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Biomedical subjects

K Edwards

Publications and source records attributed to K Edwards.

At least 19 recordsLinked to original sources

HIV/AIDS information and services: the situation experienced by adolescents with disabilities in Rwanda and Uganda.

PURPOSE: The study had two aims: (2) To explore whether knowledge about HIV and AIDS was similar among adolescents with disabilities compared with their non-disabled peers; and (2) To determine factors which may increase vulnerability of disabled adolescents to HIV infection and/or inappropriate access to HIV-related services. METHOD: A qualitative study using focus group discussions and sem-structured interviews was conducted with purposefully selected participants in Rwanda and Uganda. The participants included disabled adolescents, non-disabled adolescents, parents, teachers, members of disabled people's organisations and representatives of HIV/AIDS organisations. Interviews explored issues of HIV/AIDS knowledge, access to HIV/AIDS services and perceptions of personal risk. RESULTS: Barriers preventing adequate access to information about HIV and AIDS experienced by adolescents with disabilities depended on the nature and severity of the impairment. For example, parents and health workers were unable to communicate with deaf adolescents using sign language, adolescents with physical impairments were often unable to access community meetings about HIV and print material was not adapted for those with visual impairments. Further, assumptions by health workers and community members that people with disabilities were not sexually active led to the marginalisation of disabled people from HIV services. Adolescents with disability described low self-esteem and issues of self-efficacy affecting control of safer sexual relationships. A high level of targeted abuse, rape and exploitation was reported leading to vulnerability among this population. CONCLUSION: The impact of the HIV epidemic among people with disabilities is a neglected area. This study supports the need to develop strategies in HIV prevention programmes that include people with disabilities.

Acquired Immunodeficiency Syndrome↗

Postoperative radiographs after open reduction and internal fixation of the mandible: are they useful?

Mandibular fractures are common in oral and maxillofacial departments in the UK. The aim of this study was to find out the national practice in preoperative and postoperative radiographic investigations for fractured mandibles and to audit their diagnostic capacity, including specificity and sensitivity to short-term complications. The audit took place over a 4-month period and involved 100 patients across the Northern region. Ninety percent of patients were reviewed up to discharge and five of these patients developed a short-term postoperative complication. The postoperative radiograph was diagnostic in only one of the five cases. Overall, postoperative radiographs had a sensitivity of 20% and a specificity of 5% in their ability to predict short-term postoperative complications.

Adolescent↗

How well does fetal ultrasound predict the date of birth in Antigua and Barbuda?

This study was done to determine the accuracy of fetal ultrasound (U.S.) predicting the estimated date of delivery (EDD) in a primarily Afro-Caribbean population in Antigua and Barbuda. A total of 206 women had retrospective review offetal ultrasound tests done between July 1994 and January 1996. The EDD based on last menstrual period (LMP) was calculated for 104 women with dates and compared with EDD calculated from ultrasound test. These were then compared with actual date of birth from maternity records. For women with unreliable menstrual data (102 women), ultrasound EDD was compared with actual date of birth. Ultrasound EDD demonstrated a trend toward being more accurate than menstrual history EDD, being 10.0 +/- 9.4 (mean +/- standard deviation) days off versus 13.3 +/- 15 days, p = 0.057, (n=104), CI: -0.1, 6.73 days. Ultrasound EDD was within ten days of delivery 60% of the time versus 57% for menstrual history EDD. The average error in estimating EDD was + 1.7 days for ultrasound and + 3.7 days for menstrual history. In women without menstrual history data (n=102), the ultrasound EDD was just as accurate in both the second trimester, 11.8 +/- 9.5 versus 11.4 +/- 10.7 days off (not statistically significant) and the third trimester, 10.0 +/- 8.0 versus 8.1 +/- 7.0 days off (not statistically significant). Fetal ultrasound is marginally better at predicting the date of birth compared with menstrual history but the difference does notjustify routine use for that purpose. When menstrual history is unknown, ultrasound EDD is just as accurate as when menstrual history is known, making it a very useful test.

Antigua and Barbuda↗

Hydrothermal recharge and discharge across 50 km guided by seamounts on a young ridge flank.

