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Successful treatment of PASH syndrome with infliximab, cyclosporine and dapsone. J Eur Acad Dermatol Venereol 2014; 29:2243-7. [PMID: 25352307 DOI: 10.1111/jdv.12765] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 09/05/2014] [Indexed: 01/17/2023]
Abstract
BACKGROUND The group of autoinflammatory syndromes associated with Pyoderma gangrenosum, Acne, and Suppurative Hidradenitis are poorly defined and difficult to control with currently available treatment modalities. OBJECTIVES We describe a patient with PASH syndrome and report about the successful multimodal treatment with infliximab, cyclosporine, and dapsone. METHODS A review of the available literature to date about this group of autoinflammatory diseases was performed. We performed genetic analysis for PSTPIP1 mutations associated with PAPA syndrome. RESULTS A 22-year-old woman presented to our department with pyoderma gangrenosum, concomitant acne, and suppurative hidradenitis. She had previously been treated unsuccessfully with etanercept, adalimumab, fumaric acid and the IL-1 receptor antagonist (IL-1RA) anakinra without prolonged remission. Treatment with intravenous infliximab in combination with cyclosporine and dapsone lead to sudden and prolonged improvement of the clinical symptoms that we classified as PASH syndrome. We review the literature about this group of diseases and report the third case of PASH syndrome to date. CONCLUSION PASH syndrome and associated diseases should be considered whenever hidradenitis suppurativa is found in association with pyoderma gangrenosum. We provide a systematic overview about PASH syndrome and suggest a novel multimodal therapeutic regimen beyond isolated inhibition of TNF or IL-1.
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Palladin promotes invasion of pancreatic cancer cells by enhancing invadopodia formation in cancer-associated fibroblasts. Oncogene 2013; 33:1265-73. [PMID: 23524582 DOI: 10.1038/onc.2013.68] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 12/17/2012] [Accepted: 01/25/2013] [Indexed: 12/29/2022]
Abstract
The stromal compartment surrounding epithelial-derived pancreatic tumors is thought to have a key role in the aggressive phenotype of this malignancy. Emerging evidence suggests that cancer-associated fibroblasts (CAFs), the most abundant cells in the stroma of pancreatic tumors, contribute to the tumor's invasion, metastasis and resistance to therapy, but the precise molecular mechanisms that regulate CAFs behavior are poorly understood. In this study, we utilized immortalized human pancreatic CAFs to investigate molecular pathways that control the matrix-remodeling and invasion-promoting activity of CAFs. We showed previously that palladin, an actin-associated protein, is expressed at high levels in CAFs of pancreatic tumors and other solid tumors, and also in an immortalized line of human CAFs. In this study, we found that short-term exposure of CAFs to phorbol esters reduced the number of stress fibers and triggered the appearance of individual invadopodia and invadopodial rosettes in CAFs. Molecular analysis of invadopodia revealed that their composition resembled that of similar structures (that is, invadopodia and podosomes) described in other cell types. Pharmacological inhibition and small interfering RNA knockdown experiments demonstrated that protein kinase C, the small GTPase Cdc42 and palladin were necessary for the efficient assembly of invadopodia by CAFs. In addition, GTPase activity assays showed that palladin contributes to the activation of Cdc42. In mouse xenograft experiments using a mixture of CAFs and tumor cells, palladin expression in CAFs promoted the rapid growth and metastasis of human pancreatic tumor cells. Overall, these results indicate that high levels of palladin expression in CAFs enhance their ability to remodel the extracellular matrix by regulating the activity of Cdc42, which in turn promotes the assembly of matrix-degrading invadopodia in CAFs and tumor cell invasion. Together, these results identify a novel molecular signaling pathway that may provide new molecular targets for the inhibition of pancreatic cancer metastasis.
