Cyclosporin A, apoptosis of BAL T-cells and expression of Bcl-2 in asthmatics

The late asthmatic reaction is characterised by elevated numbers of interleukin-4/interleukin-5/CD4-positive T-helper cells type 2 in bronchoalveolar lavage fluid (BALF). Cyclosporin A (CsA) is known to inhibit T-cell proliferation, induce apoptosis of CD4-positive T-cells and downregulate cytokine gene expression. It was assessed whether CsA-induced inhibition of the late asthmatic reaction was associated with apoptosis of BALF T-lymphocytes and other cell types, as well as expression of the antiapoptotic protein B-cell leukaemia/lymphoma 2 gene product (Bcl-2). BALF cells were obtained from asthmatics at baseline and 24 h after allergen-inhalation challenge following prior administration of CsA (n=13) or placebo (n=11). The number of apoptotic CD3-positive T-lymphocytes increased in the CsA but not the placebo group. The numbers of Bcl-2-positive cells were significantly reduced in the CsA but not the placebo group. The majority of Bcl-2-positive cells were CD3-positive T-lymphocytes. The beneficial effect of cyclosporin A in asthma may be related to its inhibitory effect on the late asthmatic reaction via induction of T-cell apoptosis and decreased B-cell leukaemia/lymphoma 2 gene product levels.

Production of gamma-linolenic acid by disrupted mycelia of Mortierella isabellina

AIMS

To optimize the production of linolenic acid by disrupted mycelia of Mortierella isabellina.

METHODS AND RESULTS

Effects of incubation conditions such as incubation time, pH of reaction mixture, concentration of Mg2+ or malate and incubation temperature on production of linolenic acid were studied. The production of gamma-linolenic acid reached 224 mg g-1 dry cells when the reaction mixture was composed of 1.0 g (dry mycelial mass) of disrupted mycelia of M. isabellina, 50 ml (50 mmol l(-1)) potassium phosphate buffer supplemented with 0.312 mmol l(-1) of Mg2+ and 10 mmol l(-1) of malate, pH 7.0 and incubated at 5 degrees C for 1 day.

CONCLUSIONS

Incubation temperature, concentration of Mg2+ and malate showed major effects on the increased linolenic acid production.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlights conditions for increasing gamma-linolenic acid production by cell-free mycelia of M. isabellina and an insight into rapidly gaining high production of polyunsaturated fatty acids.

Comparison of oxygen and sulfur effects on keto-enol chemistry in benzolactone systems: benzo[b]-2,3-dihydrofuran-2-one and -2-thione and benzo[b]-2,3-dihydrothiophene-2-one and -2-thione

Carbon-acid ionization constants, Q(K)(a)(concentration quotient at ionic strength = 0.10 M), were determined by spectrophotometric titration in aqueous solution for benzo[b]-2,3-dihydrofuran-2-one (3, pQ(K)(a) = 11.87), benzo[b]-2,3-dihydrothiophene-2-one (2, pQ(K)(a) = 8.85), and benzo[b]-2,3-dihydrofuran-2-thione (1, pQ(K)(a) = 2.81). Rates of approach to keto-enol equilibrium were also measured for the latter two substrates in perchloric acid, sodium hydroxide, and buffer solutions, and the rate profiles constructed from these data gave the ionization constants of the enols ionizing as oxygen or sulfur acids pQ(E)(a) = 5.23 for 2 and pQ(E)(a) = 2.69 for 1. Combination of these acidity constants with the carbon-acid ionization constants according to the relationship Q(K)(a)/Q(E)(a) = K(E) then gave the keto-enol equilibrium constants pK(E) = 3.62 for 2 and pK(E) = 0.12 for 1. The fourth, all-sulfur, member of this series, benzo[b]-2,3-dihydrothiophene-2-thione (4), proved to exist solely as the enol in aqueous solution, and only the enol ionization constant pQ(E)(a) = 3.44 could be determined for this substance; the limits pK(E) < 1.3 and pQ(K)(a) < 2.1, however, could be set. The unusually high acidities and enol contents of these substances are discussed, as are also the relative values of the ketonization and enolization rate constants measured; in the latter cases, Marcus rate theory is used to determine intrinsic kinetic reactivities, free of thermodynamic effects.

Elevated expression of interleukin-9 mRNA in the bronchial mucosa of atopic asthmatics and allergen-induced cutaneous late-phase reaction: relationships to eosinophils, mast cells and T lymphocytes

BACKGROUND

Interleukin-9 is a T cell-derived Th2-type cytokine that has been linked to airway hyper-responsiveness, mucus hypersecretion and mast cell infiltration in animal models. We recently demonstrated the potential for IL-9 to act in human eosinophil development and survival.

OBJECTIVES

The aims of this study were: (i) to compare IL-9 mRNA expression in bronchial biopsies between atopic asthmatics and normal controls, (ii) to investigate kinetic expression of IL-9 mRNA in skin biopsies after allergen challenge; and (iii) to relate IL-9 expression to infiltration of eosinophils, mast cell and T lymphocytes in local tissue.

METHODS

Bronchial biopsies were obtained from atopic asthmatics (n = 12) and normal non-asthmatics (n = 12) at baseline. Skin biopsies were obtained from atopic subjects (n = 11) at 1, 3, 6, 24, 48 and 72 h after allergen challenge. Diluent challenge sites at 24 h were used as controls. IL-9 mRNA was identified using the technique of in situ hybridization. The numbers of eosinophils, mast cells and T cells were evaluated by immunohistochemistry.

RESULTS

The numbers of IL-9 mRNA(+) cells present in the bronchial mucosa were significantly greater in atopic asthmatics than those in normal controls (P = 0.003). The numbers of eosinophils, but not mast cells, were also significantly higher in asthmatics (P < 0.005). The numbers of IL-9 mRNA(+) cells present in the airway of asthmatics significantly correlated with the numbers of eosinophils (r = 0.623, P = 0.03), but not mast cells or T cells. Compared with diluent challenge, the numbers of IL-9 mRNA(+) cells were significantly elevated at all allergen-challenged sites in the skin, with maximal signals at 48 h (P < 0.005). At 72 h, the numbers of IL-9 mRNA(+) cells significantly correlated with the numbers of eosinophils (r = 0.707, P = 0.015).

CONCLUSION

Elevated expression of IL-9 in allergic inflammation may contribute to local eosinophil infiltration and survival in asthma and other allergic atopic diseases.

