Deep Learning Sequence Models for Transcriptional Regulation

Deciphering the regulatory code of gene expression and interpreting the transcriptional effects of genome variation are critical challenges in human genetics. Modern experimental technologies have resulted in an abundance of data, enabling the development of sequence-based deep learning models that link patterns embedded in DNA to the biochemical and regulatory properties contributing to transcriptional regulation, including modeling epigenetic marks, 3D genome organization, and gene expression, with tissue and cell-type specificity. Such methods can predict the functional consequences of any noncoding variant in the human genome, even rare or never-before-observed variants, and systematically characterize their consequences beyond what is tractable from experiments or quantitative genetics studies alone. Recently, the development and application of interpretability approaches have led to the identification of key sequence patterns contributing to the predicted tasks, providing insights into the underlying biological mechanisms learned and revealing opportunities for improvement in future models.

Genome-wide landscape of RNA-binding protein target site dysregulation reveals a major impact on psychiatric disorder risk

Despite the strong genetic basis of psychiatric disorders, the underlying molecular mechanisms are largely unmapped. RNA-binding proteins (RBPs) are responsible for most post-transcriptional regulation, from splicing to translation to localization. RBPs thus act as key gatekeepers of cellular homeostasis, especially in the brain. However, quantifying the pathogenic contribution of noncoding variants impacting RBP target sites is challenging. Here, we leverage a deep learning approach that can accurately predict the RBP target site dysregulation effects of mutations and discover that RBP dysregulation is a principal contributor to psychiatric disorder risk. RBP dysregulation explains a substantial amount of heritability not captured by large-scale molecular quantitative trait loci studies and has a stronger impact than common coding region variants. We share the genome-wide profiles of RBP dysregulation, which we use to identify DDHD2 as a candidate schizophrenia risk gene. This resource provides a new analytical framework to connect the full range of RNA regulation to complex disease.

Genomic analyses implicate noncoding de novo variants in congenital heart disease

A genetic etiology is identified for one-third of patients with congenital heart disease (CHD), with 8% of cases attributable to coding de novo variants (DNVs). To assess the contribution of noncoding DNVs to CHD, we compared genome sequences from 749 CHD probands and their parents with those from 1,611 unaffected trios. Neural network prediction of noncoding DNV transcriptional impact identified a burden of DNVs in individuals with CHD (n = 2,238 DNVs) compared to controls (n = 4,177; P = 8.7 × 10-4). Independent analyses of enhancers showed an excess of DNVs in associated genes (27 genes versus 3.7 expected, P = 1 × 10-5). We observed significant overlap between these transcription-based approaches (odds ratio (OR) = 2.5, 95% confidence interval (CI) 1.1-5.0, P = 5.4 × 10-3). CHD DNVs altered transcription levels in 5 of 31 enhancers assayed. Finally, we observed a DNV burden in RNA-binding-protein regulatory sites (OR = 1.13, 95% CI 1.1-1.2, P = 8.8 × 10-5). Our findings demonstrate an enrichment of potentially disruptive regulatory noncoding DNVs in a fraction of CHD at least as high as that observed for damaging coding DNVs.

Selene: a PyTorch-based deep learning library for sequence data

To enable the application of deep learning in biology, we present Selene (https://selene.flatironinstitute.org/), a PyTorch-based deep learning library for fast and easy development, training, and application of deep learning model architectures for any biological sequence data. We demonstrate on DNA sequences how Selene allows researchers to easily train a published architecture on new data, develop and evaluate a new architecture, and use a trained model to answer biological questions of interest.

Deep learning sequence-based ab initio prediction of variant effects on expression and disease risk

Key challenges for human genetics, precision medicine and evolutionary biology include deciphering the regulatory code of gene expression and understanding the transcriptional effects of genome variation. However, this is extremely difficult because of the enormous scale of the noncoding mutation space. We developed a deep learning-based framework, ExPecto, that can accurately predict, ab initio from a DNA sequence, the tissue-specific transcriptional effects of mutations, including those that are rare or that have not been observed. We prioritized causal variants within disease- or trait-associated loci from all publicly available genome-wide association studies and experimentally validated predictions for four immune-related diseases. By exploiting the scalability of ExPecto, we characterized the regulatory mutation space for human RNA polymerase II-transcribed genes by in silico saturation mutagenesis and profiled > 140 million promoter-proximal mutations. This enables probing of evolutionary constraints on gene expression and ab initio prediction of mutation disease effects, making ExPecto an end-to-end computational framework for the in silico prediction of expression and disease risk.

PathCORE-T: identifying and visualizing globally co-occurring pathways in large transcriptomic compendia

Background

Investigators often interpret genome-wide data by analyzing the expression levels of genes within pathways. While this within-pathway analysis is routine, the products of any one pathway can affect the activity of other pathways. Past efforts to identify relationships between biological processes have evaluated overlap in knowledge bases or evaluated changes that occur after specific treatments. Individual experiments can highlight condition-specific pathway-pathway relationships; however, constructing a complete network of such relationships across many conditions requires analyzing results from many studies.

Results

We developed PathCORE-T framework by implementing existing methods to identify pathway-pathway transcriptional relationships evident across a broad data compendium. PathCORE-T is applied to the output of feature construction algorithms; it identifies pairs of pathways observed in features more than expected by chance as functionally co-occurring. We demonstrate PathCORE-T by analyzing an existing eADAGE model of a microbial compendium and building and analyzing NMF features from the TCGA dataset of 33 cancer types. The PathCORE-T framework includes a demonstration web interface, with source code, that users can launch to (1) visualize the network and (2) review the expression levels of associated genes in the original data. PathCORE-T creates and displays the network of globally co-occurring pathways based on features observed in a machine learning analysis of gene expression data.

Conclusions

The PathCORE-T framework identifies transcriptionally co-occurring pathways from the results of unsupervised analysis of gene expression data and visualizes the relationships between pathways as a network. PathCORE-T recapitulated previously described pathway-pathway relationships and suggested experimentally testable additional hypotheses that remain to be explored.

Electronic supplementary material

The online version of this article (10.1186/s13040-018-0175-7) contains supplementary material, which is available to authorized users.

Exposure Duration Is a Determinant of the Effect of Sinusoidal Electromagnetic Fields on Peak Bone Mass of Young Rats

We proposed a three-step strategy to obtain the optimal therapeutic parameters, which is composed of large-scale screening at cellular level, verification in animal experiments, and confirmation by a clinical trial. The objective of the current study was to test the feasibility of our strategy. Newborn rat calvarial osteoblasts were treated by 50 Hz 1.8 mT sinusoidal electromagnetic fields (SEMFs) with 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 h/days, respectively. The osteogenic differentiation and maturation of the osteoblast were assayed and compared to obtain the optimal duration. One-month-old growing rats were then treated by the same SEMFs with 0.5, 1.5, and 2.5 h/days, respectively, and the peak bone mass was analyzed after 2 months. It was found that the optimal exposure duration to promote the osteogenic differentiation and maturation of osteoblasts was 1.5 h/days, judging by the increasing degrees of ALP activity, calcified nodules formed, the gene and protein expression levels of Runx-2, BMP-2, and Col-I, as well as the expression levels of signaling proteins of the BMP-2/Smad1/5/8 pathway. The highest increase of peak bone mass after 2 months was also obtained by 1.5 h/days, judging by the results of X-ray dual-energy absorptiometry, mechanical property analysis, micro-CT scanning, and serum bone turnover marker examinations. The above results indicated that exposure duration is a determinant for the therapeutic effect of EMFs, and the optimal therapeutic effects only can be obtained by the optimal exposure duration.

Methylation markers differentiate thyroid cancer from benign nodules

PURPOSE

The incidence of thyroid cancer (TC) is increasing. Cytology by itself cannot distinguish TC from some benign nodules especially in certain subtypes of TC. Our immediate goal is to identify DNA methylation markers for early detection of TC and to molecularly differentiate TC subtypes from benign nodules.

