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Biomedical subjects

D Mayo

Publications and source records attributed to D Mayo.

At least 19 recordsLinked to original sources
PubMed2003

Interaction of normal and expanded CAG repeat sizes influences age at onset of Huntington disease.

Huntington disease (HD) is a neurodegenerative disorder caused by the abnormal expansion of CAG repeats in the HD gene on chromosome 4p16.3. Past studies have shown that the size of expanded CAG repeat is inversely associated with age at onset (AO) of HD. It is not known whether the normal Huntington allele size influences the relation between the expanded repeat and AO of HD. Data collected from two independent cohorts were used to test the hypothesis that the unexpanded CAG repeat interacts with the expanded CAG repeat to influence AO of HD. In the New England Huntington Disease Center Without Walls (NEHD) cohort of 221 HD affected persons and in the HD-MAPS cohort of 533 HD affected persons, we found evidence supporting an interaction between the expanded and unexpanded CAG repeat sizes which influences AO of HD (P = 0.08 and 0.07, respectively). The association was statistically significant when both cohorts were combined (P = 0.012). The estimated heritability of the AO residual was 0.56 after adjustment for normal and expanded repeats and their interaction. An analysis of tertiles of repeats sizes revealed that the effect of the normal allele is seen among persons with large HD repeat sizes (47-83). These findings suggest that an increase in the size of the normal repeat may mitigate the expression of the disease among HD affected persons with large expanded CAG repeats.

Adolescent↗
PubMed2001

Chromosome-12 mapping of late-onset Alzheimer disease among Caribbean Hispanics.

Linkage to chromosome 12p for familial Alzheimer disease (AD) has been inconsistent. Using 35 markers near the centromere of chromosome 12, we investigated 79 Caribbean Hispanic families with AD. Two-point linkage analysis using affected sib pairs yielded LOD scores of 3.15 at D12S1623 and 1.43 at D12S1042. The LOD score at D12S1623 decreased to 1.62 in families with late-onset (age >65 years) AD (LOAD), but the LOD score at D12S1042 was unchanged. Among families negative for the apolipoprotein E (APOE-epsilon 4) allele, the LOD score for D12S1623 was lower (1.01), whereas that for D12S1042 increased to 1.73. Among families positive for the APOE-epsilon 4 allele, none of the LOD scores reached 1. Multipoint affected-relative-pair analysis showed peaks at D12S1623 (nonparametric linkage [NPL] score 1.52; P=.028) and near D12S1042, at D12S1057 (NPL score 1.57; P=.027). NPL scores for both D12S1623 and D12S1057 increased in families affected with LOAD, but, in APOE-epsilon 4-negative families, only scores for the region flanking D12S1623 remained elevated (NPL score 1.74; P=.013). This study of Caribbean Hispanics with familial AD extends and provides modest evidence of linkage to loci on chromosome 12p. Linkage varied by age at onset of AD and by the presence or absence of the APOE-epsilon 4 allele.

Adult↗
PubMed1996

Routine HIV testing of hospital patients and pregnant women: informed consent in the real world.

The Centers for Disease Control and Prevention (CDC) has recommended that HIV testing be routinely offered to certain patients in hospitals with a high prevalence of HIV infection and on all pregnant women. The CDC does not, however, offer implementation level guidelines for obtaining informed consent. We provide a moral justification for requiring informed consent for HIV testing and propose guidelines for securing such consent. In particular we argue that genuine informed consent can be secured without elaborate counseling, such as that currently used at Counseling and Testing Sites, provided that sufficient written notice is given to the patients before testing and that they are specifically asked for permission.

Centers for Disease Control and Prevention, U.S.↗
PubMed1994

Surveillance for influenza in a newborn intensive care unit.

Although influenza may cause fatal neonatal infections, the current prevalence of disease in newborn intensive care units (NICU) is unknown. Furthermore, because compliance of NICU staff with annual influenza immunization is poor, absence of antibody may provide an indication of influenza susceptibility for neonatal patients and staff. We studied our NICU staff and patients during the winter of 1992-93 to determine seroprevalence of influenza antibody and attempted to document infection serologically or by culture in symptomatic staff and by culture in neonatal patients. Before the influenza season commenced or at birth (using cord blood), antibody to influenza A was absent in 9% (4/43) of the staff and 11% (9/83) of the neonatal patients. Antibody to influenza B was absent in 26% (11/43) of the staff and in 37% (31/83) of the neonates. We were able to document influenza serologically in only one nurse during the study. None of our staff or patients had positive cultures; however, we demonstrated a susceptible population of both staff and particularly neonates who need protection. There were study limitations of sampling and a low incidence of influenza in Connecticut for 1993. Nevertheless, continuing surveillance for influenza in NICUs could provide a more rational basis for immunization and prevention practices.