Kinetics and mechanism of hydrolysis of 3-diazobenzofuran-2-one and its hydrolysis product (3-hydroxybenzofuran-2-one)

Rates of acid-catalyzed hydrolysis of 3-diazobenzofuran-2-one, measured in concentrated aqueous perchloric acid and hydrochloric acid solutions, were found to correlate well with the Cox–Yates Xo excess acidity function, giving kH+ = 1.66 × 10–4 M–1 s–1, m‡ = 0.86 and kH+ /kD+ = 2.04. The normal direction (kH/kD > 1) of this isotope effect indicates that hydrolysis occurs by rate-determining protonation of the substrate on its diazo-carbon atom. It was found previously that the next higher homolog of the present substrate, 4-diazoisochroman-3-one, also undergoes hydrolysis by this reaction mechanism but with a rate constant 15 times greater than that for the present substrate; this difference in reactivity can be understood in terms of the various resonance forms that contribute to the structures of these substrates. The product of the present hydrolysis reaction is 3-hydroxybenzofuran-2-one, which itself quickly undergoes subsequent acid-catalyzed hydrolysis to 2-hydroxymandelic acid. The acidity dependence of this subsequent hydrolysis is much shallower than that of the diazo compound precursor, and rates of reaction correlate as well with [H+] as with Xo. This is due in part to incursion of a nonproductive protonation on the hydroxy group of 3-hydroxy benzo furan-2-one that impedes hydrolysis and produces saturation of acid catalysis. Rates of hydrolysis of the hydroxy compound were also measured in dilute HClO4 and NaOH solutions as well as in CH3CO2H, H2PO4–, (CH2OH)3CNH3+, and NH4+ buffers, and the rate profile constructed from these data showed the presence of uncatalyzed and hydroxide ion-catalyzed reactions. This hydroxide-ion catalysis became saturated at [NaOH] [Formula: see text] 0.05 M, implying occurrence of yet another nonproductive substrate ionization. Key words: diazo compound hydrolysis, lactone hydrolysis, Cox–Yates excess acidity, acid catalysis, alcohol protonation.

Mutant BRCA1 genes antagonize phenotype of wild-type BRCA1

Unregulated expression of wild-type BRCA1 (wtBRCA1) confers an altered phenotype in cultured human prostate cancer cells, characterized by chemosensitivity, susceptibility to apoptosis, decreased DNA repair activity, and alterations of key cell regulatory proteins. We now report that the expression of truncated or mutant full-length BRCA1 genes can abrogate certain phenotypic characteristics and/or confer the opposite phenotype to the wild-type BRCA1 gene. In particular, several carboxyl-terminal truncated BRCA1 proteins conferred chemoresistance, decreased susceptibility to apoptosis, and decreased ability to suppress in vivo tumor growth. These truncated BRCA1 proteins also blocked the ability of ectopically expressed wtBRCA1 to induce chemosensitivity and to inhibit estrogen receptor transcriptional activity. Studies using epitope-tagged truncated proteins confirmed their expression, nuclear localization, and functionality. On the other hand, in cells with no endogenous wild-type BRCA1 (HCC1937 human breast cancer cells), the wtBRCA1 gene enhanced cellular DNA repair activity and rendered the cells resistant to DNA damage; while truncated BRCA1 proteins blocked the wtBRCA1-induced chemoresistance. Our findings suggest that truncated BRCA1 proteins can inhibit the function of wild-type BRCA1. They raise the possibility that some inherited BRCA1 mutations may actively promote oncogenesis by blocking the function of the remaining wild-type BRCA1 allele, although this hypothesis remains to be proved.

Interleukin-10 levels increase in cutaneous biopsies of patients undergoing wasp venom immunotherapy

We have studied the influence of wasp venom immunotherapy (VIT) on cellular recruitment and cytokine mRNA expression during allergen-induced cutaneous late-phase responses (LPR). Nine subjects with a history of wasp sting anaphylaxis, and specific IgE in their sera underwent wasp VIT. Skin biopsies were taken 24 h after intradermal diluent and allergen before and after 3 months VIT. Pre-immunotherapy, there were significant allergen-induced increases in EG2(+) eosinophils, elastase(+) neutrophils, CD68(+) macrophages and IL-10 protein(+) cells, and increased expression of mRNA for IL-4, IL-13, IFN-gamma, IL-12, IL-10, TGF-beta, RANTES and eotaxin. When these allergen-induced changes in cytokine mRNA and cellular profiles were compared with those obtained after 3 months VIT there was a significant reduction in IL-4 mRNA (p=0.012) and increase in IL-10 protein(+) cells (p=0.004) with a trend to an increase in IL-10 mRNA (p=0.054). There were also significant reductions in eosinophils (p<0.004) and the size of the cutaneous LPR (p<0.01) but no change in mRNA to IFN-gamma, IL-13 or IL-12. Therefore, VIT is associated with a significant increase in cells positive for IL-10 protein but not IL-12 or IFN-gamma. These results suggest that induction of IL-10 may be important in VIT and occur independently of the switch to a Th1 phenotype. IL-10 generation may down-regulate IL-4 expression and eosinophil recruitment.

Keto-enol/enolate equilibria in the isochroman-4-one system. Effect of a beta-oxygen substituent

The enol of 1-tetralone was generated flash photolytically, and rates of its ketonization were measured in aqueous HClO4 and NaOH solutions as well as in CH3CO2H, H2PO4(-), (CH2OH)3CNH3(+), and NH4(+) buffers. The enol of isochroman-4-one was also generated, by hydrolysis of its potassium salt and trimethylsilyl ether, and rates of its ketonization were measured in aqueous HClO4 and NaOH. Rates of enolization of the two ketones were measured as well. Combination of the enolization and ketonization data for isochroman-4-one gave the keto-enol equilibrium constant pK(E) = 5.26, the acidity constant of the enol ionizing as an oxygen acid p = 10.14, and the acidity constant of the ketone ionizing as a carbon acid p = 15.40. Comparison of these results with those for 1-tetralone shows that the beta-oxygen substituent in isochroman-4-one raises all three of these constants: K(E) by 2 orders of magnitude, by not quite 1 order of magnitude, and by nearly 3 orders of magnitude. The beta-oxygen substituent also retards the rate of hydronium-ion-catalyzed ketonization by more than 3 orders of magnitude. The origins of these substituent effects are discussed.

Macrophage inflammatory protein-1alpha and C-C chemokine receptor-1 in allergen-induced skin late-phase reactions: relationship to macrophages, neutrophils, basophils, eosinophils and T lymphocytes

BACKGROUND

Macrophage inflammatory protein (MIP)-1alpha binds to C-C chemokine receptor (CCR)-1 with high affinity. CCR-1 is expressed on neutrophils, eosinophils, monocytes, T lymphocytes and basophils; cells characteristic of atopic allergic inflammation. In vitro, MIP-1alpha is chemotactic for monocytes, T cells and basophils and is also a potent histamine-releasing factor for basophils and mast cells. Although increased levels of MIP-1alpha were shown in atopic allergic disorders, the kinetics of expression of these CC chemokines in vivo is largely unknown.

