[Protective effects of organic acids on human vascular endothelial cells]

OBJECTIVES

In order to examine if organic acids (OA), a kind of natural food components, will prevent from atherosclerosis formation, the effects of four OA, namely chlorogenic acid (CHA), ascorbic acid (AA), citric acid (CA), and malic acid (MA) on human vascular endothelial cells were studied.

METHODS

Primary human umbilical vein endothelial cells (EC) were cultured, and the changes of cell morphology, cell growth, lactate dehydrogenase (LDH) released from cells were measured when EC was incubated with oxidized low density lipoprotein (oxLDL) in the presence or not of four OA added at three different conditions, i.e. before 4 hours oxLDL added, at the same time as oxLDL added, and after 3 hours oxLDL added, as well as at the indicated doses (10, 20 or 40 mg/L).

RESULTS

The EC survival rate of the oxLDL control group was lower (P < 0.01) and LDH release rate was higher (P < 0.01) than those of normal control group. CHA, AA, CA and MA protected EC from damage caused by oxLDL when they were added before and/or at the same time of oxLDL, but the same beneficial effects of these four OA added after oxLDL were not observed. The EC survival rates of CHA + oxLDL and AA + oxLDL groups in three doses were higher (P < 0.05) and the LDH release rates were lower (P < 0.05) in a dose-effect manner when compared with those of oxLDL control group, respectively. Similar results were found in the CA + oxLDL and MA + oxLDL of the high dose groups.

CONCLUSION

Four tested OA could effectively prevent EC from damage induced by oxLDL. CHA and AA had the strongest effects, the next was CA, followed by MA.

Role of chaperones in nuclear translocation and transactivation of steroid receptors

Molecular chaperones assist proteins to reach their mature and functional conformation. It has become apparent in recent years that chaperones function as part of a multiprotein heterocomplex that is potentially involved not only in protein folding, but also in intracellular trafficking and in targeting proteins for degradation. In the case of steroid receptors, the activity of the chaperone heterocomplex, as well as the proteins comprising the heterocomplex, has an effect on the observed ligand-dependent transcriptional activity of the receptor. The direct interaction between chaperones and steroid receptors makes them potential therapeutic targets in a number of pathologic conditions. In the case of cancers with steroid receptor involvement, such as breast and prostate cancer, the inhibition of chaperone activity may inhibit tumor cell growth. Conversely, enhancement of chaperone activity may be beneficial in disorders of protein misfolding, as in the case of androgen receptor aggregates found in Spinal and Bulbar Muscular Atrophy.

[Ultrasonic measurement of fetal liver length and its clinical significance]

OBJECTIVE

To establish the normal growth velocity of fetal liver length and compare them with those of intrauterine growth retardation, pregnant diabetes and maternal-fetal blood types imcompatible.

METHOD

Three hundred and five normal pregnant women and 24, 10, 16 pathological pregnant women of intrauterine growth retardation (IUGR), gestational diabetes and maternal-fetal blood types incompatible respectively had ultrasonographic measurement of fetal liver length at 18 to 42 weeks' gestation.

RESULTS

Normal fetal liver length has a linear relation to gestational age, and showed a significantly rapid increase after 28th week with a growth rate of 1.76 mm per week, and 1.00 mm per week before 28th week (P < 0.05). The growth rate of IUGR group before and after therapy were 1.19 mm and 1.23 mm per week, significantly lower than those of normal group (P < 0.05). The growth rate of pregnant diabetes group before and after therapy were 1.63 mm and 1.63 mm per week, no statistical significance with normal group (P > 0.05). The growth rate of maternal-fetal blood types incompatible group before therapy was 1.98 mm, showed no difference with normal group (P > 0.05), but after therapy, the growth rate of fetal liver was 1.38 mm per week, significantly lower than normal group (P < 0.05).

CONCLUSION

Dynamic measurement of fetal liver length can help us to understand whether the fetus grow well in uterus and whether the treatments are effective.

