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Hu X, Zhou L, Lian QS, Zheng J, Yang JG, Lai F. [Effect of xanthnotoxol on contractility of isolated rabbit ileum]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 2001; 26:56-8. [PMID: 12525124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To study the effect of Xanthnotoxol on contractility of isolated rabbit ileum and its relationship with Ca2+. METHOD Routine experimental methods for isolated ileum were adopted. RESULT Xanthnotoxol (XT) and Verapamil (Ver) inhibited the contraction of isolated rabbit ileum smooth muscle induced by submaximal concentrations of acetylcholine (ACh) and serotonim (5-TH), with a IC50 value (mumol.L-1) of 10.495 +/- 1.521, 0.428 +/- 0.001 and 18.132 +/- 1.627, 0.249 +/- 0.003, respectively. XT and Ver inhibited the contraction induced by Ca2+ after high K+ depolarization and for noncompetitively antagonist CaCl2 cumulative dose-response curve, the pD'2 value was 4.69 +/- 0.03 and 6.35 +/- 0.10, respectively. XT (10 mumol.L-1) and Ver(0.06 mumol.L-1) inhibited the contraction induced by ACh in Ca(2+)-free medium, while XT (100 mumol.L-1) but not Ver(0.6 mumol.L-1) inhibited the extracellar CA(2+)-dependent contraction induced by ACh. CONCLUSION XT has a calcium-antagonistic effect which was not similar to that of Ver.
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102
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Lai F, Godley LA, Fernald AA, Orelli BJ, Pamintuan L, Zhao N, Le Beau MM. cDNA cloning and genomic structure of three genes localized to human chromosome band 5q31 encoding potential nuclear proteins. Genomics 2000; 70:123-30. [PMID: 11087669 DOI: 10.1006/geno.2000.6345] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Loss of a whole chromosome 5, or a del(5q), is a recurring abnormality in malignant myeloid diseases. By cytogenetic and molecular analyses, we delineated previously a 1- to 1.5-Mb region that is deleted in all patients with a del(5q). In our efforts to identify a myeloid tumor suppressor gene within the commonly deleted segment (CDS), we have cloned and characterized the genes encoding three putative nuclear proteins, each of which contains a bipartite nuclear localization signal (NLS). In addition, C5ORF5 contains a putative rhoGAP domain at the N-terminus, C5ORF6 has a proline-rich sequence near the N-terminus, and C5ORF7 has a zinc-finger domain that partially overlaps the NLS. All three genes are ubiquitously expressed and encode novel proteins. The C5ORF5 cDNA is 5.47 kb encoding a protein of 915 amino acids (aa) with a predicted molecular mass of approximately 105 kDa. C5ORF5 has 23 exons spanning over 27 kb. The C5ORF6 transcript is 4.1 kb encoding a protein of 392 aa with a predicted molecular mass of approximately 43 kDa. C5ORF6 has 5 exons and spans approximately 11 kb. The C5ORF7 cDNA is 6.3 kb and encodes a protein of 1417 aa with a predicted molecular mass of approximately 155 kDa. C5ORF7 has 24 exons spanning approximately 64 kb. All three genes were localized to the distal half of the CDS between D5S1983 and D5S500. We evaluated each as a candidate tumor suppressor gene by the analysis of myeloid leukemia cells from patients with -5/del(5q), but no inactivating mutations were identified.
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103
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Anderson AJ, Stoltzner S, Lai F, Su J, Nixon RA. Morphological and biochemical assessment of DNA damage and apoptosis in Down syndrome and Alzheimer disease, and effect of postmortem tissue archival on TUNEL. Neurobiol Aging 2000; 21:511-24. [PMID: 10924764 DOI: 10.1016/s0197-4580(00)00126-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have previously shown that Alzheimer disease (AD) brain exhibits terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) for DNA damage and morphological evidence for apoptosis. Down syndrome (DS) is a neurodegenerative disorder that exhibits significant neuropathological parallels with AD. In accordance with these parallels and the need to clarify the mechanism of cell death in DS and AD, we investigated two principal issues in the present study. First, we investigated the hypothesis that TUNEL labeling for DNA damage and morphological evidence for apoptosis is also present in the DS brain. All DS cases employed had a neuropathological diagnosis of AD. Analysis of these cases showed that DS brain exhibits a significant increase in the number of TUNEL-labeled nuclei relative to controls matched for age, Postmortem Delay, and Archival Length, and that a subset of TUNEL-positive nuclei exhibits apoptotic morphologies. We also report that Archival Length in 10% formalin can significantly affect TUNEL labeling in postmortem human brain, and therefore, that Archival Length must be controlled for as a variable in this type of study. Second, we investigated whether biochemical evidence for the mechanism of cell death in DS and AD could be detected. To address this question we employed pulsed-field gel electrophoresis (PFGE) as a sensitive method to evaluate DNA integrity. Although apoptotic oligonucleosomal laddering has not previously been observed in AD, PFGE of DNA from control, DS and AD brain in the present study revealed evidence of high molecular weight DNA fragmentation indicative of apoptosis. This represents biochemical support for an apoptotic mechanism of cell death in DS and AD.
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104
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Lai F, Orelli BJ, Till BG, Godley LA, Fernald AA, Pamintuan L, Le Beau MM. Molecular characterization of KLHL3, a human homologue of the Drosophila kelch gene. Genomics 2000; 66:65-75. [PMID: 10843806 DOI: 10.1006/geno.2000.6181] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Drosophila kelch protein is a structural component of ring canals and is required for oocyte maturation. Here, we report the cloning and genomic structure of a new human homologue of kelch, KLHL3. At the amino acid level, KLHL3 shares 77% similarity with Drosophila kelch and 89% similarity with Mayven (KLHL2), another human kelch homolog. The approximately 6.5-kb mRNA has a single open reading frame encoding a protein of 587 amino acids with a predicted molecular mass of 650 kDa. Like kelch and KLHL2, the KLHL3 protein contains a poxvirus and zinc finger domain at the N-terminus and six tandem repeats (kelch repeats) at the C-terminus. At least three isoforms, which differ in the length of the N-terminus, are produced and may be the result of alternative promoter usage. We also identified alternative polyadenylation sites and alternative splicing; thus, as many as 12 mRNA variants and six putative protein isoforms could be produced. The KLHL3 gene is mapped to human chromosome 5, band q31, contains 17 exons, and spans approximately 120 kb of genomic DNA. KLHL3 maps within the smallest commonly deleted segment in myeloid leukemias characterized by a deletion of 5q; however, we detected no inactivating mutations of KLHL3 in malignant myeloid disorders with loss of 5q.