Adult↗
PubMed1992

Liquid chromatographic resolution of the isomers of tipredane and phenylthioproline using urea-solubilized beta-cyclodextrin in the mobile phase.

Two LC assays were developed using urea-solubilized beta-cyclodextrin (beta-CD) as a mobile phase additive in combination with reversed-phase columns. A methylsilane column gave optimal resolution of the steroid tipredane from its epimer. An investigation of the effects of beta-CD concentration, column temperature, column type, and addition of ethanol on the chromatographic separation is detailed. The enantiomer and diastereoisomers of L-cis-phenylthioproline were best resolved by urea-solubilized beta-cyclodextrin and a trimethylsilane column. The elution order of L-cis-phenylthioproline relative to its stereoisomers was reversed after adding ethanol to the beta-CD containing mobile phase or by changing from a beta-CD to an acetylated beta-CD column. The resolution factors for these separations obtained using the beta-CD mobile phase were larger than those obtained using beta-CD columns. Mobile phases containing up to 0.15 M beta-CD and 8 M urea were investigated. The separation of these isomers are dramatically affected by column polarity.

Administration, Topical↗
PubMed1992

Cytomegalovirus antibody detection in blood donors and mothers of very low birth weight neonates by using three serologic methods.

We compared three serologic methods for cytomegalovirus (CMV) antibody detection and determined the CMV antibody seroprevalence of blood donors and mothers of very low birth weight (less than 1250 g) neonates in the Greater Hartford region. CMV serology was determined for 577 healthy blood donors as well as for 147 mothers of premature infants. Plasma from blood donors and sera from mothers were tested by either latex agglutination (LA) or by an immunofluorescent antibody assay (IFA), and results were compared with those from an enzyme-linked immunosorbent assay (ELISA). Sensitivity and specificity for LA to ELISA were significantly better than for IFA to ELISA [sensitivity 79/81 (97%) vs 171/202 (85%), and specificity 90/94 (96%) vs 257/347 (74%), p less than 0.01]. These differences remained whether plasma or sera were tested. Borderline values explained only two (33%) of six LA-ELISA as well as only 70 (58%) of 121 IFA-ELISA discordance. CMV seroprevalence rate for the donor blood population was 38%, and for the mothers was 53%. The LA assay is superior to the IFA assay for CMV screening of blood donors and maternal populations.

Antibodies, Viral↗
PubMed1990

High-performance liquid chromatography of the drug fosenopril.

High-performance liquid chromatography was used to determine the purity and impurities of fosinopril, an angiotensin-converting enzyme inhibitor used to treat hypertension. Purity values are determined using a silica column and usually are above 99%. All known possible impurities, including stereoisomeric impurities, can be resolved and quantified by injecting solutions of fosinopril onto three separate columns; silica, strong anion exchange and phenyl. Typical impurity contents total 0.5%. Validation data and a study of properties of fosinopril in solution is included.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1985

On the alleged ineffability of death.

A number of recent theorists, all proceeding on the assumption that there is no afterlife, argue that the notion of one's own death defies comprehension in ways that have important implications. Some argue this "ineffability" of death precludes a rational decision to die. Dr. Edwin Shneidman maintains that it makes the notion of our own death unintelligible to each of us. In this paper, these arguments are criticized. It is maintained that death is not so inscrutible as these theorists would have us believe.

Attitude to Death↗
PubMed1985

Comparison of four methods for typing low-passage herpes simplex virus isolates.

Clinical isolates of herpes simplex virus (HSV) were identified as HSV type 1 or type 2 by sensitivity to (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU), by differential replication in chick embryo cells versus guinea pig embryo cells, by restriction endonuclease analysis, and by a direct fluorescent antibody technique using monoclonal antibodies. More than 550 isolates were typed by two or three of the systems with complete agreements as to virus type between systems for each isolate. In appropriately equipped laboratories, any of the above typing systems can be used with complete confidence. However, the BVDU sensitivity assay, particularly when used in a continuous cell line as described, can be economically utilized in any virology laboratory.

Animals↗
PubMed1978

Activation of latent murine cytomegalovirus infection: cocultivation, cell transfer, and the effect of immunosuppression.