Greenhouse gas emissions during cattle feedlot manure composting

The emission of greenhouse gases (GHG) during feedlot manure composting reduces the agronomic value of the final compost and increases the greenhouse effect. A study was conducted to determine whether GHG emissions are affected by composting method. Feedlot cattle manure was composted with two aeration methods--passive (no turning) and active (turned six times). Carbon lost in the forms of CO2 and CH4 was 73.8 and 6.3 kg C Mg-1 manure for the passive aeration treatment and 168.0 and 8.1 kg C Mg-1 manure for the active treatment. The N loss in the form of N2O was 0.11 and 0.19 kg N Mg-1 manure for the passive and active treatments. Fuel consumption to turn and maintain the windrow added a further 4.4 kg C Mg-1 manure for the active aeration treatment. Since CH4 and N2O are 21 and 310 times more harmful than CO2 in their global warming effect, the total GHG emission expressed as CO2-C equivalent was 240.2 and 401.4 kg C Mg-1 manure for passive and active aeration. The lower emission associated with the passive treatment was mainly due to the incomplete decomposition of manure and a lower gas diffusion rate. In addition, turning affected N transformation and transport in the window profile, which contributed to higher N2O emissions for the active aeration treatment. Gas diffusion is an important factor controlling GHG emissions. Higher GHG concentrations in compost windrows do not necessarily mean higher production or emission rates.

Localization of androgen receptor expression in human bone marrow

Androgens have been shown to modulate the haematopoietic and immune systems and have been used clinically for stimulating haematopoiesis in bone marrow failure conditions. To identify the bone marrow cell types as potential targets of androgens, an androgen receptor (AR)-specific antibody was used to localize the AR in normal human bone marrow biopsies. The results show that AR was ubiquitously expressed in the bone marrow of both males and females. Furthermore, the AR expression pattern did not change with age. Stromal cells, macrophages, endothelial cells, myeloblasts, myelocytes, neutrophils, and megakaryocytes expressed AR. In contrast, AR was not detected in the lymphoid and erythroid cells, or in eosinophils. These results indicate that androgens may exert direct modulating effects on a wide spectrum of bone marrow cell types via AR-mediated responses.

Generation of full-length cDNA libraries enriched for differentially expressed genes for functional genomics

Here, we describe the application of a RecA-based cloning technology to generate full-length cDNA libraries enriched for genes that are differentially expressed between tumor and normal tissue samples. First, we show that the RecA-based method can be used to enrich cDNA libraries for several target genes in a single reaction. Then, we demonstrate that this method can be extended to enrich a cDNA library for many full-length cDNA clones using fragments derived from a subtracted cDNA population. The results of these studies show that this RecA-mediated cloning technology can be used to convert subtracted cDNAs or a mixture of several cDNA fragments corresponding to differentially expressed genes into a full-length library in a single reaction. This procedure yields a population of expression-ready clones that can be used for further high-throughput functional screening.

Epidemic keratoconjunctivitis caused by a new genotype of adenovirus type 8 (Ad8)-a chronological review of Ad8 in Southern Taiwan

PURPOSE

To understand the pathogenic evolution of viral keratoconjunctivitis in Kaohsiung, Taiwan, a retrospective molecular and clinical analysis was conducted.

METHODS

From January 1990 to December 1994, conjunctival swab samples from patients suspected of having viral conjunctivitis were collected for viral culture isolation, neutralization test (NT), and endonuclease cleavage analysis. Six restriction endonucleases, comprising HindIII, BamHI, SalI, SstI, SmaI, and PstI, were used for cleavage. Clinical examinations of patients were performed by two senior ophthalmologists.

RESULTS

Twenty-one cases of a new genotype of adenovirus (Ad) type 8, designated as Ad8H, were discovered in the 27 detected adenovirus cases. The Ad8H has a distinct cleavage pattern, especially by HindIII and SalI. The Ad8H keratoconjunctivitis induced more subconjunctival hemorrhage (33.3%), keratitis (33.3%), and lymphadenopathy (85.7%) than other genotypes of Ad8 previously isolated in Kaohsiung, Taiwan.

CONCLUSION

We have discovered a new genotype, Ad8H, which was prevalent as the main pathogen of the adenoviral keratoconjunctivitis in Kaohsiung, Taiwan from 1990 to 1994. Adenovirus type 8 is evolving into more genotypes with a trend towards more severe symptoms, including subconjunctival hemorrhage, keratitis, and lymphadenopathy.

