The taxonomic composition of the donor intestinal microbiota is a major factor influencing the efficacy of faecal microbiota transplantation in therapy refractory ulcerative colitis.

BACKGROUND: Faecal microbiota transplantation is an experimental approach for the treatment of patients with ulcerative colitis. Although there is growing evidence that faecal microbiota transplantation is effective in this disease, factors affecting its response are unknown. AIMS: To establish a faecal microbiota transplantation treatment protocol in ulcerative colitis patients, and to investigate which patient or donor factors are responsible for the treatment success. METHODS: This is an open controlled trial of repeated faecal microbiota transplantation after antibiotic pre-treatment (FMT-group, n = 17) vs antibiotic pre-treatment only (AB-group, n = 10) in 27 therapy refractory ulcerative colitis patients over 90 days. Faecal samples of donors and patients were analysed by 16SrRNA gene-based microbiota analysis. RESULTS: In the FMT-group, 10/17 (59%) of patients showed a response and 4/17 (24%) a remission to faecal microbiota transplantation. Response to faecal microbiota transplantation was mainly influenced by the taxonomic composition of the donor's microbiota. Stool of donors with a high bacterial richness (observed species remission 946 ± 93 vs no response 797 ± 181 at 15367 rps) and a high relative abundance of Akkermansia muciniphila (3.3 ± 3.1% vs 0.1 ± 0.2%), unclassified Ruminococcaceae (13.8 ± 5.0% vs 7.5 ± 3.7%), and Ruminococcus spp. (4.9 ± 3.5% vs 1.0 ± 0.7%) were more likely to induce remission. In contrast antibiotic treatment alone (AB-group) was poorly tolerated, probably because of a sustained decrease of intestinal microbial richness. CONCLUSIONS: The taxonomic composition of the donor's intestinal microbiota is a major factor influencing the efficacy of faecal microbiota transplantation in ulcerative colitis patients. The design of specific microbial preparation might lead to new treatments for ulcerative colitis.

Renin angiotensinogen system gene polymorphisms and essential hypertension among people of West African descent: a systematic review.

This systematic review investigates the high level of hypertension found among urban dwellers in West Africa and in the West African Diaspora in the Americas in relation to variants within the genes encoding the renin angiotensinogen system. For comparison, the results from the Caucasian populations are reviewed as well. Through a PubMed search, 1252 articles were identified and 28 eligible articles assessed in detail of which 13 included a Caucasian population. The results suggest that among the people of West African descent and among the people of Caucasian descent, hypertension is partly related to a number of single nucleotide polymorphisms (SNPs) and haplotypes in the renin gene, the angiotensinogen gene, the angiotensinogen I-converting enzyme gene and the angiotensinogen II type 1 receptor gene. Concordance between these two populations was found for some SNPs. However, for others, it was found that the SNPs associating with hypertension and the disease allele frequencies differed between these populations. Understanding the importance of these variants in a modern life setting may assist our understanding of the increased risk of developing hypertension among West Africans. Because of inconsistency in the results, low statistical power and methodological differences between studies, these results can only be taken as indicative of an association.

Dose-dependent modulation of HIF-1alpha/sima controls the rate of cell migration and invasion in Drosophila ovary border cells.

The role of the hypoxic response during metastasis was analysed in migrating border cells of the Drosophila ovary. Acute exposure to 1% O(2) delayed or blocked border cell migration (BCM), whereas prolonged exposure resulted in the first documented accelerated BCM phenotype. Similarly, manipulating the expression levels of sima, the Drosophila hypoxia-inducible factor (HIF)-1alpha ortholog, revealed that Sima can either block or restore BCM in a dose-dependent manner. In contrast, over-expression of Vhl (Drosophila von Hippel-Lindau) generated a range of phenotypes, including blocked, delayed and accelerated BCM, whereas over-expression of hph (Drosophila HIF prolyl hydroxylase) only accelerated BCM. Mosaic clone analysis of sima or tango (HIF-1beta ortholog) mutants revealed that cells lacking Hif-1 transcriptional activity were preferentially detected in the leading cell position of the cluster, resulting in either a delay or acceleration of BCM. Moreover, in sima mutant cell clones, there was reduced expression of nuclear slow border cells (Slbo) and basolateral DE-cadherin, proteins essential for proper BCM. These results show that Sima levels define the rate of BCM in part through regulation of Slbo and DE-cadherin, and suggest that dynamic regulation of Hif-1 activity is necessary to maintain invasive potential of migrating epithelial cells.