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105
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Lai F, Fernald AA, Zhao N, Le Beau MM. cDNA cloning, expression pattern, genomic structure and chromosomal location of RAB6KIFL, a human kinesin-like gene. Gene 2000; 248:117-25. [PMID: 10806357 DOI: 10.1016/s0378-1119(00)00135-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Kinesin-like proteins are microtubule-associated motors that play important roles in intracellular transport and cell division. We report here the characterization of a new human kinesin-like protein, Rabkinesin6 (RAB6KIFL). The composite cDNA sequence is 2957bp, and encodes a protein of 890 amino acids with a predicted molecular weight of 100kDa. It has high homology (93% similarity) with the mouse kinesin-like protein, Rab6kifl, indicating that it is the human homologue of the mouse gene. RAB6KIFL has all of the structural characteristics required to function as a microtubule-associated motor. Unlike the mouse gene which is ubiquitously expressed, RAB6KIFL expression appears to be tissue specific. It is widely expressed in fetal tissues, abundantly expressed in adult thymus, bone marrow and testis, and is expressed at low levels in heart, placenta and spleen. The RAB6KIFL gene is mapped to human chromosome 5, band q31, spans approximately 8.5kb of genomic DNA, and contains 19 exons. RAB6KIFL maps within the smallest commonly deleted segment in myeloid leukemias characterized by a deletion of 5q; however, we detected no mutations of RAB6KIFL in malignant myeloid disorders with loss of 5q. The description of this human kinesin-like protein may provide a better understanding of the diversity of this large family of proteins.
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MESH Headings
- Acute Disease
- Amino Acid Sequence
- Base Sequence
- Chromosome Mapping
- Chromosomes, Human, Pair 5/genetics
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Neoplasm/genetics
- Exons
- Female
- Gene Expression
- Genes/genetics
- Humans
- Introns
- K562 Cells
- Kinesins/genetics
- Leukemia, Myeloid/genetics
- Male
- Molecular Sequence Data
- Myelodysplastic Syndromes/genetics
- Polymorphism, Single-Stranded Conformational
- RNA/genetics
- RNA/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Tissue Distribution
- Tumor Cells, Cultured
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Chen CX, Cho DS, Wang Q, Lai F, Carter KC, Nishikura K. A third member of the RNA-specific adenosine deaminase gene family, ADAR3, contains both single- and double-stranded RNA binding domains. RNA (NEW YORK, N.Y.) 2000; 6:755-67. [PMID: 10836796 PMCID: PMC1369955 DOI: 10.1017/s1355838200000170] [Citation(s) in RCA: 385] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Members of the double-stranded RNA- (dsRNA) specific adenosine deaminase gene family convert adenosine residues into inosines in dsRNA and are involved in A-to-I RNA editing of transcripts of glutamate receptor (GluR) subunits and serotonin receptor subtype 2C (5-HT(2C)R). We have isolated hADAR3, the third member of this class of human enzyme and investigated its editing site selectivity using in vitro RNA editing assay systems. As originally reported for rat ADAR3 or RED2, purified ADAR3 proteins could not edit GluR-B RNA at the "Q/R" site, the "R/G" site, and the intronic "hot spot" site. In addition, ADAR3 did not edit any of five sites discovered recently within the intracellular loop II region of 5-HT(2C)R RNAs, confirming its total lack of editing activity for currently known substrate RNAs. Filter-binding analyses revealed that ADAR3 is capable of binding not only to dsRNA but also to single-stranded RNA (ssRNA). Deletion mutagenesis identified a region rich in arginine residues located in the N-terminus that is responsible for binding of ADAR3 to ssRNA. The presence of this ssRNA-binding domain as well as its expression in restricted brain regions and postmitotic neurons make ADAR3 distinct from the other two ADAR gene family members, editing competent ADAR1 and ADAR2. ADAR3 inhibited in vitro the activities of RNA editing enzymes of the ADAR gene family, raising the possibility of a regulatory role in RNA editing.
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107
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Bhartur SG, Calhoun BC, Woodrum J, Kurkjian J, Iyer S, Lai F, Goldenring JR. Genomic structure of murine Rab11 family members. Biochem Biophys Res Commun 2000; 269:611-7. [PMID: 10708602 DOI: 10.1006/bbrc.2000.2334] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rab11a, Rab11b, and Rab25 in mammals are thought to comprise a subfamily of Rab proteins, although Rab25 has two amino acid differences in its effector domain. We have isolated and characterized the genomic sequences of murine Rab11a and Rab25 and compared them with those of previously characterized mammalian Rab genes. The Rab11a gene spans 29 kb and Rab25 spans 9 kb. The genes have TATA-less promoters, but contain GC-rich areas in their upstream 5' regions. Both genes have 5 exons, with the introns containing characteristic repeats. Rab11a has an unusually long 8. 5-kb fourth intron. The Rab11a and Rab25 genes are localized to chromosomes 9C and 3E3/F1, respectively. The overall organization of the Rab11a, Rab11b, and Rab25 genes is similar, with homologous exon-intron boundaries, and differs markedly from those of Rab3A and Rab1A. These results confirm that Rab11A, Rab11b, and Rab25 represent a closely related gene family.