Apoptosis and Fas-ligand expression correlate to the histopathological grade of gastric smooth muscle tumors

BACKGROUND

Apoptosis is associated with the tumor grade in various types of carcinomas or lymphomas, but less is understood about the association of apoptosis in mesenchymal tumors. In the prior studies, expression of apoptotic regulatory proteins, Bcl-2, Fas and its ligand, Fas-ligand, has been related to apoptotic index (AI) and histopathological grade of tumors. Our study investigated the incidence of apoptosis in gastric smooth muscle tumor and the correlation of the apoptotic index (AI) with the histopathological grade of the tumors. We evaluated the relationship of apoptotic regulatory proteins to the AI and tumor grade.

METHODS AND MATERIALS

Using immunohistochemistry and the terminal deoxynucleotidyl transferase (TdT)-mediated digoxigenin-dUTP nick end-labeling (TUNEL) assay, we analyzed the expression of Bcl-2, Fas, Fas-ligand, and AI in 26 cases of gastric smooth muscle tumors.

RESULTS

The incidence of greater than 10 apoptotic cells per 10 high-power fields (HPFs) was 73% (19/26 cases). The AI was significantly associated with malignant tumors (P = 0.006) and mitotic counts (P = 0.006) but not with tumor size. Bcl-2, Fas, and Fas-ligand were detected in 13 (50%), 14 (53.8%), and 19 (73%) cases, respectively. Interestingly, Fas-ligand was significantly correlated to malignancy (P = 0.006), mitotic counts (P = 0.006), and AI (P = 0.035) but not to tumor size. Fas expression was significantly associated with high levels of AI (P = 0.014). In contrast, Bcl-2 expression was inversely associated with AI (P = 0.004). Expression of Bcl-2 and Fas did not show a statistically significant correlation with tumor grade, mitotic counts, or tumor size.

CONCLUSION

Apoptosis and Fas-ligand expression are statistically correlated to the histopathological grade of gastric smooth muscle tumors. This suggests that detection of apoptotic cells and Fas-ligand expression using the TUNEL assay or immunohistochemistry are useful for the evaluation of the malignant potential of gastric smooth muscle tumors.

Ministernotomy versus full sternotomy in congenital heart defects: a prospective randomized study

BACKGROUND

Although the ministernotomy is extensively used in the repair of congenital heart defects all over the world, whether this approach has additional advantages over the conventional full sternotomy is not well established. This prospective study was designed to evaluate the effects of lower ministernotomy in the repair of congenital heart defects.

METHODS

One hundred patients who underwent repair of atrial or ventricular septal defects were randomly divided into two groups: lower ministernotomy group (n = 50), and full sternotomy group (n = 50). The clinical indexes of each procedure were recorded and analyzed.

RESULTS

The age, sex, and types of cardiac defects were comparable between the two groups. Ischemic times, bypass times, intensive care unit stay, and ventilation duration were similar in both groups. The procedure time (from skin to skin) was longer in the lower ministernotomy group than in the full sternotomy group (p < 0.001). There was less drainage in the lower ministernotomy group than in the full sternotomy group for the first 24 hours after operation (186 +/- 99 mL/m2 versus 237 +/- 134 mL/m2, p = 0.03) but no significant difference in transfusions between the two groups. The hospital stay was shorter in the lower ministernotomy group than in the full sternotomy group (6.5 +/- 1.2 days versus 7.5 +/- 1.8 days, p = 0.02).

CONCLUSIONS

Ministernotomy is as safe and effective as a full sternotomy in the repair of simple congenital heart defects in older children and adults. Furthermore, this small incision reduces the postoperative drainage, shortens hospital stay, and provides better cosmetic results. Operative times are longer.

Reproducibility of hippocampal single-Voxel proton MR spectroscopy and chemical shift imaging

OBJECTIVE

We investigated between- and within-acquisition reproducibility of hippocampal metabolite ratios obtained using automated proton MR spectroscopy.