Degenerative spondylolysis: a concise report of scintigraphic observations.

OBJECTIVES: Spondylolysis is traditionally thought to be a diagnosis of adolescence and childhood, and is ascribed to mechanical stress through the immature pars interarticularis. Over the last 4 yr we have noted a presentation of spondylolysis in association with hypertrophic zygapophyseal joint disease in the lumbar spine in an older age group. METHODS: Records of 94 patients presenting with low back pain were examined. A pattern of intense zygapophyseal joint uptake in association with extended uptake in the pars interarticularis was ascribed as degenerative spondylolysis. RESULTS: The ages of the 94 cases ranged from 33 to 80 yr (mean 64 yr). There were 53 males and 41 females. In the group with degenerative spondylolysis the mean age was 72 yr, with four females and two males. None of these six patients gave a history of childhood spinal disease or back pain and all were relatively inactive in terms of current participation in sport. All cases of spondylolysis were confirmed by computed tomography scanning. CONCLUSION: The finding of hypertrophic zygapophyseal joint disease in association with spondylolysis is easily recognized by scintigraphic tomographic imaging.

The 1.4-Mb CMT1A duplication/HNPP deletion genomic region reveals unique genome architectural features and provides insights into the recent evolution of new genes.

Duplication and deletion of the 1.4-Mb region in 17p12 that is delimited by two 24-kb low copy number repeats (CMT1A-REPs) represent frequent genomic rearrangements resulting in two common inherited peripheral neuropathies, Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsy (HNPP). CMT1A and HNPP exemplify a paradigm for genomic disorders wherein unique genome architectural features result in susceptibility to DNA rearrangements that cause disease. A gene within the 1.4-Mb region, PMP22, is responsible for these disorders through a gene-dosage effect in the heterozygous duplication or deletion. However, the genomic structure of the 1.4-Mb region, including other genes contained within the rearranged genomic segment, remains essentially uncharacterized. To delineate genomic structural features, investigate higher-order genomic architecture, and identify genes in this region, we constructed PAC and BAC contigs and determined the complete nucleotide sequence. This CMT1A/HNPP genomic segment contains 1,421,129 bp of DNA. A low copy number repeat (LCR) was identified, with one copy inside and two copies outside of the 1.4-Mb region. Comparison between physical and genetic maps revealed a striking difference in recombination rates between the sexes with a lower recombination frequency in males (0.67 cM/Mb) versus females (5.5 cM/Mb). Hypothetically, this low recombination frequency in males may enable a chromosomal misalignment at proximal and distal CMT1A-REPs and promote unequal crossing over, which occurs 10 times more frequently in male meiosis. In addition to three previously described genes, five new genes (TEKT3, HS3ST3B1, NPD008/CGI-148, CDRT1, and CDRT15) and 13 predicted genes were identified. Most of these predicted genes are expressed only in embryonic stages. Analyses of the genomic region adjacent to proximal CMT1A-REP indicated an evolutionary mechanism for the formation of proximal CMT1A-REP and the creation of novel genes by DNA rearrangement during primate speciation.

A systematic analysis of human disease-associated gene sequences in Drosophila melanogaster.