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108
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Li D, Lin Y, Lin W, Zhuang F, Shi Z, Guo X, Xu D, Yang X, Lin J, Zhang J, Mo Y, Lai F. [Separation of thoracopagus conjoined twins]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 2000; 38:61-3. [PMID: 11831991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To sam up the experience in diagnosis and separation of a thoracopagus conjoined twins. METHODS Thoracopagus twin boys were admitted for evaluating possible separation and repair at age of 21 days. X-rays, CT, MRI, and ultrasound scan of torso showed separate and normal gastrointestinal and biliary tracts, little shared vasculature, but shared pericardium, diaphragm and liver parenchyma. The chest junctions were at the sternums and the most inferior two pairs of the ribs. One twin (twin A) had a protruding heart with VSD and ASD. RESULTS The infants were separated successfully at age of 45 days. The chest defect of twin A was closed with aid of a polyester pericardial patch graft and a silicon supporter. Managing anesthesia met some difficulty in understanding of the anatomical and physiological consequences of the complex anomaly. They are had brain edema and multiple system organ failures after separation, and were cured under intensive care. They are alive and well 6 months after surgery. CONCLUSIONS Careful preoperative evaluation proper anesthesia and surgical technique, and postoperative care are essential to the successful separation of the conjoined twins.
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109
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Godley LA, Lai F, Liu J, Zhao N, Le Beau MM. TTID: A novel gene at 5q31 encoding a protein with titin-like features. Genomics 1999; 60:226-33. [PMID: 10486214 DOI: 10.1006/geno.1999.5912] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A deletion of the long arm of chromosome 5 is a recurring abnormality in malignant myeloid disorders. In previous studies, we identified an approximately 1-Mb segment in 5q31 that was deleted in all patients examined. As part of a positional cloning project to identify transcribed sequences in this region, we identified and characterized the TTID gene. This gene contains 10 exons that extend over 19 kb. The composite cDNA is approximately 2.3 kb and encodes a protein of 498 amino acids, with a predicted molecular mass of 55 kDa. The C-terminal half of this putative protein contains an internally repeated domain of 43 amino acids, which resembles the N-terminal half of an immunoglobulin domain from the immense skeletal muscle protein titin. The TTID gene is expressed in multiple muscle tissue types as well as in thyroid gland and bone marrow. We evaluated the gene as a candidate tumor suppressor gene by searching for mutations in malignant myeloid disorders with abnormalities of chromosome 5. However, we detected no inactivating mutations. A single nucleotide change (G to A) was identified at nucleotide position 1889 in the untranslated region of the mRNA, which may represent a polymorphism. Therefore, TTID is unlikely to be the candidate tumor suppressor gene involved in malignant myeloid disorders.
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110
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Lai F, Kammann E, Rebeck GW, Anderson A, Chen Y, Nixon RA. APOE genotype and gender effects on Alzheimer disease in 100 adults with Down syndrome. Neurology 1999; 53:331-6. [PMID: 10430422 DOI: 10.1212/wnl.53.2.331] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Alzheimer disease (AD) neuropathology is present in Down syndrome (DS) after age 35, but dementia onset varies from ages 40 to 70 years. Because of small sample sizes and nonuniform determination of dementia, previous studies produced differing results on the influence of APOE subtypes on AD in DS. OBJECTIVE To determine the influence of the APOE genotype and gender on development of AD in adults with DS to ascertain similarities with AD in the general population. METHODS A total of 100 adults with DS (ages 35 to 79 years), almost all of whom were longitudinally assessed by neurologists, underwent APOE genotyping. Dementia onset was determined using criteria applied from the Tenth International Classification of Mental and Behavioral Disorders. This cohort contains the largest number of DS subjects with dementia (n = 57) in a single study, thus increasing reliability of the results. RESULTS The epsilon2 allele frequency was 4% in those with dementia versus 13% in those without dementia (p = 0.03); epsilon4 allele frequency was 18% in those with dementia versus 13% in those without dementia (p = 0.45). Using APOE-epsilon3/3 as the reference group, the risk ratio for the development of AD at any given time was 0.34 for the APOE-epsilon2/3 group (p = 0.04) and 1.44 for the APOE-epsilon(3/4,4/4) group (p = 0.25). Women were 1.77 times as likely to dement as men at any given point in time (p = 0.04). CONCLUSIONS The epsilon2 allele confers a protective effect, and women with DS have an increased risk for AD, as in the general population. In this sample, epsilon4 does not confer a significantly increased risk for AD in DS.
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111
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Chan PS, Coupet J, Park HC, Lai F, Hartupee D, Cervoni P, Dusza JP, Albright JD, Ru X, Mazandarani H, Tanikella T, Shepherd C, Ochalski L, Bailey T, Lock TY, Ning X, Taylor JR, Spinelli W. VPA-985, a nonpeptide orally active and selective vasopressin V2 receptor antagonist. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 449:439-43. [PMID: 10026835 DOI: 10.1007/978-1-4615-4871-3_55] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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112
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Wang G, Lai F, He M, Jing Z, Yu Y. [Detection of human cytomegalovirus infection in blood donor population by the polymerase chain reaction]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 1998; 22:206-8. [PMID: 9868113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Samples of peripheral blood from 76 different donors were detected for the presence of human cytomegalovirus (HCMV) DNA by polymerase chain reaction (PCR). The results showed that HCMVs were present in 39 out of 76 blood donors which reached an infection positive rate of 51.3%. In addition, the sensitivity and specificity on PCR were tested, it also indicated that the sensitivity can reach the level of 5fg.microliter-1. The method is simple, rapid, highly sensitive and specificity. It can be considered as a diagnostic measure in clinical detection of HCMV.