SUBJECTS AND METHODS

We examined 30 healthy adults with a 1.5-T scanner four times on 3 days using single-voxel spectroscopy over the left hippocampus, chemical shift imaging over the left hippocampus, and chemical shift imaging over the bilateral hippocampi. Metabolite ratios were derived from the integral values of three major peaks: N:-acetylaspartate (NAA), choline-containing compounds (Cho), and creatine plus phosphocreatine (Cr). The random-effects model of one-way analysis of variance was used to evaluate the reproducibility in terms of coefficient of variation; the mixed-effects model was used to compare the results of different hippocampal regions and spectroscopic techniques.

RESULTS

Most coefficients of variation for the NAA/(Cho+Cr) ratio were less than 20%. All the coefficients of variation for the posterior hippocampus (15-25%) were less than those for the anterior hippocampus (20-44%). The posterior hippocampal NAA/(Cho+Cr) ratio of unilateral chemical shift imaging had the lowest coefficient of variation (<16%). Single-voxel spectroscopy and unilateral chemical shift imaging had similar coefficients of variation for the anterior hippocampal NAA/(Cho+Cr) ratios (17-20%). There was a significant difference in metabolite ratios measured in different hippocampal regions (p<0.01) and in those acquired with different spectroscopic techniques (p<0.001).

CONCLUSION

The NAA/(Cho+Cr) ratio is the most reproducible parameter for hippocampal MR spectroscopy on a 1.5-T scanner. Regional variation and technical differences in metabolite ratios must be considered when interpreting proton spectra of the hippocampus.

The Arabidopsis eer1 mutant has enhanced ethylene responses in the hypocotyl and stem

By screening for enhanced ethylene-response (eer) mutants in Arabidopsis, we isolated a novel recessive mutant, eer1, which displays increased ethylene sensitivity in the hypocotyl and stem. Dark-grown eer1 seedlings have short and thick hypocotyls even in the absence of added ethylene. This phenotype is suppressed, however, by the ethylene biosynthesis inhibitor 1-aminoethoxyvinyl-glycine. Following ethylene treatment, the dark-grown eer1 hypocotyl response is greatly exaggerated in comparison with the wild type, indicating that the eer1 phenotype is not simply due to ethylene overproduction. eer1 seedlings have significantly elevated levels of basic-chitinase expression, suggesting that eer1 may be highly sensitive to low levels of endogenous ethylene. Adult eer1 plants display exaggerated ethylene-dependent stem thickening, which is an ethylene response previously unreported in Arabidopsis. eer1 also has enhanced responsiveness to the ethylene agonists propylene and 2,5-norbornadiene. The eer1 phenotype is completely suppressed by the ethylene-insensitive mutation etr1-1, and is additive with the constitutive ethylene-response mutation ctr1-3. Our findings suggest that the wild-type EER1 product acts to oppose ethylene responses in the hypocotyl and stem.

[The evaluation of fetal cardiac function in diabetic pregnancies]

OBJECTIVE

To assess fetal cardiac hypertrophy and ventricular function in fetuses of diabetic mothers.

METHODS

Study group was consist of 23 fetuses of diabetic pregnancies. Control group was consist of 108 fetuses of normal pregnancies. Cardiac size was measured by ultrasound as inter-ventricular septal (IVS) thickness and ventricular diastolic and systolic (VD and VS) dimensions and perimeter. Cardiac function was expressed as ventricular shortening fraction 1 (VSF1) (ventricular diastolic perimeter-ventricular systolic perimeter/ventricular diastolic perimeter) and ventricular shortening fraction 2 (VSF2) (ventricular diastolic dimension-Ventricular systolic dimension/ventricular diastolic dimension). Fetal birth weight was recorded.

