resembles SSS thrombosis in humans, and can be applied in the clinical study of this phenomenon as well as in clinical therapeutic applications.

Afferent nerve sensitivity is decreased by an iNOS-dependent mechanism during indomethacin-induced inflammation in the murine jejunum in vitro

Evidence exists that visceral afferent sensitivity is subject to regulatory mechanisms. We hypothesized that afferent sensitivity is decreased in the small intestine during intestinal inflammation by an inducible nitric oxide synthase (iNOS)-dependent mechanism. C57BL/6 mice were injected twice with vehicle or 60 mg kg(-1) indomethacin subcutaneously to induce intestinal inflammation. Afferent sensitivity was recorded on day 3 from a 2-cm segment of jejunum in vitro by extracellular multi-unit afferent recordings from the mesenteric nerve bundle. In subgroups (n = 6), iNOS was inhibited selectively by L-N6-(1-iminoethyl)-lysine (L-NIL) given either chronically from day 1-3 (3 mg kg(-1) twice daily i.p.) or acutely into the organ bath (30 micromol L(-1)). The indomethacin-induced increase of macroscopic and microscopic scores of intestinal inflammation (both P < 0.05) were unchanged after pretreatment with L-NIL. Peak afferent firing following bradykinin (0.5 micromol L(-1)) was 55 +/- 8 impulse s(-1) during inflammation vs 97 +/- 7 impulse s(-1) in controls (P < 0.05). Normal firing rate was preserved following L-NIL pretreatment (112 +/- 16 impulse s(-1)) or acute administration of L-NIL (108 +/- 14 impulse s(-1)). A similar L-NIL dependent reduction was observed for 5-HT (250 micromol L(-1)) and mechanical ramp distension from 20 to 60 cmH(2)O (both P < 0.05). Intraluminal pressure peaks were decreased to 0.66 +/- 0.1 cmH(2)O during inflammation compared to 2.51 +/- 0.3 in controls (P < 0.01). Afferent sensitivity is decreased by an iNOS-dependent mechanism during intestinal inflammation which appears to be independent of the inflammatory response. This suggests that iNOS-dependent nitric oxide production alters afferent sensitivity during inflammation by interfering with signal transduction to afferent nerves rather than by attenuating intestinal inflammation.

Effect of total flavonoid fraction of Astragalus complanatus R. Brown on angiotensin II-induced portal-vein contraction in hypertensive rats

The objective of the present study was to examine further the underlying mechanism of the antihypertensive effect of the total flavonoid (TF), extracted from the seed of Astragalus complanatus R.Brown. Renovascular hypertension rats (RHR) were established by the two-kidney one clip (2K1C) method. The effect of TF on the contraction of portal vein was studied in an isolated preparation. The response of portal vein to angiotensin II (Ang II) was expressed as a percentage of the 100 mmol/l KCl induced maximum contraction. We took the dose-response curve of portal vein to Ang II (from 10(-9) to 10(-6) mmol/l) as the control and then observed the change of curve after TF and Valsartan (Ang II receptor blocker) administration. Ang II induced a concentration-dependent increase of the contraction amplitude (maximal increase, 46.53+/-5.15% of 100 mmol/l KCl induced contraction at Ang II 10(-6) mmol/l in RHR). The Ang II-induced portal vein contraction was prevented by TF with a concentration related manner (maximal inhibition amplitude from 46.53+/-5.15% to 22.525+/-4.67% of 100 mmol/l KCl contraction at 10(-6)mmol/l Ang II and 3.12 x 10(-1) mg/l TF in RHR). The effect of TF on Ang II-induced portal vein contraction was similar to Valsartan. These results showed that the antihypertensive action of TF was attributed to the dilation of vessels and is related to the blockade of the Ang II receptor.

Sex differences in angiotensin II- induced hypertension

Sex differences in the development of hypertension and cardiovascular disease have been described in humans and in animal models. In this paper we will review some of our studies which have as their emphasis the examination of the role of sex differences and sex steroids in modulating the central actions of angiotensin II (ANG II) via interactions with free radicals and nitric oxide, generating pathways within brain circumventricular organs and in central sympathomodulatory systems. Our studies indicate that low-dose infusions of ANG II result in hypertension in wild-type male mice but not in intact wild-type females. Furthermore, we have demonstrated that ANG II-induced hypertension in males is blocked by central infusions of the androgen receptor antagonist, flutamide, and by central infusions of the superoxide dismutase mimetic, tempol. We have also found that, in comparison to females, males show greater levels of intracellular reactive oxygen species in circumventricular organ neurons following long-term ANG II infusions. In female mice, ovariectomy, central blockade of estrogen receptors or total knockout of estrogen a receptors augments the pressor effects of ANG II. Finally, in females but not in males, central blockade of nitric oxide synthase increases the pressor effects of ANG II. Taken together, these results suggest that sex differences and estrogen and testosterone play important roles in the development of ANG II-induced hypertension.

Protective effect of glutathione against lipopolysaccharide-induced inflammation and mortality in rats

OBJECTIVE

To investigate protective effect of glutathione (GSH) against lipopolysaccharide (LPS)-induced inflammation and mortality in rats.

METHODS

Male Sprague-Dawley rats were injected intraperitoneally (i. p.) with GSH (40 mg/kg) 30 min prior to LPS injection (20 mg/kg). Animal survival rate and the production of nitric oxide in serum were measured. Morphology of lung was observed using hematoxylin and eosin staining. Western blotting was used to assess the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and the phosphorylation of p38 in rat peritoneal macrophages.

RESULTS

GSH significantly decreased LPS-induced mortality, inhibited serum NO production and eliminated lung histological injury. Furthermore, GSH inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins and the phosphorylation of p38 in LPS-stimulated rat peritoneal macrophages.

CONCLUSIONS

These results indicated that GSH suppressed LPS-induced systemic inflammatory response in rats and p38 MAPK signal pathway was involved in this process.