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QTL ANALYSES OF ORANGE COLOR AND CAROTENOID CONTENT AND MAPPING OF CAROTENOID BIOSYNTHESIS GENES IN CUCUMBER (CUCUMIS SATIVUS L.). ACTA ACUST UNITED AC 2010. [DOI: 10.17660/actahortic.2010.871.83] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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A role for candidate tumor-suppressor gene TCEAL7 in the regulation of c-Myc activity, cyclin D1 levels and cellular transformation. Oncogene 2008; 27:7223-34. [PMID: 18806825 DOI: 10.1038/onc.2008.360] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The pathophysiological mechanisms that drive the development and progression of epithelial ovarian cancer remain obscure. Recently, we identified TCEAL7 as a transcriptional regulatory protein often downregulated in epithelial ovarian cancer. However, the biological significance of such downregulation in cancer is not currently known. Here, we show that TCEAL7 is downregulated frequently in many human cancers and that in immortalized human ovarian epithelial cells this event promotes anchorage-independent cell growth. Mechanistic investigations revealed that TCEAL7 associates with cyclin D1 promoter containing Myc E-box sequence and transcriptionally represses cyclin D1 expression. Moreover, downregulation of TCEAL7 promotes DNA-binding activity of Myc-Max, and upregulates the promoter activity of c-Myc-target gene, ornithine decarboxylase (ODC), whereas enhanced expression of TCEAL7 inhibits Myc-induced promoter activity of ODC. Our findings suggest that TCEAL7 may restrict ovarian epithelial cell transformation by limiting Myc activity. These results also suggest a potential, alternative mechanism by which c-Myc activity may be deregulated in cancer by the downregulation of TCEAL7.
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Abstract
To investigate the mechanism by which HSulf-1 expression is downregulated in ovarian cancer, DNA methylation and histone acetylation of HSulf-1 was analysed in ovarian cancer cell lines and primary tumors. Treatment of OV207 and SKOV3 by 5-aza-2'-deoxycytidine resulted in increased transcription of HSulf-1. Sequence analysis of bisulfite-modified genomic DNA from ovarian cell lines and primary tumors without HSulf-1 expression revealed an increase in the frequency of methylation of 12 CpG sites in exon 1A. Chromatin immunoprecipitation assays showed an increase in histone H3 methylation in cell lines without HSulf-1 expression. To assess the significance of HSulf-1 downregulation in ovarian cancer, OV167 and OV202 cells were transfected with HSulf-1 siRNA. Downregulation of HSulf-1 expression in OV167 and OV202 cells lead to an attenuation of cisplatin-induced cytotoxicity. Moreover, patients with ovarian tumors expressing higher levels of HSulf-1 showed a 90% response rate (27/30) to chemotherapy compared to a response rate of 63% (19/30) in those with weak or moderate levels (P=0.0146, chi(2) test). Collectively, these data indicate that HSulf-1 is epigenetically silenced in ovarian cancer and that epigenetic therapy targeting HSulf-1 might sensitize ovarian tumors to conventional first-line therapies.
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Cucurbits (Cucurbitaceae; Cucumis spp., Cucurbita spp., Citrullus spp.). GENETIC RESOURCES, CHROMOSOME ENGINEERING, AND CROP IMPROVEMENT 2006. [DOI: 10.1201/9781420009569.ch8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ase1p organizes antiparallel microtubule arrays during interphase and mitosis in fission yeast. Mol Biol Cell 2005; 16:1756-68. [PMID: 15689489 PMCID: PMC1073658 DOI: 10.1091/mbc.e04-10-0899] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Proper microtubule organization is essential for cellular processes such as organelle positioning during interphase and spindle formation during mitosis. The fission yeast Schizosaccharomyces pombe presents a good model for understanding microtubule organization. We identify fission yeast ase1p, a member of the conserved ASE1/PRC1/MAP65 family of microtubule bundling proteins, which functions in organizing the spindle midzone during mitosis. Using fluorescence live cell imaging, we show that ase1p localizes to sites of microtubule overlaps associated with microtubule organizing centers at both interphase and mitosis. ase1Delta mutants fail to form overlapping antiparallel microtubule bundles, leading to interphase nuclear positioning defects, and premature mitotic spindle collapse. FRAP analysis revealed that interphase ase1p at overlapping microtubule minus ends is highly dynamic. In contrast, mitotic ase1p at microtubule plus ends at the spindle midzone is more stable. We propose that ase1p functions to organize microtubules into overlapping antiparallel bundles both in interphase and mitosis and that ase1p may be differentially regulated through the cell cycle.