OBJECTIVE

To investigate the kinetics of expression of MIP-1alpha and receptor CCR-1 and the relationships between the expression and infiltration of inflammatory cells in allergen-induced cutaneous late-phase reactions in atopic subjects.

METHODS

Cryostat sections, obtained from skin biopsies from 10 human atopic subjects at 6, 24, 48, 72 h and 7 days after allergen challenge, were processed for immunohistochemistry and in situ hybridization using 35S-labelled riboprobes.

RESULTS

The peak expression of allergen-induced mRNA for MIP-1alpha and CCR-1 was 6 h. This was maintained at 24 h, and gradually returned to base line at 7 days. At 6 h, the number of cells expressing MIP-1alpha mRNA significantly correlated with elastase+ neutrophils and BB-1+ basophils. At 24 h, the MIP-1alpha mRNA+ cells significantly correlated with CD68+ macrophages. There were significant inverse correlations between the numbers of MIP-1alpha mRNA cells and the numbers of Tryptase+ mast cells at 6 and 24 h after allergen challenge.

CONCLUSION

Allergen-induced cutaneous late-phase reactions in humans were associated with increased expression of MIP-1alpha and CCR-1. This may be relevant to the infiltration of neutrophils, eosinophils, basophils and macrophages.

Regulation of transcription of the Bacillus subtilis pyrG gene, encoding cytidine triphosphate synthetase

The B. subtilis pyrG gene, which encodes CTP synthetase, is located far from the pyrimidine biosynthetic operon on the chromosome and is independently regulated. The pyrG promoter and 5' leader were fused to lacZ and integrated into the chromosomes of several B. subtilis strains having mutations in genes of pyrimidine biosynthesis and salvage. These mutations allowed the intracellular pools of cytidine and uridine nucleotides to be manipulated by the composition of the growth medium. These experiments indicated that pyrG expression is repressed by cytidine nucleotides but is largely independent of uridine nucleotides. The start of pyrG transcription was mapped by primer extension to a position 178 nucleotides upstream of the translation initiation codon. A factor-independent termination hairpin lying between the pyrG promoter and its coding region is essential for regulation of pyrG expression. Primer-extended transcripts were equally abundant in repressed and derepressed cells when the primer bound upstream of the terminator, but they were much less abundant in repressed cells when the primer bound downstream of the terminator. Furthermore, deletion of the terminator from pyrG-lacZ fusions integrated into the chromosome yielded elevated levels of expression that was not repressible by cytidine. We suggest that cytidine repression of pyrG expression is mediated by an antitermination mechanism in which antitermination by a putative trans-acting protein is reduced by elevated levels of cytidine nucleotides. Conservation of sequences and secondary structural elements in the pyrG 5' leaders of several other gram-positive bacteria indicates that their pyrG genes are regulated by a similar mechanism.

[CT and MRI and clinical study of chordoma in the skull base]

OBJECTIVE

To investigate the diagnostic features of CT and MRI in chordoma of the skull base (CSB) and to estimate their value of clinical application.

METHODS

Sixteen patients with CSB were performed CT and MRI examinations of the head, and 13 patients with nasopharyngeal carcinoma (NPC) and 11 patients with pituitary adenoma (PA) which invaded the skull base were selected as control. In addition, 7 cases of chordoma were performed multiple planar reconstruction (MPR) of MRI.

RESULTS

MRI was superior to CT in depicting the location and the extent of CSB. The bone destruction at mid-line skull base was demonstrated equally well on both CT and MRI. Based on the location of the tumor displayed on MRI, the CSB could be classified into selloclival, nasopharyngeal, and occipito-temperal types. The T2 weight imaging(T2WI) signal intensity of chordoma was significantly higher than those of NPC and PA (P < 0.01). On MPR images of MRI, oppressed and displaced optic nerves caused by chordoma were noted in 3 cases and encased optic nerves in 4 cases, encased abducent nerves in 7 cases with abducent paralysis and mildly oppressed oculomotor nerves in 3 cases.

CONCLUSION

The extremely high T2WI signal intensity is the characteristic of MRI finding in CSB and has great differential value for the tumors of the skull base. The MPR of MRI plays an important role in the surgical treatment for these tumors.

[Transposition of pedicled adrenal gland for the treatment of adrenal medullary hyperplasia]

OBJECTIVE

To investigate the operative modes for adrenal medullary hyperplasia.

METHODS

8 cases of adrenal medullary hyperplasia were treated with transposition of pedicled adrenal gland. The inferior and the medial blood vessel of adrenal gland were ligated. The superior blood vessel of adrenal gland was formed a 5.0- 6.0 cm pedicle and dragged to the subcutaneous of dorsum.

RESULT

After follow-up for an average of 2 years, only 1 of the 8 patients did not recover as a result of psychosis and others had no symptoms but normal endocrine results.

CONCLUSION

Transposition of the pedicled adrenal gland is a simple and satisfied way to treat patients with adrenal medullary hyperplasia.

Keto-enol/enolate equilibria in the N-acetylamino-p-methylacetophenone system. Effect of a beta-nitrogen substituent

The cis-enol of N-acetylamino-p-methylacetophenone was generated flash photolytically and its rates of ketonization in aqueous HClO(4) and NaOH solutions as well as in HCO(2)H, CH(3)CO(2)H, H(2)PO(4)(-), (CH(2)OH)(3)CNH(3)(+), and NH(4)(+) buffers were measured. Rates of enolization of N-acetylamino-p-methylacetophenone to the cis-enol were also measured by hydrogen exchange of its methylene protons, and combination of the enolization and ketonization data gave the keto-enol equilibrium constant pK(E) = 5.33, the acidity constant of the enol ionizing as an oxygen acid pQ(a)(E)= 9.12, and the acidity constant of the ketone ionizing as a carbon acid pQ(a)(K)= 14.45. Comparison of these results with corresponding values for p-methylacetophenone itself shows that the N-acetylamino substituent raises all three of these equilibrium constants: K(E) by 3 orders of magnitude, Q(a)(E) by 1 order of magnitude, and Q(a)(K)by 4 orders of magnitude. This substituent also retards the rate of H+ catalyzed enol ketonization by 4 orders of magnitude. The origins of these substituent effects are discussed.

Late asthmatic reactions provoked by intradermal injection of T-cell peptide epitopes are not associated with bronchial mucosal infiltration of eosinophils or T(H)2-type cells or with elevated concentrations of histamine or eicosanoids in bronchoalveolar fluid

BACKGROUND

Isolated late asthmatic reactions can be provoked by intradermal challenge of allergen-derived T-cell peptide epitopes.

