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Biomedical subjects

E Taylor

Publications and source records attributed to E Taylor.

At least 127 records · Page 7Linked to original sources

Localization of the achondroplasia gene to the distal 2.5 Mb of human chromosome 4p.

Achondroplasia has been mapped to 4p16.3 using 18 multigenerational families with achondroplasia and 10 short tandem repeat polymorphic markers from this region. No evidence of genetic heterogeneity was found. Analysis of a recombinant family localizes the achondroplasia locus to the 2.5 Mb region between D4S43 and the telomere. Multipoint linkage analysis favors placement telomeric of D4S412. The establishment of closely linked markers will facilitate positional cloning of the achondroplasia gene and permit prenatal diagnosis of homozygous achondroplasia for at risk couples.

Achondroplasia↗

Risk factors associated with prevalent HIV-1 infection among pregnant women in Rwanda. National University of Rwanda-Johns Hopkins University AIDS Research Team.

This study evaluated risk factors associated with prevalent HIV-1 infection among pregnant women in a semi-rural but densely populated area surrounding the town of Butare in Rwanda. Overall seroprevalence was 9.3% in 5690 pregnant women who sought antenatal care at one of five health centres. Factors associated with higher seroprevalence of HIV-1 included history of multiple sexual partners, history of at least one sexually transmitted disease (STD), relatively high socioeconomic status (SES), being unmarried, young age at first pregnancy, and low gravidity. Women who had used oral contraceptives, smoked more than one cigarette per day, whose partners were circumcised, and had had sex to support themselves were also at higher risk of being infected. A history of blood transfusion in the past 5 years was not associated with HIV-1 infection. History of multiple sexual partners, history of STD, high household income, partner circumcision, and past oral contraceptive use remained strongly associated with HIV-1 infection even when simultaneously controlling for other covariates. Among legally married women who lacked sexual behaviour risk factors, history of STD, high SES, young age at first pregnancy, and low gravidity were significantly associated with HIV-1 seroprevalence.

Adolescent↗

The incidence of HIV-1 infections in village populations of northern Thailand.

OBJECTIVES: To determine the age- and sex-specific prevalence of HIV-1 infection in a general ambulatory population in northern Thailand in 1990 and 1992, and the incidence of HIV-1 infections between 1990 and 1992. DESIGN: Health fairs were held in five villages in Chiang Mai province in northern Thailand between December 1989 and January 1990 and again in January 1992. Participation of all village residents was encouraged. Villagers were offered testing for serological markers of hepatitis B virus (HBV) infection and free HBV vaccine was made available to susceptible individuals. METHODS: Sera from the two surveys were linked and coded by demographic characteristics (age group and sex). Individual identifiers were removed and the sera tested for HIV-1 antibodies by enzyme-linked immunosorbent assay with Western blot confirmation. RESULTS: In 1990, 21 out of 1161 (1.8%) individuals were HIV-1-seropositive; the infection rates were 3.3% in men and 0.5% in women. In 1992, 44 out of 956 (4.6%) individuals were HIV-1-seropositive. Among people included in both surveys the 2-year incidence was 2.0% in women and 4.1% in men (annual incidence, 1.0 and 2.05%, respectively); however, among men over the age of 14 years the 2-year incidence was 6.3%, whereas among women of this age the 2-year incidence was 1.8% (annual incidence, 3.15 and 0.9%, respectively). Among men, incident HIV-1 infections were common, even among those aged 50 years or more. CONCLUSIONS: Infections with HIV-1 are disturbingly frequent and increasing among adult populations in semi-rural areas of northern Thailand. In order to contain further spread of the epidemic public-health strategies targeted to the general public, including those in rural areas, will be needed.

Adolescent↗

Monitored anesthesia care.