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Polysaccharide XXIV. Über das Vorkommen von Lichenin (Reservecellulose) in Flechten und anderen Pflanzen. (5. Mitteilung über Lichenin). Helv Chim Acta 2004. [DOI: 10.1002/hlca.19240070118] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Reproduction and cytogenetic characterization of interspecific hybrids derived from Cucumis hystrix Chakr. x Cucumis sativus L. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2003; 106:688-695. [PMID: 12595999 DOI: 10.1007/s00122-002-1118-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2002] [Accepted: 06/27/2002] [Indexed: 05/24/2023]
Abstract
Interspecific hybrids between Cucumis hystrix Chakr. (2n = 2 x = 24) and Cucumis sativus L. (2n = 2 x = 14) were produced by means of F(1) (2n = 19) embryo rescue and subsequent chromosome doubling. The hybridity was confirmed by genomic in situ hybridization (GISH) and chromosome analysis. The amphidiploid (2n = 38) was self-pollinated and backcrossed to cucumber resulting in lines with improved crossability to C. sativus. Examination of shape, stainability, and germination rate of pollen grains and yield as a function of mature fruit set per ten pollinated flowers indicated a tendency for increased fertility in BC(1)S(1) progeny when compared to F(1) and amphidiploid offspring. Cytogenetic characterization of F(1) and amphidiploid progeny was performed. Generally normal meioses produced viable pollen grains, and fertilization resulted in partial fertility restoration in amphidiploid progeny. Chromosome anomalies such as "frying-pan trivalent", chromosome lagging and spindle mis-orientation were also observed. In most of the PMCs of the F(1) diploid hybrid progeny, 19 univalents were observed at diakinesis and MI. In the amphidiploid, more than 90% of the configurations at MI consisted of the predicted 19 bivalents and less than 5% contained multivalents [trivalents (2.3%) + quadrivalents (0.3%)], suggesting the presence of preferential pairing, and a distinctive parental genome as well. The chiasmata observed between homoeologous chromosomes further demonstrated the introgression of the C. hystrix genome into that of C. sativus.
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Genetic analysis of early- versus late-stage ovarian tumors. Cancer Res 2001; 61:5895-904. [PMID: 11479231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
In the United States, ovarian cancer is the fourth most common cause of cancer-related deaths among women. The most important prognostic factor for this cancer is tumor stage, or extent of disease at diagnosis. Although women with low-stage tumors have a relatively good prognosis, most women diagnosed with late-stage disease eventually succumb to their cancer. In an attempt to understand early events in ovarian carcinogenesis, and to explore steps in its progression, we have applied multiple molecular genetic techniques to the analysis of 21 early-stage (stage I/II) and 17 advanced-stage (stage III/IV) ovarian tumors. These techniques included expression profiling with cDNA microarrays containing approximately 18,000 expressed sequences, and comparative genomic hybridization to address the chromosomal locations of copy number gains as well as losses. Results from the analysis indicate that early-stage ovarian cancers exhibit profound alterations in gene expression, many of which are similar to those identified in late-stage tumors. However, differences observed at the genomic level suggest differences between the early- and late-stage tumors and provide support for a progression model for ovarian cancer development.
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Loss of expression of a new member of the DNAJ protein family confers resistance to chemotherapeutic agents used in the treatment of ovarian cancer. Cancer Res 2001; 61:4258-65. [PMID: 11358853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Differential display-PCR between ovarian tumor cell lines and short-term cultures of normal ovarian epithelial cell brushings was used to isolate a differentially expressed transcript and its corresponding gene. The gene, which mapped to 13q14.1, has partial homology in the DNAJ domain to a number of proteins with a similar domain and was designated as methylation-controlled J protein (MCJ). MCJ has the highest similarity to a functionally undefined protein from Caenorhabditis elegans. MCJ is expressed as a 1.2-kb transcript in several adult tissues, with testis showing the highest level of expression. Expression of MCJ was absent in three of seven ovarian cancer cell lines. Similarly, expression analysis using semiquantitative reverse transcription-PCR indicated that 12 of 18 primary ovarian tumors examined had either a complete absence or lower levels of expression of this gene. 5-Aza-2'-deoxycytidine treatment of the OV202 cell line induced MCJ expression in a dose-dependent manner, implicating methylation in this induction. Loss of heterozygosity and methylation-specific PCR analysis revealed that the loss of MCJ expression in primary tumors and cell lines was attributable to deletion of one allele and methylation of the other. To assess the potential functional significance of MCJ down-regulation, the sensitivity of parental (MCJ-nonexpressing) and MCJ-transfected OV167 cells to antineoplastic agents was evaluated. MCJ expression was associated with enhanced sensitivity to paclitaxel, topotecan, and cisplatin, suggesting that MCJ loss may play a role in de novo chemoresistance in ovarian carcinoma. These observations raise the possibility that MCJ loss may: (a) have potential prognostic significance in ovarian cancer; and (b) contribute to the malignant phenotype by conferring resistance to the most commonly used chemotherapeutic agents for ovarian cancer.