OBJECTIVE

The purpose of this study was to determine whether the isolated LAR is associated with the local accumulation of inflammatory cells, the expression of T(H)2 cytokines, and the production of pharmacologic mediators.

METHODS

A randomized, placebo-controlled, crossover study design was used. The investigation involved bronchial and skin biopsies and bronchoalveolar lavage (BAL) fluids from 8 cat-allergic subjects who developed significant late asthmatic reactions 6 hours after intradermal injection of Fel d 1 chain 1-derived peptides (FC1Ps).

RESULTS

Immunostaining of bronchial biopsy specimens showed no changes in the numbers of eosinophils, neutrophils, basophils, mast cells, CD3(+), CD4(+) or CD8(+) T cells, CD25(+) cells or macrophages, or cells mRNA(+) for IL-4, IL-5, or IL-13 when the FC1P day was compared with the diluent control day. There were also no significant differences in eosinophil numbers, either in BAL fluids or in peripheral blood after FC1P challenge. Furthermore, there were no significant alterations in the concentrations of histamine, histamine-releasing factors, or eicosanoids (LTC(4)/D(4)/E(4), PGD(2), PGE(2), TXB(2), PGF(2alpha)) in BAL fluids. FC1Ps induced a significant (P <.05) elevation in CD8(+) cells in the skin and an unexpected decrease in IL-5 in BAL fluids (P =.043).

CONCLUSION

Part of the asthma process might involve T cell-dependent airway narrowing with no requirement for IgE, mast cells, or infiltrating inflammatory cells.

Disruption of BRCA1 LXCXE motif alters BRCA1 functional activity and regulation of RB family but not RB protein binding

The tumor suppressor activity of the BRCA1 gene product is due, in part, to functional interactions with other tumor suppressors, including p53 and the retinoblastoma (RB) protein. RB binding sites on BRCA1 were identified in the C-terminal BRCT domain (Yarden and Brody, 1999) and in the N-terminus (aa 304-394) (Aprelikova et al., 1999). The N-terminal site contains a consensus RB binding motif, LXCXE (aa 358-362), but the role of this motif in RB binding and BRCA1 functional activity is unclear. In both in vitro and in vivo assays, we found that the BRCA1:RB interaction does not require the BRCA1 LXCXE motif, nor does it require an intact A/B binding pocket of RB. In addition, nuclear co-localization of the endogenous BRCA1 and RB proteins was observed. Over-expression of wild-type BRCA1 (wtBRCA1) did not cause cell cycle arrest but did cause down-regulation of expression of RB, p107, p130, and other proteins (e.g., p300), associated with increased sensitivity to DNA-damaging agents. In contrast, expression of a full-length BRCA1 with an LXCXE inactivating mutation (LXCXE-->RXRXH) failed to down-regulate RB, blocked the down-regulation of RB by wtBRCA1, induced chemoresistance, and abrogated the ability of BRCA1 to mediate tumor growth suppression of DU-145 prostate cancer cells. wtBRCA1-induced chemosensitivity was partially reversed by expression of either Rb or p300 and fully reversed by co-expression of Rb plus p300. Our findings suggest that: (1) disruption of the LXCXE motif within the N-terminal RB binding region alters the biologic function of BRCA1; and (2) over-expression of BRCA1 inhibits the expression of RB and RB family (p107 and p130) proteins.

Automated multiplex assay system for simultaneous detection of hepatitis B virus DNA, hepatitis C virus RNA, and human immunodeficiency virus type 1 RNA

We have developed an automated multiplex system for simultaneously screening hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) in blood donations. The assay, designated AMPLINAT MPX HBV/HCV/HIV-1 Test (AMPLINAT MPX), consists of virus extraction and target sequence-specific probe capture on specimen preparation workstation GT-X (Roche Diagnostics K.K., Tokyo, Japan) and amplification and detection by TaqMan PCR on the ABI PRISM 7700 Analyzer (Perkin-Elmer Applied Biosystems, Foster City, Calif.). An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification, and detection processes. The assay yields qualitative results without discrimination of the three targets. Detection limits (95% confidence interval) are 22 to 60 copies/ml for HBV, 61 to 112 IU/ml for HCV, and 33 to 66 copies/ml for HIV-1, using a specimen input volume of 0.2 ml. The AMPLINAT MPX assay detects a broad range of genotypes or subtypes for all three viruses and has a specificity of 99.6% for all three viruses with seronegative specimens. In an evaluation of seroconversion panels, the AMPLINAT MPX assay detects HBV infection an average of 24 days before the detection of HBsAg by enzyme immunoassay. HCV RNA was detected an average of 31 days before HCV antibody. HIV-1 RNA was detected an average of 14 days before HIV-1 antibody and an average of 9 days before p24 antigen. The Japanese Red Cross has been evaluating the AMPLINAT MPX system since October 1999. The clinical performance indicates that the AMPLINAT MPX system is robust, sensitive, and reproducible, with a high percentage of valid assay runs (96.8%), a low false-positive rate (0.34%), and a low IC failure rate (0.24%).

The multisubstrate adapter Gab1 regulates hepatocyte growth factor (scatter factor)-c-Met signaling for cell survival and DNA repair

Hepatocyte growth factor (scatter factor) (HGF/SF) is a pleiotrophic mediator of epithelial cell motility, morphogenesis, angiogenesis, and tumorigenesis. HGF/SF protects cells against DNA damage by a pathway from its receptor c-Met to phosphatidylinositol 3-kinase (PI3K) to c-Akt, resulting in enhanced DNA repair and decreased apoptosis. We now show that protection against the DNA-damaging agent adriamycin (ADR; topoisomerase IIalpha inhibitor) requires the Grb2-binding site of c-Met, and overexpression of the Grb2-associated binder Gab1 (a multisubstrate adapter required for epithelial morphogenesis) inhibits the ability of HGF/SF to protect MDCK epithelial cells against ADR. In contrast to Gab1 and its homolog Gab2, overexpression of c-Cb1, another multisubstrate adapter that associates with c-Met, did not affect protection. Gab1 blocked the ability of HGF/SF to cause the sustained activation of c-Akt and c-Akt signaling (FKHR phosphorylation). The Gab1 inhibition of sustained c-Akt activation and of cell protection did not require the Gab1 pleckstrin homology or SHP2 phosphatase-binding domain but did require the PI3K-binding domain. HGF/SF protection of parental MDCK cells was blocked by wortmannin, expression of PTEN, and dominant negative mutants of p85 (regulatory subunit of PI3K), Akt, and Pak1; the protection of cells overexpressing Gab1 was restored by wild-type or activated mutants of p85, Akt, and Pak1. These findings suggest that the adapter Gab1 may redirect c-Met signaling through PI3K away from a c-Akt/Pak1 cell survival pathway.

