[Effect of ginkgo biloba extract and dipyridamole on transcription and translation of inducible NO synthbase in rabbits after myocardial ischemia-reperfusion injury]

OBJECTIVE

To investigate the effects of Egb761, an extract of ginkgo biloba , and dipyridamole on inducible NO synthase (iNOS) in rabbits after myocardial ischemia-reperfusion injury.

METHODS

After being established into ischemia-reperfusion injury model, 35 rabbits were divided randomly into 5 groups: Group A (the sham group), Group B (the model group), Group C (treated with dipyridamole 0.8 mg/kg), Group D (treated with Egb761, 40 mg/kg), and Group E (treated with Egb761 40 mg/kg combined with dipyridamole 0.8 mg/kg), all the medications were administered by intravenous injection 30 min after reperfusion. After administration, myocardial iNOS mRNA expression was detected by RT-PCR and western blot.

RESULTS

Myocardial iNOS mRNA transcriptive expression in the 5 groups were A 0, B 157.11 +/- 17.73, C 202.6 +/- 21.84, D 356.13 +/- 24.18 and E 562.34 +/- 35.19 respectively, showing significant difference between the treated groups and group B (P <0.01). The translative expression of myocardial iNOS in the 5 groups were A 34.24 +/- 15.78, B 75.70 +/- 13.71, C 116.89 +/- 22.57, D 143.75 +/- 16.05 and E 195.09 +/- 22.25 respectively, showing significant difference between the treated groups and group B as well (P < 0.05, P < 0.01).

CONCLUSION

Both Egb761 and dipyridamole could increase myocardial iNOS expression in transcriptive and translative levels in rabbits after myocardial ischemia-reperfusion injury, and the combined treatment of them shows a more significant effect.

The 44 kDa Pim-1 kinase directly interacts with tyrosine kinase Etk/BMX and protects human prostate cancer cells from apoptosis induced by chemotherapeutic drugs

Protein kinase Pim-1 has been implicated in the development of hematopoietic and prostatic malignancies. Here, we present the evidence that two isoforms, the 44 and 33 kDa Pim-1, are expressed in all human prostate cancer cell lines examined. The subcellular localization of human 44 kDa Pim-1 is primarily on the plasma membrane, while the 33 kDa isoform is present in both the cytosol and nucleus in PCA cells. The 44 kDa Pim-1 contains the proline-rich motif at the N-terminus and directly binds to the SH3 domain of tyrosine kinase Etk. Such interaction leads to the activation of Etk kinase activity possibly by competing with the tumor suppressor p53. This is corroborated by the fact that overexpression of the 44 kDa Pim-1 in prostate cancer cells confers the resistance to chemotherapeutic drugs. Our results suggest that these two isoforms of Pim-1 kinase may regulate distinct substrates and the 44 kDa Pim-1 may play a more prominent role in drug resistance in prostate cancer cells.

Association of asymptomatic oral candidal carriage, oral candidiasis and CD4+ lymphocyte count in HIV-positive patients in China

OBJECTIVES

To compare the prevalence of asymptomatic oral candidal carriage in healthy volunteers with human immunodeficiency virus (HIV)-positive patients in China, as well as to investigate the relationship between CD4+ lymphocyte count and oral candidal colonization or oral candidiasis.

METHODS

Oral candidal carriage and oral candidiasis were investigated in 101 patients with HIV-infection seen at Youan Hospital, Beijing, China. Two hundred and seventeen healthy volunteers were involved as a control. Culture from saliva was used to test for the presence of oral Candida. CD4+ lymphocyte count was measured by flow cytometry. All data were analyzed statistically by SAS.

RESULTS

Asymptomatic oral candidal carriage rate (28.6%) in HIV-positive group was similar to that in the healthy group (18.0%; P = 0.07). No significant difference in CD4+ lymphocyte count was found between oral Candida carriers and non-carriers among HIV-positive subjects (P = 0.89). However, the frequency of oral candidiasis increased with the decrease in CD4+ lymphocyte count (P < 0.0001), and pseudomembranous candidiasis was predominant in HIV-positive patients with CD4+ <200 cells microl(-1) (66.7%).

CONCLUSIONS

In HIV-positive subjects, asymptomatic oral candidal colonization is not related to CD4+ lymphocyte count of blood, and the carriage rate is similar to that in the healthy population. Oral candidiasis is more likely to be observed in HIV-positive patients who have a low CD4+ lymphocyte count.

