The current study investigated the neurotrophic and neuroprotective action of the complex formulation of conjugated equine estrogens (CEEs), the most frequently prescribed estrogen replacement therapy in the United States and the estrogen replacement therapy of the Women's Health Initiative. Morphologic analyses demonstrated that CEEs significantly increased neuronal outgrowth in hippocampal, basal forebrain, occipital, parietal and frontal cortex neurons. Dose-response analyses indicated that the lowest effective concentration of CEEs exerted the maximal neurotrophic effect with greatest potency occurring in hippocampal and occipital cortex neurons. CEES induced highly significant neuroprotection against beta amyloid(25-35), hydrogen peroxide and glutamate-induced toxicity. Rank order of potency and magnitude of CEE-induced neuroprotection in the brain regions investigated was hippocampal neurons > basal forebrain neurons > cortical neurons. In hippocampal neurons pre-exposed to beta amyloid(25-35), CEEs halted Abeta(25-35)-induced cell death and protected surviving neurons from further cell death induced by Abeta(25-35). Because CEEs are the estrogen replacement therapy of the Women's Health Initiative, results of the current study could provide cellular mechanisms for understanding effects of CEEs on cognitive function and risk of Alzheimer's disease derived from this prospective clinical trial.

Adenosine Triphosphate↗

PubMedDate not supplied

A new method for estimating T2 distributions from NMR measurements.

A semi-continuous relaxation model is constructed using sums of gamma functions and non-negative least squares for the inversion of Carr-Purcell-Meiboom-Gill (CPMG) echo data. No regularization is necessary for this approach, and yet the solution is stable even with noisy data. Test results derived from 60 echo trains are presented. Computational advantages of the method are presented.

Computer Graphics↗

PubMedDate not supplied

Autocrine and paracrine actions of breast tumor aromatase. A three-dimensional cell culture study involving aromatase transfected MCF-7 and T-47D cells.

Stable aromatase-expressing MCF-7 and T-47D cell lines (i.e. MCF-7aro and T-47Daro) have been prepared by aromatase cDNA transfection and G418 (neomycin) selection. MCF-7aro was further subjected to a clonal purification. Aromatase activity in the transfected MCF-7 and T-47D cell lines was determined to be 73 +/- 6 pmol/mg/h and 48 +/- 4 pmol/mg/h, respectively. It is thought that these cell lines express aromatase in a stable manner, as demonstrated by a steady expression of the enzyme during culture in the absence of G418. The growth of these cells could be stimulated by androgens (1-10 nM) as demonstrated through a spheroid culture method. The androgen-stimulated growth could be suppressed by 4-hydroxyandrostenedione (4-OHA) (0.01-0.1 mM) or tamoxifen (50 nM-1 microM). In order to test the hypothesis that tumor aromatase can affect breast tumor growth in a paracrine manner, we have carried out cell culture experiments by co-culturing MCF-7 cells with either MCF-7aro or T-47Daro cells. Testosterone (1 nM) increased cell growth to a similar degree for MCF-7/MCF-7aro co-culture (0.75 x 10(6) cells each type) as with MCF-7aro only (2- to 3-fold). In addition, the enzyme activities remained unchanged for MCF-7/MCF-7aro co-culture samples with and without androgen treatment, indicating that estrogen produced by transfected cells can also stimulate the growth of untransfected cells. The androgen response could be inhibited by an addition of 4-OHA (0.01-0.1 mM). For MCF-7/T-47Daro co-culture experiments, a clear induction of cell growth by androgen was observed, and the level of the increase was similar to that on T-47Daro only. However, for either culture with T-47D only or with MCF-7/T-47Daro co-culture, the aromatase activity was found to increase significantly after testosterone treatment. T-47Daro cells were not subjected to a clonal purification, and it is therefore thought that the androgen treatment may selectively stimulate the growth of high aromatase-expressing T-47Daro cells. These results indicate that estrogen synthesized by tumor aromatase can stimulate breast tumor growth in both an autocrine and a paracrine manner.

Androgens↗

PubMedDate not supplied

Successful therapy of a human lung cancer xenograft using MAb RS7 labeled with residualizing radioiodine.