Seasonal changes in weight and body composition of yak grazing on alpine-meadow grassland in the Qinghai-Tibetan plateau of China

Forty-five male yaks (born April 2001) were studied to determine how seasonal changes on the Qinghai-Tibetan plateau affected BW and body composition. Thirty yaks were weighed monthly from birth to 26 mo of age to determine seasonal changes in BW. The remaining 15 yaks were allocated randomly to five groups (three yaks per group), designated for slaughter at 13, 15, 18, 22, and 25 mo to measure seasonal effects on body chemical composition. All yaks were grazed on the alpine-meadow grassland of the plateau without any supplementation. All BW and body composition data were calculated on an individual basis. Body weight and body composition data were both compared across seven growth periods spanning 2 yr and defined by season. From April (birth) to December 2001 of the first growing season, yak BW increased (P < 0.01); however, during the subsequent cold season (December 2001 to May 2002), BW decreased (P < 0.01). The second growing season ran from May 2002 (13 mo of age) to October 2002 (18 mo of age), and the second live weight-loss season ran from October 2002 until May 2003. The weight loss experienced by yaks during the first weight-loss season was 25.64% of the total weight gain in the first growing season. The weight loss experienced by yaks during the second weight-loss season was 29.73% of the total weight gain in the second growing season. Energy retention in the second growing season was 291.07 MJ, 50.8% of which was consumed during the subsequent cold season. Energy accumulation in the summer (from May to July) and fall (from July to October) of the second growing season did not differ (5.01 and 6.30 MJ/kg of EBW gain, respectively; P = 0.63). The energy mobilized during the second winter (from October 2002 to February 2003) was 16.49 MJ/kg of EBW, and in the second spring (from February to May 2003), it was 9.06 MJ/kg of EBW. These data suggest that the decrease in grazing yak BW during the first cold season is much less than during the second cold season, and that the energy content per unit of BW mobilized is greater (P = 0.02) in winter than in spring. Results from this study demonstrate highly efficient compensatory growth in grazing yaks following the first weight loss period during the first cold season. This benefit could be exploited by herders to improve yak production. Yaks may have developed a type of self-protection mechanism to overcome the long cold seasons in the Qinghai-Tibetan plateau.

Human glutathione S-transferase P1-1 interacts with TRAF2 and regulates TRAF2-ASK1 signals

Human glutathione S-transferase P1-1 (GSTP1-1) is an ubiquitously expressed protein that plays an important role in the detoxification and xenobiotics metabolism. It has been shown that GSTP1-1 interacts with c-Jun NH(2)-terminal kinase (JNK) and suppresses its activity. Here, we report a novel function of GSTP1-1 in regulating tumor necrosis factor-alpha (TNF-alpha)-triggered signaling. The present experiments showed that GSTP1-1 physically associated with tumor necrosis factor receptor-associated factor 2 (TRAF2) in vivo and in vitro. Overexpression of GSTP1-1 inhibited TRAF2-induced activation of both JNK and p38 but not of nuclear factor-kappaB (NF-kappaB). Glutathione S-transferase P1-1 also attenuated TRAF2-enhanced apoptosis signal-regulating kinase 1 (ASK1) autophosphorylation and inhibited TRAF2-ASK1-induced cell apoptosis by suppressing the interaction of TRAF2 and ASK1. Conversely, silencing of GSTP1-1 expression through RNA interference (RNAi) resulted in increase of TNF-alpha-dependent TRAF2-ASK1 association followed by hyper-activation of ASK1 and JNK. A mutant GSTP1-1 lacking TRAF domain-binding motif exhibited a significant decline of capacity to bind TRAF2 and block TRAF2-ASK1 signaling compared with the wild type of GSTP1-1. Moreover, the glutathione-conjugating activity of GSTP1-1 was not involved in the regulation of TRAF2 signaling. These findings indicate that GSTP1-1 plays an important regulatory role in TNF-alpha-induced signaling by forming ligand-binding interactions with TRAF2, which provides a new insight for analysing the protective effects of GSTP1-1 in tumor cells.

Characterization of a MYBR2R3 gene from black spruce (Picea mariana) that shares functional conservation with maize C1

PCR amplification with degenerate primers targeted to highly conserved amino acid motifs within the MYB domain was used to demonstrate that black spruce (Picea mariana) possesses a diverse MYB gene family. Amino acid sequence comparisons revealed three broad MYB subfamilies, one of which shares extensive similarity with maize C1, a central regulator of anthocyanin biosynthesis. A cDNA clone encoding a MYBR2R3 protein from P. mariana with high levels of sequence homology to maize C1 was shown to transactivate the Bz2 promoter in combination with maize R in embryonal tissues of both black spruce and larch. Functional dependence on the maize R protein, and the presence of a conserved C-terminal GIDPxTH motif, support the conservation of MYBR2R3 function in conifers, and demonstrate that the basic components of MYBR2R3-dependent transcriptional regulation have been conserved between angiosperms and gymnosperms.