No free virus was detectable in any organ of DBA/2 mice greater than or equal to 16 weeks after infection with murine cytomegalovirus. Spleens were free of free lytic virus six weeks after infection. Spleen cells from such mice were shown to be latently infected by three methods. First, virus was recovered by cocultivation of spleen cells for two weeks or longer on either syngeneic or allogeneic (CDI) embryonic fibroblast cultures. Second, virus was recovered from salivary glands of either syngeneic (DBA/2) or allogeneic (C57BL/10) mice that received 10(8) spleen cells. Recovery was enhanced by treatment of allogeneic recipients with cyclophosphamide but not with azathioprine. Third, latently infected mice, after treatment with either cyclophosphamide or azathioprine, developed free murine cytomegalovirus in their salivary glands. The last two findings parallel observations of human cytomegalovirus in immunosuppressed patients and in patients receiving latently infected cells during transplantation. Both cyclophosphamide and azathioprine elevated titers of free lytic virus in the salivary glands.

Animals↗
PubMedDate not supplied

Prevention of transfusion-associated cytomegalovirus infection in neonatal patients by the removal of white cells from blood.

The usual methods employed to reduce the risk of transfusion-associated cytomegalovirus (TA CMV) disease have been to transfuse blood or cellular blood components that are CMV antibody-negative or to administer deglycerolized frozen red cells. To determine if the reduction of white cells (WBCs) in blood by filtration will also eliminate TA CMV disease in a high-risk population, 48 surviving very low birth weight (less than 1250 g) neonatal infants born to CMV-seronegative mothers at three participating institutions in the Hartford, Connecticut area and receiving at least one CMV-seropositive blood transfusion were studied. The incidence of TA CMV disease in 26 neonatal patients who received blood prepared by a modified spin-cool-filter technique and in 22 neonatal patients who received blood filtered through a WBC-reduction filter was compared with the incidence of transfusion-associated disease in similar populations reported in other studies. The CMV antibody prevalence of the blood donor population was found to be 37 percent. At the time of discharge of the individual neonatal infants in the population studied, and/or 2 to 6 months later, 47 of the 48 who had undergone transfusion had CMV antibody-negative serologic tests and/or urine culture. The other infant transiently seroconverted because of passive transfer of the antibody. None of the 48 neonatal infants had clinical evidence of CMV infection. This study indicates that WBC reduction of donor blood can reduce and perhaps prevent TA CMV disease in high-risk neonatal patients.

Cytomegalovirus Infections↗
PubMedDate not supplied

West Nile virus surveillance in Connecticut in 2000: an intense epizootic without high risk for severe human disease.

In 1999, Connecticut was one of three states in which West Nile (WN) virus actively circulated prior to its recognition. In 2000, prospective surveillance was established, including monitoring bird deaths, testing dead crows, trapping and testing mosquitoes, testing horses and hospitalized humans with neurologic illness, and conducting a human seroprevalence survey. WN virus was first detected in a dead crow found on July 5 in Fairfield County. Ultimately, 1,095 dead crows, 14 mosquito pools, 7 horses, and one mildly symptomatic person were documented with WN virus infection. None of 86 hospitalized persons with neurologic illness (meningitis, encephalitis, Guillain-Barré-like syndrome) and no person in the seroprevalence survey were infected. Spraying in response to positive surveillance findings was minimal. An intense epizootic of WN virus can occur without having an outbreak of severe human disease in the absence of emergency adult mosquito management.

Animals↗
PubMedDate not supplied

[Spinocerebellar ataxia type VII (AEC 7). Report of a Spanish family with the disease].

INTRODUCTION: The dominant autosomic ataxias are a group of neurodegenerative disorders caused by expansion of a CAG triplet in different genes, found along the genome. The dominant autosomic ataxias present very varied clinical findings. However, genetic studies are being done to establish the genotype-phenotype relationship of the different autosomal dominant ataxias. CLINICAL CASE: A 50 year old man had alterations in gait, dysarthria and visual changes (retinal degeneration). Study of the different genes known to be responsible for the dominant autosomic ataxias have an expansion of the superior CAG of more than 37 repetitions of the gene SCA 7, whilst in the normal control population there are 9-18 repetitions of this gene. Other members of the family had similar clinical findings, although the age of onset varied. One did not have retinal degeneration but did have expansion of the SCA 7 gene. CONCLUSIONS: The non-pathological range of SCA 7 in the Spanish population, according to our study, is between 9-18 repetitions of triplet CAG, whilst in members of the patient's family they were over 37. The clinical findings, which were similar in all patients were found in all patients except for one, who did not have retinal degeneration. We observed the phenomenon of genetic anticipation in the family studied.

Aged↗