We have recently reported that a radioiodinated, DTPA-appended peptide, designated IMP-R1, is a residualizing iodine label that overcomes many of the limitations that have impeded the development of residualizing iodine for clinical use. In this study the potential of 131I-IMP-R1-RS7, an internalizing anti-EGP-1 monoclonal antibody, was evaluated by performing preclinical therapy studies in nude mice bearing Calu-3 human non-small cell carcinoma of the lung xenografis. Elimination of 6 of 9 established tumors (mean tumor volume=0.3 cm(3)) was observed using a single dose of 350 microCi/mouse of 131I-IMP-R1-RS7, with all animals tolerating the dose. At the same dose and specific activity of 131I-RS7, labeled using the conventional chloramine-T method, there were four deaths, and one complete remission in nine treated mice. At the maximum tolerated dose of conventionally 131I-labeled RS7, 275 microCi, mean stable disease for approximately 5 weeks was observed, with no complete responses. Specificity of the therapeutic effect was shown in an isotype-matched control experiment, where 131I-IMP-R1-RS7 was markedly more effective than the (131)I-IMP-R1-labeled control antibody. These studies demonstrate that (131)I-IMP-R1-RS7 provides a therapeutic advantage in comparison to conventional 131I-labeled RS7, as predicted by the increased tumor accretion observed previously in targeting studies. A direct comparison of the maximum tolerated doses of (131)I-IMP-R1-RS7 (350 microCi) and 90Y-DOTA-RS7 (105 microCi) was performed in this tumor model using large established tumors (mean tumor volume=0.85 cm(3)). Anti-tumor efficacy and toxicity of the two treatments were comparable.

Animals↗

PubMedDate not supplied

A droplet medium selection for cultivation of Bacillus thuringiensis.

For an industrial fermentation system, design of a suitable medium for cultivation of cells is an important step. Medium selection is commonly carried out with a lot of experimental works. In the present study, a simple method was proposed for medium selection in cultivation of Bacillus thuringiensis for production of thuringiensin. A droplet of medium was employed to test the suitability of the medium.

Bacillus thuringiensis↗

PubMedDate not supplied

Hg2+ removal by genetically engineered Escherichia coli in a hollow fiber bioreactor.

Escherichia coli cells engineered to express an Hg2+ transport system and metallothionein accumulated Hg2+ effectively over a concentration range of 0.2-4 mg/L in batch systems. Bioaccumulation was selective against other metal ions and resistant to changes in ambient conditions such as pH, ionic strength, and the presence of common metal chelators or complexing agents (Chen, S.-L.; Wilson, D. B. Appl. Environ. Microbiol. 1997, 63, 2442-2445; Biodegradation 1997, 8, 97-103). Here we report the characterization of the bioaccumulation system based on its kinetics and an isotherm. Bioaccumulation was rapid and followed Michaelis-Menten kinetics. A hollow fiber bioreactor was constructed to retain the genetically engineered cells. The bioreactor was capable of removing and recovering Hg2+ effectively at low concentrations, reducing a 2 mg/L solution to about 5 microgram/L. A mathematical equation that quantitatively described Hg2+ removal by the bioreactor provides a basis for the optimization and extrapolation of the bioreactor. The genetically engineered E. colicells and the bioreactor system have excellent properties for bioremediation of Hg2+-contaminated environments.

Bioreactors↗

PubMedDate not supplied

Expression of testis specific ankyrin repeat and SOCS box-containing 17 gene.

Human ASB-17 (Ankyrin Repeat and SOCS Box-containing 17) is a recently identified gene belonging to the ASB family, isolated from testis cDNA library. Human ASB-17 is expressed exclusively in testis among 16 tissues, revealed by Northern blot. Mouse Asb-17 was shown to be expressed from the third week post birth to adult by semi-quantitative RT-PCR analysis. In situ hybridization on frozen sections demonstrated that Asb-17 is expressed in spermatogenic cells in adult mouse, but not in Leydig cell and epididymis in adult mouse. ASB-17 proteins are highly conserved in mammals including human, mouse, rat, Canis familiaris and Macaca fascicularis.

Adaptor Proteins, Signal Transducing↗

PubMedDate not supplied

The key role of the transforming growth factor-beta system in the pathogenesis of diabetic nephropathy.

Progressive renal injury in diabetes mellitus leads to major morbidity and mortality. The manifestations of diabetic nephropathy may be a consequence of the actions of certain cytokines and growth factors. Prominent among these is transforming growth factor-beta (TGF-beta) because it promotes renal cell hypertrophy and stimulates extracellular matrix accumulation, the two hallmarks of diabetic renal disease. In cell culture, high ambient glucose increases TGF-beta mRNA and protein in proximal tubular, glomerular epithelial, and mesangial cells. Neutralizing anti-TGF-beta antibodies prevent the hypertrophic and matrix stimulatory effects of high glucose in these cells. In experimental and human diabetes mellitus, several reports describe overexpression of TGF-beta in the glomeruli and tubulointerstitium. We demonstrate that short-term treatment of diabetic mice with neutralizing monoclonal antibodies against TGF-beta significantly reduces kidney weight and glomerular hypertrophy and attenuates the increase in extracellular matrix mRNAs. Long-term treatment of diabetic mice further improves the renal pathology and also ameliorates the functional abnormalities of diabetic nephropathy. Finally, we provide evidence that the renal TGF-beta system is significantly up-regulated in human diabetes. The kidney of a diabetic patient actually elaborates TGF-beta1 protein into the circulation whereas the kidney of a non-diabetic subject extracts TGF-beta1 from the circulation. The data we review here strongly support the hypothesis that elevated production or activity of the TGF-beta system mediates diabetic renal hypertrophy and extracellular matrix expansion.

