Anomalous rotational resonance spectra in magic-angle spinning NMR

Magic-angle spinning NMR spectra of samples containing dilute spin-1/2 pairs display broadenings or splittings when a rotational resonance condition is satisfied, meaning that a small integer multiple of the spinning frequency matches the difference in the two isotropic shift frequencies. We show experimental rotational resonance NMR spectra of a 13C2-labeled retinal which are in qualitative disagreement with existing theory. We propose an explanation of these anomalous rotational spectra involving residual heteronuclear couplings between the 13C nuclei and the neighboring 1H nuclei. These couplings strongly influence the rotational resonance 13C spectrum, despite the presence of a strong radiofrequency decoupling field at the 1H Larmor frequency. We model the residual heteronuclear couplings by differential transverse relaxation of the 13C single-quantum coherences. We present a superoperator theory of the phenomenon and describe a numerical algorithm for rapid Liouville space simulations in periodic systems. Good agreement with experimental results is obtained by using a biexponential transverse relaxation model for each spin site.

Measurements of fractionated gaseous mercury concentrations over northwestern and central Europe, 1995-99

Although it makes up only a few per cent. of total gaseous mercury (TGM) in the atmosphere, the fraction of oxidised (divalent) mercury plays a major role in the biogeochemical cycle of mercury due to its high affinity for water and surfaces. Quantitative knowledge of this fraction present in mixing ratios in the parts-per-10(15) (ppq) range is currently very scarce. This work is based on approximately 220 data for divalent gaseous mercury (DGM) collected during 1995-99 in ambient air. Over the course of the measurements, the sampling and analytical methods were modified and improved. This is described here in detail and includes transition from wet leaching and reduction procedures to thermo-reductive desorption, the use of annular as well as tubular denuders and adoption of an automated sampling system. The concentration of DGM exhibited a strong seasonal behaviour in contrast to atomic gaseous mercury, with low values in winter and maximum values in summer. The DGM/TGM ratios were frequently found to be below the detection limit (< or = 1%) and in the range 1-5%. A trend of diurnal DGM patterns was observed and implies photolytically induced sources. Scavenging of DGM during rain events was also noticed.

[Detection of low temperature rheologic behavior of lubricating oil by FTIR]

The composition and structure of lubricating oil expressed by FTIR were used for its characterization. Artificial nervous network was used as a mathematical model. CCS-15C viscosity of base oil was forecasted and good result was obtained. The result has shown that the artificial nervous network is an effective mathematical model for studying the relation between the composition and structure of lubricating oil and its performance.

[Morphological studies on 18 species of gualoupi]

OBJECTIVE

To gain a clear idea of the drug Gualoupi and its adulterants.

METHOD

Collecting data and spot investigating in 30 provinces, cities and autonomous regions in China.

RESULT

Gualoupi used as drug in China consists of 15 species of Trichosanthes, 1 species of Momordica, 1 species of Citrullus and 1 species of Adenia(Passifloraceae).

CONCLUSION

The main commodity is the rind of T. kirilowii or T. rosthornii, and the main adulterant is the rind of T. hupehensis.

[Observation of special stain and ultrastructure of lattice, granular and macular corneal dystrophy]

OBJECTIVE

To investigate the histopathological changes of lattice, granular and macular corneal dystrophy.

METHODS

Corneal buttons were obtained from penetrating keratoplasty due to severe corneal dystrophy, and their sections and ultrathin sections with several special stains were observed under a light microscope (LM) and electron microscope (EM).

RESULTS

In cases with lattice dystrophy, the stromal fusiform deposits seen under LM were confirmed to be amorphous materiel with filaments by EM and stained positively for Masson trichrome, PAS and Congo red. In cases with granular dystrophy, the granular or bread debris deposits found between laminae under LM were extracellular material observed by EM and they were stained positively for Masson trichrome and alcian blue. In cases with macular dystrophy, the stromal spheroid or macular deposits were seen under LM, and there were numerous vacuoles containing fibrils and granules in the cytoplasm of keratocytes and accumulative amorphous material in the stroma under EM; the deposits were positive for colloidal iron and alcian blue stain.

CONCLUSION

In corneal lattice dystrophy, there are amyloid deposits; in granular dystrophy, there are extracellular material deposits; and in macular dystrophy, there is mucopolysaccharide accumulation.