METHODS

Promoter methylation status of 21 candidate genes was examined on formalin-fixed paraffin-embedded tissue (FFPE) utilizing quantitative methylation-specific polymerase chain reaction (QMSP) in a retrospective cohort of 329 patients (56% white, 29% African American, 61% female) comprising 71 normal thyroid, 83 benign nodules [follicular adenomas (FA)], 90 follicular TC (FTC) and 85 papillary TC (PTC). All genes were analyzed individually (Kruskal-Wallis and Wilcoxon rank sum tests) and in combination (logistic regression models) to identify genes whose methylation levels might best separate groups.

RESULTS

Combination gene panels TPO and UCHL1 (ROC = 0.607, sensitivity 78%) discriminated FTC from FA, and RASSF1 and TPO (ROC = 0.881, sensitivity 78%) discriminated FTC from normal. Methylation of TSHR distinguished PTC from FTC (ROC = 0.701, sensitivity 84%) and PTC from FA (ROC = 0.685, sensitivity 70%). The six gene panel of TIMP3, RARB2, SERPINB5, RASSF1, TPO and TSHR, which differentiates PTC from normal thyroid, had the best combination sensitivity (91%) and specificity (81%) of the panels addressing discrimination of cancer tissue.

CONCLUSIONS

Aberrant gene methylation used in combination panels may be useful clinically in differentiating FTC and PTC from benign nodules. If confirmed in additional studies, these findings could help reduce the over diagnosis of thyroid cancer and surgeries related to over diagnosis.

Unsupervised Extraction of Stable Expression Signatures from Public Compendia with an Ensemble of Neural Networks

Cross-experiment comparisons in public data compendia are challenged by unmatched conditions and technical noise. The ADAGE method, which performs unsupervised integration with denoising autoencoder neural networks, can identify biological patterns, but because ADAGE models, like many neural networks, are over-parameterized, different ADAGE models perform equally well. To enhance model robustness and better build signatures consistent with biological pathways, we developed an ensemble ADAGE (eADAGE) that integrated stable signatures across models. We applied eADAGE to a compendium of Pseudomonas aeruginosa gene expression profiling experiments performed in 78 media. eADAGE revealed a phosphate starvation response controlled by PhoB in media with moderate phosphate and predicted that a second stimulus provided by the sensor kinase, KinB, is required for this PhoB activation. We validated this relationship using both targeted and unbiased genetic approaches. eADAGE, which captures stable biological patterns, enables cross-experiment comparisons that can highlight measured but undiscovered relationships.

Abstract P1-04-06: Network integration of epigenomic data: Leveraging the concept of master regulators in ER negative breast cancer

Background: There has been relatively little advancement in changing the management of women with estrogen receptor (ER) negative breast cancer (BC), mainly due to a dearth of actionable therapeutic targets. Therefore, understanding the underlying biology of such a complex disease is necessary for bringing new therapeutic treatments to light. A key question in cancer genomics is how to distinguish 'driver' or essential alterations, which contribute to tumorigenesis, from functionally neutral or 'passenger' alterations that go along for the ride. The majority of published studies investigating driver genes have focused primarily on genomic mutations which have led to novel study designs (basket trials) where patients with a rare mutation, regardless of tumor histology, are matched to a drug expected to work through the mutated pathway. This dominant focus on mutations has overshadowed consideration of inclusion of epigenetic information. This study illustrates network integration of epigenomic data to prioritize ER negative specific methylated genes as potential epigenetic drivers of aggressive disease.

Methods: Causal Networks are small hierarchical networks of regulators whose activity can be modulated by the expression of downstream target genes to enhance understanding of the effect of upstream master regulators on disease or function. A master regulator is a gene or drug positioned as the central or master hub that has the ability to command or influence downstream events. Causal Network Analysis (CNA) was used to find networks that connect upstream master regulators with a 16 candidate methylation gene signature differentiating ER negative from ER positive BC. The 16 ER-negative specific gene methylation signature (AHNAK, ALPL, ANXA2R, CCND1, CIRBP, CPQ, DST, EGFR, ESR1, GPRC5B, HERC5, IL22RA2, MITF, OBSL1, POU3F3, RB1CC1) was identified via our drill-down approach starting from a discovery approach (Illumina 450k BeadChip) followed by expression verification, significant rankings in biological pathways (Ingenuity Pathway Analysis), confirmation by targeted sequencing using Illumina MiSeq, and additional filtering in 450K TCGA data sets.

Results: CNA software identified 4 hierarchical networks and their corresponding master regulatory molecules, diethylstilbestrol, transcription regulator SP1, MSH2, and 15-ketoprotaglandin E2. Diethylstilbestrol and SP1 had direct regulatory influence (depth level 1) to the candidate molecules ALPL, CCND1, EGFR, ESR1 and CCND1, CIRBP, EGFR, ESR1, respectively.

Conclusion: In this study, direct regulatory influence, noted for 5/16 candidate genes indicates additional rationale for further consideration and validation of ALPL, CCND1, CIRBP, EGFR, ESR1 as potential epigenetic driver targets in ER negative BC. As cancer therapies become increasingly more specific and begin to move past cytotoxic agents, determining the molecular features of a tumor that predict response to a given drug has become increasingly essential to match patients with optimal therapy. Currently epigenetic therapy in the form of hypomethylating agents (e.g: decitabine) exhibit clinical efficacy in patients with AML and MDS including those patients not responding to cytotoxic therapy.

Support: Komen Foundation: KG110218.

Citation Format: Worsham MJ, Chen KM, Datta I, Stephen JK, Chitale D, Divine G. Network integration of epigenomic data: Leveraging the concept of master regulators in ER negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-04-06.

Abstract P2-03-01: Differentially methylated miRNA methylomes of normal breast tissue from ER negative and ER positive breast cancer mimic their respective tumor phenotypes

Background: The unique structure and function of normal tissues is known to be regulated by epigenetic mechanisms. Understanding how normal cells in their respective tumor milieus might affect their susceptibility to become not only malignant but acquire breast cancer (BC) subtype-specific phenotypes, may determine tumor clinical behavior outcomes. The goal was to compare genome wide methylation profiles of non-coding miRNAs of breast cancer tissue and normal breast epithelium, respectively, from ER negative and ER positive tumors, and assess their miRNA methylomes in the context of tumor ER phenotypes as ER negative vs ER positive.

Methods: Breast cancer tissue from 79 patients (40 ER-positive and 39 ER-negative) and normal tissue from 39 of these patients (19 ER-negative and 20-ER-positive) were assayed using the Illumina 450K bead array. A sub analysis focused on 2249 miRNA CpGs assigned to 615 unique miRNAs. M-values were computed as a logit function [(log (beta/ (1-beta))] of the methylation beta values. T-tests were used to compare the means of the M-values for the ER-positive and ER-negative groups. The t-test p-values were used to generate adaptive FDR (aFDR) levels and aFDRs of 0.05 or lower were considered to be statistically significant (Tier 1). Tier 1 CpGs were subsequently filtered to select only those with a mean beta ratio between ER-positive and ER-negative of under 0.5 or over 2.0 (Tier 2). The Tier 2 CpGs were further filtered to select only those with a mean beta difference of 0.2 or more (Tier 3).

Results: In the tumor cohort, 1224/2249 (54%) CpGs were differentially methylated between ER negative and ER positive BC at Tier 1 (aFDR 0.05 or lower). Of the 1224, 963 (78.7%) were hypermethylated, and 1035 (84.6%) were associated with the promoter region. The 1224, 24 and 2 CpGs were associated with 379, 22 and 2 genes for Tiers 1, 2 and 3, respectively. When the same analysis was performed on normal tissue only (19 ER-negative and 20-ER-positive) 76 of the 2249 CpGs had significant aFDR values and none of those met the Tier 2 or Tier 3 criteria. Seventy-one of the 76 (93.4%) where hypermethylated, and 65 (85.5%) were associated with the promoter region. The 76 significant Tier 1 (aFDR) differentially methylated CpGs were associated with 48 genes of which 43 were common to tumor Tier 1 differentially methylated miRNA genes, 10 were common to tumor Tier 2 genes, and 5 were restricted to normal tissue only.