We performed a systematic analysis of 929 human disease gene entries associated with at least one mutant allele in the Online Mendelian Inheritance in Man (OMIM) database against the recently completed genome sequence of Drosophila melanogaster. The results of this search have been formatted as an updateable and searchable on-line database called Homophila. Our analysis identified 714 distinct human disease genes (77% of disease genes searched) matching 548 unique Drosophila sequences, which we have summarized by disease category. This breakdown into disease classes creates a picture of disease genes that are amenable to study using Drosophila as the model organism. Of the 548 Drosophila genes related to human disease genes, 153 are associated with known mutant alleles and 56 more are tagged by P-element insertions in or near the gene. Examples of how to use the database to identify Drosophila genes related to human disease genes are presented. We anticipate that cross-genomic analysis of human disease genes using the power of Drosophila second-site modifier screens will promote interaction between human and Drosophila research groups, accelerating the understanding of the pathogenesis of human genetic disease. The Homophila database is available at http://homophila.sdsc.edu.

Difluoroketones as inhibitors of matrix metalloprotease-13.

Substrate-like difluoroketones have been prepared as potential inhibitors of MMP-13. Weak inhibition was seen with the key target 2. This and the more potent activity of intermediate 7b illustrates that hydrated ketones can be used to inhibit MMP-13 and perhaps other members of this class of enzymes.

Molecular mechanisms for CMT1A duplication and HNPP deletion.

As the best characterized human genomic disorders, CMT1A and HNPP illustrate several common mechanistic features of genomic rearrangements. These features include the following: (1) Recombination occurs between homologous sequences flanking the duplicated/deleted genomic segment. (2) The evolution of the mammalian genome may result in an architecture consisting of region-specific low-copy repeats that predispose to rearrangement secondary to providing homologous regions as substrate for recombination. (3) Strand exchange occurs preferentially in a region of perfect sequence identity within the flanking repeat sequences. (4) Double-strand breaks likely initiate recombination between the flanking repeats. (5) The mechanism and rate of homologous recombination resulting in DNA rearrangement may differ for male and female gametogenesis. (6) Homologous recombination resulting in DNA rearrangement occurs with high frequency in the human genome. (7) Genomic disorders result from structural features of the human genome and not population specific alleles or founder effects; therefore, genomic disorders appear to occur with equal frequencies in different world populations.

Localization of mariner DNA transposons in the human genome by PRINS.

Homologous recombination occurring among misaligned repeated sequences is a significant source of the molecular rearrangements resulting in human genetic disease. Studies of the Charcot-Marie-Tooth disease locus on chromosome 17 have implicated the involvement of an ancient DNA transposon of the mariner family (Hsmar2) in the initiation of double-strand break events leading to homologous recombination. In this study, the genomic locations of 109 Hsmar2 elements were determined by primed in situ labeling (PRINS) using primers designed to match the right and left inverted terminal repeats (ITRs) of the transposon. Although the resolution of the PRINS technique is approximately 400 chromosomal Giemsa bands, the data presented here provide the first large-scale mapping study of these elements, which may be involved in initiation of homologous recombination events in the human genome.

Inhibition of MMP-1 and MMP-13 with phosphinic acids that exploit binding in the S2 pocket.

Through the use of empirical and computational methods, phosphinate-based inhibitors of MMP-1 and MMP-13 that bind into the S2 pocket of these enzymes were designed. The synthesis and testing of 2 suggested that binding was occurring as hypothesized. Structure determination of a co-crystal of 2 bound to the catalytic domain of MMP-1 confirmed the binding mode. Substituents binding into S2, S1', S2' and S3', were optimized yielding compounds with low double-digit nM IC50's against these enzymes.

Molecular Mechanisms for CMT1A Duplication and HNPP Deletion.

As the best characterized human genomic disorders, 118 CMT1A and HNPP illustrate several common mechanistic features of genomic rearrangements. These features include the following: (1) Recombination occurs between homologous sequences flanking the duplicated/deleted genomic segment. (2) The evolution of the mammalian genome may result in an architecture consisting of region-specific low-copy repeats that predispose to rearrangement secondary to providing homologous regions as substrate for recombination. (3) Strand exchange occurs preferentially in a region of perfect sequence identity within the flanking repeat sequences. (4) Double-strand breaks likely initiate recombination between the flanking repeats. (5) The mechanism and rate of homologous recombination resulting in DNA rearrangement may differ for male and female gametogenesis. (6) Homologous recombination resulting in DNA rearrangement occurs with high frequency in the human genome. (7) Genomic disorders result from structural features of the human genome and not population specific alleles or founder effects; therefore, genomic disorders appear to occur with equal frequencies in different world populations.