The use of sedative and analgesic adjuvants during local and regional anesthesia can improve patient comfort while optimizing intraoperative conditions and increasing the range of procedures that can be safely and comfortably performed. Similarly, these techniques may be applied to procedures in which local anesthetic agents are unnecessary, or in which their administration is impractical. Although local anesthetic-based techniques are frequently perceived as safer than general anesthesia, the use of potent sedative-hypnotic and analgesic drugs (especially when used together) may cause significant depression of respiratory function. The need for vigilant monitoring, supplemental oxygen administration, careful titration of sedative-analgesic medications, and facilities and equipment for resuscitation is no different than when general anesthesia is employed. The availability of agents with more specific actions, shorter half-life values, and fewer adverse side effects, combined with a better understanding of drug actions and interactions, as well as new administration techniques, should make MAC safer and even more acceptable to patients.

Ambulatory Surgical Procedures↗

Obstetric complications in histories of monozygotic twins discordant and concordant for schizophrenia.

Histories of obstetric complications (OCs) during pregnancy, labor-delivery and the neonatal period were investigated by detailed maternal report for 23 monozygotic (MZ) twin pairs discordant for schizophrenia, 10 MZ twin pairs concordant for schizophrenia and 7 normal MZ control pairs. Statistically significant differences in OC rates were found across these 3 groups. OCs being most frequent in discordant pairs and least frequent in normal control pairs. Labor complications were significantly more frequent in discordant than concordant pairs. OC rates were equivalent in sick and well discordant twins. The results provide evidence for the role of OCs in the development of schizophrenia, complications at the time of birth being especially associated with the development of schizophrenia in discordant twins.

Adult↗

PCR SSCP reveals haplotype related polymorphism of PERB1: a new marker for MHC beta block typing.

Many new Major Histocompatibility Complex (MHC) genes have been discovered in the last 5 years. Defining the polymorphism of these new genes may elucidate their function and their relevance to diseases with MHC associations. Polymerase chain reaction and single stranded conformation polymorphism (PCR SSCP) analyses were used to detect sequence polymorphisms of PERB1 demonstrated by comparing the available genomic sequence of four haplotypes. This study showed that PCR SSCP of PERB1 is reproducible. In addition, PERB1 alleles segregate within families together with MHC haplotypes. Typing results from the Forth Asia and Oceania Histocompatibility Workshop (4AOHW) cell panel indicate that the identified polymorphisms of PERB1 are "haplotypic', i.e., unrelated individuals carrying the same MHC ancestral haplotypes carry the same PERB1 SSCP pattern. Interestingly, PERB1 SSCP patterns allow the distinction of ancestral haplotypes which share HLA-B serological specificities, such as HLA-B44 and therefore this analysis can be used to further define MHC haplotypes and thus to improve our understanding of the evolution of this complex.

Alleles↗

Inhibitory effect of milk fat on milk secretion in the mouse: a re-examination.

Lactating mice were treated I.P. with cow milk, skim milk, milk lipid extract, preparations of milk fat globule membranes and fat globule-enriched milk (cream). Milk, but not skim milk, inhibited litter growth significantly. None of the fractions of milk fat globules had any apparent effect on litter growth. Litter growth was reduced markedly and maternal health adversely affected by cream. It is concluded that previous studies in which milk was injected I.P. cannot be taken to indicate that milk contains a lipid or lipid-soluble inhibitor of milk secretion in addition to the protein inhibitor discovered in milk more recently.

Animals↗

Comparison of tracheal extubation in patients deeply anesthetized with desflurane or isoflurane.

A randomized, single-blind study design was used to compare desflurane with isoflurane in 31 adults undergoing intraocular surgery to determine whether the lower blood:gas partition coefficient of desflurane would result in a more rapid emergence after endotracheal extubation of deeply anesthetized patients. A standardized general anesthetic technique was used, consisting of sufentanil, 0.25 microgram/kg, and propofol, 1.5 mg/kg, followed by either isoflurane (n = 15) or desflurane (n = 16) in an air/oxygen mixture. After the operation and reversal of residual neuromuscular block, spontaneous ventilation was reestablished and the patients' tracheas were extubated at equianesthetic concentrations of desflurane and isoflurane (i.e., approximately 1.4 times the minimum alveolar anesthetic concentration [MAC]). Spontaneous movements occurred 5.7 (+/- 2.4) and 8.7 min (+/- 3.1; P = 0.005) after extubation in the desflurane and isoflurane groups, respectively. Eye opening and orientation also occurred significantly earlier after desflurane compared to isoflurane. Patients receiving desflurane (versus isoflurane) were also able to be transferred from the operating room significantly earlier (10.4 +/- 3.7 vs 14.5 +/- 4.3 min, P = 0.01). Use of desflurane (versus isoflurane) was not associated with an increased incidence of coughing or airway irritation during the emergence period. However, use of desflurane did not significantly reduce the duration of the postanesthesia care unit (PACU) stay or alter later recovery events compared to isoflurane. In conclusion, the more rapid emergence would favor the use of desflurane when tracheal extubation during deep anesthesia is required.