Hydrothermal circulation within the sea floor, through lithosphere older than one million years (Myr), is responsible for 30% of the energy released from plate cooling, and for 70% of the global heat flow anomaly (the difference between observed thermal output and that predicted by conductive cooling models). Hydrothermal fluids remove significant amounts of heat from the oceanic lithosphere for plates typically up to about 65 Myr old. But in view of the relatively impermeable sediments that cover most ridge flanks, it has been difficult to explain how these fluids transport heat from the crust to the ocean. Here we present results of swath mapping, heat flow, geochemistry and seismic surveys from the young eastern flank of the Juan de Fuca ridge, which show that isolated basement outcrops penetrating through thick sediments guide hydrothermal discharge and recharge between sites separated by more than 50 km. Our analyses reveal distinct thermal patterns at the sea floor adjacent to recharging and discharging outcrops. We find that such a circulation through basement outcrops can be sustained in a setting of pressure differences and crustal properties as reported in independent observations and modelling studies.

Journal Article↗

Experience with femoro-popliteal vein as a conduit for vascular reconstruction in infected fields.

OBJECTIVE: to review the outcome of femoro-popliteal vein grafts for arterial reconstruction in the presence of sepsis. PATIENTS AND METHODS: twenty-six patients underwent 27 arterial reconstructions with femoro-popliteal vein in the presence of infection. Five had mycotic aneurysms (3 aortic, 1 iliac and 1 femoral), 21 had prosthetic graft infections (9 aortic, 8 femoro-femoral, 2 axillo-femoral, 1 ilio-femoral and 1 femoral dacron patch) and one underwent superior mesenteric artery reconstruction following ischaemic small bowel perforation.Arterial reconstruction followed debridement of infected tissue, removing any infected graft, povidone iodine washout and appropriate antibiotic cover. Where possible, new grafts were placed in a clean field or wrapped in omentum. Four femoral anastomoses were covered by rectus femoris flaps. RESULTS: there was one early postoperative death (4%) and no limb loss. All others remained free from infection with patent grafts at 1 month to 5 years (median 22 months). Three major wound infections healed without exposing the graft. One infarcted rectus femoris flap required removal. Donor limb swelling was transient. Five required percutaneous angioplasty and one underwent open profundaplasty within 3 months. CONCLUSION: femoro-popliteal vein reconstruction with debridement and appropriate antibiotic therapy is recommended for the treatment of arterial or graft infections.

Aged↗

Comparative analysis of the Band 4.1/ezrin-related protein tyrosine phosphatase Pez from two Drosophila species: implications for structure and function.

The FERM-PTPs are a group of proteins that have FERM (Band 4.1, ezrin, radixin, moesin homology) domains at or near their N-termini, and PTP (protein tyrosine phosphatase) domains at their C-termini. Their central regions contain either PSD-95, Dlg, ZO-1 homology domains or putative Src homology 3 domain binding sites. The known FERM-PTPs fall into three distinct classes, which we name BAS, MEG, and PEZ, after representative human PTPs. Here we analyze Pez, a novel gene encoding the single PEZ-class protein present in Drosophila. Pez cDNAs were sequenced from the distantly related flies Drosophila melanogaster and Drosophila silvestris, and found to be highly conserved except in the central region, which contains at least 21 insertions and deletions. Comparison of fly and human Pez reveals several short conserved motifs in the central region that are likely protein binding sites and/or phosphorylation sites. We also identified novel invertebrate members of the BAS and MEG classes using genome data, and generated an alignment of vertebrate and invertebrate FERM domains of each class. 'Specialized' residues were identified that are conserved only within a given class of PTPs. These residues highlight surface regions that may bind class-specific ligands; for PEZ, these residues cluster on and near FERM subdomain F1. Finally, the PTP domain of fly Pez was modeled based on known PTP tertiary structures, and we conclude that Pez is likely a functional phosphatase despite some unusual features of the active site cleft sequences. Biochemical confirmation of this hypothesis and genetic analysis of Pez are currently underway.

Amino Acid Sequence↗

Genetic variability among archival cultures of Salmonella typhimurium.