RESULTS

IVS of study group (6.1 +/- 0.7) mm, which was significantly thicker than IVS of control group (4.4 +/- 0.7) mm. Left ventricular diastolic dimension (LVDD) and Left ventricular systolic dimension (LVSD) of study group were (3.3 +/- 0.8) cm2 and (2.2 +/- 0.6) cm2, which were greater than those of control group (2.6 +/- 0.6) cm2 and (2.0 +/- 0.5) cm2. Right ventricular diastolic dimension (RVDD) and Right ventricular systolic dimension (RVSD) of study group were (3.9 +/- 0.7) cm2 and (2.6 +/- 0.7) cm2, which were also greater than those of control group (3.5 +/- 0.5) cm2 and (2.4 +/- 0.7) cm2. Left ventricular shortening fraction 1 of left ventricular (LVSF1) of study group was 0.20 +/- 0.07, which was greater than that of control group (0.12 +/- 0.04). LVSF2 of study group was 0.35 +/- 0.11, which was greater than that of control group too (0.23 +/- 0.10). Right ventricular shortening fraction 1 of left ventricular (RVSF1) of study group was 0.19 +/- 0.05, which was greater than that of control group (0.13 +/- 0.11). RVSF2 of study group was 0.33 +/- 0.09, which was greater than that of control group (0.23 +/- 0.14). Estimated fetal birth weight of study group was (4,076 +/- 608) g, which was greater than that of control group (3,440 +/- 377) g.

CONCLUSION

These findings showed that fetal hyperinsulinemia result in fetal weight increasing, global cardiac enlarger inter-ventricular septal thickness larger and revealed hypercontractilty of ventricle in fetuses of diabetes mothers.

Regulation of Smad degradation and activity by Smurf2, an E3 ubiquitin ligase

Smad proteins are key intracellular signaling effectors for the transforming growth factor-beta superfamily of peptide growth factors. Following receptor-induced activation, Smads move into the nucleus to activate transcription of a select set of target genes. The activity of Smad proteins must be tightly regulated to exert the biological effects of different ligands in a timely manner. Here, we report the identification of Smurf2, a new member of the Hect family of E3 ubiquitin ligases. Smurf2 selectively interacts with receptor-regulated Smads and preferentially targets Smad1 for ubiquitination and proteasome-mediated degradation. At higher expression levels, Smurf2 also decreases the protein levels of Smad2, but not Smad3. In Xenopus embryos, ectopic Smurf2 expression specifically inhibits Smad1 responses and thereby affects embryonic patterning by bone morphogenetic protein signals. These findings suggest that Smurf2 may regulate the competence of a cell to respond to transforming growth factor-beta/bone morphogenetic protein signaling through a distinct degradation pathway that is similar to, yet independent of, Smurf1.

Donor origin of neuroendocrine carcinoma in 2 transplant patients determined by molecular cytogenetics

Organ transplant recipients have an increased tumor incidence owing to their immunocompromised state. The origin of such tumors, whether donor or recipient, will have a clinical impact on decision-making concerning immunosuppressive therapy, retransplantation, and for recipients of other organs from the same donors. We report molecular cytogenetic determination of donor origin in 2 cases of small-cell neuroendocrine carcinoma developing in sex-mismatched transplant recipients (kidney and liver). Fluorescence in situ hybridization (FISH) analysis was performed on liver core needle biopsy material from the liver transplant patient and on liver fine needle aspiration cytopreparations from the kidney transplant patient. The results for the liver transplant patient were confirmed with microsatellite allelic analysis and with comparative genomic hybridization. In both cases, FISH showed the presence of only X chromosomes within the tumor cells, indicating the donor origin of the neoplasms. FISH is an excellent method to determine neoplastic origin in sex-mismatched transplant patients. HUM PATHOL 31:1425-1429.

Phosphorus accumulation in cultivated soils from long-term annual applications of cattle feedlot manure

Historically, manure has been recognized as an excellent soil amendment that can improve soil quality and provide nutrients for crop production. In areas of high animal density, however, the potential for water pollution resulting from improper storage or disposal of manure may be significant. The objective of this study was to determine the P balance of cultivated soils under barley (Hordeum vulgare L.) production that have received long-term annual manure amendments. Nonirrigated soils at the study site in Lethbridge, AB, Canada, have received 0, 30, 60, or 90 Mg manure ha(-1) (wet wt. basis) while irrigated plots received 0, 60, 120, and 180 Mg ha(-1) annually for 16 yr. The amount of P removed in barley grain and straw during the 16-yr period was between 5 and 18% of the cumulative manure P applied. There was a balance between P applied in manure and P recovered in crops and soils (to the 150-cm depth) of nonirrigated plots during the 16-yr study. In irrigated plots, as much as 1.4 Mg P ha(-1) added (180 Mg ha(-1) yr(-1) treatment) was not recovered over 16 yr, and was probably lost through leaching. The risk of ground water contamination with P from manure was greater in irrigated than nonirrigated plots that have received long-term annual manure amendments. Manure application rates should be reduced in nonirrigated and irrigated plots to more closely match manure P inputs to crop P requirements.