Conclusions Normal epithelial tissues demonstrated similar differential methylation directionality as their respective tumor counterparts (although to a lesser extent), favoring promoter region localization. Accordingly, the recognition of normal breast tissue-specific epigenetic propensities that align with their tumor phenotypes, suggest the possibility of progression markers specific for estrogen receptor status as well as markers not associated with progression. This provides insights into our view of possible links between epigenetic programming, progression continuums, and how hormonal receptor subtypes may be determined. Support: Komen Foundation: KG110218.

Citation Format: Worsham MJ, Chen KM, Chitale D, Stephen JK, Divine G. Differentially methylated miRNA methylomes of normal breast tissue from ER negative and ER positive breast cancer mimic their respective tumor phenotypes. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-03-01.

Abstract P4-09-10: Epigenetically altered microRNA mediated pathway dysregulation in ER negative breast cancer

Background: Micro RNAs (miRNA) are endogenous, small non-coding RNAs that control gene expression by directing their target mRNAs for degradation and/or posttranscriptional repression. Compared to mRNA signatures, miRNAs have better and stronger biomarker properties with 20 times more power in biomarker studies as compared to mRNAs (when comparing 20,000 mRNAs to ∼1,000 miRNAs). Emerging evidence now supports the idea that DNA methylation is crucially involved in the dysregulation of miRNAs in cancer, representing a novel class of potential biomarkers for diagnosis, prediction of treatment, or prognosis. ER-negative breast cancer (BC) is an aggressive histological subtype with limited treatment options and very poor prognosis. Our long term objective is to derive a diagnostic, prognostic, and predictive ER-negative specific miRNA panel for detection of early cancer, recurrence/metastasis, and as potential therapeutic targets for better management of ER-negative BC.

Methods: The initial discovery step profiled 39 primary ER negative and 40 ER positive BC cases using the Illumina Infinium HumanMethylation450 BeadChip followed by a subanalysis focusing on 2249 miRNA CpGs assigned to 615 unique miRNAs. T-tests were used to compare the means of the M-values for the ER-positive and ER-negative groups. The t-test p-values were used to generate adaptive FDR (aFDR) levels and aFDRs of 0.05 or lower were considered to be statistically significant (Tier 1). Tier 1 CpGs were subsequently filtered to select only those with a mean beta ratio between ER positive and ER negative of under 0.5 or over 2.0 (Tier 2). The Tier 2 CpGs were further filtered to select only those with a mean beta difference of 0.2 or more (Tier 3). Because miRNAs perform their important functions via their targets, the targets of miRNAs were assessed for functional enrichment analysis in IPA for biologic involvement.

Results: Over half of the miRNA CpGs (1224/2249, 54%) were differentially methylated between ER negative and ER positive BC with significant aFDR levels. The 1224 CpGs at Tier 1 were associated with 379 miRNAs; the 24 and 2 CpGs for Tiers 2 and 3 with 22 and 2 miRNAs, respectively. The 22 miRNA genes were assigned to 4621 targets using online databases that predict miRNA targets. The degree of confidence that a target gene is associated with a miRNA is characterized in these databases as either "experimentally observed", or just as "high" (predicted). Of these 4621 targets, 87 were designated as experimentally observed and were examined in IPA. Top pathways and networks designated by miRNA targets included the cell cycle G1/S checkpoint regulation canonical pathway, and the cell-to-cell interaction/cancer networks among others. MiRNA targets in top pathways and networks were circled back to their respective miRNAs revealing cooperatively mediated pathway dysregulation of ER negative BC.

Conclusion: Aberrantly methylated miRNAs showed perturbation of biologically significant pathways and networks, suggesting that miRNAs mediate pathway dysregulation in a coordinated manner, strengthening the case for utility of miRNAs as viable biomarkers in ER negative BC. Support: Komen Foundation: KG110218.

Citation Format: Worsham MJ, Chen KM, Datta I, Stephen JK, Chitale D, Divine G. Epigenetically altered microRNA mediated pathway dysregulation in ER negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-10.

Comparison between 8-prenylnarigenin and narigenin concerning their activities on promotion of rat bone marrow stromal cells' osteogenic differentiation in vitro

A number of recent studies have suggested that flavonols (a class of phytochemical with many biological activities), might exert protective effects against post-menopausal bone loss. In the present study, we compared naringenin (NG) and 8-prenylnaringenin (PNG), two major naturally occurring flavonols, on in vitro differentiation of osteoblasts and bone resorbing activity, of rat bone marrow stromal cells (BMSCs). Our results indicated that both compounds, at 10(-6)  m, enhanced BMSCs' differentiation. Then effects of the two compounds at 10(-6)  m on ALP activity, osteocalcin secretion and calcium deposition, were compared over a time course. Numbers and areas of colonies stained for ALP (CFU-F(ALP) ) expression, and mineralized bone nodules, were histochemically analysed after 12 days and 16 days osteogenic induction, respectively. Expression of BMP-2, OPG, OSX, RUNX-2 genes and p38MAPK protein were examined using real-time PCR and western blotting, respectively. The data presented indicate that PNG, significantly enhanced the rat BMSCs' differentiation and mineralization through the BMP-2/p38MAPK/Runx2/Osterix signal pathway, greater than did NG. In conclusion, PNG has a more pronounced ability to enhance osteoblast differentiation and mineralization, than NG.

Abstract P2-09-04: DNA methylation landscapes in ER-negative breast cancer

The biological significance of DNA methylation in the regulation of gene expression and its role in cancer is increasingly recognized. The underlying hypothesis of this study is that strategic global approaches will identify aberrantly methylated genes that underlie the pathogenesis of ER-negative (ER−) breast cancer (BC). We used the Infinium HumanMethylation450 BeadChip to profile the methylome of ER− breast cancers. The 450K array includes 485,577 cytosine positions of the human genome. From these cytosine sites, 99.3% are CpG dinucleotides.

Whole genomic DNA from 20 primary ER− and 8 normal breast tissue samples were assayed for genome-wide methylation using the Illumina 450K array. We had 8634 hypermethylated CpGs or 1.8% of the 485,577 sites on the 450K array. The proportion with hypermethylation was higher for promoter regions (2.1% vs 1.5%), and highest for the “FirstExon” promoter subregion. Of the 8634 CpGs, 2980 (adjusted p = 0.05) were differentially methylated between tumor and normal samples. This resulted in 206 genes with significant hypermethylation (all mean breast cancer betas >= −0.2, and ratio of tumor to normal mean beta >= 2.0).

Estrogen receptor-negative BC is a more aggressive form than ER positive BC with approximately double the incidence in African Americans than in Caucasian Americans. The emerging differential methylation pattern within hormone receptor negative breast cancers would further help stratify them into distinct subgroups. Promotor methylation being potentially reversible, methylated genes may serve as future molecular targets for demethylating therapies.

Support: Komen Foundation: KG110218

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-09-04.

FlowCytomix analysis for Toxoplasma gondii infection in pregnant women in central Taiwan

The study was to determine the seroprevalence of toxoplasmosis in the sera of pregnant women in central Taiwan and to investigate the levels of cytokine in the sera of pregnant women with Toxoplasma gondii infection. The 220 blood samples were collected from pregnant women. The haematological parameters of peripheral blood were analysed by a haematology analyser. Serum samples of the pregnant women were analysed by a commercially available anti-T. gondii IgM/IgG antibody enzyme-linked immunosorbent assay (ELISA) kit and FlowCytomix assays. Six (2.7%) of the sera samples had IgM anti-T. gondii antibodies, and twenty (9.1%) had T. gondii IgG seropositive. All six IgM seropositive samples had low IgG avidity, indicative of acute infection. Total white blood cells and eosinophils were statistically significantly increased (p<0.05) in pregnant women with T. gondii infection, as compared with healthy pregnant women. Th1 cytokines IFN-γ, IL-1β, IL-2 and IL-12 p70, and Th2 cytokines IL-10 in pregnant women with T. gondii IgM/IgG seropositive were significantly increased (p<0.05), as compared with healthy pregnant women. These results showed that both of Th1 and Th2 cytokines play an important role in the toxoplasmosis of pregnant women.