Adult↗

Evidence that the Saethre-Chotzen syndrome locus lies between D7S664 and D7S507, by genetic analysis and detection of a microdeletion in a patient.

The locus for Saethre-Chotzen syndrome, a common autosomal dominant disorder of craniosynostosis and digital anomalies, was previously mapped to chromosome 7p between D7S513 and D7S516. We used linkage and haplotype analyses to narrow the disease locus to an 8-cM region between D7S664 and D7S507. The tightest linkage was to locus D7S664 (Z = 7.16, theta = .00). Chromosomes from a Saethre-Chotzen syndrome patient with t(2;7) (p23;p22) were used for in situ hybridization with YAC clones containing D7S664 and D7S507. The D7S664 locus was found to lie distal to the 7p22 breakpoint, and the D7S507 locus was deleted from the translocation chromosomes. These genetic and physical mapping data independently show that the disease locus resides in this interval.

Acrocephalosyndactylia↗

Viral hepatitis in health care personnel at The Johns Hopkins Hospital. The seroprevalence of and risk factors for hepatitis B virus and hepatitis C virus infection.

BACKGROUND: Health care personnel are at increased risk of occupational acquisition of hepatitis B virus (HBV) infection. While effective vaccination for HBV is widely available, the prevalence of HBV and vaccine acceptance in hospital personnel have not been recently assessed. In addition, hepatitis C virus (HCV) is a newly recognized cause of parenterally acquired hepatitis, and the risk of HCV transmission to health care personnel remains unclear. METHODS: From April to December 1991, health care personnel at The Johns Hopkins Hospital, Baltimore, Md, were offered anonymous testing for HBV and HCV and were asked to complete a confidential questionnaire. Serum samples were tested for HBV surface antigen and antibodies to HBV core antigen, HBV surface antigen, and HCV. Seroprevalence rates were compared with those detected in local blood donors during the same year. RESULTS: Antibodies to HBV core antigen were found in 59 (6.2%) of 943 health care workers compared with 1879 (1.8%) of 104,239 local blood donors (P < .001). In contrast, antibodies to HCV were found in seven (0.7%) of 943 health care workers and 0.4% of local blood donors (P = .10). Infection with HBV was associated with age (> or = 33 years) (P < .001), black race (P < .001), type of health care worker (nurse) (P = .02), 10 ore more years of clinical employment (P = .003), and lack of HBV vaccination (P < .001). After logistic regression, only absence of HBV vaccination was independently associated with HBV infection (P < .001). CONCLUSION: These data suggest that the prevalence of HCV infection in health care personnel at The Johns Hopkins Hospital is similar to that observed in local blood donors, and that HBV may be more efficiently transmitted than HCV in the health care setting. Efforts to vaccinate health care personnel against HBV should be vigorously pursued since 23% remain unvaccinated after 9 years of HBV vaccine availability.

Adult↗

Cloning and characterization of a human Mac-2-binding protein, a new member of the superfamily defined by the macrophage scavenger receptor cysteine-rich domain.