Quercetin cumulatively enhances copper induction of metallothionein in intestinal cells

Wilson's disease, a genetic copper-overload condition, is currently treated with zinc because of the ability of zinc to induce metallothionein. We are interested in nonmetal chemicals that may alter intestinal copper metabolism and thus help to alleviate copper toxicity. Previously, we have shown that quercetin, a dietary flavonoid, can chelate copper. This study further examined the interaction of quercetin and copper in intestinal epithelial cells. We found that quercetin enhanced metallothoinein induction by copper and the effect was dose dependent. Quercetin also exerted a cumulative effect after repeated exposure. Repeated low-dose treatment (3-10 microM) of cells with quercetin can lead to the same effect on metallothoinein as one higher concentration treatment (100 microM). This property of quercetin is distinct from its chemical interaction with copper, but both can contribute to a reduction of copper toxicity. Among other flavonoids tested, two other copper chelators, catechin and rutin, did not increase copper induction of metallothionein, whereas genistein, an isoflavone that does not interact with copper chemically, increased copper induction of metallothionein. The effect of quercetin on copper metabolism is unique. Quercetin decreased zinc-stimulated metallothionein expression and had no effect on the cadmium induction of metallothionein. The clinical application of our observation needs to be explored.

Anti-hepatitis B virus effects of wogonin isolated from Scutellaria baicalensis

By using an HBV-producing cell line (MS-G2) in vitro culture system, we found that wogonin isolated from Scutellaria baicalensis can suppress HBV surface antigen production (P < 0.001) without evidence of cytotoxicity. By assaying the endogenous HBV DNA polymerase activity, we found that both the relaxed circular and the linear forms of HBV DNA are significantly reduced in the wogonin-treated group. Wogonin deserves to be further evaluated for the treatment of human HBV infection.

Functional analysis of androgen receptor N-terminal and ligand binding domain interacting coregulators in prostate cancer

Several new androgen receptor (AR) coregulators, including ARA70, ARA55, ARA54, ARA160 and ARA24, associated with the N-terminal or the ligand-binding domain (LBD) of AR, have been identified by our group. We first identified the AR-LBD coregulators ARA70, ARA55, and ARA54. Our previous reports suggest that ARA70 can enhance the androgenic activity of 17 beta-estradiol (E2) and antiandrogens toward AR. It is of interest to compare and determine if the specificity of sex hormones and antiandrogens can be modulated by different coregulators. Our results indicate that, ARA70 is the best coregulator for increasing the androgenic activity of E2. Only ARA70 and ARA55 were able to significantly increase the androgenic activity of hydroxyflutamide, the active metabolite of a widely-used antiandrogen for the treatment of prostate cancer. Furthermore, our results suggest that among the LBD coregulators, ARA70 has a relatively high specificity for AR in the human prostate cancer cell line DU145. Together, our data suggest that the androgenic activity of some sex hormones and antiandrogens can be modulated by selective AR coactivators. In addition to the AR-LBD associated proteins, ARA24 and ARA160 have been identified as AR coregulators, interacting with the AR N-terminal instead of the LBD. Functional analysis revealed that the AR N-terminal coregulator ARA160 could cooperate with the AR LBD-associated coregulator ARA70. Our data indicate that ARA24 could also interact with AR, and that this binding is decreased by an expanding poly-glutamine (Q) length within AR. The length of the poly-Q stretch in the AR N-terminal domain is inversely correlated with the transcriptional activity of AR. Our data suggest that optimal AR transactivation may require interaction of AR with AR coregulators. The identification of factors or peptides that can interrupt androgen-mediated AR-ARA interactions may be useful in the development of better antiandrogens for treating androgen-related diseases, such as prostate cancer.