Induction of plasminogen activators in pregnant women with Toxoplasma gondii infection

OBJECTIVE

To determine whether plasminogen activators (PAs) are involved in the pathologic process of toxoplasmosis.

MATERIALS AND METHODS

Out of 220 pregnant women the study included 26 with a diagnosis of toxoplasmosis: six based on seropositivity for Toxoplasma gondii IgM and 20 based on seropositivity for T. gondii IgG. We measured serum activities and protein levels of PAs by casein zymography and Western blotting, respectively.

RESULTS

Serum PAs were higher in healthy pregnant women than in their healthy nonpregnant counterparts. Furthermore, serum PAs were significantly higher in pregnant women infected with T. gondii than in their healthy counterparts.

CONCLUSION

PAs participate in the pathogenesis of toxoplasmosis in pregnant women and may be useful markers of T. gondii infection.

The value of multidetector-row CT in the preoperative detection of pancreatic insulinomas

PURPOSE

The authors sought to quantitatively analyse enhancement characteristics of pancreatic insulinomas in different phases and determine the value of multidetector-row computed tomography (CT) for detecting insulinomas.

MATERIALS AND METHODS

Forty-six patients with surgically proven insulinomas diagnosed between 2002 and 2007 were retrospectively reviewed. These patients underwent single-phase (group 1) or dual-phase (group 2) helical CT scanning.

RESULTS

Sensitivity for detecting insulinomas in group 2 was superior to that in group 1 (p<0.05).The sensitivity for insulinoma detection in the arterial phase was superior to that in the portal-venous phase (p<0.05). The mean attenuation values of the insulinomas and normal pancreas during the unenhanced arterial and portal-venous phases were, respectively, 40.5+/-8.75 HU (Hounsfield units), 114.48+/-27.30 HU, 112.19+/-19.52 HU and 44.56+/-6.48 HU, 81.16+/-15.22 HU, 90.54+/-13.80 HU, and there was statistical difference between them (p=0.000). The contrast enhancement of insulinomas in the arterial and portal-venous phases was 74.03+/-29.51 HU and 70.90+/-21.93 HU, respectively, and there was no statistical difference between them (p=0.499). The tumour to normal-pancreas attenuation differences in the arterial and portal-venous phases were respectively 33.32+/-20.96 HU and 20.58+/-16.32 HU, respectively, and there was statistical difference between them (p=0.011).

CONCLUSIONS

Dual-phase CT has a promising sensitivity in detecting pancreatic insulinomas. The acquisition of images in the arterial phase is more helpful for detecting insulinomas.

Comparative efficacies of albendazole and the Chinese herbal medicine long-dan-xie-gan-tan, used alone or in combination, in the treatment of experimental eosinophilic meningitis induced by Angiostrongylus cantonensis

Angiostrongylus cantonensis, the rat lungworm, is the principal cause of human eosinophilic meningitis or meningoencephalitis world-wide. In the present study, the efficacies of early-stage treatment with the Chinese herbal medicine long-dan-xie-gan-tan (LDXGT) and albendazole, used alone or in combination, were evaluated in BALB/c mice with A. cantonensis-induced dysfunction of the blood-central-nervous-system barrier and eosinophilic meningo-encephalitis. Indicators of the therapeutic effect included worm recovery, histopathological scores for the meningitis, assays of tissue-type plasminogen activator (PA), urokinase-type PA and matrix metalloproteinase-9 (MMP-9) in the brain, the ratio between albumin concentrations in the cerebrospinal fluid (CSF) and serum, and counts of eosinophils in the CSF. Combined treatment with albendazole and LDXGT gave better results than monotherapy based on either drug, apparently inhibiting eosinophilic meningitis via antagonists of the PA/MMP-9 system. LDXGT may have a therapeutic role in reducing inflammatory reaction in the subarachnoid space. Monotherapy with such an anti-inflammatory drug may relieve the symptoms of mild infection and the host's immune responses to A. cantonensis larvae. In severe infection, however, co-therapy with an anthelmintic (to kill the larvae) and an anti-inflammatory agent (to provide symptomatic relief) is probably a better approach. The therapeutic strategy should be tailored to the severity of the illness and the numbers of eosinophils in the CSF.

Changes to plasminogen activators and matrix metalloproteinase-9 in dogs with toxocarosis

The relationship between proteolytic enzymes and hematological response to infection was studied in five 1-month-old dogs inoculated experimentally with 2000 eggs of Toxocara canis. Moderate leukocytosis and marked eosinophilia occurred 14 days post-infection with T. canis. Plasminogen activators (PAs) and matrix metalloproteinase-9 (MMP-9) activity in serum was significantly different in dogs infected with T. canis, compared with controls. Urokinase-type PA (uPA) activity was positively correlated with eosinophilia, and tissue-type PA (tPA) and MMP-9 activity was negatively correlated with eosinophilia. However, there was no correlation between inflammation and MMP-2. The use of uPA, tPA or MMP-9 proteolytic enzymes as laboratory reference markers for toxocarosis requires further study.

Icariin enhances the osteogenic differentiation of bone marrow stromal cells but has no effects on the differentiation of newborn calvarial osteoblasts of rats

Since the total flavonoid extract (TFE) of Epimedium herb was found to prevent osteoporosis induced by ovariectomy in rats, we have been attempting to identify the exact compound responsible for the bone-strengthening activity. In this experiment, four flavonoid extracts were obtained from Epimedium sagittatum (Siebold & Zucc.) Maxim, which contained 25.3%, 51.2%, 82.3% and 99.2% icariin respectively. They were separately supplemented into the culture media of newborn rat calvarial osteoblasts (ROB) or primary rat bone marrow stroma cells (rMSCs) at 0.1, 1, 10 and 100 microg/ml respectively, in order to observe their effects on the cells. Not any appreciable effect was found on the differentiation of ROB, but an enhancing effect on the osteogenic differentiation of rMSCs was found, and the enhancing degree was icariin-dependent, that is, a higher concentration of icariin in the extract caused more mineralized bone nodules and higher calcium deposition levels. The gene expressions involved in osteogenesis were also improved which was revealed by RT-PCR, including alkaline phosphatase, bone matrix protein (osteocalcin, osteopontin, bone sialoprotein) and cytokines (TGF-beta1 and IGF-I). The effect of icariin on cell proliferation was assayed by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Icariin inhibited the proliferation of rMSCs and ROB when its concentration was higher than 10(-5) microM (6.7 microg/ml), no stimulative effect was found. The above results indicated that icariin may exert bone-strengthening activity by enhancing the osteogenic differentiation of MSCs, which partially explains the anti-osteoporosis action of Epimedium herb.

Efficacy of curcumin therapy against Angiostrongylus cantonensis-induced eosinophilic meningitis

Angiostrongylus cantonensis can invade the central nervous system, leading to human eosinophilic meningitis or eosinophilic meningoencephalitis. Curcumin is a natural product which has the effects of anti-inflammation, anti-oxidation and anti-carcinogensis, while the administration of curcumin has been reported to possibly relieve the symptoms of meningitis. The present study tested the potential efficacy of curcumin in A. cantonensis-induced eosinophilic meningitis of BALB/c mice. Assay indicators for the therapeutic effect included the larvicidal effect, eosinophil counts and matrix metalloproteinase-9 (MMP-9) activity in angiostrongyliasis. Eosinophils were mildly reduced in treatment groups compared with infected-untreated mice. However, there were no significant differences in larvicidal effects or MMP-9 activity. This study suggests that anti-inflammatory treatment with curcumin alone has low efficacy, but the treatment does not interfere with MMP-9 expression and is not useful for larvicidal effects. The possible reasons include low curcumin across the blood-brain barrier and also those larvae that survive stimulate MMP-9 production, which promotes blood-brain barrier damage, with leukocytes then crossing the blood-brain barrier to cause meningitis. Further studies will be required to test these possibilities.

