First quarter births in Alzheimer's disease.
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Alzheimer Disease↗
Biomedical subjects
T M Ryan
Publications and source records attributed to T M Ryan.
Human beta-globin locus control region: analysis of the 5' DNase I hypersensitive site HS 2 in transgenic mice.
The human beta-globin locus control region (LCR) is essential for high-level expression of human epsilon-, gamma-, and beta-globin genes. Developmentally stable DNase I hypersensitive sites (designated HS) mark sequences within this region that are important for LCR activity. A 1.9-kilobase (kb) fragment containing the 5' HS 2 site enhances human beta-globin gene expression 100-fold in transgenic mice and also confers position-independent expression. To further define important sequences within this region, deletion mutations of the 1.9-kb fragment were introduced upstream of the human beta-globin gene, and the constructs were tested for activity in transgenic mice. Although enhancer activity was gradually lost with deletions of both 5' and 3' sequences, a 373-base-pair (bp) fragment retained the ability to confer relative position-independent expression. Three prominent DNase I footprints were observed in this region with extracts from the human erythroleukemia cell line K-562, one of which contained duplicated binding sites for transcription factor AP-1 (activator protein 1). When the 1.9-kb fragment containing an 18-bp deletion of the AP-1 binding sites was tested in transgenic mice, enhancer activity decreased 20-fold but position-independent expression was retained.
Animals↗
Thymus-dependent antiidiotype and anti-antiidiotype responses to a dinitrophenyl-specific monoclonal antibody.
BALB/c mice were inoculated i.p. with graded doses of a DNP-specific, IgM mAb (designated 57.1). Injection with unmodified 57.1 in the absence of adjuvants resulted in the generation of an anti-Id response (Ab2) and an anti-anti-Id response (Ab3). The generation of serum anti-Id antibodies was found to be thymus dependent. Nude mice immunized with 57.1 were unable to produce a serum Ab2 response above nonimmunized controls whereas euthymic mice receiving identical doses of 57.1 produced strong Ab2 responses. To examine the specificity of serum anti-Id, sera from mice receiving 57.1 were screened against a panel of mAb representing at least five distinct VH gene families. Serum titers were significantly higher against 57.1 than against any of the other antibodies in the panel. Three of the antibodies in this panel bind FD5-1, a monoclonal anti-Id (Ab2) that also binds 57.1. However, sera from mice receiving 57.1 bound 57.1 only. Thus, the serum Ab2 response appears to be highly specific for idiotopes on 57.1. The predominant isotype of these anti-Id antibodies was IgG1. The number of isotypes detected increased in a dose dependent manner with all IgG subclasses having anti-Id specificity in sera from animals receiving the higher doses of 57.1. Further analysis of the serum demonstrated that approximately 8% of the Ab2 response was paratope-specific (inhibitable by the monovalent hapten DNP-lysine). The same sera were analyzed for the presence of Ab3 by binding to the monoclonal anti-Id antibody FD5-1. Lower serum titers of Ab3 were generated in comparison to serum titers of Ab2. Analysis of the binding specificity of the Ab3 response revealed that DNP-BSA was able to partially inhibit the binding of serum IgM and IgG Ab3 to FD5-1. A subset of the Ab3 response. Ab1' that is specific for DNP was observed in a direct binding assay where detectable amounts of DNP binding IgM, IgG1, and IgG3 isotypes were present. We have thus described a complete circuit (Ab1----Ab2----Ab3) of antibodies within the Id network by immunizing animals with an unmodified mAb in the absence of Ag or adjuvants.
Animals↗
Human sickle hemoglobin in transgenic mice.
DNA molecules that contain the human alpha- and beta s-globin genes inserted downstream of erythroid-specific, deoxyribonuclease I super-hypersensitive sites were coinjected into fertilized mouse eggs and a transgenic mouse line was established that synthesizes human sickle hemoglobin (Hb S). These animals were bred to beta-thalassemic mice to reduce endogenous mouse globin levels. When erythrocytes from these mice were deoxygenated, greater than 90 percent of the cells displayed the same characteristic sickled shapes as erythrocytes from humans with sickle cell disease. Compared to controls the mice have decreased hematocrits, elevated reticulocyte counts, lower hemoglobin concentrations, and splenomegaly, which are all indications of the anemia associated with human sickle cell disease.
Anemia, Sickle Cell↗
Human gamma- to beta-globin gene switching in transgenic mice.