Nucleoside diphosphate kinase from the hyperthermophilic archaeon Methanococcus jannaschii: overexpression, crystallization and preliminary X-ray crystallographic analysis

Nucleoside diphosphate (NDP) kinase is a key enzyme in maintaining cellular pools of all nucleoside triphosphates. NDP kinase from the hyperthermophilic archaebacterium Methanococcus jannaschii has been overexpressed in Escherichia coli and crystallized at 297 K using polyethylene glycol 4000 as precipitant. The crystal is hexagonal, belonging to the space group P6(3), with unit-cell parameters a = b = 72.89, c = 100.87 A. The asymmetric unit contains two subunits of NDP kinase, with a corresponding crystal volume per protein mass (V(M)) of 2.38 A(3) Da(-1) and a solvent content of 48.3%. Native X-ray diffraction data to 2.30 A resolution have been collected using synchrotron X-rays.

Requirements of multiple domains of SLI-1, a Caenorhabditis elegans homologue of c-Cbl, and an inhibitory tyrosine in LET-23 in regulating vulval differentiation

SLI-1, a Caenorhabditis elegans homologue of the proto-oncogene product c-Cbl, is a negative regulator of LET-23-mediated vulval differentiation. Lack of SLI-1 activity can compensate for decreased function of the LET-23 epidermal growth factor receptor, the SEM-5 adaptor, but not the LET-60 RAS, suggesting that SLI-1 acts before RAS activation. SLI-1 and c-Cbl comprise an N-terminal region (termed SLI-1:N/Cbl-N, containing a four-helix bundle, an EF hand calcium-binding domain, and a divergent SH2 domain) followed by a RING finger domain and a proline-rich C-terminus. In a transgenic functional assay, the proline-rich C-terminal domain is not essential for sli-1(+) function. A protein lacking the SH2 and RING finger domains has no activity, but a chimeric protein with the SH2 and RING finger domains of SLI-1 replaced by the equivalent domains of c-Cbl has activity. The RING finger domain of c-Cbl has been shown recently to enhance ubiquitination of active RTKs by acting as an E3 ubiquitin-protein ligase. We find that the RING finger domain of SLI-1 is partially dispensable. Further, we identify an inhibitory tyrosine of LET-23 requiring sli-1(+) for its effects: removal of this tyrosine closely mimics the loss of sli-1 but not of another negative regulator, ark-1. Thus, we suggest that this inhibitory tyrosine mediates its effects through SLI-1, which in turn inhibits signaling upstream of LET-60 RAS in a manner not wholly dependent on the ubiquitin-ligase domain.

Increase of androgen-induced cell death and androgen receptor transactivation by BRCA1 in prostate cancer cells

Although mutations of the breast cancer susceptibility gene 1 (BRCA1) may play important roles in breast and prostate cancers, the detailed mechanism linking the functions of BRCA1 to these two hormone-related tumors remains to be elucidated. Here, we report that BRCA1 interacts with androgen receptor (AR) and enhances AR target genes, such as p21((WAF1/CIP1)), that may result in the increase of androgen-induced cell death in prostate cancer cells. The BRCA1-enhanced AR transactivation can be further induced synergistically with AR coregulators, such as CBP, ARA55, and ARA70. Together, these data suggest that the BRCA1 may function as an AR coregulator and play positive roles in androgen-induced cell death in prostate cancer cells and other androgen/AR target organs.