Icariin inhibits the osteoclast formation induced by RANKL and macrophage-colony stimulating factor in mouse bone marrow culture

Icariin is a prenylated flavonol glycoside contained in the herb Epimedium, which has long been used to improve bone fracture healing or prevent osteoporosis because of the belief that the herb has bone-strengthening action. We have previously demonstrated that icariin enhances the osteogenic differentiation of rat bone marrow stromal cells, and partially explained the bone-strengthening mechanism of the herb. In the present study, the effect of icariin on osteoclastogenesis and bone resorption activity was investigated in mouse bone marrow culture. It was found that icariin dose-dependently inhibited the growth and differentiation of hemopoietic cells from which osteoclasts were formed. Far less TRAP+ multinuclear cells appeared in the 10 microM icariin group than in the control. The bone resorption pits formed in the 10 microM icariin group was also significantly less than that of the control. RT-PCR analysis showed that the gene expression of TRAP, RANK and CTR was obviously lower than that of the control. It can be concluded that icariin has the ability to inhibit the formation and bone resorption activity of osteoclasts, which suggests that icariin should be the effective component for the bone-strengthening action of herb Epimedium.

Comparison of the effects of thoracic epidural analgesia and i.v. infusion with lidocaine on cytokine response, postoperative pain and bowel function in patients undergoing colonic surgery

BACKGROUND

Both thoracic epidural analgesia (TEA) and i.v. lidocaine were able to decrease postoperative pain and duration of ileus. We compared TEA and i.v. lidocaine (IV) regarding their effects on cytokines, pain and bowel function after colonic surgery.

METHODS

Sixty patients were randomly allocated to one of the three groups. TEA group had lidocaine 2 mg kg(-1) followed by 3 mg kg(-1) h(-1) epidurally and an equal volume of i.v. normal saline. The IV group received the same amount of lidocaine i.v. and normal saline epidurally. The control group received normal saline via both routes. These regimens were started 30 min before surgery and were continued throughout. Blood cytokines were measured at scheduled times within 72 h.

RESULTS

Both TEA and IV groups had better pain relief. The total consumptions using patient-controlled epidural analgesia were 81.6 (6.5), 55.0 (5.3) and 45.6 (3.9) ml (P<0.01) and the times of flatus passage were 50.2 (4.9), 60.2 (5.8) and 71.7 (4.7) h (P<0.01) in the TEA, IV and control groups, respectively. The TEA group exhibited the best postoperative pain relief and the least cytokine surge. The IV group experienced better pain relief and less cytokine release than the control group.

CONCLUSIONS

The TEA lidocaine had better pain relief, lower opioid consumption, earlier return of bowel function and lesser production of cytokines than IV lidocaine during 72 h after colonic surgery; IV group was better than the control group.

Six cases of ectopic ACTH syndrome caused by thymic carcinoid

The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.

Icariin, a flavonoid from the herb Epimedium enhances the osteogenic differentiation of rat primary bone marrow stromal cells

The herb Epimedium has long been used in Traditional Chinese Medicine to treat bone fracture and prevent osteoporosis. Researchers believe that the flavonoids contained in the herb are the effective component for this activity. However, no single flavonoid has been studied for its effect on bone-related cells. In the present study, icariin, one of the major flavonoids of the herb, supplemented the primary culture medium of rat bone marrow stromal cells (rMSCs) at 0.1 microM , 1 microM and 10 microM respectively. It was found that icariin stimulated the proliferation of rMSCs and increased the number of CFU-F stained positive for alkaline phosphatase in a dose-dependent manner. Icariin also dose-dependently increased the alkaline phosphatase activity, osteoalcin secretion and calcium deposition level of rMSCs during osteogenic induction. The addition of 10 microM icariin caused four times more mineralized bone nodules to be formed by rMSCs than in the control. The results demonstrated that icariin should be an effective component for bone-strengthening activity, and one of the mechanisms is to stimulate the proliferation and enhance the osteogenic differentiation of MSCs.

Matrix metalloproteinases activity demonstrated in the infective stage of the nematodes, Angiostrongylus cantonensis

Ingestion of the larval nematode Angiostrongylus cantonensis can cause the human eosinophilic meningitis known as angiostrongyliasis. Analysis of the extracts and excretory-secretory (ES) products of A. cantonensis larvae and adult stages on gelatin substrate zymography demonstrated the presence of distinct gelatinolytic enzymes. In worm extracts, inhibitor studies showed that the metalloproteinases revealed in L(1) (23 kDa), L(3) (66, 42 and 30 kDa), young adult worm (72 and 94 kDa) and adult worm (72 and 94 kDa). In ES products, the L(1) revealed one low (42 kDa) and two high (105 and 94 kDa) molecular weight proteolytic bands that degraded gelatin in substrate gels. The L(3) revealed three low (66, 50, and 30 kDa) and one high (105 kDa) molecular weight proteolytic bands. Inhibitor studies confirmed that the 105 and 94 proteolytic bands of the L(1), and the 50 and 30 kDa proteolytic bands of the L(3) classification were metalloproteinases. These metalloproteinases secreted in the infective larvae may be associated with the parasite dissemination or pathogenesis.

Ultrastructural localization of matrix metalloproteinase-9 in eosinophils from the cerebrospinal fluid of mice with eosinophilic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of eosinophilic meningitis caused by Angiostrongylus cantonensis. In the present study, such meningitis in mice was found to be associated with elevated expression of MMP-9 mRNA, elevated MMP-9 concentrations and enhanced MMP-9 activity in the cerebrospinal fluid (CSF). Immunocytochemistry showed that an anti-MMP-9 antibody reacted with macrophages, neutrophils and eosinophils from the CSF. As eosinophils are generally considered to be effector cells in host defence against A. cantonensis infection, high-resolution immuno-electron microscopy was then used to confirm the localization of MMP-9 in the eosinophils from the CSF. The method used, which was based on immunogold, indicated that the eosinophilic MMP-9 was mostly localized in the 'small' granules in the cytoplasm and along the cell membrane, and not in the crystalloid-containing secretory granules observed. It therefore appears that MMP-9 is synthesised and/or stored in the small granules of the eosinophils, and is released into the subarachnoid space of the host's brain by secretion or cell rupture.

Matrix metalloproteinase-2 and -9 in the granulomatous fibrosis of rats infected with Angiostrongylus cantonensis

The histomorphology of granuloma formation and gelatinase production were investigated in the brains, hearts, lungs and livers of Sprague-Dawley rats infected with Angiostrongylus cantonensis. The relationships between two gelatinases and granulomatous fibrosis were explored, following infection of each rat with 60 infective larvae of the nematode. Worm recovery from the brain was maximal on day 15 post-inoculation whereas peak recovery from the lungs was maximal 75 days later, on day 90. The granulomatous reactions and fibrosis were marked in the lungs but only mild, if present at all, in the brain, heart and liver. Gelatin zymography revealed that matrix metalloproteinase2 (MMP-2) was present, at all time-points, in the heart and lungs, although only in the lungs was there partial conversion of the 72-kDa pro-enzyme to the 64-kDa active form during granulomatous fibrosis. The activity of the MMP-9 pro-enzyme was significantly higher at the time-points when granuloma formation was observed than at other times. Immuno-histochemistry revealed MMP-2 and MMP-9 within the lung granulomas, around infiltrating leucocytes and the epithelial cells of the alveoli. As the granulomatous fibrosis appeared to be strongly associated with MMP-2 and MMP-9, these enzymes may be useful markers in the lungs of rats infected with A. cantonensis.