Mutagenicity at the Hprt locus in T cells of female mice following inhalation exposures to low levels of 1,3-butadiene

A study was conducted to test the hypothesis that repeated low level exposures to 1,3-butadiene (BD), approaching the OSHA occupational threshold for this chemical, produce a significant mutagenic response in mice. Female B6C3F1 mice (4-5 weeks of age) were exposed by inhalation for 2 weeks (6 h/day, 5 days/week) to 0 or 3 ppm BD, and then necropsied at 4 weeks after the cessation of exposures to measure the frequency of mutations (MF) at the Hprt locus using the T-lymphocyte clonal assay. At necropsy, T cells were isolated from spleen and cultured in the presence of mitogen, growth factors, and a selection agent. Cells were scored for growth on days 8-9 after plating to determine cloning efficiencies (CEs) and Hprt MFs. There was a marginal but significant reduction in the growth of splenic T cells from mice exposed to 3 ppm (n=27) compared with control mice (n=24) (P=0.004), suggesting the occurrence of BD-induced cytotoxicity at this low exposure concentration. In addition, the average Hprt MF in mice exposed to 3 ppm BD [1.54+/-0.82 (S.D.)x10(-6)] was significantly increased by 1.6-fold over the average control value of 0.96+/-0.51 (S.D.)x10(-6) (P=0.004). Comparisons of these data to earlier Hprt mutagenicity studies of mice exposed to high concentrations of BD (where significant mutagenic but not cytotoxic effects were observed) indicate that the ability to detect the cytotoxic and mutagenic responses of T cells to low levels of BD was enhanced by using a much larger sample size than usual for both the control and treatment groups. Additional analyses of the quantitative relationships between CE and MF demonstrated that CE had no significant effect upon MF values in sham-exposed control mice or mice exposed to low-level BD. Furthermore, the approaches for assessing the impact of CE and clonality on Hprt MFs in these control and BD-exposed mice were applied with the same rigor as in in vivo Hprt mutagenicity studies in human children. The overall study results support the conclusion that short-term low-level BD exposure is mutagenic in the mouse.

[A study on the risk factors of cerebral infarction as complication of type 2 diabetes mellitu patients]

OBJECTIVE

Cerebral infarction, a common acute cereovascular disease, is one of the main complications of type 2 diabetes mellitus (DM). This paper is to explore the risk factors of cerebral infarction among type 2 DM patients.

METHODS

A pair-matched case-control study was carried out. Data was analyzed with conditional logistic regression.

RESULTS

One hundred and ten type 2 DM patients with cerebral infarction and controls were selected respectively. Results showed that higher educational level and physical exercises lowered the risk of cerebral infarction among type 2 DM patients. Higher HDL-C and blood sugar under control could also lower the risk of developing cerebral infarction among type 2 DM patients. The above factors seemed to have protective functions. Excessive salt intake and snoring increased the risks of cerebral infarction development among type 2 DM patients. Hypertension served as an independent risk factor while atrial fibrillation and hyperinsulinemia were important risk factors. High LDL-C, Apo-A, Lp(a), Fg increased the risk of cerebral infarction among type 2 DM patients. The study did not discover the relationship of smoking, drinking, oral contraception, menstrual and obstetrical history, TC, TG, Apo-A and cerebral infarction among type 2 DM patients.

CONCLUSION

To prevent cerebral infarction among type 2 DM, measures need to be taken as control of salt intake; eating more vegetables; regular physical exercises; control of blood sugar, blood pressure and Hyperinsulinemia.

[An inquiry into the relationship among pathology, clinic and laboratory indexes of the severe viral hepatitis]

OBJECTIVE

This study was to analyze the relationship among pathology, clinic and laboratory indexes in 62 cases of the acute severe hepatitis (ASH) and 72 cases of the subacute severe hepatitis(SSH) to offer a correct diagnosis and recognition of the disease.

METHODS

A total of 134 severe hepatitis cases with confirmed pathology treated in a course of 24 years were analyzed by programs of EXCEL 2000.

RESULTS

When compared ASH with SSH, the onset of the age were 40 +/- 13 years old and 44 +/- 15 years old, P < 0.05, the rates of hepatitis coma were 100% and 66.7% respectively. The liver weight of all the cases decreased. The tests of TBiL, PTA, Cho, NH3 and WBC between ASH and SSH had significant differences.

CONCLUSION

Hepatic encephalopathy is a necessary criterion for ASH. The TBiL, PTA and Cho changes are closely related with severe viral hepatitis, they not only are the essential laboratory indexes but also the indispensable factors for disease development and prognosis of severe viral hepatitis.

P53-independent downregulation of p73 in human cancer cells treated with Adriamycin

P73, a new p53 homologue, has been recently identified as a candidate tumor suppressor gene.

PURPOSE

We studied the alterations in p73 in a panel of human cancer cell lines treated with the chemotherapeutic agent, Adriamycin (ADR), in comparison with the changes in p53.

METHODS

P73 and p53 mRNA and protein were determined using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. ADR cytotoxicity was examined by a trypan blue dye exclusion assay.

RESULTS

The cell lines bearing wild-type p53 were more susceptible to ADR than the cell lines bearing mutant p53. ADR treatment resulted in a significant accumulation of p53 protein and mRNA expression in the wild-type p53 cell lines and caused little (slight increase) or no influence on p53 expression in the cell lines with p53 mutation and deletion. However, in striking contrast to the alterations in p53, a decline in p73 at both the protein and mRNA levels was observed in all the cell lines examined following ADR treatment. Further studies indicated that this p53-independent downregulation of p73 was induced by ADR in a dose- and time-dependent manner. Moreover, the p73 protein decline was abrogated by the presence of proteasome inhibitors.

CONCLUSIONS

Our findings revealed that although p73 shares a similar structural and functional composition with p53, there is a significant difference in the mechanisms that govern the responses of p53 and p73 to ADR-induced DNA damage.

Influence of chemically modified tetracyclines on proliferation, invasion and migration properties of MDA-MB-468 human breast cancer cells

Chemically modified tetracyclines (CMTs) are promising anti-cancer agents. In this study, we found that CMT-3 and CMT-8 showed dose-dependent cytotoxicities in MDA-MB-468 human breast cancer cells. Moreover, both CMT-3 and CMT-8 significantly inhibited in vitro cell migration and invasion at non-cytotoxic concentrations. Anti-invasion and migration potentials of the CMTs were associated with an increased expression of E-cadherin/catenins (alpha, beta and gamma-catenin) and tumor suppressor BRCA1. In addition, CMT-3 and CMT-8 abolished or reduced spontaneous and HGF/SF-induced cell invasion and migration in U-373 MG human glioblastoma cells. Our current finding is the first demonstration that CMT-3 and CMT-8 can activate the function of invasion suppressor molecules associated with the suppression of breast cancer cell invasion and migration. Thus, clinical application of CMTs may provide potential benefit for suppression of breast cancer growth, invasion and metastasis.