Rotational resonance NMR of 13C2-labelled retinal: quantitative internuclear distance determination

Rotational resonance phenomena are investigated in the solid-state magic-angle spinning NMR of all-E-[11,20-13C2]-retinal at a magnetic field of 4.7 T. We find good agreement between experiments and numerical simulations for the rotational resonance spectral peakshapes and for the rotor-driven magnetization exchange. The internuclear distance between the 13C-labelled C11 and C20 sites is determined to be 0.301 +/- 0.008 nm (from rotational resonance spectra) and 0.300 +/- 0.010 nm (from rotor-driven magnetization exchange), in agreement with the X-ray crystallographic distance of 0.296 nm. We show rotational resonance spectra which display perturbations from intermolecular homonuclear spin-spin interactions.

DNA methylation represses transcription in vivo

DNA in somatic tissue is characterized by a bimodal pattern of methylation, which is established in the animal through a series of developmental events. In the mouse blastula, most DNA is unmethylated, but after implantation a wave of de novo methylation modifies most of the genome, excluding the majority of CpG islands, which are mainly associated with housekeeping genes. This genomic methylation pattern is broadly maintained during the life of the organism by maintenance methylation, and generally correlates with gene expression. Experiments both in vitro and in vivo indicate that methylation inhibits transcription. It has not yet been possible, however, to determine the role of DNA methylation on specific sequences during normal development. Cis-acting regulatory elements and trans-acting factors appear to be involved in both stage- and tissue-specific demethylation processes. Sp1-like elements have a key role in protecting the CpG island of Aprt (encoding adenine phosphoribosyltransferase) from de novo methylation, and when these elements are specifically mutated, the Aprt CpG island becomes methylated in transgenic mice. We have now characterized an embryo-specific element from the CpG island sequence upstream of Aprt that can protect itself from de novo methylation in transgenic mice as well as reduce methylation of flanking sequences. We placed this element on a removable cassette adjacent to a human HBB (encoding beta-globin) reporter and generated a transgene whose methylation pattern can be switched in vivo. Analysis of globin transcription in this system showed that methylation in cis inhibits gene expression in a variety of tissues, indicating that DNA modification may serve as a global genomic repressor.

[The analysis of pathological changes of cardiac conduction system in 54 cases of cardiac sudden deaths]

OBJECTIVE

To elucidate the exact cause of death in cases of cardiac sudden deaths.

METHODS

Sampling of cardiac conduction system (CCS) designed by the research group was adopted. The CCS of 120 cases died of cardiac sudden deaths were collected for routine histological examination.

RESULTS

In 54 out of 120 cases, the causes of death were attributed to lesions present in the CCS, and 85.2% of them were young adults. The peak age range was from 20 - 30. Much more in males (6.7:1). The pathological changes in CCS include: inflammation (46.2%), fatty infiltration, hypertrophic cardiomyopathy associated with CCS changes; hemorrhage, developmental anomalies, fibrosis and tumors.

CONCLUSION

The pathological changes of CCS are relatively common, as the cause of sudden deaths. Which is considered to be the pathological basis of the unstable cardiac electric potentials and arrhythmia. This study recommended the necessity of routine examination on CCS in cases of sudden deaths.

[Analysis of rRNA gene restriction fragments length polymorphism of Leptospira in China]

Sixty-four Leptospira international and domestic reference strains, which belonging to fifty-four serovars, and twenty-seven field strains were examined by using EcoR I restriction endonuclease analysis of genomic DNA and restriction fragments length polymorphism of rRNA gene, fifty-six Leptospiral ribotypes(RTs) were described. Most serovars gave specific patterns. Serovars in the same serogroup possess common core-segments, but we found RTs of reference strains from China and other countries are different. Most field strains have RTs with correspond of reference strains, only a few bands were shown different if RTs were different. A notable result was that the field strains of serovar pomona have the same Rt as the international reference strain but different from the domestic reference strain.

Adenoviral-mediated gene transfer of interleukin-6 in rat lung enhances antiviral immunoglobulin A and G responses in distinct tissue compartments

The effect of IL-6 transgene expression following lung gene transfer on anti-adenovirus humoral responses of immunoglobulin (Ig) G and A both in the lung and peripheral blood was investigated. Lung infection by a control adenovirus caused an increased level of circulating anti-adenoviral IgG antibodies. However, the magnitude of this response was many times higher in the peripheral blood of rats receiving an adenovirus engineered to express IL-6 transgene. In comparison, much lower levels of anti-adenoviral IgG were detected in the bronchoalveolar fluids of rats receiving either virus. In contrast, there was no detectable level of anti-adenoviral IgA in the peripheral blood in any cases, yet significantly detectable levels of anti-adenoviral IgA were measured in the lung. The levels of this IgA were much higher in the lung of rats expressing IL-6 than in the lung of control animals (15 times higher by day 14). Our findings thus provide evidence that IL-6 plays a significant role in enhancing specific airways mucosal IgA and systemic IgG responses during local lung viral infection, and provide the rationale for using IL-6 locally at mucosa sites as an immune adjuvant for antiviral vaccination program.