The preclinical pharmacological profile of the potent and selective leukotriene B4 antagonist CP-195543.

CP-195543 [(+)-2-(3-benzyl-4-hydroxy-chroman-7-yl)-4-trifluoromethyl-benzoic acid] is a structurally novel, selective and potent leukotriene B4 (LTB4) receptor antagonist. In vitro CP-195543 inhibited [3H]LTB4 binding to high-affinity LTB4 receptors on human neutrophils (HN) and murine spleen membranes with IC50 values of 6.8 nM (Ki = 4.9 nM) and 37.0 nM (Ki = 26.9 nM), respectively. CP-195543 inhibited human and mouse neutrophil chemotaxis mediated by LTB4 with IC50 values of 2.4 nM and 7.5 nM, respectively. Evidence of noncompetitive antagonist effects on the HN high-affinity LTB4 receptor was obtained by Scatchard analysis of [3H]LTB4 binding to and chemotaxis of HN to LTB4. Scatchard analyses of [3H]LTB4 binding to low-affinity receptors on HN indicated that CP-195543 acted as a competitive antagonist at this receptor, and inhibition of LTB4-mediated CD11b up-regulation on HN was inhibited competitively by CP-195543 (pA2 = 7.66). In whole blood, CP-195543 also blocked CD11b up-regulation on HN (pA2 = 7.12) and murine neutrophils (pA2 = 7.06) with a similar potency. LTB4-mediated CD11b up-regulation on human monocytes and eosinophils in whole blood were inhibited by CP-195543 with IC50 values of 270 nM and 420 nM, respectively. CP-195543 at 10 microM failed to inhibit HN chemotaxis and CD11b up-regulation mediated through alternative (i.e., complement fragment 5a, interleukin-8, platelet-activating factor) G-protein-coupled chemotactic factor receptors. In vivo, after oral administration, CP-195543 blocked LTB4-mediated neutrophil infiltration in guinea pig and murine skin with ED50 values of 0.1 mg/kg and 2.8 mg/kg p.o., respectively. When administered in osmotic pumps, CP-195543 reduced the clinical symptoms and attendant weight loss in an IL-1-exacerbated murine model of collagen-induced arthritis with half-maximal effects associated with plasma drug levels of 0.4 to 0.5 microg/ml. Collectively these data provide evidence of the in vitro potency and in vivo efficacy of a novel LTB4 antagonist and support its clinical evaluation in a variety of inflammatory diseases in man.

Human meiotic recombination products revealed by sequencing a hotspot for homologous strand exchange in multiple HNPP deletion patients.

The HNPP (hereditary neuropathy with liability to pressure palsies) deletion and CMT1A (Charcot-Marie-Tooth disease type 1A) duplication are the reciprocal products of homologous recombination events between misaligned flanking CMT1A-REP repeats on chromosome 17p11. 2-p12. A 1.7-kb hotspot for homologous recombination was previously identified wherein the relative risk of an exchange event is 50 times higher than in the surrounding 98.7% identical sequence shared by the CMT1A-REPs. To refine the region of exchange further, we designed a PCR strategy to amplify the recombinant CMT1A-REP from HNPP patients as well as the proximal and distal CMT1A-REPs from control individuals. By comparing the sequences across recombinant CMT1A-REPs to that of the proximal and distal CMT1A-REPs, the exchange was mapped to a 557-bp region within the previously identified 1.7-kb hotspot in 21 of 23 unrelated HNPP deletion patients. Two patients had recombined sequences suggesting an exchange event closer to the mariner-like element previously identified near the hotspot. Five individuals also had interspersed patches of proximal or distal repeat specific DNA sequence indicating potential gene conversion during the exchange of genetic material. Our studies provide a direct observation of human meiotic recombination products. These results are consistent with the hypothesis that minimum efficient processing segments, which have been characterized in Escherichia coli, yeast, and cultured mammalian cells, may be required for efficient homologous meiotic recombination in humans.