The existence in our laboratory of over 10000 Salmonella typhimurium LT2 cultures sealed in agar stab vials for 33-46 years offers an opportunity for evolutionary and mutational studies. In each of 77 vials examined, 10(3)-10(5) colony forming units per vial were recovered (less than 0.01% of the original population) even after decades of undisturbed storage. Considerable genetic variability was observed in these populations. Three genetic variables, chromosome fragment size as determined by pulsed-field gel electrophoresis, extensive mutational reversions from nutritional auxotrophy to prototrophy, and differences in protein content as assayed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, were measured.

Bacterial Proteins↗

Population-based incidence of pertussis among adolescents and adults, Minnesota, 1995-1996.

To estimate the incidence of pertussis, a prospective study was done among members of a managed care organization in Minneapolis/St. Paul, Minnesota. Of 212 patients 10-49 years old enrolled from January 1995 through December 1996, 8 were found to be culture positive, 10 were found to be positive by polymerase chain reaction assay, 13 had a > or =2-fold increase in IgG or IgA to pertussis toxin (PT), and 18 had IgG to PT in a single serum specimen > or =3 SD above the mean of an age-matched control group. At least 1 positive laboratory test result for pertussis infection was found in 27 (13%) patients, among whom the duration of cough illness was a median of 42 days (range, 27-66 days). On the basis of any positive laboratory result, the estimated annual incidence of pertussis was 507 cases per 100,000 person-years (95% confidence interval, 307-706 cases). Bordetella pertussis infection may be a more common cause of cough illness among adolescents and adults than was recognized previously.

Adolescent↗

Phase behavior and aggregate structure in mixtures of dioleoylphosphatidylethanolamine and poly(ethylene glycol)-lipids.

Cryo-transmission electron microscopy has been used to investigate the phase behavior and aggregate structure in dilute aqueous mixtures of dioleoylphosphatidylethanolamine (DOPE) and poly(ethylene glycol)-phospholipids (PEG-lipids). It is shown that PEG-lipids (micelle-forming lipids) induce a lamellar phase in mixtures with DOPE (inverted hexagonal forming lipid). The amount of PEG-lipid that is needed to induce a pure dispersed lamellar phase, at physiological conditions, depends on the size of the PEG headgroup. In the transition region between the inverted hexagonal phase and the lamellar phase, particles with dense inner textures are formed. It is proposed that these aggregates constitute dispersed cubic phase particles. Above bilayer saturating concentration of PEG-lipid, small disks and spherical micelles are formed. The stability of DOPE/PEG-lipid liposomes, prepared at high pH, against a rapid drop of the pH was also investigated. It is shown that the density of PEG-lipid in the membrane, sufficient to prevent liposome aggregation and subsequent phase transition, depends on the size of the PEG headgroup. Below a certain density of PEG-lipid, aggregation and phase transition occurs, but the processes involved proceed relatively slow, over the time scale of weeks. This allows detailed studies of the aggregate structure during membrane fusion.

Biophysical Phenomena↗

Randomized phase 2 trial of ketoconazole and ketoconazole/doxorubicin in androgen independent prostate cancer.

Eighty-nine patients with progressive prostate cancer despite suppression of testosterone and withdrawal of anti-androgens were studied. This was a relatively advanced population, with 63 of 89 having either osseous metastases (mets) beyond the axial skeleton or visceral mets. Patients were randomly assigned to receive either ketoconazole alone, or ketoconazole with weekly doxorubicin. All patients received replacement hydrocortisone. The primary endpoints were response and survival. Based on PSA reduction criteria (>/= 80% maintained for at least 8 weeks), 14 of 45 patients (31%) in the single-agent ketoconazole arm responded. Sixteen of 44 patients (36%) in the combination ketoconazole/doxorubicin arm responded. There were no important differences between the two treatments in any outcome measure. The median overall survival for all patients was 12.5 months; median time to progression was 3.3 months. Toxicity was significant with both regimens, and more severe in the doxorubicin arm. Fully 20% of patients in each arm discontinued therapy due to intolerable side effects.Each of these regimens is toxic, and produced responses in fewer than half of treated patients. Although the observed median survival does compare favorably with reports from similar cohorts treated in the community, the potential benefit is only modest. In our view, neither of these regimens is sufficiently promising to justify phase 3 evaluation.