Epidemiologic study of type 2 diabetes in Taiwan

Diabetes mellitus (DM) in adults is a global health problem, although its prevalence varies widely between different populations and the rate has generally increased worldwide. In Taiwan, the mortality rate from DM has almost doubled over the past 10 years. The prevalence of DM in Taiwan was established between 1985 and 1996 and the rates were between 4.9 and 9.2%. The prevalence of impaired glucose tolerance (IGT) was 15.5% (men 15% and women 15.9%). The prevalence of DM and IGT increased significantly with age for both genders. The significant factors associated with newly diagnosed DM were age, BMI, family history of DM, systolic blood pressure (hypertension), physical activity and serum triglyceride levels. The prevalence of large vessel disease (LVD) in DM and non-diabetic subjects were 20.0 and 12.9%, respectively. Among diabetics, 15.8% had ischemic heart disease (IHD), 1.7% leg vessel disease (leg VD), and 2.5% stroke. In non-diabetics, the prevalence of the aforementioned macroangiopathies were 11.5, 0.2 and 1.2%, respectively. The diabetics had a significantly higher prevalence of macrovascular disease than non-diabetic subjects. The most significantly associated with the LVD was serum cholesterol levels. Serum cholesterol and HbA1(c) were significantly associated with the development of IHD. Cigarette smoking and female gender were significantly associated with the leg VD. The prevalence of diabetic retinopathy (DR) was 35.0%. (background DR 30%, preproliferative DR 2.8% and proliferative DR 2.2%, respectively.) The prevalence of DR for previously and newly diagnosed diabetics were 45.2 and 28.3% (men 42.8 vs. 33.3% and women 47.5 vs. 24.8%), respectively. From multiple logistic regression analysis, duration of DM was the most important risk factor related to DR. Diabetic subjects treated with insulin had a higher risk of developing retinopathy than those treated with dietary control. The prevalence of nephropathy and neuropathy were 12.9 and 23.5%, respectively. For those patients with and those without nephropathy and neuropathy, the duration of DM, percentage of insulin treatment, percentage of hypertension, and fasting plasma glucose were significantly different. Diabetic duration, hypertension, insulin treatment and glycemic control consistently correlated with nephropathy and neuropathy. In conclusion, the prevalence of DM in Taiwan was between 4.9 and 9.2%, and the prevalence of IGT was 15.5%. The possible risk factors of newly diagnosed diabetes were age, family history of DM, BMI, SBP (hypertension), physical activity and triglyceride levels. Diabetes in Chinese subjects share many characteristics similar to other Asian populations. The burden imposed by the chronic complications of diabetes is massive. In Taiwan, the mortality rates from DM have increased greatly over the past 10 years. Reduction of the modificable risk factors such as BMI, hypertenion and dyslipidemia, and increase of physical activity and good glycemic control through public health efforts may help to reduce the risk of DM and its chronic complications.

Uninsured under TennCare: a case study of public health clinic users

BACKGROUND

We characterized public health clinic users 4 years after implementation of a major public health insurance reform and identified barriers to health care access.

METHODS

We used face-to-face interviews and profile analysis of survey findings.

RESULTS

The typical public health client household is larger, poorer, and more likely to be black than the wider population. The health status of participants is generally good; the level of insurance coverage is preponderantly TennCare; and 90% of respondents are willing to pay some premium.

CONCLUSIONS

Lack of health insurance does not present a serious health care access barrier, nor do transportation or location; but taking time off from work with loss of wages is a problem for those employed. A cost-effective way to enroll uninsured children is to use the County Health Department clinics as a contact point.

Ligation-mediated PCR for quantitative in vivo footprinting

Ligation-mediated polymerase chain reaction (LM-PCR) is a genomic analysis technique for determination of (1) primary DNA nucleotide sequences (2) cytosine methylation patterns (3) DNA lesion formation and repair, and (4) in vivo protein-DNA footprints. However, LM-PCR can be limited by the multiple steps required and the relatively short stretch of sequence (usually <200 bp) that can be analyzed per reaction. We report here a simplified, one-day LM-PCR protocol in which all pipetting steps can be performed by a robotic workstation and which, moreover, provides longer reads (>350 bp) and enhanced signal quality by use of nonradioactive detection and a LI-COR DNA sequencing instrument. Sensitivity comparable to radiolabeling is achieved using oligonucleotide primers that are 5'-end labeled with infrared fluorochromes. We showed that the technique could be used for sensitive and reproducible in vivo photofootprinting of the human phosphoglycerate kinase 1 (PGK1) promoter, as well as providing good Maxam-Gilbert sequence information. The methods described here should allow high-throughput, high-resolution analysis of transcription factor binding and chromatin structure, and also may be useful for sequencing gaps that are refractory to cloning.