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113
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Zhao N, Lai F, Fernald AA, Eisenbart JD, Espinosa R, Wang PW, Le Beau MM. Human CDC23: cDNA cloning, mapping to 5q31, genomic structure, and evaluation as a candidate tumor suppressor gene in myeloid leukemias. Genomics 1998; 53:184-90. [PMID: 9790767 DOI: 10.1006/geno.1998.5473] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The transition from metaphase to anaphase and exit from mitosis involve the degradation of active cyclin B-CDC2 complexes by ubiquitin-mediated proteolysis. The anaphase-promoting complex (APC) catalyzes the formation of cyclin B-ubiquitin conjugates, thereby targeting cyclin B for degradation. The APC is composed of eight proteins, including four members of a family characterized by multiple tetratricopeptide repeats (TPR). We mapped two overlapping expressed sequence tag clones within a genomic contig on human chromosome 5, band q31. A search revealed high homology to Saccharomyces cerevisiae CDC23, a TPR protein component of the APC. We have isolated the human CDC23 cDNA containing the full-length predicted open reading frame. The approximately 3.3-kb message is ubiquitously expressed and encodes a protein with 591 amino acids (MW = 68,293 Da) and 9 TPR units. The protein has 30% identity and 51% similarity to the S. cerevisiae protein. The human CDC23 gene contains 16 exons and spans approximately 31 kb. CDC23 maps within the smallest commonly deleted segment in myeloid leukemias characterized by a deletion of 5q; however, we detected no mutations of CDC23 in leukemia cells with loss of 5q. Thus, CDC23 is unlikely to be involved in the pathogenesis of myeloid leukemias characterized by abnormalities of chromosome 5.
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114
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Lai F, Chen CX, Lee VM, Nishikura K. Dramatic increase of the RNA editing for glutamate receptor subunits during terminal differentiation of clonal human neurons. J Neurochem 1997; 69:43-52. [PMID: 9202292 DOI: 10.1046/j.1471-4159.1997.69010043.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
RNA editing plays an important role in determining physiological characteristics of certain glutamate-gated receptor (GluR) channels such as Ca2+ permeability and desensitization kinetics. In one case, the editing changes a gene-encoded glutamine (Q) to an arginine (R) codon located in the channel-forming domain of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit GluR-B and also the kainate receptor subunits GluR5 and GluR6. Another case of RNA editing alters an arginine (R) to a glycine (G) codon at a position termed the "R/G" site of AMPA subunits GluR-B, C, and D. Double-stranded RNA-specific adenosine deaminases (DRADA) have been implicated as agents involved in the editing. By using a human teratocarcinoma cell line, NT2, we investigated the change of the RNA editing of GluR subunits in conjunction with the expression of two DRADA members, DRADA1 and DRADA2 genes, during neuronal differentiation. Whereas Q/R and R/G site RNA editing both become progressively activated in differentiating NT2 cells, the expression of the two DRADA genes can already be detected even in the undifferentiated NT2 cells. Development of the editing machinery appears to require, in addition to DRADA enzymes, a currently unidentified mechanism(s) that may become activated during neuronal differentiation.
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MESH Headings
- Adenosine Deaminase/genetics
- Cell Differentiation/genetics
- Gene Expression Regulation, Developmental/physiology
- Gene Expression Regulation, Enzymologic/physiology
- Humans
- Neurons/chemistry
- Neurons/cytology
- Neurons/enzymology
- RNA Editing/physiology
- RNA, Messenger/analysis
- RNA-Binding Proteins
- Receptors, AMPA/chemistry
- Receptors, AMPA/genetics
- Receptors, Kainic Acid/chemistry
- Receptors, Kainic Acid/genetics
- Teratocarcinoma
- Tumor Cells, Cultured/chemistry
- Tumor Cells, Cultured/cytology
- Tumor Cells, Cultured/physiology
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Abstract
Patients with Alzheimer disease (AD) show visual impairments in color discrimination (blue hues), stereoacuity, and contrast sensitivity. We asked whether the AD-type visual profile occurs in Down syndrome (DS) in light of the fact that AD neuropathology is present in DS by age 40. We tested 22 adults with DS and 18 adults with mental retardation of non-DS etiology (MR). DS subjects made more tritanomalous errors on the test of color vision than predicated by chance (p < 0.05), indicating a deficiency in the discrimination of short wavelengths (blue hues) but not more of other types of hue discrimination errors. DS subjects had higher stereoacuity thresholds than MR subjects (p < 0.01) and reduced contrast sensitivity across the frequency range (p < 0.01). Taken together, the results point to AD-like visual deficits in DS. Like classic AD, DS may be associated with pathological changes in the parastriate and peristriate visual cortex. DS performance was not correlated with age, suggesting that in individual subjects, the AD-like visual deficits may present prior to and independent of age-associated dementia.
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116
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Lai F, Chen CX, Carter KC, Nishikura K. Editing of glutamate receptor B subunit ion channel RNAs by four alternatively spliced DRADA2 double-stranded RNA adenosine deaminases. Mol Cell Biol 1997; 17:2413-24. [PMID: 9111310 PMCID: PMC232090 DOI: 10.1128/mcb.17.5.2413] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Double-stranded (ds) RNA-specific adenosine deaminase converts adenosine residues into inosines in dsRNA and edits transcripts of certain cellular and viral genes such as glutamate receptor (GluR) subunits and hepatitis delta antigen. The first member of this type of deaminase, DRADA1, has been recently cloned based on the amino acid sequence information derived from biochemically purified proteins. Our search for DRADA1-like genes through expressed sequence tag databases led to the cloning of the second member of this class of enzyme, DRADA2, which has a high degree of sequence homology to DRADA1 yet exhibits a distinctive RNA editing site selectivity. There are four differentially spliced isoforms of human DRADA2. These different isoforms of recombinant DRADA2 proteins, including one which is a human homolog of the recently reported rat RED1, were analyzed in vitro for their GluR B subunit (GluR-B) RNA editing site selectivity. As originally reported for rat RED1, the DRADA2a and -2b isoforms edit GluR-B RNA efficiently at the so-called Q/R site, whereas DRADA1 barely edits this site. In contrast, the R/G site of GluR-B RNA was edited efficiently by the DRADA2a and -2b isoforms as well as DRADA1. Isoforms DRADA2c and -2d, which have a distinctive truncated shorter C-terminal structure, displayed weak adenosine-to-inosine conversion activity but no editing activity tested at three known sites of GluR-B RNA. The possible role of these DRADA2c and -2d isoforms in the regulatory mechanism of RNA editing is discussed.