Synthesis of A/B-Ring Partial Analogs of Bruceantin as Potential Antimalarial Agents

Bruceantin (1), a classical quassinoid with the highest reported antimalarial activity among the quassinoids examined thus far, was selected as a natural product lead for the design of a series of A/B-ring analogs. A viable strategy for the synthesis of the series was developed. The functionalized A-ring and the C-15 ester moiety in bruceantin are incorporated in all designed compounds. The preliminary bioassay results will be discussed in detail.

Biologically Active Quassinoids and Their Chemistry: Potential Leads for Drug Design

Quassinoids are highly oxygenated triterpenes, which were isolated as bitter principles from the plants of Simaroubaceae family. Their synthesis has attracted much attention because of the wide spectrum of their biological properties. The most prevalent quassinoids have C-20 picrasane skeleton, some known as bruceolides as they were isolated from the genus Brucea, which showed marked antileukemic and antimalarial activities.

Rapid effects of androgens in macrophages

We investigated the existence of membrane receptors for testosterone (mAR) in mouse macrophages of the cell lines IC-21 and RAW 264.7 as well as their roles in nongenomic pathways, gene expression and cell functioning. Both cell lines lack intracellular androgen receptors (iARs) and respond to testosterone with rapid rises in [Ca2+]i. These rises in [Ca2+]i can neither be inhibited by iAR- nor by iER blockers, but are rather mediated through mAR. Pharmacological approaches suggest that the mAR belongs to the class of membrane receptors which are coupled to phospholipase C via pertussis toxin (PTX) sensitive G-proteins. The mAR can be localized as specific surface binding sites for testosterone-BSA-FITC by confocal laser scanning microscopy (CLSM)and flow cytometry, and are characterized by their agonist-sequestrability. In order to examine a possible role of the testosterone-induced rise in [Ca2+]i on gene expression, a c-fos promoter reporter gene construct was transfected into RAW 264.7 macrophages. The increase in [Ca2+]i induced by testosterone cannot significantly activate the c-fos promoter directly. Also, no significant activation of ERK1/2, JNK/SAPK and p38 can be observed following testosterone-stimulation alone. However, testosterone-induced rises in [Ca2+]i do have specific effects on gene expression in context with lipopolysaccharide (LPS)-induced genotropic signaling: testosterone specifically down-regulates LPS-induced activation of c-fos promoter, p38 MAPK and NO production. In fetal calf serum (FCS)-induced genotropic signaling, the situation is reversed, i.e. testosterone augments the activation of c-fos promoter and ERK1/2. Our studies demonstrate a cross-talk between the testosterone-induced nongenomic Ca2+ signaling and the genotropic signaling induced by LPS and FCS in macrophages.

Cloning and characterization of the mouse Arht2 gene which encodes a putative atypical GTPase

ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.

Comments onSmall-angle neutron scattering analysis of the precipitation behaviour in a maraging steelby Staron, Jamnig, Leitner, Ebner & Clemens (2003)

Further to the paper by Staron, Jamnig, Leitner, Ebner & Clemens [J. Appl. Cryst.(2003),36, 415–419], the following points are made. Characterization of the precipitation process in maraging steels is difficult, primarily because the precipitates formed are on the nanometre scale. Identification of the precipitate type is complicated by the fact that its composition evolves during ageing, even when the precipitate type remains unchanged. Interpretation of experimental results should be treated with caution, especially when indirect methods, such as small-angle neutron scattering (SANS), are used. Atom-probe field ion microscopy (APFIM) has proved to be capable of determining the type and composition of the fine precipitates in maraging steels. The advantages and disadvantages of SANS and APFIM are briefly discussed.

Cbfa1/osf2 transduced bone marrow stromal cells facilitate bone formation in vitro and in vivo

It has been well established that core binding factor a-1/osteoblast-specific factor-2 (cbfa1/osf2) is a key regulator of osteoblast differentiation and function, however, it is not known whether it can induce bone formation in vitro and in vivo. To investigate the effect of cbfa1/osf2 on bone formation, we used a recombinant adenoviral vector carrying the mouse cbfa1/osf2 gene to transduce primary cultured bone marrow stromal cells (MSCs) of BALB/c mice. We found that Ad-cbfa1/osf2-transduced MSCs produced cbfa1/osf2 protein and differentiated into osteoblast-like cells. The transduced MSCs had increased alkaline phosphatase activity, increased expression of osteocalcin, osteopontin and bone sialoprotein, and increased matrix mineralization in vitro. To observe the induction of bone formation in vivo, MSCs transduced with Ad-cbfa1/osf2 were transplanted into a 5 mm diameter critical-sized skull defect in BALB/c mice, with type I collagen as scaffolding material. Healing of the defect in treatment and control groups was examined grossly and histologically at four weeks. Skull defects transplanted with Ad-cbfa1/osf2-transduced MSCs had an average of 85% osseous closure at four weeks. Control groups in which the defects were not treated (group 1), treated with collagen only (group 2), or treated with collagen and nontransduced MSCs (group 3) showed little or no osseous healing. These studies indicate that cbfa1/osf2 can induce osteoblast differentiation and bone formation both in vitro and in vivo, suggesting that MSCs transduced with the cbfa1/osf2 gene may be useful in treating bone defects.