Induction of matrix metalloproteinase-9 in murine eosinophilic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinases (MMP) have been implicated in the pathogenesis of various inflammatory diseases of the central nervous system. In the present study, a gelatinase was found to be induced in parasitic meningitis caused, in mice, by Angiostrongylus cantonensis. The enzyme had a molecular weight of about 94 kDa, showed maximal activity between pH 6 and pH 8, and was clearly inhibited by EDTA and 1,10-phenanthroline but not by leupeptin or phenylmethanesulphonyl fluoride. When samples of cerebrospinal fluid from the mice with meningitis were blotted with specific antiserum against gelatinase B (MMP-9), a 94-kDa immunopositive band was observed, indicating that the induced gelatinase was MMP-9. In the A. cantonensis-infected mice, immuno-histochemistry demonstrated MMP-9 within the endothelial cells lining the vascular spaces of the brain and in the leucocytes that were found, in aggregates, in the subarachnoid space. Leucocytes may play an important role in the pathogenesis of inflammatory disorders of the central nervous system.

Efficacy of albendazole-GM6001 co-therapy against Angiostrongylus cantonensis-induced meningitis in BALB/c mice

Angiostrongylus cantonensis causes a form of parasitic meningitis in humans. Albendazole kills the nematode larvae staying in the brain. However, the dead larvae are capable of evoking a severe inflammatory response resulting in the brain damage. Matrix metalloproteinase 9 (MMP-9) is associated with the development of meningitis and with the immune inflammatory reaction. Presently, we studied the combination effects of albendazole and GM6001 (a MMP-9 inhibitor) against angiostrongyliasis in BALB/c mice. Co-administration of drugs produced marked effects; to kill the infecting larvae and to block MMP-9 activity. The combination treatment reduced MMP-9 activity by 89.2% in cerebrospinal fluid. The numbers of inflammatory cells increased significantly upon establishment of infection, but subsided upon co-treatment. Significantly fewer larvae were recovered from treated mice than from untreated, infected mice. The present results strongly suggest that co-therapy with albendazole and GM6001 may be an useful approach for the treatment of human angiostrongyliasis.

Induced eosinophilia and proliferation in Angiostrongylus cantonensis-infected mouse brain are associated with the induction of JAK/STAT1, IAP/NF-kappaB and MEKK1/JNK signals

Eosinophilic meningitis or meningoencephalitis caused by Angiostrongylus cantonensis is endemic to the Pacific area of Asia, especially Taiwan, Thailand, and Japan. Although eosinophilia is an important clinical manifestation of A. cantonensis infection, the role of eosinophils in the progress of the infection remains to be elucidated. In this experiment, we show that A. cantonensis-induced eosinophilia and inflammation might lead to the induction of IAP/NF-kappaB, JAK/STAT1 and MEKK1/JNK signals. The phosphorylation levels of JAK and JNK, STAT1, IAP, NF-kappaB and MEKK1 protein products were significantly increased after 12 days or 15 days of A. cantonensis infection. However, no significant differences in MAPKs such as Raf, MEK-1, ERK1/2 and p38 expression were found between control and infected mice. The activation potency of JAK/STAT1, IAP/NF-kappaB and MEKK1/JNK started increasing on day 3, with significant induction on day 12 or day 15 after A. cantonensis infection. Consistent results were noted in the pathological observations, including eosinophilia, leukocyte infiltration, granulomatous reactions, and time responses in the brain tissues of infected mice. These data suggest that the development of brain injury by eosinophilia of A. cantonensis infection is associated with activation of JAK/STAT1 signals by cytokines, and/or activation of MEKK1/JNK by oxidant stress, and/or activation of NF-kappaB by increasing IAP expression.

Induction of matrix metalloproteinase-9 in mice during Toxocara canis larvae migration

The relationships between inflammation in organs with Toxocara canis larval migration and matrix metalloproteinase-9 (MMP-9) were investigated following the infection of mice with 1,000 infective eggs. Gelatinase activity was defined by gelatin zymography, optimum pH, inhibitor specificity and Western blot analysis. MMP-9 activity was present in the lungs, liver, muscles, and brain during T. canis larval migration. This enzyme had a molecular weight of about 94 kDa and showed maximum activity in the pH range of 6-8. The increased MMP-9 proteinases coincided with larval recovery and the degree of inflammation among the four organs. These results suggest that MMP-9 may be associated with the inflammatory reaction to larval toxocariasis during early migration, and may therefore be a useful marker during T. canis larvae migration.

Association of matrix metalloproteinase-9 in eosinophilic meningitis of BALB/c mice caused by Angiostrongylus cantonensis

Induction of gelatinase in eosinophilic meningitis of BALB/c-strain mice was caused by Angiostrongylus cantonensis. Time-course studies showed that the molecular weight of 94-kDa gelatinase was detected at day 10 post-inoculation (PI), and reached a high intensity from days 15 to 25 PI. The 94-kDa gelatinase activity was clearly inhibited by EDTA and 1,10-phenanthroline, but not by leupeptin and phenylmethanesulphonyl fluoride. When immunoblots were performed using specific antiserums against the 94-kDa gelatinase B (matrix metalloproteinase-9; MMP-9) with cerebrospinal fluid (CSF), the 94-kDa immunopositive band was MMP-9. Immunohistochemistry studies demonstrated MMP-9 localisation within eosinophils and macrophages. The increased MMP-9 activity was closely associated with the rapid rise of CSF eosinophils, and the inflammatory reaction of the subarachnoid space. In contrast to changes in MMP-9, MMP-2 activity was constitutive and unaffected in this parasitic meningitis. These results show that MMP-9 was associated with eosinophilic meningitis, and that the enzyme may be a useful marker for angiostrongyliasis meningitis.

The efficacy of therapy with albendazole in mice with parasitic meningitis caused by Angiostrongylus cantonensis

Matrix metalloproteinase 9 (MMP-9) is involved in the pathogenesis of parasitic meningitis caused by the nematode Angiostrongylus cantonensis. The present study evaluated the efficacy of albendazole therapy in BALB/c mice infected with the third stage larvae of this nematode. Albendazole showed a pronounced larvicidal activity. Eosinophil numbers significantly increased in infected mice but decreased upon administration of albendazole. Densitometric scanning indicated that albendazole reduced gelatinolytic activity detected by gelatin-substrate zymography. In the cerebrospinal fluid, albendazole reduced the lytic area intensity of the 94 kDa MMP-9 band by 46.5% within 7 days, and by 51.5% by day 14. Examination of brain tissue revealed a similar pattern of decrease (48.6% by day 7, and 53.9% by day 14). Albendazole may thus be an effective compound for the treatment of angiostrongyliasis through its larvicidal activity and facilitation of an improved inflammatory response via the reduction of MMP-9 activity.

The serum of rats administered flavonoid extract from Epimedium sagittatum but not the extract itself enhances the development of rat calvarial osteoblast-like cells in vitro

The flavonoid extract from Epimedium sagittatum (FES) has been found by us to be effective in preventing osteoporosis induced by ovariectomy in rats. In the present study, the effect of FES on the development of rat calvarial osteoblast-like (ROB) cells was investigated. No appreciable effect was observed when ROB cells were exposed to FES in vitro. However, serum isolated from rats administered FES orally was able to significantly stimulate the proliferation as well as the osteoblastic differentiation of ROB cells compared to serum from control rats. The results indicate that the serum of rats administered FES contains active metabolites ofFES that enhance the development of osteoblasts, while the original form of FES itself is inactive.