Identification of 10 novel snoRNA gene clusters from Arabidopsis thaliana

Ten novel small nucleolar RNA (snoRNA) gene clusters, consisting of two or three snoRNA genes, respectively, were identified from Arabidopsis thaliana. Twelve of the 25 snoRNA genes in these clusters are homologous to those of yeast and mammals according to the conserved antisense sequences that guide 2'-O-ribose methylation of rRNA. The remaining 13 snoRNA genes, including two 5.8S rRNA methylation guides, are new genes identified from A.thaliana. Interestingly, seven methylated nucleotides, predicted by novel snoRNAs Z41a-Z46, are methylated neither in yeast nor in vertebrates. Using primer extension at low dNTP concentration the six methylation sites were determined as expected. These snoRNAs were recognized as specific guides for 2'-O:-ribose methylation of plant rRNAs. Z42, however, did not guide the expected methylation of 25S rRNA in our assay. Thus, its function remains to be elucidated. The intergenic spacers of the gene clusters are rich in uridine (up to 40%) and most of them range in size from 35 to 100 nt. Lack of a conserved promoter element in each spacer and the determination of polycistronic transcription from a cluster by RT-PCR assay suggest that the snoRNAs encoded in the clusters are transcribed as a polycistron under an upstream promoter, and individual snoRNAs are released after processing of the precursor. Numerous snoRNA gene clusters identified from A.thaliana and other organisms suggest that the snoRNA gene cluster is an ancient gene organization existing abundantly in plants.

Local expression of epsilon germline gene transcripts and RNA for the epsilon heavy chain of IgE in the bronchial mucosa in atopic and nonatopic asthma

BACKGROUND

The demonstration of epsilon germline gene (Cepsilon) transcripts and mature mRNA for the epsilon heavy chain gene (Iepsilon) in the nasal mucosa suggested that IgE synthesis may occur in allergic rhinitis.

OBJECTIVE

In view of our previous demonstration of increases in IL-4 mRNA(+) cells in asthmatic subjects, we assessed whether local IgE synthesis may also be a feature of bronchial asthma.

METHODS

Fiberoptic bronchoscopic mucosa biopsy specimens were obtained from 9 atopic asthmatic subjects and 10 nonatopic normal (intrinsic) control subjects. To control for atopy, we also studied 9 nonatopic asthmatic subjects and 10 atopic nonasthmatic control subjects. Tissue was processed for immunohistochemistry for B cells (CD20) and in situ hybridization for Iepsilon and Cepsilon RNA(+) cells and IL-4 mRNA(+) cells.

RESULTS

B-cell numbers in the bronchial mucosa were similar for asthmatic subjects compared with control subjects, whereas significantly higher numbers of Iepsilon RNA(+) (P =.02 and P =.04, respectively), Cepsilon RNA(+) (P =.01 and P =.03, respectively), and IL-4 mRNA(+) (P =.001 and P =.001, respectively) cells were observed in atopic asthmatic subjects and nonatopic asthmatic subjects, respectively, but not in atopic control subjects compared with nonatopic control subjects. In asthmatic subjects there were significant correlations between Iepsilon RNA(+) cells (r = 0.54, P =.02) and Cepsilon RNA(+) cells (r = 0.48, P =.05) when compared with the number of IL-4 mRNA(+) cells.

CONCLUSION

Increases in Iepsilon and Cepsilon RNA(+) cells, but not B-cell numbers, in the bronchial mucosa provide evidence for local IgE synthesis in both atopic and nonatopic asthma. These changes appear to relate to asthma rather than atopy per se and, at least in part, may be under the regulation of IL-4.

Suppression of breast cancer invasion and migration by indole-3-carbinol: associated with up-regulation of BRCA1 and E-cadherin/catenin complexes

Indole-3-carbinol (I3C) is a compound occurring naturally in cruciferous vegetables and has been indicated as a promising agent in preventing breast cancer development and progression. In the present study we have investigated the effect of I3C on the cell migration and invasion behavior in estrogen receptor positive MCF-7 and estrogen receptor negative MDA-MB-468 human breast cancer cell lines. Both MCF-7 and MDA-MB-468 were poorly invasive cell lines and exhibited modest invasion and migration capacity in the presence of fibronectin as the chemoattractant. I3C (50 or 100 microM) elicited a significant inhibition of in vitro cell adhesion, migration, and invasion as well as in vivo lung metastasis formation in both cell lines. I3C also suppressed the 17beta-estradiol stimulated migration and invasion in estrogen-responsive MCF-7 cells. These results indicate that anti-invasion and antimigration activities of I3C occur via estrogen-independent and estrogen-dependent pathways. Moreover, I3C significantly caused a dose-dependent increase in E-cadherin, three major catenins (alpha, beta, and gamma-catenin) and BRCA1 expression. Our current finding is the first demonstration that I3C can activate the function of invasion suppressor molecules associated with the suppression of invasion and migration in breast cancer cells. Thus, clinical application of I3C may contribute to the potential benefit for suppression of breast cancer invasion and metastasis.

Constitutive activation of JAK-STAT3 signaling by BRCA1 in human prostate cancer cells

Germ-line mutations of the breast cancer susceptibility gene 1 (BRCA1) confer a high risk for breast and ovarian cancer in women and prostate cancer in men. The BRCA1 protein contributes to cell proliferation, cell cycle regulation, DNA repair and apoptosis; however, the mechanisms underlying these functions of BRCA1 remain largely unknown. Here, we showed that, in Du-145 human prostate cancer cells, enhanced expression of BRCA1 resulted in constitutive activation of signal transducer and activator transcription factor 3 (STAT3) tyrosine and serine phosphorylation. Moreover, Janus kinase 1 (JAK1) and JAK2, the upstream activators of STAT3, were also activated by BRCA1. Immunoprecipitation assay showed that BRCA1 interacted with JAK1 and JAK2. Blocking STAT3 activation using antisense oligonucleotides significantly inhibited cell proliferation and triggered apoptosis in Du-145 cells with enhanced expression of BRCA1. These findings indicate that BRCA1 interacts with the components of the JAK-STAT signaling cascade and modulates its activation, which may provide a new critical survival signal for the growth of breast, ovarian and prostate cancers in the presence of normal BRCA1.