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Aylward EH, Burt DB, Thorpe LU, Lai F, Dalton A. Diagnosis of dementia in individuals with intellectual disability. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 1997; 41 ( Pt 2):152-164. [PMID: 9161927 DOI: 10.1111/j.1365-2788.1997.tb00692.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The foremost impediment to progress in the understanding and treatment of dementia in adults with intellectual disability is the lack of standardized criteria and diagnostic procedures. Standardized criteria for the diagnosis of dementia in individuals with intellectual disability are proposed, and their application is discussed. In addition, procedures for determining whether or not criteria are met in individual cases are outlined. It is the intention of the authors, who were participants of an International Colloquium on Alzheimer Disease and Mental Retardation, that these criteria be appropriate for use by both clinicians and researchers. Their use will improve communication among clinicians and researchers, and will allow researchers to test hypotheses concerning discrepancies in findings among research groups (e.g. dementia prevalence ranges and age of onset).
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118
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Dabiri GA, Lai F, Drakas RA, Nishikura K. Editing of the GLuR-B ion channel RNA in vitro by recombinant double-stranded RNA adenosine deaminase. EMBO J 1996. [DOI: 10.1002/j.1460-2075.1996.tb00331.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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119
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Dabiri GA, Lai F, Drakas RA, Nishikura K. Editing of the GLuR-B ion channel RNA in vitro by recombinant double-stranded RNA adenosine deaminase. EMBO J 1996; 15:34-45. [PMID: 8598204 PMCID: PMC449915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Double-stranded RNA (dsRNA)-specific adenosine deaminase (DRADA) has been implicated as an enzyme responsible for the editing of RNA transcripts encoding glutamate-gated ion channel subunits (GLuR) in brain. In one case, the editing alters the gene-encoded glutamine (Q) to an arginine (R) located within the channel-forming domain of the alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) receptor subunit GLuR-B. The result of editing at this site, called the 'Q/R' site, is a profound alteration of the Ca2+ permeability of the GLuR channel. Using recombinantly expressed DRADA proteins, we now demonstrate in vitro that DRADA is indeed involved in editing of the GLuR-B RNA. In addition to the formation of an RNA duplex structure involving exon and intron sequences, Q/R site-selective editing by DRADA also requires a cofactor protein(s) commonly present even in non-neuronal cells. The accuracy and efficiency of this RNA editing system appear to be determined by the quantitative balance between DRADA, cofactor and substrate GLuR-B RNA.
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Di Natale M, Fiusti R, Lai F, Corradi F. [Extrapulmonary tuberculosis. An unusual case]. Minerva Med 1995; 86:555-7. [PMID: 8684683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Skeletal tuberculosis with extravertebral location is rare. We report a case of tuberculous osteomyelitis simultaneously affecting two right ribs and the left ulna. We emphasize the diagnostic problems (failure or delay in diagnosis) in extrapulmonary tuberculosis interesting uncommon sites and having relatively indolent presenting symptoms.
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Lai F, Drakas R, Nishikura K. Mutagenic analysis of double-stranded RNA adenosine deaminase, a candidate enzyme for RNA editing of glutamate-gated ion channel transcripts. J Biol Chem 1995; 270:17098-105. [PMID: 7615504 DOI: 10.1074/jbc.270.29.17098] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Mutagenic analysis of the substrate binding and catalytic domains of double-stranded RNA (dsRNA) adenosine deaminase (DRADA) was carried out. This nuclear enzyme is likely to be involved in the RNA editing of glutamate-gated ion channels that are essential for fast excitatory neurotransmission in mammalian brain. The deletion of the first or the third of the three dsRNA binding motifs within the substrate binding domain dramatically decreases enzyme activity, whereas the second motif seems to be dispensable. The results indicate that the three motifs are not functionally equivalent in the catalytic action of DRADA. Mutation of the putative zinc-coordinating residues, His910, Cys966, and Cys1036, abolished the DRADA activity. Similarly, the Glu912 residue, predicted to be involved in the proton transfer functions of the enzyme, was found to be indispensable. Our results reinforce the previous proposal that the hydrolytic deamination mechanism of DRADA may be more similar to that of the cytidine deaminases than of adenosine deaminases.
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Di Natale M, Fiusti R, Grassi M, Lai F, Corradi F. Heparin-induced thrombocytopenia with arterial thrombosis: an unusual case. Haematologica 1995; 80:246-7. [PMID: 7672719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A case of heparin-induced thrombocytopenia with thrombosis (HITT) is described. The patient, treated for several days with porcine Ca-heparin at a dosage of 10,000 IU/day, presented severe thrombocytopenia (Plt 36 x 10(9)/L), intermittent right leg ischemia, and a positive heparin-induced platelet aggregation assay. We promptly discontinued heparin and started picotamide, an antiplatelet drug. Rapid clinical improvement was observed in a few days. We stress the unusual features of the reported case (HITT during prophylactic therapy with low doses of porcine heparin; intermittent thrombosis), and we suggest picotamide represents a rational therapy for HITT on the basis of clinical and pathogenetic considerations.