We have purified and sequenced a secreted glycoprotein from both the human breast carcinoma cell line, SK-BR-3, and human breast milk. The native protein binds specifically to a human macrophage-associated lectin known as Mac-2. This Mac-2 binding protein (Mac-2-BP) has an apparent native molecular mass of several million daltons and contains subunits of 85-97 kDa that are very susceptible to proteolysis at a dibasic cleavage site. Western analysis suggests that Mac-2-BP is found in serum, semen, saliva, urine, and tears, in addition to breast milk. The gene encoding Mac-2-BP was cloned from a cDNA bank of a human monocytic cell line, using degenerate PCR primers based on the protein sequence. Recombinant Mac-2-BP was expressed in Cos cells and secreted as a high molecular weight complex. The cDNA clone encodes a mature protein of 567 amino acids, preceded by an 18-amino acid leader. The mature protein contains 16 cysteines and has seven potential N-linked glycosylation sites. The first 106 amino acids represent a domain that is highly similar to an ancient protein superfamily defined by the macrophage scavenger receptor cysteine-rich domain.

Amino Acid Sequence↗

The overdiagnosis of Lyme disease.

OBJECTIVE: To analyze the diagnoses, serological test results, and treatment results of the patients evaluated in a Lyme disease clinic, both prior to referral and from current evaluation. DESIGN: Retrospective case survey of prescreened patients. SETTING: Research and diagnostic Lyme disease clinic in a university hospital. PATIENTS: All 788 patients referred to the clinic during a 4.5-year period who were thought by the referring physician or the patient to have a diagnosis of Lyme disease. MAIN OUTCOME MEASUREMENTS: Symptoms and signs of disease, immunodiagnostic tests of Lyme disease, and tests of neurological function. RESULTS: Of the 788 patients, 180 (23%) had active Lyme disease, usually arthritis, encephalopathy, or polyneuropathy. One hundred fifty-six patients (20%) had previous Lyme disease and another current illness, most commonly chronic fatigue syndrome or fibromyalgia; and in 49 patients, these symptoms began soon after objective manifestations of Lyme disease. The remaining 452 patients (57%) did not have Lyme disease. The majority of these patients also had the chronic fatigue syndrome or fibromyalgia; the others usually had rheumatic or neurological diseases. Of the patients who did not have Lyme disease, 45% had had positive serological test results for Lyme disease in other laboratories, but all were seronegative in our laboratory. Prior to referral, 409 of the 788 patients had been treated with antibiotic therapy. In 322 (79%) of these patients, the reason for lack of response was incorrect diagnosis. CONCLUSIONS: Only a minority of the patients referred to the clinic met diagnostic criteria for Lyme disease. The most common reason for lack of response to antibiotic therapy was misdiagnosis.

Adolescent↗

A novel type of class I gene organization in vertebrates: a large family of non-MHC-linked class I genes is expressed at the RNA level in the amphibian Xenopus.

A Xenopus class I cDNA clone, isolated from a cDNA expression library using antisera, is a member of a large family of non-classical class I genes (class Ib) composed of at least nine subfamilies, all of which are expressed at the RNA level. The subfamilies are well conserved in their immunoglobulin-like alpha 3 domains, but their peptide-binding regions (PBRs) and cytoplasmic domains are very divergent. In contrast to the great allelic diversity found in the PBR of classical class I genes, the alleles of one of the Xenopus non-classical subfamilies are extremely well conserved in all regions. Several of the invariant amino acids essential for the anchoring of peptides in the classical class I groove are not conserved in some subfamilies, but the class Ib genes are nevertheless more closely related in the PBR to classical and non-classical genes linked to the MHC in mammals and birds than to any other described class I genes like CD1 and the neonatal rat intestinal Fc receptor. Comparison with the Xenopus MHC-linked class Ia protein indicate that amino acids presumed to interact with beta 2-microglobulin are identical or conservatively changed in the two major class I families. Genomic analyses of Xenopus species suggest that the classical and non-classical families diverged from a common ancestor before the emergence of the genus Xenopus over 100 million years ago; all of the non-classical genes appear to be linked on a chromosome distinct from the one harboring the MHC. We hypothesize that this class Ib gene family is under very different selection pressures from the classical MHC genes, and that each subfamily may have evolved for a particular function.

Alleles↗

Genetic and physical mapping of the Treacher Collins syndrome locus with respect to loci in the chromosome 5q3 region.