Radiographic contrast media induced nephropathy: experimental observations and the protective effect of calcium channel blockers

Combined acute inhibition of the synthesis of nitric oxide with L-nitroarginine methyl ester (L-NAME) and of prostacycline synthesis with indomethacin predisposes rats to severe renal injury from radiographic contrast media. The reliability of this pharmacological manipulation in the study of radiographic contrast medium induced nephropathy (RCMN) was investigated. Adult male Sprague-Dawley rats were injected with iv L-NAME (10 mg kg(-1)) and iv indomethacin (10 mg kg(-1)) 15 min apart and prior to injection of RCM or normal saline (control group). A dose-dependent reduction in renal function was observed after intravascular injection of the high osmolar RCM diatrizoate (Angiografin, 306 mgI ml(-1)). A significant (p<0.01) increase in serum creatinine (Cr) (from 54.66+/-8.39 micromol l(-1) to 171.96+/-24.49 micromol l(-1) and from 80.95+/-6.73 micromol l(-1) to 204.76+/-16.73 micromol (-1), n=5 per group) was observed 24 h after injection of 6 ml and 8 ml of diatrizoate, respectively. The increase in serum Cr after injection of 8 ml of diatrizoate recovered spontaneously to 80.87+/-8.70 micromol l(-1) 7 days after injection. No significant change in renal function was observed in the control group (n=5) receiving 8 ml kg(-1) of normal saline or after injection of 4 ml of diatrizoate (serum Cr 69.84+/-5.5 micromol l(-1) pre contrast injection and 66.67+/-13.47 micromol l(-1) 24 h post contrast injection, n=5). The increase in serum Cr observed with 6 ml of diatrizoate was significantly higher (p<0.01) than the rise induced by equivolume of the low osmolar non-ionic monomer iopromide (Ultravist, 300 mgI ml(-1)) (serum CR 68.47+/-8.39 micromol l(-1) pre contrast injection and 143.59+/-32.03 micromol l(-1) 24 h post contrast injection, n=5). The calcium channel blocker diltiazem (10 mg kg(-1) injected intraperitoneally 30 min prior to RCM injection) prevented the rise in serum Cr observed with 6 ml of diatrizoate (serum Cr pre contrast injection 70.31+/-7.28 micromol(-1) and 78.21+/-17.81 micromol(-1) 24 h post contrast injection in animals pre-treated with diltiazem, n=5). The protective effect against RCM-induced reduction in renal function was less with lower doses of diltiazem. In conclusion, the animal model used is reliable and reproduced previously established observations in the field of RCMN. The protective effect of a calcium channel blocker at the appropriate dose against RCMN has also been shown. The clinical effectiveness of this class of drugs in preventing RCMN requires further evaluation.

Progressive supranuclear palsy on Guam

This is the first report demonstrating that progressive supranuclear palsy (PSP) exists on Guam. This 75-year-old Guamanian Chamorro patient with slight dementia and rigidity with restriction of ocular up gaze was diagnosed as parkinsonism-dementia complex (PDC) of Guam clinically. However, neurofibrillary tangles (NFTs) were scarcely seen in the cerebral cortices and hippocampus, but many NFTs, composed of 15-17 nm straight tubules, were detected in the subthalamic nucleus and brain stem. A large number of tuft-shaped astrocytes were observed in the putamen and motor cortex, and numerous argyrophilic grains were seen in the CA1 and subiculum. These pathological findings are different from those of PDC and consistent with PSP. The present case indicates that PSP and PDC clinically resemble each other, and that precise neuropathological examination is indispensable for the final diagnosis of the patient with parkinsonism, dementia and disturbance of vertical external ocular movement.

Facilitators and barriers to elders' practice of t'ai chi. A mind-body, low-intensity exercise

Research has documented the positive effects that t'ai chi has on the well-being of elders. However, the reasons that elders practice t'ai chi have not been explored. The purpose of this study was to describe the facilitators and barriers to t'ai chi practice in elderly populations. Taiwanese community-dwelling elders (40 of whom practiced t'ai chi and 40 who did not) aged 65 and older, matched on age and gender, were interviewed. Results showed that encouragement from others was the most important factor for elders to practice t'ai chi, whereas positive health outcomes were the reason they continued to practice it. Most of the non-t'ai chi group participants had never thought about practicing t'ai chi because they felt they were too weak to practice. Because t'ai chi can be helpful in promoting the well-being of elders, it is essential for health care professionals to overcome the barriers to its uses in elderly populations.

Clinical use of tai chi in elderly populations

Tai chi, a type of low-intensity exercise, has received growing attention in both eastern and western cultures, especially its use with the most rapidly increasing segment of the population-elders. Previous research findings further supported the idea that tai chi is appropriate for elderly populations and helps promote their well-being. In this article, the beneficial effects of tai chi for elders are summarized, resources to increase awareness about the exercise are provided, and ways to promote tai chi in elderly populations are suggested.

Glutamine utilization in activated lymphocytes from rats receiving endotoxin

BACKGROUND

A beneficial effect of supplemental glutamine for lymphocyte function in patients under metabolic stress has been suggested. Nevertheless, it is not clear how glutamine is used by lymphocytes when under stress. This time course study investigated the effect of endotoxin-induced stress on in vitro glutamine utilization and glutamine-dependent proliferation of activated lymphocytes.

METHODS

Metabolic stress was modeled by intraperitoneal (ip) administration of endotoxin (5 mg/kg body wt) to rats. Control animals were injected with sterile saline. Cervical lymph node lymphocytes collected from animals 6, 12, 24, and 48 h following injection were activated with concanavalin A. Proliferation of these activated lymphocytes in the presence of 0.1-2 mM glutamine was determined. The glutamine utilization rate and glutaminase activity in the activated lymphocytes were also determined.

RESULTS

The proliferation rate of lymphocytes was not affected by ip administration of endotoxin 6 h following the insult, however, 12, 24, and 48 h following the insult, the maximal response was suppressed (P < 0.05). In addition, at 12, 24, and 48 h, the concentration of glutamine for the maximal response of lymphocytes was lower than that for the control group (P < 0.05). Throughout the investigation period, both the glutamine utilization rate and glutaminase activity in the activated lymphocytes were decreased time-dependently.

CONCLUSION

The present study demonstrates that glutamine utilization by lymphocytes under a mitogenic challenge in vitro is significantly decreased in the late period after endotoxin injection. This is at least partly due to decreased glutaminase activity and is associated with decreased proliferation rate of mitogen-activated lymphocytes.

Effect of electromagnetic field exposure on chemically induced differentiation of friend erythroleukemia cells

Whether exposure of humans to extremely low frequency electromagnetic fields (ELF-EMF) can cause cancer is controversial and therefore needs further research. We used a Friend erythroleukemia cell line that can be chemically induced to differentiate to determine whether ELF-EMF could alter proliferation and differentiation in these cells in a manner similar to that of a chemical tumor promoter. Exposure of this cell line to 60 Hz ELF-EMF resulted in a dose dependent inhibition of differentiation, with maximal inhibition peaking at 40% and 40 mG (4 microT). ELF-EMF at 10 mG (1.0 microT) and 25 mG (2.5 microT) inhibited differentiation at 0 and 20%, respectively. ELF-EMF at 1.0 (100) and 10.0 G (1,000 microT) stimulated cell proliferation 50% above the sham-treated cells. The activity of telomerase, a marker of undifferentiated cells, decreased 100[times] when the cells were induced to differentiate under sham conditions, but when the cells were exposed to 0.5 G (50 microT) there was only a 10[times] decrease. In summary, ELF-EMF can partially block the differentiation of Friend erythroleukemia cells, and this results in a larger population of cells remaining in the undifferentiated, proliferative state, which is similar to the published results of Friend erythroleukemia cells treated with chemical-tumor promoters.

The natural resistance-associated macrophage protein gene in African Americans with sarcoidosis

The histologic and clinical similarities between tuberculosis and sarcoidosis suggest a shared underlying pathophysiology. Human natural resistance-associated macrophage protein (NRAMP1), which is closely related to the mouse gene, has been associated with susceptibility to tuberculosis in some human populations. Given the importance of the Nramp1 gene in animal models of granulomatous disorders, the association with human tuberculosis, and the possible role of NRAMP1 in macrophage activation and function, we hypothesized that human NRAMP1 plays a role in susceptibility to sarcoidosis. We analyzed several NRAMP1 gene polymorphisms in a case-control study of 157 African American patients with sarcoidosis and 111 African American control subjects. Our results, in contrast to those in tuberculosis patients, showed that the less common genotypes were found more often in control subjects than in case patients (odds ratio, 0.48; 95% confidence interval, 0.28-0.81). In particular, one polymorphism, a (CA)(n) repeat in the immediate 5' region of the gene, was found to have a protective effect (P = 0. 014). Whereas NRAMP1 polymorphisms have been associated with increased susceptibility to tuberculosis, our results suggest that at least one NRAMP1 polymorphism may decrease susceptibility in sarcoidosis.