Working with culture: a qualitative analysis of barriers to the recruitment of Chinese-American family caregivers for dementia research

The National Institutes of Health is making efforts to increase the representation of minority elders in aging research. While it is often noted that cultural barriers may make the recruitment of minority elders into research more difficult, relatively little empirical exists to support this claim. The purpose of this study was to identify sociocultural barriers to recruitment that emerged during a four-year study of dementia caregiving among Chinese families in the Boston area. More specifically, this paper examines how culturally shaped conceptions of health, aging, and dementia impacted the recruitment process. This paper is based on a qualitative analysis of interviews with 23 Chinese families and extensive fieldnotes generated by project ethnographers and interviewers. The following themes emerged in this analysis: 1) dementia-related changes were construed as a normal part of the aging process rather than a disease, making it more difficult to identify dementia-affected elders and to recruit families, 2) research participation was viewed as potentially harmful because it can lead to excessive worry 3) Alzheimer's disease carries a social stigma among Chinese, leading families to shun formal diagnosis and research participation, and 4) practitioners viewed research as an intrusion offering no direct benefit to participants.

Anemia during pregnancy in a Chinese population

OBJECTIVES

To study prevalence, risk factors, and birth outcomes of women with anemia during pregnancy in a Chinese population.

METHODS

A retrospective cohort study was performed based on 16936 pregnancies delivered between January 1989 and December 1990 in Suzhou, China. Anemia was defined as hemoglobin less than 10 g/dl. Multivariate logistic regression was used to estimate odds ratio, 95% confidence interval, and to control for confounding variables.

RESULTS

The prevalence of anemia was 10.3% at the first trimester, 18.9% at the third trimester. Overall, 26.2% pregnant women experienced anemia in pregnancy. Anemia during early pregnancy was not associated with increased risk of adverse perinatal outcomes. However, anemia in later pregnancy was inversely associated with preterm birth and low birth weight.

CONCLUSIONS

Anemia during pregnancy does not increase the risk of poor birth outcomes.

The inhibitory effect of VitD3 on proliferation of keratinocyte cell line HACAT is mediated by down-regulation of CXCR2 expression

Psoriasis is a disease characterized by inflammation and increased population of hyperproliferative keratinocytes. It is well known that chemokines and chemokine receptors, such as interleukin-8 and its receptors (CXCR1 and CXCR2), play important roles in the pathogenesis of psoriasis. So far, examination of CXCR2 expression in psoriatic lesional keratinocytes by FACS calibur has not been reported and whether VitD3 inhibits psoriatic lesional keratinocyte proliferation through down-regulation of CXCR2 expression has not been elucidated. In the present study, CXCR2 expression in psoriatic lesional keratinocytes and HACAT treated with VitD3 was detected by flow cytometry. The proliferative capacity of HACAT treated with VitD3 was assayed by MTT assay. The results showed that CXCR2 expression in psoriatic lesional keratinocytes was higher than that in normal human keratinocytes. At the correct concentration VitD3 could inhibit human keratinocyte proliferation and down-regulate CXCR2 expression in HACAT. The data demonstrate that the inhibitory effect of VitD3 on keratinocyte proliferation might be mediated by down-regulation of CXCR2 expression.

Overall mass transfer coefficient for pollutant emissions from small water pools under simulated indoor environmental conditions

Small chamber tests were conducted to experimentally determine the overall mass transfer coefficient for pollutant emissions from still aqueous solutions under simulated indoor (residential or occupational) environmental conditions. The tests covered six organic compounds with a Henry's constant range from 3.33 x 10(-7) to 3.67 x 10(-3) (atm m(3)/mol). The estimated overall liquid phase mass transfer coefficients for still solutions varied from 1.8 x 10(-6) to 5.7 x 10(-3) m/h; the estimated liquid phase mass transfer coefficients were 9.7 x 10(-3) m/h for the reference compound (oxygen) and 5.00 x 10(-3) to 6.04 x 10-(3) m/h for the test compounds. An empirical model is proposed to estimate the overall mass transfer coefficient, which can be used to predict pollutant emissions from still aqueous solutions (e.g. pools and puddles) in indoor environments.