Mechanism of intracellular calcium ([Ca2+]i) inhibition of lipolysis in human adipocytes

We investigated the mechanisms responsible for the anti-lipolytic effect of intracellular Ca2+ ([Ca2+]i) in human adipocytes. Increasing [Ca2+]i inhibited lipolysis induced by b-adrenergic receptor activation, A1 adenosine receptor inhibition, adenylate cyclase activation, and phosphodiesterase (PDE) inhibition, as well as by a hydrolyzable cAMP analog, but not by a nonhydrolyzable cAMP analog. This finding indicates that the anti-lipolytic effect of [Ca2+]i may be mediated by the activation of adipocyte PDE. Consistent with this theory, [Ca2+]i inhibition of isoproterenol-stimulated lipolysis was reversed completely by the nonselective PDE inhibitor isobutyl methylxanthine and also by the selective PDE 3B inhibitor cilostamide, but not by selective PDE 1 and 4 inhibitors. In addition, phosphatidylinositol-3 kinase inhibition with wortmannin completely prevented insulin's anti-lipolytic effect but only minimally blocked [Ca2+]i's effect, which suggests that [Ca2+]i and insulin may activate PDE 3B via different mechanisms. In contrast, the antilipolytic effect of [Ca2+]i was not affected by inhibitors of calmodulin, Ca2+/calmodulin-dependent kinase, protein phosphatase 2B, and protein kinase C. Finally, [Ca2+]i inhibited significantly isoproterenol-stimulated increases in cAMP levels and hormone-sensitive lipase phosphorylation in human adipocytes. In conclusion, increasing [Ca2+]i exerts an antilipolytic effect mainly by activation of PDE, leading to a decrease in cAMP and HSL phosphorylation and, consequently, inhibition of lipolysis.

Enhancing protein capacity of rigid macroporous polymeric adsorbent

A macroporous poly(glycidyl methacrylate-triallyl isocyanurate-divinylbenzene) resin was synthesized and modified with diethylamine to yield an anion-exchange resin suitable for protein adsorption. Efforts were made to enhance protein ion exchange capacity of the resin by investigating the copolymer composition. Different synthesis recipes were attempted, and the resultant resins were characterized by measuring the specific surface area and the adsorption ability using bovine serum albumin (BSA) as a model protein. The intraparticle pore size distribution measured by mercury porosimetry showed that the pores in the range of 40-120 nm took 75% of the total pore volume, indicating that the ion exchanger was favorable for protein adsorption. BSA capacity obtained with an appropriate recipe was as high as 78.6 mg/g wet resin or 50 mg/mL packed volume, which was higher than the capacities of some commercially available ion exchangers. Moreover, by using a pore diffusion model, the effective pore diffusivity of BSA was found to be 5.5 x 10(-12) m(2)/s, similar to those in the commercial ion exchangers.

Protein adsorption equilibria and kinetics to a poly(vinyl alcohol)-based magnetic affinity support

A poly(vinyl alcohol)-based magnetic gel entrapping Fe3O4 colloids has been prepared by an emulsification-crosslinking method. The gel was modified with Cibacron blue 3GA, and thus a magnetic affinity support was produced. The adsorption equilibrium studies showed that the adsorption isotherm of lysozyme was nearly rectangular, with a capacity of 254 mg/ml, while the adsorption isotherm of bovine serum albumin obeyed the Henry's law. Uptake kinetics of the two proteins was investigated and analyzed with a pore diffusion model and a homogeneous diffusion model. Experimental results showed that the magnetic affinity gel had magnetic responsiveness and favorable properties in protein adsorption, and was mechanically and chemically stable.

Agouti signaling protein stimulates islet amyloid polypeptide (amylin) secretion in pancreatic beta-cells

Ectopic overexpression of the murine agouti gene results in yellow coat color, obesity, hyperinsulinemia, and type II diabetes. We have shown the human homologue of agouti (agouti signaling protein; ASP) to regulate human adipocyte metabolism and lipid storage via a Ca(2+)-dependent mechanism. We have also demonstrated agouti expression in human pancreas, and that ASP stimulates insulin release via a similar Ca(2+)-dependent mechanism. Plasma amylin is also elevated in agouti mutant mice. Amylin is cosecreted with insulin from beta-cells, and overexpression of human amylin in beta-cells in yellow agouti mutant mice resulted in accelerated pancreatic amyloid deposition, severely impaired beta-cell function, and a diabetic phenotype. We report here that ASP stimulates amylin release in both the HIT-T15 beta-cell line and human pancreatic islets in the presence of a wide range of glucose concentrations (0-16.7 mmol/L), similar to its effect on insulin release; this effect was blocked by 30 mumol/L nitrendipine, confirming a Ca(2+)-dependent mechanism. Accordingly, ASP stimulation of amylin release may serve as a compensatory system to regulate blood glucose in yellow agouti mutants.

A novel magnetic affinity support for protein adsorption and purification

A novel magnetic support was prepared by an oxidization-precipitation method with poly(vinyl alcohol) (PVA) as the entrapment material. Transmission electron microscopy indicated that the magnetic particles had a core-shell structure, containing many nanometer-sized magnetic cores stabilized by the cross-linked PVA. The particles showed a high magnetic responsiveness in magnetic field, and no aggregation of the particles was observed after the particles had been treated in the magnetic field. These facts indicated that the particles were superparamagnetic. Cibacron blue 3GA (CB) was coupled to the particles to prepare a magnetic affinity support (MAS) for protein adsorption. Lysozyme was used as a model protein to test the adsorption properties of the MAS. The adsorption equilibrium of lysozyme to the MAS was described by the Langmuir-type isotherm. The capacity for lysozyme adsorption was more than 70 mg/g MAS (wet weight) at a relatively low CB coupling density (3-5 micromol/g). In addition, 1.0 M NaCl solution could be used to dissociate the adsorbed lysozyme. Finally, the MAS was recycled for the purification of alcohol dehydrogenase (ADH) from clarified yeast homogenates. Under proper conditions, the magnetic separation yielded over 5-fold purification of the enzyme with 60% recovery of the enzyme activity.

[The relationship between cadmium-induced inhibition of splenic lymphocyte function and cell apoptosis]

OBJECTIVE

To explore the relationship between cadmium-induced inhibition of splenic lymphocyte function and cell apoptosis in vitro.

METHODS

The splenic lymphocytes of mice were exposed to 3.10, 6.25, 12.50, 25.00, 50.00 micromol/L of cadmiun chloride (CdCl(2)) for various time period, to measure the lymphocyte transformation by MTT colorimetric assay and to detect the apoptosis in splenocytes by DNA agarose electrophoresis and flow cytometry (FACS).