Parkinsonism, dementia and vertical gaze palsy in a Guamanian with atypical neuroglial degeneration

A 58-year-old Chamorro female patient, who died in 1993, was examined clinicopathologically. At the age of 51, she suffered from hemiparkinsonism, then bradykinesia, rigidity without tremor, and dementia. Extrapyramidal symptoms developed, and at the age of 57, vertical gaze palsy was noted. The clinical diagnosis was parkinsonism-dementia complex (PDC) with vertical gaze palsy. The brain showed atrophy in the frontal and temporal lobes, and the atrophy was accentuated in the dentate gyrus, Ammon's horn and parahippocampal gyrus. The basal ganglia, thalamus and midbrain were moderately atrophic. The substantia nigra and locus ceruleus were completely depigmented. Numerous neurofibrillary tangles (NFTs) were seen in the subiculum and amygdaloid nucleus. Many NFTs were evident in the parahippocampal gyrus, lateral occipitotemporal gyrus, insula, Sommer sector, basal nucleus of Meynert, lateral nucleus of the thalamus, subthalamic nucleus and brain stem, and several were observed in the globus pallidus and hypothalamus. The Sommer sector, substantia nigra, locus ceruleus and basal nucleus of Meynert showed severe loss of neurons, and a moderate loss of neurons was exhibited by the globus pallidus. These findings were apparently consistent with those associated with PDC. However, in this patient, severe neuronal loss was seen in the subthalamic nucleus and lateral nucleus of the thalamus, and grumose degeneration, which has not previously been reported in PDC, was seen in the dentate nucleus. In addition, many tufted astrocytes, which have been reported to occur in progressive supranuclear palsy (PSP) and postencephalitic parkinsonism, but scarcely observed in PDC, were present. Furthermore, astrocytic plaques, which have been considered as a specific finding of corticobasal degeneration (CBD), were observed in the cerebral cortex. On the other hand, granular hazy astrocytic inclusions, previously reported to occur in PDC, were not seen. Chromatolytic neurons were not observed. The question thus arises as to whether it is appropriate to consider this patient as having suffered from a combination of PDC, PSP and CBD. From the view points of absence of granular hazy astrocytic inclusions and chromatolytic neurons, and of tufted astrocytes in the neostriatum, it is conceivable that this patient is a case of a new disease entity.

Microwave life-detection systems for searching human subjects under earthquake rubble or behind barrier

A new sensitive microwave life-detection system which can be used to locate human subjects buried under earthquake rubble or hidden behind various barriers has been constructed. This system operating at 1150 MHz or 450 MHz can detect the breathing and heartbeat signals of human subjects through an earthquake rubble or a construction barrier of about 10-ft thickness. The basic physical principle for the operation of a microwave life-detection system is rather simple. When a microwave beam of appropriate frequency (L or S band) is aimed at a pile of earthquake rubble covering a human subject or illuminated through a barrier obstructing a human subject, the microwave beam can penetrate the rubble or the barrier to reach the human subject. When the human subject is illuminated by a microwave beam, the reflected wave from the human subject will be modulated by the subject's body movements, which include the breathing and the heartbeat. If the clutter consisting of the reflected wave from stationary background can be completely eliminated and the reflected wave from the human subject's body is properly modulated, the breathing and heartbeat signals of the subject can be extracted. Thus, a human subject buried under earthquake rubble or hidden behind barriers can be located. This system has been tested extensively in a simulated earthquake rubble in the laboratory and also in a field test using realistic earthquake rubble conducted by a Federal Emergency Management Agency (FEMA) Task Force.

Oral urografin in postoperative small bowel obstruction

The aim of our study was to determine whether Urografin has the potential to offer surgeons a way of differentiating complete from partial small bowel obstruction and whether partial small bowel obstruction can be treated nonoperatively. Altogether 116 patients who had postoperative small bowel obstructions without any toxic signs underwent Urografin studies. Urografin (40 ml) mixed with 40 ml of distilled water was administrated either orally or via nasogastric tube to each patient. Serial plain abdominal radiographs were taken 2, 4, and 8 hours later. A total of 74 patients (63.8%) whose contrast medium reached the colon within the first 8 hours were considered to have partial obstruction and were successfully treated with intravenous hydration and nasogastric decompression. The remaining 42 patients (36.2%) in whom the contrast medium failed to reach the colon within the first 8 hours were regarded as having complete obstruction, and 34 of those patients (81.0%) underwent surgery; 8 (19.0%) received conservative treatment. Adhesion bands with complete bowel obstruction were observed in all 34 patients (100.0%) during laparotomy. Regardless of the presence of an air-fluid level on a plain abdominal radiograph or abdominal pain, a liquid diet followed by a soft diet could be given to those patients whose Urografin emptied into the colon. All the patients with partial bowel obstruction were treated successfully with nonoperative methods. The presence of Urografin in the colon within 8 hours of ingestion as an indicator for nonoperative treatment had a sensitivity of 90.2%, a specificity of 100%, and an accuracy of 93. 1%. Urografin, a safe and reliable water-soluble contrast medium, can be used to differentiate partial intestinal obstruction from complete intestinal obstruction. Early oral intake was found to be a major advantage of Urografin use in this study, and the potential of Urografin use to shorten the period of conservative treatment for postoperative small bowel obstruction needs further investigation.

A research-based use of Tai Chi/movement therapy as a nursing intervention

Tai Chi has been widely practiced in China for centuries as an art form, religious ritual, relaxation technique, exercise, and a method of self-defense for people of all ages. It has been used to improve balance; promote postural stability; decrease falls; enhance cardiovascular and ventilatory functions; rehabilitate persons with acute myocardial infarction and rheumatoid arthritis; and reduce pain, stress, and nightmares. The purpose of this article is to summarize, synthesize, and critically evaluate the research-based use of Tai Chi presented in the current literature and give implications and directions for future research. Additional studies about the effects of Tai Chi from a nursing perspective are needed to make clear when it is beneficial as a nursing intervention.

The Blau syndrome gene is not a major risk factor for sarcoidosis

BACKGROUND

A genetic predisposition to sarcoidosis has long been postulated, although no specific susceptibility genes are known. Candidate genes for the two granulomatous inflammatory disorders with clinical similarities to sarcoidosis, Blau syndrome and Crohn's disease, have been localized to a 40 centimorgan region spanning the chromosome 16 centromere.

PATIENTS AND METHODS

Using a sample of 35 African-American sibling pairs, who both had clinically confirmed sarcoidosis, we tested for genetic linkage between the 16p12-q21 interval (the likely location of the Blau syndrome gene) and sarcoidosis.

RESULTS

We found no evidence for linkage to any of the eight markers we tested in the 16p12-q21 interval. Ninety percent of the 16p12-q21 region had a LOD score < -2 for a dominant gene conferring a relative risk of 3 or greater for sarcoidosis. One hundred percent of the region had a LOD score < -2 for a dominant gene with a relative risk of 3.5 or greater or recessive gene with relative risk of 2.5 or greater. Based on simulation results we could not exclude a dominant gene with relative risk < 5 at the 0.05 significance level, nor a recessive gene with relative risk < 3, over the entire 16p12-q21 interval.

CONCLUSIONS

While the clinical similarities between Blau Syndrome and sarcoidosis suggest genetic homogeneity between the disorders, we found no evidence for linkage of sarcoidosis to the Blau syndrome locus. Our exclusion results suggest that the Blau Syndrome gene does not have a major effect on sarcoidosis susceptibility.