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Abstract
It has been suggested that the basal ganglia preferentially contribute to movements made to remembered targets, whereas the cerebellum preferentially contributes to movements based on visual cues. Thus, it is possible that eye-hand coordination may differ in these two types of movement. To examine this issue we compared the response characteristics of combined eye and hand movements made towards visual versus remembered targets. In addition, the influence of the eye movement on the hand movement was investigated by comparing the effects of visual fixation in each task. Our results demonstrated that hand movement amplitude was greater when the hand movements were produced in isolation versus in combination with an eye movement. This was true regardless of whether the movement was made to a visual or a remembered target. This suggests that the integration of eye position information into the manual motor response occurs at a common neural site for both tasks. By contrast, the timing between saccade and hand onsets and offsets differed in the two conditions. This is consistent with the idea that the timing inherent in eye-hand coordination is the result of separate processing within either the basal ganglia or cerebellar systems. Taken together, the results from this study demonstrate that certain processes underlying eye-hand coordination during movements to visual versus remembered targets share a common neural substrate whereas others function independently.
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Involvement of H-cadherin (CDH13) on 16q in the region of frequent deletion in ovarian cancer. Int J Oncol 1999; 15:715-20. [PMID: 10493953 DOI: 10.3892/ijo.15.4.715] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ovarian cancer is one of the leading causes of mortality unique to women. Deletions within chromosome 6q are the most frequent events in high-grade invasive epithelial ovarian cancer (IEOC). While previous reports seem to indicate that there is loss of 16q sequences in IOEC, only a very small number of markers (single marker in two different reports) were used. In order to more precisely define the regions of deletions on 16q, we first analyzed LOH with 13 polymorphic markers on 16q in 10 benign, 3 low-grade and 21 high-grade invasive ovarian cancer samples. There was no loss with any of the markers with the benign ovarian samples and loss of one marker in one of three low-grade tumors. In contrast, 14 of 21 (67%) high-grade invasive ovarian tumors showed loss of one or more markers. Detailed deletion mapping revealed three distinct commonly deleted regions on this chromosomal arm: 10/21 (48%) of high-grade tumors showed loss at 16q23.1-23.2 (D16S518, D16S3049 and D16S3029). The second region of loss at 16q23.3-16q24.1 (D16S3144, D16S504, HSD17B2 and D16S507) was observed in 11/21 (52%) of the tumors. The highest frequency of loss was seen at 16q24.2-16q24.3 (D16S422, D16S402 and D16S520) in 12/21 (57%) of tumors. The genomic map of CDH13 indicates that the marker D16S422 that was lost in 5 of these 12 tumors is part of this gene. Three of these 5 tumors showed very low levels of CDH13 expression. Three tumors with LOH of other markers in this region also showed lower levels of CDH13 expression. Analysis of the methylation status of CDH13 in tumors with low levels of expression with methylation-specific PCR revealed that four of six (67%) tumors had methylation of one of the CDH13 alleles. These results suggest that a combination of hyper-methylation and deletion cause the inactivation of CDH13 in ovarian tumors.