RESULTS

CdCl(2) could significantly inhibit the function of lymphocyte transformation in a dose-response pattern at concentrations of 25.00 and 50.00 micromol/L, with inhibition rates of 50% and 78% in ConA-stimulating group and 39% and 55% in LPS-stimulating group, respectively. CdCl(2) could also induce apoptosis of splenic cells at concentrations of 12.50 to 50.00 micromol/L.

RESULTS

of FACS analysis showed 30% - 60% of cell apoptosis. Higher concentration of CdCl(2) could also cause reduction of cell survival. Effect of Cd-induced apoptosis was earlier and at a lower concentration of CdCl(2) than that of Cd-induced inhibition of lymphocyte transformation.

CONCLUSION

CdCl(2) could induce cell apoptosis in vitro, which was one of the mechanisms of its suppression of lymphocyte function.

[Effect of sodium azide on mitochondrial membrane potential in SH-SY5Y human neuroblastoma cells]

OBJECTIVE

To study the role of mitochondrial deficiency in the pathogenesis of neurodegenerative disease by investigating the energy metabolism in a sodium azide inhibited cytochrome-c oxidase SH-SY5Y Cell model.

METHODS

Human neuroblastoma SH-SY5Y Cells were exposed to sodium azide, then mitochondrial complex IV activity was assayed by microassay method; cell viability was measured by Thiazolyl blue(MTT) method; mitochondrial membrane potential (MMP) was detected by confocal microscopy and flow cytometry.

RESULTS

Cultured SH-SY5Y cells were exposed to 16-64 mmol/L sodium azide for 1 hour, the mitochondrial complex IV activity decreased dose-dependently. MTT absorbance decreased does- and time-dependently in cultured nerve cells treated by 16-128 mmol/L sodium azide for 1-8 hours. After the treatment of 16 mmol/L sodium azide for 1 hour, both the fluorescence intensity of MMP and normal cell events reduced. Decrease of MMP was significant especially in cell processes.

CONCLUSION

Sodium azide induced the impairment of mitochondrial energy synthesis in the cultured nerve cells which is an important cause in cell death.

Relationship between human adipose tissue agouti and fatty acid synthase (FAS)

The human homologue of the murine obesity gene, agouti, is expressed in adipose tissue. We have shown that recombinant agouti protein regulates adipocyte lipogenesis and lipolysis coordinately and promotes lipid storage via a Ca(2+)-dependent mechanism in vitro, which may contribute to agouti-induced obesity. However, little is known about agouti's physiologic function in humans. We first studied the agouti content in human mature adipocytes vs. preadipocytes. The agouti content of human mature adipocytes was five times as abundant as in preadipocytes (19.18 +/- 2.46 vs. 4.07 +/- 0.51 pg/microg protein, P: < 0.005), suggesting that agouti is up-regulated during adipocyte differentiation. We next studied the relationship of agouti mRNA and protein to fatty acid synthase (FAS) mRNA and activity in adipose tissue obtained from nonobese and mildly obese patients (body mass index range, 21-31 kg/m(2)). Agouti protein was correlated with FAS activity (r = 0.782, P: < 0.005). Similarly, human adipose tissue agouti mRNA level was also correlated with FAS mRNA level (r = 0.846, P: < 0.001). These data suggest that agouti may be another adipocyte-produced factor that modulates adipocyte lipid metabolism via a paracrine/autocrine mechanism.

Collision relaxation cross section of highly vibrationally excited molecules

Through quantum-beat spectroscopy collision relaxation of a high vibrational level of SO2 at 44 877.52 cm(-1) is characterized. This is a first measurement of collision relaxation for a single, highly excited vibrational level. The deduced relaxation cross section of this excited level by Ar is 216 A(2), 5 times the area of the hard sphere, and by an ambient temperature SO2 molecule is 969 A(2), almost 20 times the hard sphere. These cross sections indicate that relaxation collisions of highly vibrationally excited molecules have effective distances much longer than van der Waals radii and involve mechanisms qualitatively different from lower excitations.

[A study on hemostatic and immunological actions of fresh and dry Dihuang]

OBJECTIVE

To investigate the difference between fresh and dry Dihuang (Radix Rehmanniae) in hemostatic and immunological actions.

METHODS

The hemostatic action was assessed in aspirin-treated mice; immunological action was assessed by phagocytosis of macrophages in dexamethasone-treated mice; and Con A-induced mitogenesis and LPS-induced alkaline phosphatase activity of splenocytes were determined in thyroxin-treated mice.

RESULT

The blood clotting in mice induced by aspirin was inhibited by oral administrations of juice decoction of fresh Dihuang or decoction of dry Dihuang alike. The action of fresh Dihuang juice was stronger than that of dry Dihuang decoction. Oral administrarion of fresh Dihuang juice or decoction for 10 days enhanced LPS-induced alkaline phosphatase activity of splenocytes in thyroxin-treated mice. The juice also enhanced Con A-induced splenocyte mitogenesis. The action of dry Dihuang decoction was weaker than that of fresh juice in increasing LPS-induced alkaline phosphatase activity.

CONCLUSION

It is recommended to follow the tradition of using fresh Dihuang juice or decoction to treat some diseases such as hemorrhagenic troubles.

[Synergistic interaction between Ys-96, a bisbenzylisoquinoline compound derived from Stephania tetrandra, and adriamycin or vincristine against human cancer cell lines in vitro]

OBJECTIVE

To study in vitro the anticancer interaction between Ys-96, a bisbenzylisoquinoline compound derived from Stephania tetrandra, and adriamycin or vincristine against human cancer cell lines.

METHOD

Using human breast cancer cell MCF-7 and its adriamycin-resistant cell line MCF-7/Adr, and human nasopharyngeal cancer cell KB and its vincristine-resistant cell line KBv200 in an in vitro system, anticancer interaction between Ys-96 and adriamycin or vincristine was evaluated with a method reported by Berenbaum.