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Hyman BT, West HL, Rebeck GW, Lai F, Mann DM. Neuropathological changes in Down's syndrome hippocampal formation. Effect of age and apolipoprotein E genotype. ARCHIVES OF NEUROLOGY 1995; 52:373-8. [PMID: 7710373 DOI: 10.1001/archneur.1995.00540280059019] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The neuropathological changes of Alzheimer's disease occur universally in individuals with Down's syndrome as they reach middle age and worsen with increasing age. Thus, evaluation of patients of various ages with Down's syndrome allows one to construct a life history of the development of neuropathological changes associated with Alzheimer's disease at various points in the disease process. METHODS We have used semiquantitative scales and quantitative computerized image analysis techniques to analyze the characteristics of neurofibrillary tangle formation and A beta amyloid deposition in the hippocampal formation and inferior temporal gyrus in 36 individuals with Down's syndrome ranging in age from 4 to 73 years. RESULTS Neurofibrillary tangles occur in a hierarchical distribution in a circumscribed set of neuronal fields, affecting the entorhinal cortex, area CA1/subiculum, then other hippocampal subfields. Although amyloid deposition occurs more evenly in a more widespread distribution, it also accumulates over the years 30 to 50. Surprisingly, examination of the patients available older than 50 years showed no trend toward continued increased deposition of amyloid. Within this group, however, individuals who had inherited the apolipoprotein E (Apo E) epsilon 4 genotype contained more than twice the amyloid burden of individuals who did not inherit the Apo E epsilon 4 genotype. COMMENT This large series of cases confirms earlier observations that had suggested early vulnerability of entorhinal cortex and CA1/subiculum for neurofibrillary tangles and a more widespread but specific topography of A beta deposition. Moreover, it demonstrates quantitatively that the lesions increase to a certain level and then apparently reach a plateau. The level of amyloid deposition in Down's syndrome is higher than in sporadic Alzheimer's disease. Inheritance of the Apo E epsilon 4 genotype appears to be an additional (independent) risk factor for developing higher levels of amyloid accumulation.
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Chan CH, Lai F, Daly B, Ho AK, Yu CM, Cheng A. Scrub typhus pneumonitis with delayed resolution. THE JOURNAL OF TROPICAL MEDICINE AND HYGIENE 1995; 98:114-6. [PMID: 7714933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A 35-year-old lady was admitted to hospital with fever and dry cough. Chest radiograph showed bilateral basal infiltrate. Her Weil-Felix test was strongly positive (OX-K > 1:160) and her fever came down with intravenous tetracycline. There was no improvement in the lung shadow and spirometry showed a severe restrictive defect. Open lung biopsy confirmed the diagnosis of interstitial pneumonitis. CT of thorax 6 months after presentation showed partial resolution of the interstitial shadow.
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125
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Lai F, Stubbs L, Lehrach H, Huang Y, Yeom Y, Artzt K. Genomic organization and expressed sequences of the mouse extended H-2K region. Genomics 1994; 23:338-43. [PMID: 7835882 DOI: 10.1006/geno.1994.1509] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The mouse major histocompatibility complex (MHC) has long been of great interest to many biologists because of not only its critical role in the immune system, but also its association with at least three embryonic lethal genes. Here, we present an analysis of the mouse extended H-2K region using YAC technology. Six new expressed sequences were identified, demonstrating that the high gene density previously described continues. Restriction mapping of a YAC clone extending proximal of the MHC region defined a CpG-rich region located up to 320 kb away from H-2K. The absence of any CpG-rich region for a distance spanning approximately 200 kb near the YAC's proximal end suggests that the high gene density probably diminishes at a distance of 360 kb away from H-2K. The description of genomic organization of both H-2K and the extended H-2K region provides insight into the characteristics of this whole region with respect to gene diversity and density.
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Lai F, Stubbs L, Artzt K. Molecular analysis of mouse Rab11b: a new type of mammalian YPT/Rab protein. Genomics 1994; 22:610-6. [PMID: 8001972 DOI: 10.1006/geno.1994.1434] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Since the realization that the vesicular transport machinery is conserved from yeast to vertebrate neurons, much interest in the proteins involved has been generated. Here we describe a new type of mammalian YPT/Rab protein, named Rab11b, that is most abundantly expressed in brain, heart, and testis. It has all the hallmarks of a YPT3/Rab11 protein, but is more closely related to a ypt3-related gene isolated from fish (97% homology) than to the previously described four mammalian Rab11 genes (89% homology). The mammalian Rab11 genes discovered previously are, by contrast, 100% identical to each other. The genomic structure of a mammalian Rab11 protein is described for the first time. It is surprisingly asymmetrical, with 96% of the coding sequence contained in one-third of the transcription unit. Two copies of this gene are mapped to mouse chromosomes 1 and 17. The fine structural analysis of Rab11b and the protein sequence comparison provides a close look at all YPT3/Rab11-related genes cloned so far and clues to their possible relationship.
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Levin J, Chan P, Coupet J, Bailey T, Vice G, Thibault L, Lai F, Venkatesan A, Cobuzzi A. 6-isoxazolinyl and isoxazolidinyl substituted quinazolinones as angiotensin II receptor antagonists. Bioorg Med Chem Lett 1994. [DOI: 10.1016/s0960-894x(00)80365-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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128
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Levin J, Venkatesan A, Chan P, Baker J, Francisco G, Bailey T, Vice G, Katocs A, Lai F, Coupet J. 2,3,6-Substituted quinazolinones as angiotensin II receptor antagonists. Bioorg Med Chem Lett 1994. [DOI: 10.1016/s0960-894x(01)80243-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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129
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Lai F, Sheehan T. Matrix effects in the derivatization of amino acids with naphthalene dicarboxaldehyde, 9-fluorenylmethyl chloroformate and phenylisothiocyanate. Biotechniques 1993; 14:642-9. [PMID: 8476607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pre-column derivatizations of amino acids often present two major challenges: 1) automation, due to the multi-step manipulations for pH control, reagent addition, mixing and extraction, and 2) effect of matrices in the sample such as salts, buffers and surfactants. Both issues have been addressed in a previous publication on derivatization methods using 9-fluorenylmethyl chloroformate (FMOC) and phenylisothiocyanate (PITC). In this paper, a third method of derivatization, which has recently been developed and published, was studied to address the same issues. The derivatization reagent, naphthalene-2,3-dicarboxaldehyde (NDA), is a modification from o-phthalaldehyde (OPA) and yields more stable derivatives with high fluorescence efficiencies. An autosampler was programmed to mix amino acid samples with cyanide and NDA reagent, allow a programmed reaction time and finally inject onto the HPLC. To study sample matrix effects, amino acid samples were spiked with various concentrations of Tris-HCl, phenol, citrate, sulfosalicylic acid, sodium chloride and sodium dodecyl sulfate. The recoveries of amino acids in varied sample matrices were compared to pure amino acid standards. The matrix effects using the NDA method were similar to those using the FMOC method. Comparisons of all three methods (NDA, FMOC and PITC) are discussed and tabulated.