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A novel region of deletion on chromosome 6q23.3 spanning less than 500 Kb in high grade invasive epithelial ovarian cancer. Oncogene 1999; 18:3913-8. [PMID: 10445856 DOI: 10.1038/sj.onc.1202756] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Detailed deletion mapping of chromosome 6q sequences in invasive ovarian tumors have implicated several broad regions involving 6q14-16, 6q21-23, 6q25-26, and the telomeric portion in band 6q27 as regions of frequent loss in this malignancy. In order to define regions of loss involved in the development of ovarian cancer, we used 23 polymorphic markers on 6q to examine allelic loss in 25 high-grade, late stage ovarian tumors. Four non-overlapping deletion regions were observed: (1) at 6q21-22.3 (D6S301-D6S292); (2) within a 1 cM region at 23.2-23.3 between markers D6S978-D6S1637 (at D6S311); (3) at 6q26 (between markers D6S411-D6S1277) and (4) at 6q27 with the markers D6S297 and D6S193. The highest region of loss was observed with marker D6S311 (lost in 17 of 19 informative cases, 89%) in 6q23.3, followed by D6S977 and D6S1637 (71 and 55%, respectively). The average fractional allele loss in the high-grade tumors was around 35%. Previous reports have shown 6q27 as the region of most frequent loss in invasive ovarian cancer. However, our results indicate a novel region in 6q23.3 (spanning less than 500 Kb distance between the markers) with the highest loss, implicating this region of chromosome 6q to harbor a putative tumor suppressor gene involved in the development of invasive epithelial ovarian cancer.
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Immunogenicity and safety of Haemophilus influenzae type b polysaccharide-Neisseria meningitidis conjugate vaccine in 7.5 micrograms liquid formulation: a comparison of three lots with the 15.0 micrograms lyophilized formulation. Study Group for 7.5 micrograms Liquid PedvaxHIB. Vaccine 1997; 15:775-81. [PMID: 9178481 DOI: 10.1016/s0264-410x(96)00129-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We conducted a multicenter, single-blind, randomized comparisons of the immunogenicity and safety of three manufacturing-scale lots of 7.5 micrograms liquid Haemophilus influenzae type b polysaccharide- Neisseria meningitidis conjugate vaccine (PRP-OMPC) and a single lot of 15.0 micrograms lyophilized PRP OMPC. A total of 908 infants were entered into the study. Each infant received two primary injections intramuscularly 2 months apart beginning at age 2-6 months and a booster injection at 12-15 months. Blood samples for serology were obtained before each injection and 1 month after the second and the booster dose. Immune responses were measured by radioimmunoassay. Approximately 80% of the infants achieved a titer > 1.0 micrograms ml-1 after the second primary dose of all four lots tested: the geometric mean titer (GMT) was ca 3 micrograms ml-1 for each vaccine group. After the booster dose, more than 90% of infants from each vaccine group had a titer > 1.0 microgram ml-1;GMTs ranged from 8 to 10 micrograms ml-1. No serious vaccine-associated adverse reactions were reported. Thus the 7.5 liquid PRP OMPC vaccine was at least as immunogenic and well tolerated as the 15.0 micrograms lyophilized vaccine.
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Light scattering from transparent substrates: Theory and experiment. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:1848-1860. [PMID: 9976375 DOI: 10.1103/physrevb.50.1848] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Plastid engineering in land plants: a conservative genome is open to change. Philos Trans R Soc Lond B Biol Sci 1993; 342:203-8. [PMID: 8115448 DOI: 10.1098/rstb.1993.0148] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We have developed efficient transformation protocols to modify each of the 500-10,000 plastid genome copies in a tobacco cell. The transforming DNA is introduced on the surface of microscopic tungsten particles by the biolistic process. Selection for transplastomes is by spectinomycin resistance based on expression of aminoglycoside-3"-adenyltransferase from a chimeric aadA gene in the transforming DNA. Manipulations that are now feasible include replacement of endogenous plastid genes with DNA sequences modified in vitro, targeted gene disruption, and insertion of reporter genes into the plastid genome. Alternative methods for plastid genome manipulations may be developed utilizing an extrachromosomal element which was identified during the transformation studies. Introduction of foreign genes under control of plastid gene expression elements results in duplication of endogenous regulatory sequences. A sensitive somatic assay to detect deletions via such direct repeats confirmed that these sequence duplications do not result in significant genome instability. The ability to transform plastids will facilitate the study of plastid gene regulation, and the application of genetic engineering to crop improvement.