The U.S. federal framework for research on endocrine disruptors and an analysis of research programs supported during fiscal year 1996.

The potential health and ecological effects of endocrine disrupting chemicals has become a high visibility environmental issue. The 1990s have witnessed a growing concern, both on the part of the scientific community and the public, that environmental chemicals may be causing widespread effects in humans and in a variety of fish and wildlife species. This growing concern led the Committee on the Environment and Natural Resources (CENR) of the National Science and Technology Council to identify the endocrine disruptor issue as a major research initiative in early 1995 and subsequently establish an ad hoc Working Group on Endocrine Disruptors. The objectives of the working group are to 1) develop a planning framework for federal research related to human and ecological health effects of endocrine disrupting chemicals; 2) conduct an inventory of ongoing federal research programs; and 3) identify research gaps and develop a coordinated interagency plan to address priority research needs. This communication summarizes the activities of the federal government in defining a common framework for planning an endocrine disruptor research program and in assessing the status of the current effort. After developing the research framework and compiling an inventory of active research projects supported by the federal government in fiscal year 1996, the CENR working group evaluated the current federal effort by comparing the ongoing activities with the research needs identified in the framework. The analysis showed that the federal government supports considerable research on human health effects, ecological effects, and exposure assessment, with a predominance of activity occurring under human health effects. The analysis also indicates that studies on reproductive development and carcinogenesis are more prevalent than studies on neurotoxicity and immunotoxicity, that mammals (mostly laboratory animals) are the main species under study, and that chlorinated dibenzodioxins and polychlorinated biphenyls are the most commonly studied chemical classes. Comparison of the inventory with the research needs should allow identification of underrepresented research areas in need of attention.

trans-3-Benzyl-4-hydroxy-7-chromanylbenzoic acid derivatives as antagonists of the leukotriene B4 (LTB4) receptor.

The SAR of a series of 2-(7-chromanyl)benzoic acids has been investigated with the aim of identifying potent and selective LTB4 receptor antagonists that maintain potency in complex biological fluids. We found optimal activity in derivatives with electron-withdrawing groups in the benzoic acid ring and with an unsubstituted C-3 benzyl group on the chromanol nucleus. While compounds containing a 3-(4-phenyl)benzyl chromanol substituent were potent LTB4 receptor antagonists, the increased lipophilicity imparted by the additional phenyl substituent led to decreased potency in the presence of plasma proteins. From among the potent compounds identified, CP-195543, the 5'-trifluoromethyl 3-benzyl chromanol, was selected for development.

The human COX10 gene is disrupted during homologous recombination between the 24 kb proximal and distal CMT1A-REPs.

The CMT1A-REPs are two large directly repeating DNA sequences located on chromosome 17p11.2-p12 flanking the region duplicated in patients with Charcot-Marie-Tooth disease type 1A (CMT1A) and deleted in patients with hereditary neuropathy with liability to pressure palsies (HNPP). We have sequenced two cosmids, c74F4 and c15H12, which contain the entire proximal and distal CMT1A-REPs and determined that these repeats are approximately 99% identical across a 24,011 bp region. In addition, both contain an exon of the human heme A:farnesyltransferase gene (COX10). Hybridization studies revealed that COX10 spans the distal CMT1A-REP, while the proximal CMT1A-REP contains an isolated COX10 'pseudo-exon'. There is also a COX10 hybridization signal on chromosome 10 which appears to represent a processed pseudogene. We propose that the distal CMT1A-REP represents the progenitor copy of COX10 exon VI which was duplicated with surrounding intronic sequences during mammalian genome evolution and that the HNPP deletion results in a COX10 null allele.

Genomic structure and expression of the human heme A:farnesyltransferase (COX10) gene.