Testosterone inhibits apoptosis of Leishmania donovani-infected macrophages

AIM

Investigate the effect of the male sex hormone, testosterone (Te), on apoptosis of bone marrow derived macrophages (BMMs) from female C57BL/6j mice

METHODS

Propidium iodide (PI) staining and transmission electron microscopy (TEM) techniques were used to investigate apoptosis specific-morphological changes. BMMs derived from Te-treated mice and Oil-treated mice were challenged with Leishmania donovani (L. d.), Oligo-nucleosomal DNA were extracted 24 h post infection to detect apoptosis.

RESULTS

The removal of M-CSF from the medium could induce BMM apoptofsis. And the DNA fragmentation assay also indicated that: 1. there was no difference in the amount of apoptotic cells between Te and Oil group; 2. Te + L. d. group had significantly less dead cells than Oil + L. d. group demonstrating that Te could prevent apoptosis of macrophage infected with L. d. to a greater extent.

CONCLUSION

Te inhibits apoptosis of the macrophages infected with L. d., however, this inhibition did not occur in the macrophages uninfected with L. d. Te-induced macrophage apoptosis-inhibition may play an important role in Te-induced immunosuppression.

[Cervical carcinoma progression-associated genetic alterations on chromosome 6]

To identify the loci associated with progression of cervical carcinoma, chromosome 6 regions were tested for loss of heterozygosity. Detailed analysis with 28 microsatellite markers revealed a high frequency of allelic deletions for several loci of the short (6p25, 6p22, 6p21.3) and long (6q14, 6q16-21, 6q23-24, 6q25, 6q27) arms of chromosome 6. Examination of 37 microdissected carcinoma and 22 cervical dysplasia specimens revealed allelic deletions from the HLA class I-III genes (6p22-21.3) and subtelomeric locus 6p25 were found in more than 40% dysplasia specimens. With multiple microdissection of cryosections, genetic heterogeneity of squamous cervical carcinoma was analyzed, and clonal and subclonal allelic deletions from chromosome 6 were identified. Half of the tumors had clonal allelic deletion of D6S273 (6p21.3), which is in a Ly6G6D (MEGT1) intron in the HLA class III gene locus. The frequency of allelic deletions from the chromosome 6 long arm was no more than 20% in dysplasias. Allelic deletions from two loci, 6q14 and 6q16-21, were for the first time associated with invasion and metastasis in cervical carcinoma.

A review of electrical impedance techniques for breast cancer detection

Some evidence has been found that malignant breast tumors have lower electrical impedance than surrounding normal tissues. Although the separation of malignant tumors from benign lesions based on impedance measurements needs further investigation, electrical impedance could be used as an indicator for breast cancer detection. In this paper, we provide a systematic technical review of the existing electrical impedance techniques proposed for breast cancer detection, with an emphasis on noninvasive impedance imaging techniques. The electrical impedance of human breast tissue is first introduced, with tabulation of previous in vitro impedance measurement results on cancerous and normal breast tissues, and a brief description on the limited in vivo impedance measurements completed with invasive, or noninvasive, non-imaging techniques. A detailed review on noninvasive impedance imaging techniques for breast cancer detection, such as electrical impedance tomography (EIT) and electrical impedance mapping (EIM), is then presented. We suggest that for better breast cancer detection, an invasive impedance technique may be enhanced by combination with other cancer indicators. 3D EIT should be improved through collective efforts. EIM using a pair of electrode arrays is a viable method with great potential. Magnetic induction tomography and other magnetic induction based impedance imaging for breast cancer detection are promising and merit further exploration as well.

Expression of pokeweed antiviral proteins in creeping bentgrass

Fungal diseases of creeping bentgrass, an important amenity grass used extensively on golf courses, are a serious problem in golf course management. Transgenic approaches to improving disease resistance to fungal diseases are being explored in many species, and in some cases ribosome-inactivating proteins have been found to be effective. We have generated transgenic creeping bentgrass plants expressing three forms of ribosome-inactivating proteins from pokeweed, which are termed pokeweed antiviral proteins (PAP). PAP-Y and PAP-C are nontoxic mutants of PAP; PAPII is the native form of another ribosome-inactivating protein from pokeweed. In creeping bentgrass, PAP-C transformants did not accumulate the protein, suggesting that it is unstable, and in a field test these plants were not protected from infection by the fungal pathogen Sclerotinia homoeocarpa, the causal agent of dollar spot disease. PAPII transformants could accumulate stable levels of the protein but had symptoms of toxicity; one low-expressing line exhibited good disease resistance. PAP-Y transformants accumulated stable levels of protein, and under greenhouse conditions they appeared to be phenotypically normal.