[Cartilage matrix synthetic ability of rabbit articular chondrocytes cultured in vitro]

OBJECTIVE

To observe the ability of matrix synthesis of rabbit articular chondrocytes cultured in vitro.

METHODS

Rabbit articular chondrocytes were acquired by digestion of 0.1% type II collagenase and cultured in vitro, then cell morphology and ultrastructure were observed with phase-contrast microscope and scanning electronic microscope. With continuous culturing of chondrocytes in DMEM medium containing 15% FBS, synthesis of cartilage matrix was observed by using microscope and safranine-O staining.

RESULTS

The cultured chondrocytes were polygonal cells. There were many rough endoplasmic reticula and mitochondria in cytoplasm, and a lot of secretory vesicles under cell membrane and in the cytoplasm. When cultured for 10 days, some small and white nodules were formed on the bottom of the culture dishes, and volcanic-mouth-like structures were formed when cultured for 20 days. Both these nodules and structures contained GAG-positive substances were demonstrated by safranine-O staining.

CONCLUSION

Chondrocytes can produce matrix and cartilage-like tissue in vitro, so it is feasible to produce cartilage by culturing chondrocytes in vitro.

Enhanced function conferred on low-abundance chemoreceptor Trg by a methyltransferase-docking site

In Escherichia coli, high-abundance chemoreceptors are present in cellular amounts approximately 10-fold higher than those of low-abundance receptors. These two classes exhibit inherent differences in functional activity. As sole cellular chemoreceptors, high-abundance receptors are effective in methyl-accepting activity, in establishing a functional balance between the two directions of flagellar rotation, in timely adaptation, and in mediating efficient chemotaxis. Low-abundance receptors are not, even when their cellular content is increased. We found that the low-abundance receptor Trg acquired essential functional features of a high-abundance receptor by the addition of the final 19 residues of the high-abundance receptor Tsr. The carboxy terminus of this addition carried a methyltransferase-binding pentapeptide, NWETF, present in high-abundance receptors but absent in the low-abundance class. Provision of this docking site not only enhanced steady-state and adaptational methylation but also shifted the abnormal, counterclockwise bias of flagellar rotation toward a more normal rotational balance and vastly improved chemotaxis in spatial gradients. These improvements can be understood as the result of both enhanced kinase activation by the more methylated receptor and timely adaptation by more efficient methyl-accepting activity. We conclude that the crucial functional difference between the low-abundance receptor Trg and its high-abundance counterparts is the level of methyl-accepting activity conferred by the methyltransferase-docking site.

Hepatitis C infection: a review

Hepatitis C, transmitted through body fluid exchange, affects approximately 1.8% of the U.S. population, roughly 3.9 million persons. Transfusion of blood and blood products was once an important source of hepatitis C transmission. Since the initiation of the hepatitis C screening program in 1985, however, injection drug use has become a major route. Hepatitis C is a leading cause of chronic liver disease. In 80% to 85% of those infected with the virus, chronic hepatitis C eventually develops, which can lead to cirrhosis and hepatocellular carcinoma, with alcohol abuse and coinfection with hepatitis B as additional risk factors. Screening for hepatitis C can be achieved with serologic assays. Molecular assays are helpful in confirming the diagnosis, assessing viral load, and characterizing the genetic nature of the viruses. Interferon alpha (IFN-alpha) and a combination of IFN-alpha 2B and ribavirin are therapies available in treatment of hepatitis C, but sustained response to the treatment has been unsatisfactory. Further studies are indicated to obtain more effective therapies for eradication of the disease. Hepatitis C is preventable, and clinicians should use every opportunity possible in their practice to assess those at risk and actively engage them in risk factor reductions.

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing.