Charcot-Marie-Tooth disease type 1A (CMT1A) is associated with a 1.5-Mb tandem DNA duplication in chromosome 17p11.2-p12, while hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a 1.5-Mb deletion at this locus. The 1.5-Mb CMT1A monomer unit duplicated in CMT1A and deleted in HNPP is flanked by two 24-kb direct repeats termed the CMT1A-REPs. Recently, sequence analysis of the CMT1A-REPs revealed that they contain an internal exon of the COX10 gene. To characterize COX10, encoding human heme A:farnesyltransferase, the genomic region was isolated and the gene structure and expression profile were determined. COX10 spans approximately 135 kb and consists of seven exons. Exons I-V are telomeric to the 1.5-Mb CMT1A monomer unit, whereas exon VII is located within this 1.5-Mb region. Exon VI is contained within the distal CMT1A-REP. All splice sites conform to the GT/AG rule. Analysis of the putative promoter region of the COX10 gene indicates that it lacks conventional TATA and CAAT boxes, but it does have several potential transcription factor-binding sites. This gene is expressed in multiple tissues with highest expression observed in the heart, skeletal muscle, and testis.

Plasminogen activators play an essential role in extracellular-matrix invasion by lymphoblastic T cells.

Involvement of extravascular sites, in particular infiltration of the central nervous system, is a frequent complication of T-lymphoblastic leukemia and contributes to leukemia-associated morbidity. In this report, we studied the contribution of plasminogen activators to the invasive properties of 7 human T-cell lines in a model of transmigration through an extracellular matrix. The T-cell lines were found to express either urokinase (u-PA) and high levels of u-PA receptor or tissue-type plasminogen activator (t-PA) and low levels of u-PA receptor. The rate of transmigration was consistently higher for u-PA-expressing cells than for t-PA-expressing cells. PA-inhibitor type 1 (PAI-1) was detected in the conditioned medium of one cell line and PAI-2 was detected in cell extracts from 6 lines. The transmigration of 6 out of 7 cell lines was inhibited by trasylol, an inhibitor of plasmin, by an excess of exogenous PAI-1 or PAI-2, and by antibodies to the particular PA type expressed by the cells. Partial inhibition of transmigration by the amino-terminal fragment of u-PA implies that the u-PA receptor contributes to transmigration. Thus, the transmigration of T-leukemia cells through a barrier of extracellular matrix requires PA-dependent proteolysis, which can be provided either by u-PA or t-PA. Specific inhibition of the PA system could provide a means to inhibit tissue invasion by T lymphoblastic cells.

Detection of the CMT1A/HNPP recombination hotspot in unrelated patients of European descent.

Charcot-Marie-Tooth type 1 disease (CMT1) and hereditary neuropathy with liability to pressure palsies (HNPP) are common inherited disorders of the peripheral nervous system. The majority of CMT1 patients have a 1.5Mb tandem duplication (CMT1A) in chromosome 17p11.2 while most HNPP patients have a deletion of the same 1.5 Mb region. The CMT1A duplication and HNPP deletion are the reciprocal products of an unequal crossing over event between misaligned flanking CMT1A-REP elements. We analysed 162 unrelated CMT1A duplication patients and HNPP deletion patients from 11 different countries for the presence of a recombination hotspot in the CMT1A-REP sequences. A hotspot for unequal crossing over between the misaligned flanking CMT1A-REP elements was observed through the detection of novel junction fragments in 76.9% of 130 unrelated CMT1A patients and in 71.9% of 32 unrelated HNPP patients. This recombination hotspot was also detected in eight out of 10 de novo CMT1A duplication and in two de novo HNPP deletion patients. These data indicate that the hotspot of unequal crossing over occurs in several populations independently of ethnic background and is directly involved in the pathogenesis of CMT1A and HNPP. We conclude that the detection of junction fragments from the CMT1A-REP element on Southern blot analysis is a simple and reliable DNA diagnostic tool for the identification of the CMT1A duplication and HNPP deletion in most patients.