Role of direct interaction in BRCA1 inhibition of estrogen receptor activity

The BRCA1 gene was previously found to inhibit the transcriptional activity of the estrogen receptor [ER-alpha] in human breast and prostate cancer cell lines. In this study, we found that breast cancer-associated mutations of BRCA1 abolish or reduce its ability to inhibit ER-alpha activity and that domains within the amino- and carboxyl-termini of the BRCA1 protein are required for the inhibition. BRCA1 inhibition of ER-alpha activity was demonstrated under conditions in which a BRCA1 transgene was transiently or stably over-expressed in cell lines with endogenous wild-type BRCA1 and in a breast cancer cell line that lacks endogenous functional BRCA1 (HCC1937). In addition, BRCA1 blocked the expression of two endogenous estrogen-regulated gene products in human breast cancer cells: pS2 and cathepsin D. The BRCA1 protein was found to associate with ER-alpha in vivo and to bind to ER-alpha in vitro, by an estrogen-independent interaction that mapped to the amino-terminal region of BRCA1 (ca. amino acid 1-300) and the conserved carboxyl-terminal activation function [AF-2] domain of ER-alpha. Furthermore, several truncated BRCA1 proteins containing the amino-terminal ER-alpha binding region blocked the ability of the full-length BRCA1 protein to inhibit ER-alpha activity. Our findings suggest that the amino-terminus of BRCA1 interacts with ER-alpha, while the carboxyl-terminus of BRCA1 may function as a transcriptional repression domain. Oncogene (2001) 20, 77 - 87.

Mechanisms of T cell peptide epitope-dependent late asthmatic reactions

Short peptide sequences corresponding to T cell epitopes have been identified in the major cat allergen Fel d 1. In order to directly activate allergen-specific T cells in cat-allergic asthmatic individuals, peptides were administered by intradermal injection. Subsequently, a proportion of subjects experienced a delayed reduction of airway calibre manifested as a decrease in FEV(1). Changes in lung function occurred approximately 3 h after peptide injection, peaked at 6 h and resembled an isolated late asthmatic reaction (LAR). Using molecular tissue typing techniques, it was determined that many of the individuals experiencing isolated LAR expressed particular HLA-DR molecules. These molecules were shown in subsequent experiments to bind individual peptides within the preparation and thus to activate T cells in a major histocompatibility complex (MHC)-restricted fashion. The precise mechanisms whereby MHC-restricted activation of allergen-specific T cells gives rise to bronchoconstriction are currently under investigation.

Comparing the services and quality of private and public clinics in rural China

After 15 years eradication of the private health sector in Socialist China, private practice was restored in 1980 along with the market oriented economic reform. In recent years, however, debates on its pros and cons are increasing. Arguments against private practice have led to a ban on private practice in some rural counties. The arguments against private practice state that the service quality of private clinics tends to be lower than that of public ones; private clinics are less likely to provide preventive care; and private clinics are more likely to provide over-treatment. This paper presents the major findings from a study conducted in China, aiming at comparing private and public village health clinics in terms of quality of services, willingness to provide preventive care and over-prescription of drugs. While it was found that the quality of services was poor and a large proportion of patient expenditure was due to over-treatment for all village clinics, there was no difference between public and private clinics. Both private and public clinics were willing to provide preventive services if they were subsidized for the provision. This study finds no evidence that care provided by private clinics is inferior to that of public clinics.

Indole-3-carbinol is a negative regulator of estrogen receptor-alpha signaling in human tumor cells

Estrogen, via its binding to the estrogen receptor (ER), plays an important role in breast cancer cell proliferation and tumor development. Indole-3-carbinol (I3C), a compound occurring naturally in cruciferous vegetables, exhibits a potent antitumor activity via its regulation of estrogen activity and metabolism. This study was designed to determine the effect of I3C on the potential to inhibit the ER-alpha. Using a reporter gene driven by the estrogen receptor, I3C (10-125 micromol/L) significantly repressed the 17ss-estradiol (E2)-activated ER-alpha signaling in a dose-dependent manner. I3C and breast cancer susceptibility gene 1 (BRCA1) synergistically inhibited transcriptional activity of ER-alpha. Moreover, I3C down-regulated the expression of the estrogen-responsive genes, pS2 and cathepsin-D, and up-regulated BRCA1. The inhibitory effects of I3C did not contribute to its cytotoxic effects because these activities were observed at less than toxic concentrations. These results further suggest that antitumor activities of I3C are associated not only with its regulation of estrogen activity and metabolism, but also its modulation of ER transcription activity.

[Study of relativity between HBV M and HBV DNA in the cases with hepatitis B]

OBJECTIVE

Serum samples of 414 cases with hepatitis B were detected for hepatitis B markers (HBV M) and HBV DNA, in order to investigation the relationship between HBV M and HBV DNA, and its clinical significant.

METHODS

HBV M and HBV DNA were detected by ELISA and blot hybridization methods respectively.

RESULTS

HBV DNA positive rates in the groups of acute and chronic hepatitis B were higher than that in the group of liver cirrhosis (P <0.01); HBV DNA positive rates had no apparent difference between the HBsAg, HBeAg, anti-HBc positive group and the HBsAg, anti-HBs, anti-HBc positive group. Direct relativity was shown between the titer of HBsAg and/or HBeAg and the positive rate of HBV DNA.

CONCLUSIONS

HBV DNA can be treated as a sign of HBV activity; the appearance of anti-HBs can not be taken as indicator of ceasing of HBV replication; the changes in HBsAg and HBeAg titers may be used as clinical evaluation on HBV replication and index for anti-viral therapeutic effect.

Zidovudine-didanosine coexposure potentiates DNA incorporation of zidovudine and mutagenesis in human cells

Drug combinations that include nucleoside reverse transcriptase inhibitors (NRTIs) are remarkably effective in preventing maternal-viral transmission of HIV during pregnancy. However, there may be potential long-term risks for children exposed in utero. Examination of the genotoxic and mutagenic effects of two NRTIs, zidovudine [AZT (3'-azido-3'-deoxythymidine)] and didanosine [ddI (2',3'-dideoxyinosine)], in cultured human lymphoblastoid cells revealed multiplicative synergistic enhancement of AZT-DNA incorporation and mutant frequency induction in response to the combined drug exposure, as compared with single-drug exposures. Dose-related increases in DNA incorporation of AZT (as measured by a competitive RIA) and mutagenicity at the HPRT and TK loci (as assessed by cell-cloning assays) were observed in cells exposed in culture to AZT, or equimolar combinations of AZT + ddI, at exposure concentrations ranging from 3 to 30 times the maximum plasma levels found in humans. Because mutagenesis is strongly associated with tumor induction in experimental models, children exposed transplacentally to combinations of NRTIs may be at risk for cancer development later in life.

Expression of eotaxin in induced sputum of atopic and nonatopic asthmatics

BACKGROUND

The chemokine eotaxin has been implicated in airway eosinophilia in atopic asthma. We have compared airway eosinophils and eotaxin expression in induced sputum from well-matched atopic and nonatopic asthmatics.