RESULT

The SFIC values (sum of fractional inhibitory concentration) of the combinations with 3 different ratios between Ys-96 and adriamycin or vincristine were markedly less than 1.0, and the shapes of all the isobologram curves were concave.

CONCLUSION

The synergistic interaction between Ys-96 and adriamycin or vincristine against the above human cancer cell lines was positively observed in vitro.

Discussion to the angular aperture narrowing behavior inside AOTF crystal

An off-perpendicular incident arrangement is suggested and tested in AOTF system design to improve the spectrum resolution and angular aperture. A special discussion is given to the "equivalent point design" of Si=56ø where the optimum design parameters are reached.

[The change in bacterial flora and antibiotic resistance of bacteria of burn patients in our hospital during 1986-1996]

OBJECTIVE

In this article we investigated and analyzed the pathogenetic bacteria of burn infection and their drug resistance in recent 5 years from 1991.

METHODS

The patients are divided into 2 groups. The 1st group is from June 1986 to May 1991, and the 2nd group is from June 1991 to June 1996. Blood culture and burn wound bacteria culture were done, and bacteria and their drug sensitivity were analyzed.

RESULTS

In blood culture, Micrococcus had risen to rank the top (21.6%), while Staphylococcus aureus fell to rank the third. Among these G+ cocci comprised 56.5%, and G- bacilli 30.1%. In burn wound culture, Pseudomonas aeruginosa with rate of 18.1% was still in the 1st place. Enterobacter cloacae was in the 2nd place with the rate of 13.1%. Among these G- bacilli comprised 58.6%, G+ cocci 35.3%. Micrococcus enterobacter cloacae, Pseudomonas maltophilia, fecal Staphylococcus and candida albicans increased remarkably.

CONCLUSION

The changes of pathogenetic bacteria of burn infection and bacteria drug resistance have certain relations with the wide usage of broad spectrum antibiotics such as cefazidime and imipenem.

Discussion to the equivalent point realized by the two polarized beams in AOTF system

By an accurate theoretical analysis, an equivalent point is found where the filtered optic wave lengths of the two acoustic-optic reactions of "e in o out" and "o in e out" are the same with the same acoustic frequency. Two cases of d=0 and d10 are discussed and compared. The merits of the equivalent point is discussed in different points of view. The discussions conclude that the parameters set around the equivalent point leading to the optimum designing.

[Analysis of the protein of Haemophilus influenzae]

OBJECTIVE

To understand Haemophilus influenzae special protein and to help for preparing Haemophilus influenzae Vaccine.

METHODS

Proteins from isolates of Haemophilus influenzae were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

RESULTS

23 isolates were from nasopharyngeal secretions of children with pneumonia and 33 from pharyx swab of healthy children. Conventional tests showed that 79% of fifty-six strains of Haemophilus influenzae were non-serotypable and all belonged to one of eight biotypes. The common biotypes were II (48%). All strains contained more than 10 proteins with molecular weights of 96,000, 86,000, 55,000, 51,000, 46,000, 40,000, 39,000, 31,000, 29,000, 25,000, and 16,000. Among them, three were major proteins (31,000, 51,000 and 96,000) and different proteins were mainly between peptide 31,000 and 51,000. A possible association between biotype and protein was unclear.

CONCLUSION

Analysis of protein of Haemophilus influenzae is helpful for epidemiological study of non-serotypable Haemophilus influenzae and making Haemophilus influenzae vaccine.

The agouti gene product inhibits lipolysis in human adipocytes via a Ca2+-dependent mechanism

Overexpression of the murine agouti gene results in obesity. The human homologue of agouti is expressed primarily in human adipocytes, and we have shown recombinant agouti protein to increase adipocyte intracellular Ca2+([Ca2+]i) and thereby stimulate lipogenesis. However, since recent data demonstrate that increasing adipocyte [Ca2+]i may also inhibit lipolysis, we have investigated the role of agouti-induced [Ca2+]i increases in regulating lipolysis in human adipocytes. Short-term (1 h) exposure to recombinant agouti (100 nM) protein had no effect on basal lipolysis, although longer term treatment (24 h) caused a 60% decrease in basal lipolysis (P<0.0001). Short-term agouti treatment totally inhibited ACTH-induced lipolysis (P<0.05). Since melanocortin receptors (MCR) are involved in some actions of agouti, we next determined whether agouti's antilipolytic effect is exerted through competitive antagonism of the ACTH receptor (MCR-2). Forskolin (1 microM), an adenylate cyclase activator, induced a 48% increase in lipolysis in human adipocytes (P<0.05); this effect was reversed by 100 nM agouti (P<005), demonstrating that the antilipolytic effect of agouti is distal to the ACTH receptor. To determine the role of [Ca2+]i in the antilipolytic effect of agouti, human adipocytes were treated with KCl or arginine vasopressin to stimulate voltage- and receptor-stimulated Ca2+ influx, respectively. Both agents caused inhibition of forskolin-induced lipolysis (P<0.005). Furthermore, agouti's antilipolytic effect was also blocked by the Ca2+ channel blocker nitrendipine. These data demonstrate that agouti exerts a potent antilipolytic effect in human adipocytes via a Ca2+-dependent mechanism. This effect, combined with agouti-induced lipogenesis, represents a coordinate control of adipocyte lipid metabolism that may contribute to an agouti-induced obesity syndrome.

A clinical study on bing gan ling oral liquid for treatment of hepatitis C

Based on the principles of cooling the blood to expel the pathogenic toxins and regulating the function of liver and activating the spleen in traditional Chinese medicine, 60 cases of chronic hepatitis C were treated with Bing Gan Ling (BGL), an oral liquid, which is composed mainly of Shuiniujiao (Cornu Bubali), Huzhang (Rhizoma Polygoni Cuspidati), Chishao (Radix Paeoniae Rubra), and Huangqi (Radix Astragali), etc. The total effective rate was 86.7%, which is considerably better than that of the control group (P < 0.01). The animal experiments and pathological studies suggest that the above-mentioned prescription has marked action of protecting the liver and lowering the activity of enzymes; and that it can ameliorate the acute liver injury induced by D-galactosamine.