Real-time visualization of the cellular redistribution of G protein-coupled receptor kinase 2 and beta-arrestin 2 during homologous desensitization of the substance P receptor

The substance P receptor (SPR) is a G protein-coupled receptor (GPCR) that plays a key role in pain regulation. The SPR desensitizes in the continued presence of agonist, presumably via mechanisms that implicate G protein-coupled receptor kinases (GRKs) and beta-arrestins. The temporal relationship of these proposed biochemical events has never been established for any GPCR other than rhodopsin beyond the resolution provided by biochemical assays. We investigate the real-time activation and desensitization of the human SPR in live HEK293 cells using green fluorescent protein conjugates of protein kinase C, GRK2, and beta-arrestin 2. The translocation of protein kinase C betaII-green fluorescent protein to and from the plasma membrane in response to substance P indicates that the human SPR becomes activated within seconds of agonist exposure, and the response desensitizes within 30 s. This desensitization process coincides with a redistribution of GRK2 from the cytosol to the plasma membrane, followed by a robust redistribution of beta-arrestin 2 and a profound change in cell morphology that occurs after 1 min of SPR stimulation. These data establish a role for GRKs and beta-arrestins in homologous desensitization of the SPR and provide the first visual and temporal resolution of the sequence of events underlying homologous desensitization of a GPCR in living cells.

[Clinico-pathologic characteristics of malignant thymoma]

OBJECTIVE

To assess the histopathology, clinical staging and treatment of malignant thymoma in relation to prognosis.

METHODS

Sixty four cases with malignant epithelial thymic tumors treated in the period of 1958-1995 were retrospectively studied. Archived specimens were categorized according to Levine and Rosai into type I malignant thymoma(MT) and type II thymic carcinoma (TC). MT was histologically classified according to Müller-Hermelink(M-H). Clinical staging was ascertained according to Masaoka's criteria.

RESULTS

There were 41 cases of MT and 23 cases of TC. No medullary or mixed thymoma was observed in this series of MT. The 5-year survival rate of patients with MT of predominantly cortical, cortical, and well-differentiated thymic carcinoma (MDTC) subtypes was 75.3%, 44.7% and 43.3%, respectively. That of patients with TC of squamous-cell carcinoma and lympho-epithelioid subtypes was 27.5% and 60.0%, respectively. The 10-year survival rate of these 5 subtypes was 25.3%, 10.0%, 0, 0, 20.0%, respectively(P < 0.05). The 5-year and 10-year survival rates decreased with increase in staging. In 22 patients in stage III and IV who received thoracotomy with biopsy only, their survival rate was significantly lower than that in patients with their tumor resected.

CONCLUSION

Histomorphology of the tumor, heterogeneity in cell types, clinical staging and the extent of tumor resection are factors affecting survival.

[The feature of pancreatic microcirculatory impairment in caerulein induced acute pancreatitis]

OBJECTIVE

To study the feature of pancreatic microcirculatory impairment in caerulein-induced acute pancreatitis.

METHODS

The AP model of subcutaneous injection of caerulein was studied by intravital fluorescence microscopy of erythrocytes labeled by FITC (FITC-RBC) and by scanning electron microscopy of vascular corrosion casts and light microscopy of Chinese ink-injected/cleared tissues.

RESULTS

Animals treated with caerulein showed hyper-amylases. Contractions of intralobular arteriolar sphincter, presence of vacuoles in all the layers of sphincter, gross irregularity in capillary network of acini were observed in caerulein-induced groups. The decrease of pancreatic capillary blood flow (P < 0.01), reduction of functional capillary density, and irregular intermittent perfusion (P < 0.05) were found.

CONCLUSIONS

Impairment and contraction of pancreatic intralobular arteriolar sphincter are the initial microcirculatory lesions in the early phase of acute pancreatitis induced by Caerulein, and play a key role in the pancreatic ischemia and pancreatic microvascular failure in acute pancreatitis.

[Effect of mutation (T1762A1764) on hepatitis B virus core promoter activity]

OBJECTIVE

With the knowledge that the substituted mutation of T1762A1764 in hepatitis B virus (HBV) core promoter (CP) region was the most common variation during chronic HBV infection, we proceed to study the role that the mutation T1762A1764 plays in effecting the core promoter.

METHODS

Seven patients with fulminant hepatitis and one asymptomatic HBV carrier were investigated for screening T1762A1764 mutation by cloning and PCR products direct sequencing. PCR products containing HBV precore/core gene regulatory sequences were directly cloned into chloramphenicol acetyltransferase (CAT) expressing plasmid. CAT assay was done to compare CAT expressing level after transfecting into HepG2 cell line and transient expression.