Treacher Collins syndrome is an autosomal dominant, craniofacial developmental disorder, and its locus (TCOF1) has been mapped to chromosome 5q3. To refine the location of the gene within this region, linkage analysis was performed among the TCOF1 locus and 12 loci (IL9, FGFA, GRL, D5S207, D5S210, D5S376, CSF1R, SPARC, D5S119, D5S209, D5S527, FGFR4) in 13 Treacher Collins syndrome families. The highest maximum lod score was obtained between loci TCOF1 and D5S210 (Z = 10.52; theta = 0.02 +/- 0.07). The best order, IL9-GRL-D5S207/D5S210-CSF1R-SPARC-++ +D5S119, and genetic distances among these loci were determined in the 40 CEPH families by multipoint linkage analysis. YAC clones were used to establish the order of loci, centromere-5'GRL3'-D5S207-D5S210-D5S376-CSF1R -SPARC-D5S119-telomere. By combining known physical mapping data with ours, the order of chromosome 5q3 markers is centromere-IL9-FGFA-5'GRL3'-D5S207-D5S210- D5S376-CSF1R-SPARC-D5S119-D5S209- FGFR4-telomere. Based on this order, haplotype analysis suggests that the TCOF1 locus resides distal of CSF1R and proximal to SPARC within a region less than 1 Mb in size.

Base Sequence↗

Detection of human immunodeficiency virus type 1 infection by polymerase chain reaction in a cohort of seronegative intravenous drug users.

The frequency of serologically undetected human immunodeficiency virus type 1 (HIV-1) infection among a large cohort of seronegative intravenous drug users (IVDUs) was determined by polymerase chain reaction (PCR). In total, 2159 blood specimens were obtained from 945 seronegative IVDUs; of these, 182 had 1 specimen, 339 had 2, 397 had 3, and 27 had 4 semiannual specimens. No proviral DNA was detected in 2134 (98.8%) of the samples. Specimens from 7 persons (0.3%) were reactive by PCR. Within 6 months, all 5 of these 7 who returned for follow-up visits had seroconverted. Serum from 19 persons (0.9%) were equivocal by PCR analysis, that is, single primer pair amplification; 1 person seroconverted while others subsequently remained seronegative and nonreactive by PCR. The concordance between PCR and serology was 98.6%. It is concluded that immunosilent HIV-1 infection is uncommon and that serologic screening for HIV-1 antibodies is highly sensitive in this population.

Adolescent↗

Elevated serum levels of neopterin but not beta 2-microglobulin in HIV-1-seronegative injecting drug users.

OBJECTIVE: To determine whether injecting drug use is associated with cellular immune activation in the absence of HIV-1 infection. DESIGN: Serum levels of neopterin and beta 2-microglobulin (beta 2M) were measured cross-sectionally in injecting drug users (IDU) enrolled in a prospective study. SUBJECTS AND METHODS: Two hundred and nineteen HIV-1-seronegative, healthy heterosexual black male IDU aged 21-49 years were selected from the Baltimore-based AIDS Linked to Intravenous Experiences (ALIVE) study. The possibility of including subjects in the process of seroconverting to HIV-1 was minimized by restricting the study to individuals who remained seronegative 6 months after the specimens used for analysis were collected. RESULTS: Mean serum beta 2M levels were not statistically different among groups of IDU whose usual pattern of injection was at least once a day for up to 3 consecutive days (daily users; n = 65), less than once per day (less-than-daily users; n = 75), or not at all for at least 2 weeks (non-recent users; n = 79). In contrast, the mean neopterin level was significantly (P = 0.039) greater in daily users (6.17 nmol/l) than in the other two groups (5.07 and 5.19 nmol/l, respectively, which were not statistically different). These results were not affected, by the frequency of using borrowed non-sterile works or by other demographic and risk factor variables. CONCLUSIONS: Frequent injecting drug use may be independently associated with a small elevation of serum neopterin levels, but not beta 2M levels. Although the occurrence of a type I error in this sample cannot be completely excluded, serum neopterin may be more sensitive than serum beta 2M in detecting activation of immunocompetent cells associated with frequent injecting drug use in this population.

Adult↗