[Reversal effect of Ys-96, a bisbenzylisoquinoline, on adriamycin or vincristine resistance in human cancer cells in vitro]

OBJECTIVE

Reversal effect of Ys-96, a bisbenzylisoquinoline, on the resistance of human cancer cells to adriamycin or vincristine was studied in vitro.

METHOD

In an in vitro culture system of human cancer cells MCF-7 and its adriamycin-resistant line MCF-7/Ad or KB and its vincristine-resistant line KBv200, the sensitivity(IC50) of the resistant cell lines to adriamycin or vincristine was evaluated with a MTT assay.

RESULT

IC50 value of adriamycin or vincristine in combination with Ys-96 at a concentration of 1.00 mumol/L against MCF-7/Ad or KBv200 was found to be close to that of adriamycin alone or vincristine alone against the sensitive cell line MCF-7 or KB.

CONCLUSION

The drug resistance of MCF-7/Ad or KBv200 could be essentially reversed by Ys-96 at a concentration of 1.00 mumol/L.

[Effects of cadmium chloride on the function of peritoneal macrophage in mice]

OBJECTIVE

To study the effects of cadmium on macrophage function.

METHODS

Many indicators, such as phagocytic function, abilities to produce nitrous oxide and hydrogen peroxide, in mice were determined 14 days after they were administered continuously with 0.3, 0.6 and 1.2 mg/kg cadmiuCell count decreased in the mouse peritoneal lavage with the effects of cadmium chloride, with a significant difference, as compared with the control group. Phagocytic function of macrophage was inhibited significantly, with inhibition rates of 21.8%, 39.9% and 44.4%, respectively for various doses of cadmium, in a dose-response pattern. The ability of microphage to produce nitrous oxide was significantly inhibited, also, with 61.90 +/- 27.83, 36.67 +/- 23.86, 46.60 +/- 13.33 mumol/L, respectively, as compared with 76.10 +/- 14.22 mumol/L in the control group. The ability of microphage to produce O2.- was obviously inhibited by three different doses of cadmium, showing a dose-response relationship (r = 0.9790). The ability of microphage to produce hydrogen peroxide was inhibited only at a dose of 1.2 mg/kg of cadmium, with a significant difference as compared with the control group. There was a dose-response relationship between cadmium and production of hydrogen peroxide, with a coefficient of regression (r) of -0.9847.

CONCLUSION

Cadmium chloride, at the doses of 0.3, 0.6 and 1.2 mg/kg, could inhibit the phagocytic function of microphage, and the production of biological molecules, such as nitrous oxide, O2.- and hydrogen peroxide. It indicated that cadmium chloride could directly affect the transmission of antigen and non-specific defence function of macrophage.

Capillary electrophoretic mobility shift assay (CEMSA) of a protein-DNA complex

The utility of capillary electrophoresis in the study of DNA-protein binding is demonstrated, using the minimal DNA binding domain of the onco-protein c-Myb (R2R3) and a specific target DNA sequence as a model system. The capillary electrophoresis method is based on simple UV detection at 260 nm with a linear polymer buffer and a coated capillary, and requires no labeling or derivatization of the DNA. A specific protein-DNA complex is observable as a retarded peak, which increases with increasing protein concentration with a corresponding reduction in the free DNA peak. With DNA and protein preparations of known concentrations, a test for sequence-specific binding can be completed within 10 min.

The effect of aging on the immune response: influence of phosphatidylcholine-containing lipid on IgD-receptor expression and antibody formation

It was reported previously that IgD-receptors (IgD-R) are expressed on both CD4+ and CD8+ human T cells and CD4+ murine T cells after exposure to oligomeric IgD, certain cytokines, or various pharmacological agents, as shown by rosetting with IgD-coated erythrocytes. Enhancement of antibody production is observed in mice after injection of oligomeric IgD and is mediated by these IgD-R+ T cells, while injection of monomeric IgD inhibits both IgD-R upregulation and augmentation of antibody responses induced by simultaneously injected oligomeric IgD. The effects of oligomeric IgD on IgD-R upregulation are lacking in aged mice. However, the oligomeric IgD induced enhanced antibody production can be transferred to aged mice with IgD-R+ T cells from young donors suggesting that the environment of the aged mouse supports the effector function of IgD-R+ T cells. We now report, in addition, that exposure to phosphatidylcholine (PC) and a PC-containing lipid mixture, AL721, is effective in causing IgD-R upregulation on T cells from both young and aged mice, and young humans. This effect can also be demonstrated in mice in vivo after administration of AL721. Moreover, this agent causes a two-fold enhancement of antibody production, as measured by PFC/spleen, to 4-hydroxy-5-iodo-3-nitrophenyl(acetyl)-Brucella abortus (NIP-BA) and NIP-horse red blood cells (RBC) in young and aged mice. There is no difference in the baseline membrane fluidity of lymphocytes from aged and young mice. Although PC causes an increase in membrane fluidity of lymphocytes from both young and old mice, and from humans, this effect on fluidity is not prevented by a protein kinase inhibitor, while PC's effect on IgD-R upregulation is prevented by the inhibitor. Moreover, no correlation was observed between IgD-R upregulation and membrane fluidity changes induced by AL721 administered in vivo. To evaluate the role of IgD-R induction in the augmentation of antibody production by phospholipids, the effect of monomeric IgD was investigated. The augmenting effect of AL721 on antibody production was prevented by a single injection of monomeric IgD at the time of antigen administration. We conclude that (1) PC-containing lipid mixtures are effective in enhancing antibody production in aged mice, (2) induction of IgD-R is responsible for the augmenting effects of AL721 on antibody production, and (3) monomeric IgD not only blocks the upregulation of IgD-R, as shown previously, but also the augmenting effect of previously upregulated IgD-R on T cells by preventing their interaction with surface IgD+ B cells.