RESULTS

Results reveal that T1762A1764 mutation was the main factor that represses CAT expression in vitro.

CONCLUSION

Among the several other variations within hepatitis B virus' core promoter region, T1762A1764 mutation has mainly affected the down-regulating activity of core promoter.

[Activation of neutrophil and its relation to neutrophil-endothelial cell adherence]

Neutrophil was activated by chemotactic tripeptide N-formyl-methionyl-leucyl-phenylalanine(fMLP) of different concentration. The activation rate was tested by the method of nitroblue tetrazolium reduction. Using flow chamber system, we quantitatively studied the properties of neutrophil adhesion to human umbilical vein endothelial cell (HUVEC) under different shear stress. The results showed that the activation rate of neutrophil significantly increased with increase of fMLP concentration that the adhesion rate of neutrophil pretreated with fMLP decreased with the gradual increase of shear stress, such a change was also found in the control group; and that the adhesion rate of neutrophil to HUVEC increased with the increase of activation rate of neutrophil, but the adhesion rate had a tendency to decrease when shear stress increased. These indicated that shear stress induced by bloodstream might play an important role in inhibiting neutrophil-endothelial cell adherence in vivo and the enhanced activation of neutrophil could increase neutrophil-endothelial cell adherence.

CD4+ cells play a major role in xenogeneic human anti-pig cytotoxicity through the Fas/Fas ligand lytic pathway

BACKGROUND

In this study, the role of cell-mediated cytotoxicity by human leukocytes against pig endothelial cells was examined in vitro. The aim was to determine which cell subsets were responsible for this phenomenon and which pathways were involved in cell lysis.

METHODS

Primed human peripheral blood mononuclear cells (PBMC) or purified CD4+ or CD8+ T cells were used in a cell-mediated cytotoxicity assay in which cytotoxicity of an SV40 transformed porcine endothelial cell (EC) line (SVAP) was determined by Annexin V binding.

RESULTS

Human PBMC demonstrated specific lysis of porcine EC that was proportional to the effector: target ratio. CD4+ T cells accounted for >60% of this lysis, whereas CD8+ T cells accounted for <20%. CD4+ T cell-mediated lysis depended on direct recognition of porcine major histocompatibility complex class II molecules as inhibition of swine leukocyte antigen class II on porcine EC-inhibited CD4+ T cell cytotoxicity. This lysis was mediated through the Fas/FasL pathway as addition of anti-Fas and/or anti-FasL antibody profoundly inhibited antiporcine lysis. In addition, FasL gene expression was detected in primed PBMC and CD4+ T cells by RT-PCR, whereas granzyme B gene expression was not. Primed CD4+ T cells demonstrated high level FasL protein by Western blotting and two-color FACS analysis, whereas NK cells and CD8+ T cells did not. Finally, recombinant human FasL induced apoptosis in Fas expressing porcine EC cells, demonstrating that human FasL interacted with and activated Fas on porcine EC cells.

CONCLUSIONS

In conclusion, human to pig cell-mediated cytotoxicity was mediated predominantly by CD4+ T cells through the Fas/FasL pathway of apoptosis. These results suggest that direct cytotoxicity by xenoreactive CD4+ T cells may be one of several effector mechanisms involved in cellular xenograft rejection.

Neutron activation analysis of fluoride release after treatment with a fluoride varnish in vitro

OBJECTIVE

To use neutron activation analysis to study a new type of cariostatic material, fluoride varnish, in terms of its anti-caries mechanism and its release in vitro.

MATERIALS AND METHODS

Twenty enamel specimens were measured for baseline fluoride content using neutron activation analysis. The enamel specimens were then fluoridated with 1.5% sodium fluoride varnish for 24 hours, and their enamel fluoride content was measured again with neutron activation analysis.

RESULTS

The baseline fluoride content in the enamel specimens was 161.7 micrograms/g; after fluoridation, the fluoride content in the enamel specimens increased to 277.8 micrograms/g, or about 1.7 times.

CONCLUSION

It is evident that this sodium fluoride varnish can significantly increase enamel fluoride content. The neutron activation analysis is a good method for fluoride measurement in vitro.