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Lai F, Mayer A, Sheehan T. Chiral separation and detection enhancement of propranolol using automated pre-column derivatization. J Pharm Biomed Anal 1993; 11:117-20. [PMID: 8504182 DOI: 10.1016/0731-7085(93)80131-j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In the liquid chromatographic analysis of pharmaceuticals, two challenges are often encountered: detectivity and chiral separations. Propranolol, a beta adrenergic blocker, is a pharmaceutical compound that faces both of these limitations. In this study, both limitations are overcome simultaneously using derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate (FLEC), a highly fluorescent and chiral reagent. The derivatization is automated using an autosampler with an AutoMix microrobotic feature, which greatly contributes to the efficiency and reproducibility of the method when manipulating microliter volumes of sample and reagents. The method yields excellent separation of the diasteriomers, has a detection limit of 1 picomol, good reproducibility and linearity in the 50-400 pmol range (on column). In addition, this method is simple, requires no elevated temperature, no chiral stationary or mobile phases and can be easily automated.
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Lai F, Sheehan T. Enhancement of detection sensitivity and cleanup selectivity for tobramycin through pre-column derivatization. J Chromatogr A 1992; 609:173-9. [PMID: 1430042 DOI: 10.1016/0021-9673(92)80160-v] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Reversed-phase high-performance liquid chromatography, UV detection and reversed-phase solid-phase extraction (SPE) as analytical methods for pharmaceutical compounds face a challenge when the compound is rather polar and lack UV absorptivity. A good example is tobramycin. To overcome these problems, a method has been developed using pre-column derivatization of tobramycin with o-phthalaldehyde and automated with an autosampler with microrobotic routines. The detection enhancement of the derivatives was achieved by using fluorescence detection which was forty times more sensitive than using UV detection. Recovery studies of standards and spiked serum samples show that pre-SPE derivatization significantly enhances the recoveries (by at least a factor of 3) and the quality of cleanup over post-SPE derivatization.
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Ebersole T, Lai F, Artzt K. New molecular markers for the distal end of the t-complex and their relationships to mutations affecting mouse development. Genetics 1992; 131:175-82. [PMID: 1350556 PMCID: PMC1204951 DOI: 10.1093/genetics/131.1.175] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Many mutations affecting mouse development have been mapped to the t-complex of mouse chromosome 17. We have obtained 17 cosmid clones as molecular markers for this region by screening a hamster-mouse chromosome 17 and 18 cell hybrid cosmid library with mouse-specific repetitive elements and mapping positive clones via t-haplotype vs. C3H restriction fragment length polymorphism (RFLP) analysis. Twelve of the clones mapping distal to Leh66B in t-haplotypes are described here. Using standard RFLP analysis or simple sequence length polymorphism between t-haplotypes, exceptional partial t-haplotypes and nested sets of inter-t-haplotype recombinants, five cosmids have been mapped in or around In(17)3 and seven in the most distal inversion In17(4). More precise mapping of four of the cosmids from In(17)4 shows that they will be useful in the molecular identification of some of the recessive lethals mapped to the t-complex: two cosmids map between H-2K and Crya-1, setting a distal limit in t-haplotypes for the position of the tw5 lethal, one is inseparable from the tw12 lethal, and one maps distal to tf near the t0(t6) lethal and cld.
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Lai F, Mayer A, Sheehan T. Matrix effects in the derivatization of amino acids with 9-fluorenylmethyl chloroformate and phenylisothiocyanate. Biotechniques 1991; 11:236-44. [PMID: 1931023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pre-column derivatization of amino acids is widely practiced today for the HPLC analysis of amino acids. Due to the requirement for pH control, excess reagent removal and multi-step manipulations, automation is a major challenge in the derivatization of amino acids. Another challenge for pre-column chemistries is the effect of matrices in the sample such as salts, buffers and surfactants. This paper reports on automated derivatization using phenylisothiocyanate (PITC) and compares matrix effects between this PITC method and that of derivatization using 9-fluorenylmethyl chloroformate (FMOC). An autosampler was programmed to mix amino acid samples with PITC or FMOC reagent, allow a programmed reaction time, extract excess reagent and finally inject onto the HPLC. To study sample matrix effects, amino acid samples were spiked with various concentrations of Tris-HCl, phenol, citrate, sulfosalicylic acid, sodium chloride and sodium dodecyl sulfate. Using the PITC method and the FMOC method, the recoveries of amino acids in varied sample matrices were compared to pure amino acid standards. The PITC method appears to be affected less by matrix effects than the FMOC method. However, the FMOC method has a higher sensitivity so that sample dilution (up to 30 times) can be used to eliminate matrix effects.
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135
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Lai F, Schurig GG, Boyle SM. Electroporation of a suicide plasmid bearing a transposon into Brucella abortus. Microb Pathog 1990; 9:363-8. [PMID: 1965986 DOI: 10.1016/0882-4010(90)90070-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The creation of bacterial mutants by transposon mutagenesis has facilitated the identification of regulatory and structural genes. In the case of B. abortus the number of reported transposon mutants created by mating or P1 infection has been relatively small. We studied the conditions necessary to introduce Tn5 bearing a kanamycin resistance gene (KnR) into B. abortus by electroporation. The highest frequency of Tn5 transposition was obtained using B. abortus 2308 harvested at a density of 5.2 x 10(8) cells/ml; 0.5 microgram of plasmid was electroporated for 10 ms at 625 V (equivalent to 12.5 kV/cm). The frequency of Tn5 transposition obtained under optimum conditions was estimated to be around 18-20 insertions per 10(10) Brucella. The phase of growth (or the number of generations) had a strong influence on the frequency of transposition. Dot blot analysis confirmed that all KnR clones appearing after 4 days of incubation at 37 degrees C carried Tn5 in their genomes. Furthermore, the randomnes of Tn5 insertion was verified by Southern analysis of chromosomal DNA extracted from knR clones and hybridized with labeled Tn5.