Animals↗

PubMedDate not supplied

Effect of food on the absorption of vitamin B12.

Explore the source record for details and available documents.

Food↗

PubMedDate not supplied

Developmental changes in brain metabolism in sedated rhesus macaques and vervet monkeys revealed by positron emission tomography.

The present positron emission tomography study used 2-deoxy-2[18F]fluoro-D-glucose to examine age-related changes in local cerebral metabolic rates for glucose (LCMRglc) in sedated rhesus macaques and vervet monkeys. Nineteen vervet monkeys were scanned in a cross-sectional design, which consisted of three age groups (birth to 59 d, 60-179 d, 180 d to adult) that captured the developmental period of greatest synaptic density within the second group. Two rhesus and two vervet monkeys were also examined longitudinally. Subjects were sedated throughout the procedure with a combination of ketamine and midazolam. Longitudinal and cross-sectional analyses of 20 brain regions indicated lowest LCMRglc in rhesus and vervet monkeys < 2 months of age (about 60% of adult levels). These metabolic rates more than doubled to approximately 155% of adult levels after the second postnatal month, coincident with transient synaptic overproduction and increased sociobehavioral activity. LCMRglc remained high until 6 months postnatally, coincident with continued dendritic growth and the emerging sociobehavioral independence of the young monkey. After 6 months, LCMRglc decreased gradually to adult levels. Thus, the period between 2 and 6 months is a time of peak metabolic activity, which coincides with increased histologic and behavioral activity in the developing monkey.

Age Distribution↗

PubMedDate not supplied

Hepatic metastases from breast carcinoma: comparison of noncontrast, arterial-dominant, and portal-dominant phase spiral CT.

PURPOSE: The purpose of this work was to determine the relative value of noncontrast (NC), arterial-dominant (AD), and portal-dominant (PD) phase images in spiral CT of the liver for breast cancer metastases. METHOD: Forty-four spiral CT scans in 18 patients with hepatic metastases from breast cancer were retrospectively reviewed by three radiologists. Subjective evaluations of overall lesion conspicuity and margination were graded on a 5 point scale for NC, AD, and PD phase images, and the three phases were also ranked for demonstration of overall tumor volume. Those scans with hypervascular lesions were separately analyzed, resulting in three groups (all, hypervascular, hypovascular). RESULTS: For lesion conspicuity and margination for the entire study group, AD phase images showed the lowest grades (1.97 and 1.83), whereas the PD phase showed the highest grade (3.34 and 3.14; p < 0.0001) followed by NC (2.36 and 2.42; p < 0.0001). For the hypervascular subgroup, the AD phase also showed the lowest grades (2.39 and 2.24). In no case did the AD phase show more lesions than the combination of NC and PD phases. For depiction of overall tumor volume, the AD phase had the lowest ranking (2.51) compared with the NC and PD phases (1.71 and 1.78; p < 0.001). For the hypervascular subgroup, the AD phase had the lowest ranking (2.33) compared with the NC and PD phases (1.39 and 2.27; p < 0.0001). CONCLUSION: The AD phase is not required for lesion detection in spiral CT for hepatic metastases from breast carcinoma. The NC phase depicts the maximal tumor volume.

Adult↗

PubMedDate not supplied

Patient-administered tampon-collected genital cells in the assessment of Chlamydia trachomatis infection using polymerase chain reaction.

BACKGROUND: Diagnosis of genital Chlamydia trachomatis infection in women traditionally requires a speculum examination to collect endocervical cells, followed by cell culture. This method is time consuming, requires stringent transport conditions, and is technically demanding. GOALS: To compare tampons as a patient-administered collection method followed by detection with polymerase chain reaction (PCR) with the traditional endocervical swab culture followed by cell culture detection. STUDY DESIGN: At the emergency department of a hospital for obstetrics and gynecology, 1,000 consecutive women with symptoms suggestive of infection with C. trachomatis were tested for C. trachomatis infection by PCR on both tampon (PCR-T) and swab (PCR-S) specimen and by culture of the swab specimen. RESULTS: Seventeen PCR-T and 16 PCR-S specimens were positive; 16 endocervical specimens were positive by culture, and 14 of the endocervical samples were positive by the three methods. Sixty-one PCR-S samples were inadequate as shown by the lack of amplification of the beta-globin gene segment, indicating poor collection of specimens by endocervical swab for chlamydial testing. CONCLUSIONS: Tampon specimens collected for PCR detection provided an easy and sensitive method of detection of C. trachomatis and overcame the obstacle of endocervical sampling and subsequent stringent transport requirements of culture.

Chlamydia Infections↗