[Pharmacological comparative study on baiqian and baiwei]

The decoction of Cynanchum glaucescens and the ethanol extract of C. stauntonii show significant antitussive and expectorant actions. The decoctions of C. stauntonii or C. glaucescens have antiasthmatic and anti-inflammatory effects. The decoction of C. atratum has some expectorant effect but no antitussive or antiasthmatic actions. On the other hand, the decoction of C. versicolor cannot relieve cough nor sputum. The results indicate that both C. atratum and C. versicolor cannot be used as C. glaucescens or C. stauntonii.

[Effects of processing on specific toxicity and pharmacodynamics of radix Kansui, radix Achyranthis bidentatae and semen Armeniacae amarum]

The comparative toxicological researches on crude and processed drugs show that the activating action of Radix Kansui, Radix Achyranthis Bidentatae and Semen Armeniacae Amarum on EBV-EA can be decreased by processing. Processing can also decrease stimulating activity on mouse skin, inhibit tumor-promoting activity in two stage skin tumor promoting test and lapactic effect by Radix Kansui. Meanwhile the pharmacological effects of these drugs can be retained or increased by processing.

[Antitussive, expectorant and anti-inflammatory effects of rhizoma Cynanchi stauntonii]

Experiments indicated that the ethanol extract and ether extract from Rhizoma Cynanchi Stauntonii showed obvious antitussive and expectorant effects in mice with stomach administration. The antitussive effect of ethanol extract was stronger than the expectorant effect. The water extract showed a certain expectorant effect but no marked antitussive effect with oral administration. Obvious anti-inflammatory effect was observed on croton oil-caused mouse ear swell with intraperitoneal injection.

[The status quo and prospect of experimental study on channel tropism of Chinese herbal drugs]

The assay of metabolism and distribution of effective components of Chinese herbal drugs, microelement assay, pharmacodynamic assay and cAMP, cGMP assay are the essential methods usually used in the experimental study of channel tropism of Chinese herbal drugs. The problems of each method as well as the points for attention in the experimental study of channel tropism are discussed.

[Antifebrile and anti-inflammatory effects of radix Cynanchi atrati]

The water extract of Radix Cynanchi Atrati used as intraperitoneal injection has been proved to have an obvious antifebrile++ effect on rat fever caused by 15% yeast suspension hypodermic injection as well as a significant anti-inflammatory effect. But the antiferbrile effect of its ethanol extract is not clear.

[Studies on comprehensive evaluation of toxic hazard in low-concentration benzene pollution]

Early adverse effects of exposure to benzene in a concentration less than 32 mg/m3 on the employees' health were comprehensively evaluated with WHO neurobehavioral core test battery, cytokinesis-block micronucleus assay for peripheral blood lymphocytes, determination of serum level of sialic acid and T-lymphocyte assay with alpha-naphthyl acetate esterase (ANAE) stain. Results revealed emotional irritability could be found in the exposed employees and 24% of them showed an abnormal percentage of micronuclei formation and increased serum level of sialic acid.

[Effect of processing on specific toxicity of radix Achyranthis bidentatae]

To activate Epstein-barr virus in Raji cells in vitro the lowest activation concentrations of ether extracts from Radix Achyranthis Bidentatae unprepared (I), stir-baked with wine (II) and stir-baked with salt (III) required were 0.8.20 and 0.16 micrograms/ml respectively. 5 microliters (equal to 250 mg herb weight)/ear of these extracts had inflammatory effect on mouse ear skin in 4 hours. Ethanol extract of I at concentration 0.04-125 mg/ml did not increase the chromosomal aberration rates in CHL cells. The decoctions of I, II, and III given orally at 15 g/kg x 3d showed no effect on micronucleus rates in mouse bone marrow. Ethanol extracts of I, II, and III at 10 g/kg x 10d did not show any evident antifertility action.

[Antitussive, expectorant and anti-asthmatic effects of Cynanchum glaucescens (Decne.) Hand. -Mazz]

The water, ethanol and ether extracts from Cynanchum glaucescems administrated orally showed significant antitussive effect in ammonia-induced cough model in mice. The water and ethanol extracts had obvious expectorant effect. The filtered solution of water decoction injected intraperitoneally could effectively prevent guinea pigs from asthma induced by acetulcholine and histamine mixture, and also inhibit the ear inflammation in mice caused by croton oil. All these effects showed close dose-effect relationship.

Detection of Leptosphaeria korrae with the polymerase chain reaction and primers from the ribosomal internal transcribed spacers

Leptosphaeria korrae, the causal agent of necrotic ring spot, is a destructive patch disease of Kentucky bluegrass. To develop a rapid molecular test for the detection of this pathogen, an assay based on the polymerase chain reaction (PCR) was developed utilizing the internal transcribed spacer region 1 (ITS 1) of L. korrae ribosomal DNA. DNA sequence comparison showed 94.8% similarity of the ITS 1 region among L. korrae isolates and only 45–50% similarity between L. korrae and other fungal species. Based on ITS 1 sequence differences, a pair of oligonucleotide primers, LK17S and 5.8SC, were selected. With PCR, the primers specifically amplified L. korrae DNA and did not amplify DNA isolated from 15 other fungal species or healthy Kentucky bluegrass. The assay could also specifically detect L. korrae in diseased turfgrass samples. Key words: detection, ITS 1, Leptosphaeria korrae, necrotic ring spot, polymerase chain reaction, ribosomal DNA.