METHODS

Eosinophil numbers, eosinophil cationic protein (ECP), and the expression of eotaxin were examined in induced sputum from atopic asthmatics (AA = 11), nonatopic asthmatics (NAA = 11), and atopic (AC = 12) and normal (NC = 10) controls. Slides were prepared for differential cell counts by Romanowsky stain, and ECP levels were measured by RIA. Eotaxin expression was detected by in situ hybridization, with 35S-labelled riboprobes and immunocytochemistry.

RESULTS

The numbers of eosinophils and ECP concentration were increased in the sputum of AA and NAA compared with AC and NC (P < 0.05). The numbers of eotaxin mRNA+ and immunoreactive cells were increased in NAA, but not AA, when compared with controls (P < 0.05). Eotaxin immunoreactive cells in NAA were significantly higher than in AA (P < 0.05). Eotaxin was expressed predominantly by macrophages, eosinophils, and epithelial cells. In NAA, but not AA, the numbers of eotaxin mRNA+ cells were correlated with histamine PC20 (r = -0.81, P < 0.01) and eosinophil numbers in sputum (r = 0.7, P < 0.05).

CONCLUSIONS

Eotaxin production by macrophages, eosinophils, and epithelial cells may play a more pronounced role in airway eosinophilia in nonatopic than in atopic asthma.

Alcohol stimulates estrogen receptor signaling in human breast cancer cell lines

Epidemiological studies suggest that moderate alcohol consumption increases the risk of breast cancer, and that alcohol combined with estrogen replacement therapy may synergistically enhance the risk. However, the mechanism(s) of alcohol-induced mammary cancer is unknown. In human breast cancer cell lines, we found that ethanol (EtOH) caused a dose-dependent increase of up to 10- to 15-fold in the transcriptional activity of the liganded estrogen receptor (ER-alpha), but did not activate the nonliganded receptor. Significant stimulation of ER-alpha activity was observed at EtOH concentrations comparable with or less than blood alcohol levels associated with intoxication and at doses below the threshold for in vitro cytotoxicity. These findings may be explained, in part, by an EtOH-induced down-regulation of the expression of BRCA1, a potent inhibitor of ER-alpha activity, and, in part, by a modest increase in the ER-alpha levels. Our findings suggest that inactivation of BRCA1 and increased estrogen-responsiveness might contribute to alcohol-induced breast cancer.

TIMP-3 binds to sulfated glycosaminoglycans of the extracellular matrix

Of the four known tissue inhibitors of metalloproteinases (TIMPs), TIMP-3 is distinguished by its tighter binding to the extracellular matrix. The present results show that glycosaminoglycans such as heparin, heparan sulfate, chondroitin sulfates A, B, and C, and sulfated compounds such as suramin and pentosan efficiently extract TIMP-3 from the postpartum rat uterus. Enzymatic treatment by heparinase III or chondroitinase ABC also releases TIMP-3, but neither one alone gives complete release. Confocal microscopy shows colocalization of heparan sulfate and TIMP-3 in the endometrium subjacent to the lumen of the uterus. Immunostaining of TIMP-3 is lost upon digestion of tissue sections with heparinase III and chondroitinase ABC. The N-terminal domain of human TIMP-3 was expressed and found to bind to heparin with affinity similar to that of full-length mouse TIMP-3. The A and B beta-strands of the N-terminal domain of TIMP-3 contain two potential heparin-binding sequences rich in lysine and arginine; these strands should form a double track on the outer surface of TIMP-3. Synthetic peptides corresponding to segments of these two strands compete for heparin in the DNase II binding assay. TIMP-3 binding may be important for the cellular regulation of activity of the matrix metalloproteinases.

[N cycle of rubber-tea-chicken agro-forestry model in tropical area of China]

The N cycle of rubber-tea-chicken eco-agricultural model, a typical tropical agro-forestry system in Wenchang municipality of Hainan province, was studied with quantitative experiment and qualitative analysis, compared with rubber and rubeer-tea systems. The results showed that the N cycling rate, N output and soil surplus N of chicken garden were all the highest, being 43%; 196.5% kg.hm-2 and 237.6 kg.hm-2, respectively. The N output/input rate of chicken sub-system was 91%, and the transformation rate was very high. Compared with the other two systems, the chicken garden had a decreased external N input rate, and its internal cycling N was the highest, being 824.1 kg.hm-2. Rubber-tea-chicken agro-forestry system had a rational N cycling structure, and its N cycle was most active.

Macrophage subpopulations and macrophage-derived cytokines in sputum of atopic and nonatopic asthmatic subjects and atopic and normal control subjects

BACKGROUND

Previous studies have shown a prominent macrophage signal in the bronchial mucosa from nonatopic (intrinsic) compared with atopic (extrinsic) asthmatic subjects. This observation might have represented an expansion of a proinflammatory macrophage population or a homeostatic mechanism to decrease T(H)2-type inflammation.

OBJECTIVE

The aim of the study was to investigate the numbers of macrophages and macrophage subpopulations and the expression of IL-10 and IL-12 in sputum from asthmatic and control subjects.

METHODS

Eight atopic asthmatic (AA) subjects, 10 nonatopic asthmatic (NAA) subjects, 6 atopic control (AC) subjects, and 7 normal control (NC) subjects underwent sputum induction. Macrophages were enumerated by using Romanowsky stain and immunocytochemistry (CD68). RFD1 (interdigitating cell marker) and RFD7 (mature phagocyte marker) mAbs were used for immunocytochemical phenotyping, whereas IL-10 and IL-12 messenger (m)RNA was examined with in situ hybridization by using (35)S-labeled riboprobes. The phenotype of cells expressing IL-10 or IL-12 mRNA was examined by simultaneous in situ hybridization and immunostaining.

RESULTS

No differences in the numbers of CD68(+) macrophages and RFD1(+), RFD7(+), and RFD1(+)/RFD7(+) subpopulations were found between AA, NAA, AC, and NC subjects. However, the numbers of IL-10 and IL-12 mRNA(+) cells were increased in AA subjects compared with NAA, AC, and NC subjects (P <.05). No other differences were found among the groups. Most of the IL-10 and IL-12 mRNA(+) cells in sputum from asthmatic subjects were macrophages (>80%), with less than 10% of mRNA colocalizing to epithelial cells.

CONCLUSIONS

Sputum macrophage numbers, unlike tissue macrophages, as previously reported, were not elevated in NAA subjects. Increased IL-10 and IL-12 expression in atopic asthma may indicate the existence of a homeostatic mechanism to decrease lung inflammation. The lack of such cytokines in intrinsic asthma may predispose to bronchial inflammation in these subjects.