Previous studies demonstrated correct tissue- and temporal-specific expression of human gamma- and beta-globin genes in transgenic mice; however, expression was extremely low. When the erythroid-specific DNase I super-hypersensitive (HS) sites that are normally located upstream of the human beta-globin locus were fused individually to gamma- or beta-globin genes, expression increased to endogenous mouse globin levels but temporal specificity was lost. In contrast, when the HS sequences were combined with fragments containing both gamma- and beta-globin genes, correct developmental regulation was restored. We suggest that human gamma- to beta-globin gene switching during development results from competition of individual globin gene family members for interaction with the HS sequences and that factors influencing these competitive interactions determine temporal specificity.
Animals↗
Synthesis of functional human hemoglobin in transgenic mice.
Human alpha- and beta-globin genes were separately fused downstream of two erythroid-specific deoxyribonuclease (DNase) I super-hypersensitive sites that are normally located 50 kilobases upstream of the human beta-globin gene. These two constructs were coinjected into fertilized mouse eggs, and expression was analyzed in transgenic animals that developed. Mice that had intact copies of the transgenes expressed high levels of correctly initiated human alpha- and beta-globin messenger RNA specifically in erythroid tissue. An authentic human hemoglobin was formed in adult erythrocytes that when purified had an oxygen equilibrium curve identical to the curve of native human hemoglobin A (Hb A). Thus, functional human hemoglobin can be synthesized in transgenic mice. This provides a foundation for production of mouse models of human hemoglobinopathies such as sickle cell disease.
Animals↗
Consequences and costs of shutting off methadone.
In the face of rising fiscal conservatism, many states and localities with sizable addict populations have reduced or eliminated public funding for methadone maintenance (MM) programs and permitted private-fee-for-service programs to replace them. The social and economic costs of these changed funding policies with reference to the California experience were analyzed. A two-and-a-half year follow-up of a sample of San Diego MM clients (195 men, 129 women) terminated from a public subsidized program compared outcome results to clients from publicly funded MM programs in Orange, Riverside and San Bernardino counties (129 men, 131 women). In a secondary analysis, San Diego clients who transferred into private (fee-for-service) treatment programs were compared with those who did not transfer. Major adverse consequences were found for clients unable or unwilling to transfer to private programs: higher crime and dealing rates, more contact with the criminal justice system, and higher rates of illicit drug use were demonstrated by nontransfer clients. Moreover, the savings resulting from a reduction of MM program costs were nearly offset by increased direct costs for incarceration, legal supervision, and other government-funded drug treatment. Indirect costs were not assessed.
Adult↗
High-level erythroid expression of human alpha-globin genes in transgenic mice.
The human alpha 1-globin gene was fused downstream of two erythroid-specific DNase I super-hypersensitive sites that are normally located upstream of the human beta-globin locus. This construct was injected into fertilized mouse eggs, and expression was analyzed in 16-day fetal livers and brains. All 11 fetuses that contained intact copies of the transgene expressed correctly initiated human alpha-globin mRNA in the erythroid fetal liver but not in brain. Levels of expression ranged from 4% to 337% of endogenous mouse beta-globin mRNA. A human alpha-globin construct that did not contain super-hypersensitive sites was not expressed. These results demonstrate that human beta-globin locus activation sequences can stimulate high levels of human alpha-globin gene expression in erythroid tissue of transgenic mice. The results also provide a foundation for experiments designed to coexpress human alpha- and beta-globin genes in transgenic mice and suggest a feasible approach for production of a mouse model for human sickle cell disease.
Animals↗
A single erythroid-specific DNase I super-hypersensitive site activates high levels of human beta-globin gene expression in transgenic mice.
Erythroid-specific DNase I super-hypersensitive (HS) sites that are normally located far upstream of the human beta-globin locus were inserted immediately upstream of a 4.1-kb fragment containing the human beta-globin gene. These constructs (HS beta) and a construct containing the beta-globin gene alone (beta) were microinjected into fertilized mouse eggs, and expression was analyzed in erythroid fetal liver and brain of day-16 embryos that developed. Only 7 of 23 animals that contained the beta gene alone expressed human beta-globin mRNA in erythroid tissue, and the average level of expression per gene copy was 0.3% of endogenous mouse beta-globin mRNA. In contrast, 50 of 51 transgenic mice that contained various HS beta constructs expressed the transgene specifically in erythroid tissue. The average level of expression per gene copy for constructs containing all five upstream HS sites was 109% of endogenous mouse beta-globin mRNA. Constructs that contained a single super-hypersensitive site (HS II beta) expressed 40% as much human beta-globin as mouse beta-globin mRNA per gene copy. These results demonstrate that the HS VI site, normally located downstream of the human beta-globin locus, is not required for high-level expression. Furthermore, the results demonstrate that high levels of human beta-globin gene expression can be obtained in transgenic mice even when a relatively small fragment of DNA (1.9 kb) containing erythroid-specific super-hypersensitive site II (HS II) is inserted upstream of the human beta-globin gene.