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Stress and psychopathology in the aged. Psychiatr Clin North Am 1982; 5:131-43. [PMID: 7099989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
There is a general agreement that the elderly experience a higher proportion of significant life event changes than the younger adult population, and research suggests that life event changes often precede episodes of psychiatric illness. It is also evident, however, that most people over 60 successfully adapt to their changing circumstances without psychiatric disorders. Clearly, the presence of certain physical, psychological, and social mediators may modify the stress response in a predictable fashion. Off-time life events, absence of a confidante, and intrapunitive personality, and a dependence on alcohol, psychotropic, and sedative/hypnotic medications are all examples of mediators that indicate an individual who may be at risk. It is our hope that researchers will continue to identify specific risk factors associated with psychiatric illness in the elderly for use in designing specific prevention and intervention programs for those at risk.
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[Parathyroid hormone and 25-hydroxy-cholecalciferol during hypoparathyroidism]. LA NOUVELLE PRESSE MEDICALE 1977; 6:1979. [PMID: 887398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Four carcinogens, dimethylnitrosamine (DMN), acetylaminofluorene (AAF), aflatoxin B1 (AFB1), and 3-methylcholanthrene (3-MC) were tested acutely and chronically in the micronucleus test in both mice and hamsters. In acute studies using mice, all compounds increased the relative frequency of micronuclei when compared to controls. There was a dose response which tended to tail off as bone-marrow suppression was observed. The order of activity appears to be DMN greater than AFB1 greater than or equal to 3-MC greater than AAF. In acute hamster studies, AFB1 was inactive at the highest dose tested (3 mg/kg). In the case of hamsters, all other compounds increased the incidence of micronuclei with DMN greater than 3-MC greater than AAF. Subacute studies with hamsters revealed that 3-MC was active at 1 week but not 8 weeks while DMN was active at both 1 and 8 weeks. AAF was active at 8 and 12 weeks and AFB1 was active at 12 weeks but not 8 weeks. The authors conclude that this test does not appear useful in chronic protocols and probably more reflects carcinogenicity of the test compounds than acute toxicity. Nevertheless, acute studies demonstrate that this test procedure is of value in the characterization of a compound's relative mutagenic potential.
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Inhibition of mouse testicular DNA synthesis by mutagens and carcinogens as a potential sample mammalian assay for mutagenesis. Mutat Res 1976; 37:67-76. [PMID: 967187 DOI: 10.1016/0027-5107(76)90055-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Since mutagenic substances induce structural changes in DNA, studies were undertaken to determine whether substances would modify DNA replicative activity. DNA synthesis was quantitated 3.5 h after drug administration as uptake into DNA of a 30-min pulse of 10 muCi of [3H] thymidine. Combinations of methylurea (20000 mg/kg) and sodium nitrite (150 mg/kg) administered p.o. resulted in gastric synthesis of nitrosomethylurea and inhibited testicular DNA synthesis by 83%. Combinations of methylurea and sodium nitrite of 1000 and 100 mg/kg respectively inhibited DNA synthesis by 75%. With dimethylamine and sodium nitrite, a combination which results in gastric synthesis of dimethylnitrosamine, inhibitions of 65 and 57% were observed at 2000 mg/kg together with 150 mg/kg and 1000 mg/kg in combination with 100 mg/kg, respectively. In separate experiments, dimethylnitrosamine (50 mg/kg, p.o.) and diethylnitrosamine (100 mg/kg, i.p.) inhibited thymidine uptake by 30 and 89%, respectively. The mutagenic polynucelar hydrocarbon 3-methylcholanthrene (15 mg/kg) inhibited DNA synthesis by 95% and safrole (640 mg/kg), a mutagenic methylenedioxybenzene derivative, inhibited by 60%. Cadmium chloride (10 mg/kg), acetylaminofluorene (160 mg/kg) and dibutylnitrosamine (500 mg/kg) also induced statistically significant effects. Noncarcinogenic analogues of these substances (anthracene, 125 mg/kg; diphenyl-nitrosamine, 500 mg/kg; piperonyl butoxide, 640 mg/kg, and methylurea, 2000 mg/kg in combination with sodium nitrate) were inactive. Highly toxic substances (potassium cyanide, 2.5 mg/kg; 2,4-dinitrophenol, 20 mg/kg; and lead acetate, 150 mg/kg) were also inactive. This index of mutagenicity appears to have considerable sensitivity and therefore may have potential in drug evaluation.
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