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Abstract
Ninety-six individuals with Down syndrome over age 35 years were evaluated and followed up for evidence of nontreatable dementia. Dementia was judged to be present when a functional decline occurred in areas such as orientation, memory, verbal and motor skills, and self-care abilities. Forty-nine patients with Down syndrome fit this criterion, with an average onset of dementia at 54.2 +/- 6.1 years. The prevalence of dementia in the institutionalized Down syndrome population of our study (n = 53) was 8% (2/25 patients) between 35 and 49 years, 55% (11/20 patients) between 50 and 59 years, and 75% (6/8 patients) of those over 60 years old. Of note, 41 (84%) demented individuals with Down syndrome developed seizures. Ten (20%) had parkinsonian features. Adequately treated hypothyroidism was present in 27 (59%) of 46 demented patients with Down syndrome tested. The average duration of dementia in the 23 patients who died was 4.6 +/- 3.2 years. Computed tomographic scans in 43 patients all showed brain tissue loss, most pronounced in the temporal lobes. Brains from 12 autopsied cases showed large numbers of plaques and tangles in the same locations as in persons with Alzheimer disease.
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Wang L, Lai F. [Molecular biology research on ApoA-I]. SHENG LI KE XUE JIN ZHAN [PROGRESS IN PHYSIOLOGY] 1989; 20:26-31. [PMID: 2570459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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138
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Lai F, Zhao SY, Jiang ZL, Liu ZD, Sun JW. The distribution of P elements in D. melanogaster along the coast of China studied by DNA hybridization method. SCIENTIA SINICA. SERIES B, CHEMICAL, BIOLOGICAL, AGRICULTURAL, MEDICAL & EARTH SCIENCES 1988; 31:563-71. [PMID: 2843983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The distribution of the P-M system in four local Drosophila melanogaster populations obtained in southern China has been examined by mating tests. There was no P strain. A HindIII fragment of the P element has been cloned, named as pPH 0.86, and used as probe in this study. The distribution of the P element itself in thirteen local D. melanogaster populations along the eastern coast of China has been studied by the method of DNA hybridization. It is found that all the populations obtained from the north of Shanghai carry P elements but few populations from the south of Shanghai carry P elements. In comparison with the mating test, the method of DNA hybridization is more direct and reliable. The origin and trends of distribution of P elements in China are discussed in this paper.
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Bobbio M, Ottello B, Pinnavaia A, Lai F. [Cardiologic research through the pages of the "Giornale Italiano di Cardiologia"]. GIORNALE ITALIANO DI CARDIOLOGIA 1986; 16:604-7. [PMID: 3781151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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140
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Coupet J, Fisher SK, Rauh CE, Lai F, Beer B. Interaction of amoxapine with muscarinic cholinergic receptors: an in vitro assessment. Eur J Pharmacol 1985; 112:231-5. [PMID: 4029261 DOI: 10.1016/0014-2999(85)90500-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Amoxapine, an antidepressant with a rapid onset of therapeutic efficacy and great utility in psychotic depression, has been reported to produce anticholinergic side effects in man similar to those observed with imipramine and amitriptyline. To establish its cholinergic disposition, amoxapine and its metabolites 7-hydroxyamoxapine and 8-hydroxyamoxapine, have been evaluated by determining their effects on quinuclidinyl benzilate (QNB) binding to membrane fractions of rat and human brain, on the carbamoylcholine-stimulated accumulation of inositol phosphates in rat cerebral cortex and on the acetylcholine-induced contraction of the guinea pig ileum. In all three preparations, amoxapine was found to be a considerably weaker antagonist of muscarinic cholinergic receptors than either imipramine (4-27 fold) or amitriptyline (51-300 fold). These results indicate that for amoxapine, no correlation exists between the magnitude of muscarinic receptor inhibition and the extent of 'anticholinergic' side effects found in the clinic. Neither the metabolites of amoxapine nor species differences could account for this discrepancy.
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Bobbio M, Bianchini B, Lai F, Pistis G, Ottello B, Pinnavaia A. [Ambulatory cardiological diagnosis. Contribution of anamnesis, physical examination and the electrocardiogram]. CARDIOLOGIA (ROME, ITALY) 1984; 29:511-6. [PMID: 6543497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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142
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Lott IT, Lai F. Dementia in Down's syndrome: observations from a neurology clinic. APPLIED RESEARCH IN MENTAL RETARDATION 1982; 3:233-9. [PMID: 6216849 DOI: 10.1016/0270-3092(82)90017-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Clinical manifestations of dementia were reviewed in 15 Down's syndrome (DS) patients referred to a neurological clinic over a 24-month period for mental deterioration. The ages ranged from 32-64 years. One hundred percent showed personality changes and loss of independent daily living skills, the presenting symptoms in two-thirds of the cases. Other manifestations included seizures (53%), gait deterioration (73%), sphincteric incontinence (40%), and pathological release reflexes (67%). All 7 patients with CT-scans showed moderate or severe central and peripheral cortical atrophy. Detailed clinical information is presented for two patients, one of whom showed a temporary remission with imipramine. A characteristic dementia syndrome appears to be present in a subpopulation of aging DA patients with radiographic findings of Alzheimer's disease.
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Lai F, Scheuer J. Early changes in myocardial hypoxia: relations between mechanical function, pH and intracellular compartmental metabolites. J Mol Cell Cardiol 1975; 7:289-303. [PMID: 236392 DOI: 10.1016/0022-2828(75)90086-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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