Animals↗
DNase I super-hypersensitive sites direct high level erythroid expression of human alpha-, beta- and beta s- globin genes in transgenic mice.
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Animals↗
Combined administration of physostigmine and clonidine to patients with dementia of the Alzheimer type: a pilot safety study.
Reports of cholinergic and noradrenergic deficits in brain specimens from Alzheimer patients have suggested that concomitant augmentation of cholinergic and noradrenergic neurotransmission can benefit some dementia of the Alzheimer type (DAT) patients. However, pharmacological agents that enhance central cholinergic and noradrenergic neurotransmission, like physostigmine and clonidine, might have serious adverse effects. Therefore, prior to the commitment of major resources in efficacy studies, feasibility pilot studies are necessary to ensure that physostigmine and clonidine, combined, can be safely administered to DAT patients. Physostigmine, 2 mg every 2 h, and clonidine, up to 0.3 mg/day, were tolerated by the nine DAT patients without clinically meaningful adverse effects.
Aged↗
Ethnic differences in narcotics addiction. II. Chicano and Anglo addiction career patterns.
Part I of this series compared characteristics of 546 Chicanos and Anglo men and women methadone maintenance (MM) clients. In Part II, specific differences between Chicanos and Anglos are analyzed, by sex, for each of five stages in the addiction career: preexperimentation, experimentation addiction, initial MM treatment, and posttreatment. The analysis examines narcotic and other drug use, arrest, incarceration and legal supervision histories, criminal involvement, employment, interpersonal relationships, and treatment history. Whereas preaddiction differences between addicts parallel ethnic differences found in the general population, after addiction occurs the similarities are greater than the dissimilarities between ethnic groups, except for Chicanas. Chicanos appear to continue to function as part of their community after addiction, but Chicanas appear to risk becoming marginal. Treatment outcomes for Chicanos were, in general, less successful than for Anglos.
Adult↗
Ethnic differences in narcotics addiction. I. Characteristics of Chicano and Anglo methadone maintenance clients.
This paper reviews the research literature comparing Chicano (Mexican American) to Anglo heroin addicts. In addition, characteristics of 546 Chicano and Anglo men and women who had been clients of southern California methadone maintenance programs in 1978 are compared. Background factors examined include nativity, family socioeconomic status (SES) and family interpersonal relationships, education, and gang membership. Lifetime characteristics and status at follow-up interview are reported with particular attention to legal status, criminality, employment, and interpersonal relationships. Drug experimentation history and circumstances surrounding narcotics initiation are also compared. Most observed differences prior to addiction are similar to ethnic differences found in the general population. Part II analyzes ethnic differences progressing through five stages of the addiction career.
Adult↗
Quantitative determination of acivicin in bulk drug and pharmaceutical formulations by ion-pair high-performance liquid chromatography.
An ion-pair reversed-phase high-performance liquid chromatographic method for the determination of the purity of acivicin and the amount of drug in a sterile powder and two sterile solution formulations is described. The method displays good recoveries (98.4-100.4%) for all formulations and a linear range of 0.002-20 micrograms of drug injected. Estimates of assay precision were 1.3% for the bulk drug, 0.6% for sterile solution formulations and 1.6% for the sterile powder formulations.
Antineoplastic Agents↗
Quantitative determination of alprostadil (PGE) in bulk drug and pharmaceutical formulations by high-performance liquid chromatography.
An adsorption high-performance liquid chromatographic method suitable for the quantitative determination of the purity of alprostadil (prostaglandin E1) bulk drug and of the concentration of alprostadil in Prostin V.R. Pediatric Sterile Solution is described. A variety of isomers and related compounds including 8-iso-PGE1, 11-epi-PGE1, 15-epi-PGE1, PGE2, 5,6-trans-PGE2, and 8-iso-PGE2 are separated from alprostadil and are quantifiable. The 2-naphthacyl ester derivatives are employed and derivatization conditions providing maximum response are described.
Alprostadil↗
Quantitative determination of prostaglandins A1 and B1 in alprostadil (PGE1) by high-performance liquid chromatography.
An absorption high-performance liquid chromatography assay for the quantitative determination of prostaglandins A1 and B1 in alprostadil (prostaglandin E1) and in Prostin VR Pediatric Sterile Solution was developed. Prostaglandins A1 and B1 have been shown to be the major degradation products of prostaglandin E1. The adsorption system provided baseline resolution of the 2-naphthacyl esters of prostaglandin A1 from prostaglandin B1. Derivatization conditions providing maximal response for prostaglandins A1 and B1 while minimizing the conversion of prostaglandin E1 to prostaglandins A1 and B1 were established.
Alprostadil↗