Cloning of the murine beta5 integrin subunit promoter. Identification of a novel sequence mediating granulocyte-macrophage colony-stimulating factor-dependent repression of beta5 integrin gene transcription

We previously noted that the initial receptor by which murine osteoclast precursors bind matrix is the integrin alphav beta5 and that granulocyte-macrophage colony-stimulating factor (GM-CSF) decreases expression of this heterodimer by suppressing transcription of the beta5 gene. We herein report cloning of the beta5 integrin gene promoter and identification of a GM-CSF-responsive sequence. A 13-kilobase (kb) genomic fragment containing part of the beta5 gene was isolated by screening a mouse genomic library with a probe derived from the most 5'-end of a murine beta5 cDNA. A combination of primer extension and S1 nuclease studies identifies two transcriptional start sites, with the major one designated +1. A 1-kb subclone containing sequence -875 to + 110 is transcriptionally active in a murine myeloid cell line. This 1-kb fragment contains consensus binding sequences for basal (Sp1), lineage-specific (PU.1), and regulatable (signal transducer and activator of transcription) transcription factors. Reflecting our earlier findings, promoter activity is repressed in transfected myeloid cells treated with GM-CSF. Using deletion mutants, we localized a 109-base pair (bp) promoter region responsible for GM-CSF-inhibited beta5 transcription. We further identified a 19-bp sequence within the 109-bp region that binds GM-CSF-induced nuclear proteins by gel shift/competition assays. Mutation of the 19-bp sequence not only ablates its capacity to bind nuclear proteins from GM-CSF-treated cells, in vitro, but the same mutation, when introduced in the 1-kb promoter, abolishes its ability to respond to GM-CSF treatment. Northern analysis demonstrates that cycloheximide treatment abrogates the capacity of GM-CSF to decrease beta5 mRNA levels. In summary, we have identified a 19-bp cis-element mediating GM-CSF-induced down-regulation of beta5 by a mechanism requiring protein synthesis.

Apoptosis in hematopoietic cells (FL5.12) caused by interleukin-3 withdrawal: relationship to caspase activity and the loss of glutathione

The mechanism of cell death caused by cytokine deprivation remains largely unknown. FL5.12 cells (a murine prolymphocytic cell line), following interleukin-3 (IL-3) withdrawal, undergo a decrease in intracellular glutathione (GSH) that precedes the onset of apoptosis. In the present study, the induction of apoptosis following IL-3 withdrawal or GSH depletion with DL-buthionine-[S,R,]-sulfoximine (BSO) was examined. Both conditions caused time-dependent increases in phosphatidylserine externalization, acridine orange and ethidium bromide staining, decreases in mitochondrial membrane potential, processing and activation of caspase-3 and proteolysis of the endogenous caspase substrate poly(adenosine diphosphate ribose)polymerase (PARP). Apoptosis induced by IL-3 deprivation but not BSO also caused lamin B1 cleavage, suggesting activation of caspase-6. Despite a more profound depletion of GSH after BSO than withdrawal of IL-3, the extent of apoptosis was somewhat lower. Benzyloxycarbonyl-Val-Ala-Asp(OMe)fluoromethyl ketone (z-VAD.fmk) blocked this caspase activity and prevented cell death after BSO exposure but not after IL-3 deprivation. Following IL-3 withdrawal, the caspase inhibitors z-VAD.fmk and boc-asp(OMe)fluoromethylketone (boc-asp.fmk) prevented the cleavage and activation of caspase-3, the breakdown of lamin B1 and partially mitigated PARP degradation. However, the externalization of phosphatidylserine, the fall in mitochondrial membrane potential and subsequent apoptotic cell death still occurred. These results suggest that IL-3 withdrawal may mediate cell death by a mechanism independent of both caspase activation and the accompanying loss of GSH.

[Analysis of constituents of essential oil from Anemone altaica Fisch. ex C. A. Mey]

OBJECTIVE

Analyzing the constituents of the essential oil from Waichangpu(dried rhizome of Anemone altaica, often mistakenly called "Jiujiechangpu").

METHOD

Separating and identifying the constituents by GC-MS.

RESULT

Twenty-two compounds from the essential oil from Waichangpu were separated and identified, the main ones being cedrenol(23.69%), beta-eudesmol(8.49%), elemol(2.80%), hexadecanoic acid(4.77%) and 9, 12-octadecadienoic acid(14.93%).

CONCLUSION

The essential oil content is very low in Waichangpu, and the oil structure of Waichangpu is obviously different from that of Shichangpu(dried rhizome of Acorus tatarinowii, whose another name is Jiujiechangpu). The present study provides a chemical basis to support the view that Waichangpu should not be confused with Shichangpu as a medicinal herb.