Regulation of IgD-receptor expression on murine T cells. II. Upregulation of IgD receptors is obtained after activation of various intracellular second-messenger systems; tyrosine kinase activity is required for the effect of IgD

The presence of IgD receptors (IgD-R) on T cells during a primary response to antigen causes augmented antibody production and facilitates priming for a secondary response. Cross-linked, but not monomeric IgD leads to a rapid upregulation of these receptors on T cells. As shown in the present study, the rapid upregulation of IgD-specific receptors is also induced by cross-linking of T cell surface molecules known to mediate triggering of T cell activation, such as CD3, CD2, and Thy 1. Furthermore, IgD-R are also upregulated by pharmacologically active compounds that increase intracellular cAMP and by PMA/DiOG plus ionomycin, but not by either PMA or ionomycin alone. The upregulation of IgD-R by anti-CD3 is inhibited by both calphostin C and herbimycin A, while that due to DiOG plus ionomycin is only inhibited by calphostin C. Upregulation of IgD-R by increased cAMP is blocked by HA1004, but not by low concentrations of staurosporine or herbimycin A. IgD itself does not cause an increase in intracellular cAMP, protein kinase C translocation, influx of extracellular Ca2+, or a change in membrane potential. Relatively specific inhibitors of these activation pathways, HA1004, calphostin C, and neomycin, also fail to interfere with IgD-receptor upregulation by IgD itself. However, tyrosine kinase inhibitors, including herbimycin A, tyrphostin C11, and genistein, completely prevent the effect of IgD on IgD-R expression. Although an influx of Ca2+ is apparently not involved, a role for intracellular Ca2+ in the upregulation of IgD-R by IgD on T cells is indicated by the susceptibility to inhibition by BAPTA, W7, and FK520. We conclude that activation of at least three different second-messenger systems can cause IgD-R upregulation, but that the effect of IgD itself requires tyrosine kinase activity, perhaps in an intracellular Ca(2+)-dependent manner.

Regulation of IgD-receptor expression on murine T cells. I. Characterization and metabolic requirements of the process leading to their expression

Receptors for IgD (IgD-R) are found on murine CD4+ T cells and T cell clones. Previous work has shown that incubation with aggregated (but not monomeric) IgD causes the rapid upregulation of IgD-R and enables the T cells to respond with augmented helper function in antibody production. In the present study, IgD-R upregulation is shown to be (a) rapid, reaching plateau levels by 60 min, (b) independent of de novo protein or RNA synthesis, and (c) only slightly reduced at 4 degrees C. The IgD-R+ T cells present both before and after upregulation of IgD-R expression are predominantly resting T cells, whose ability to rosette with IgD-SRBC is inhibited by soluble IgD. The upregulation of IgD-R, even after overnight exposure to IgD, does not cause any detectable change in the expression of other T cell surface markers. Also characteristic of resting T cells is that they exhibit IgD-R in response to IL-2 and IL-4 only after overnight incubation with these cytokines, and fail to respond at all to IL-1. In contrast, cloned Th2 cells, expressing IL-1 and IL-2 receptors, show IgD-R upregulation after a 2-hr exposure to IL-1 or IL-2. GM-CSF, TNF-alpha, IL-6, and IL-10 do not modulate IgD-R expression. T hybridoma cells constitutively express much higher IgD-R levels than resting splenic T cells and can be stained with aggregated IgD followed by FITC-anti-IgD. Their levels of IgD-R expression decrease, as assayed both by rosetting and by staining, on 4-14 hr of incubation with tunicamycin or deoxynojirimycin, suggesting that N-linked glycosylation and oligosaccharide processing, respectively, are needed for continued expression of IgD-R. Tunicamycin-treated cells without detectable IgD-R on their surface still show IgD-binding protein in the cell extracts, suggesting that surface expression is more dependent on glycosylation of the IgD-R molecules than on the ability to bind IgD. Ca2+ ions are needed for optimal binding of IgD to IgD-R, in line with previous findings showing IgD-R to be lectin-like in binding carbohydrate rather than peptide regions of the IgD molecule.

Physiology of IgD. IX. Effect of IgD on immunoglobulin production in young and old mice

Weekly i.p. injections of IgD from birth in (SJL X BALB/c)F1 mice were found to accelerate the development of IgG- and IgA-secreting cells and to increase the numbers of Ig-secreting cells of all isotypes in 17-28-day-old mice, but not in 7-10-day-old mice. Similarly, repeated weekly injections of IgD in normal adult BALB/c mice increased the numbers of reverse plaque-forming cells/spleen for all isotypes studied, including IgM, IgG1, IgG2, and IgA, but not for IgD itself. No such effect was observed in IgD-treated aged (20 months old) BALB/c mice. The absence of an effect of IgD on Ig secretion appeared to correlate with a lack of induction of receptors for IgD on T cells of the host, both in 7-10-day-old and in aged mice. In 7-10-day-old mice this lack of induction appeared due to their very low numbers of L3T4+ T cells. A comparison was made between the effect of a single injection of IgD or lipopolysaccharide (LPS) on numbers of Ig-secreting cells in the spleen determined 1-7 days after injection. Both agents caused increases, but the increase in IgM-producing cells was much greater after LPS (day 4), while IgD caused a relatively greater increase in IgG2 and IgA (days 4-7). Increases in IgG1 and IgG3-producing cells induced by LPS and IgD were of similar magnitude (days 6-7). IgD production, however, was not increased. The number of cells producing antibody of anti-trinitrophenyl (TNP) specificity was enhanced by LPS (day 4), but not by a single injection of IgD, although more than one injection of IgD caused a significant increase in anti-TNP-producing cells above background. LPS, but not IgD, caused B cell proliferation in vitro in the presence or absence of gamma-irradiated T delta cells. However, in vivo, IgD injections caused a significant increase in the percentage of lymphoid follicles with germinal centers in lymph nodes from 17-21-day-old and normal adult mice, but not in 7-10-day-old or aged mice. Such an effect was also absent in 24-28-day-old mice, where germinal center development, even in untreated mice, was very high.