Journal Article↗

Chitosan as a nonviral gene delivery system. Structure-property relationships and characteristics compared with polyethylenimine in vitro and after lung administration in vivo.

Chitosan is a natural cationic linear polymer that has recently emerged as an alternative nonviral gene delivery system. We have established the relationships between the structure and the properties of chitosan-pDNA polyplexes in vitro. Further, we have compared polyplexes of ultrapure chitosan (UPC) of preferred molecular structure with those of optimised polyethylenimine (PEI) polyplexes in vitro and after intratracheal administration to mice in vivo. Chitosans in which over two out of three monomer units carried a primary amino group formed stable colloidal polyplexes with pDNA. Optimized UPC and PEI polyplexes protected the pDNA from serum degradation to approximately the same degree, and they gave a comparable maximal transgene expression in 293 cells. In contrast to PEI, UPC was non toxic at escalating doses. After intratracheal administration, both polyplexes distributed to the mid-airways, where transgene expression was observed in virtually every epithelial cell, using a sensitive pLacZ reporter containing a translational enhancer element. However, the kinetics of gene expression differed - PEI polyplexes induced a more rapid onset of gene expression than UPC. This was attributed to a more rapid endosomal escape of the PEI polyplexes. Although this resulted in a more efficient gene expression with PEI polyplexes, UPC had an efficiency comparable to that of commonly used cationic lipids. In conclusion, this study provides insights into the use of chitosan as a gene delivery system. It emphasises that chitosan is a nontoxic alternative to other cationic polymers and it forms a platform for further studies of chitosan-based gene delivery systems.

Cell Line↗

Close relationships between Asian American and European American college students.

The authors examined attitudes and behaviors regarding close relationships between European and Asian Americans, with a particular emphasis on 5 major subgroups of Asian Americans (Chinese, Japanese, Korean, Vietnamese, and Filipino Americans). Participants were 218 Asian American college students and 171 European American college students attending a culturally diverse university. The European Americans did not differentiate among the various subgroups of Asian Americans. Their attitudes regarding close relationships were less positive toward Asian Americans than toward Mexican and African Americans, a finding contrary to the prediction of social exchange theory (H. Tajfel, 1975). In contrast to the European Americans' view of homogeneity among Asian Americans, the 5 major subgroups of Asian Americans expressed a distinctive hierarchy of social preference among themselves. Results are discussed in terms of their implications for future research on interethnic relations involving Asian Americans.

Adolescent↗

A major gene effect on fasting insulin and insulin sensitivity in familial combined hyperlipidemia.

The most common inherited dyslipidemia, familial combined hyperlipidemia (FCHL), is associated with insulin resistance. Whether insulin sensitivity in these families is inherited is not known. Therefore, we investigated the inheritance of insulin sensitivity in 352 nondiabetic family members from 37 families with FCHL, 105 of whom had undergone testing using the hyperinsulinemic-euglycemic clamp technique for the measurement of insulin sensitivity. First, complex segregation analysis of fasting insulin levels (both unadjusted and age-, age(2)-, and BMI-adjusted) was used for modeling of the variance in fasting insulin levels. In these analyses, Mendelian codominant inheritance (P = 0.320 for unadjusted and P = 0.295 for adjusted insulin values) was not rejected over the most general model and fit the data significantly better than the sporadic model (P < 0.001). Polygenic and environmental models were rejected (P < 0.001). The Mendelian codominant model explained 44 and 45% of the variance in unadjusted and adjusted fasting insulin levels, respectively. The proposed genotypes of this locus, based on segregation analysis, were associated with directly measured insulin sensitivity in 105 FCHL family members who underwent the hyperinsulinemic-euglycemic clamp (P < 0.001). These results provide evidence for a major gene regulating insulin sensitivity in FCHL families. Possible pleiotropic effects of this insulin sensitivity locus on dyslipidemias in FCHL remain to be elucidated.

Adult↗

The cardiac anxiety questionnaire: development and preliminary validity.

Heart-focused anxiety (HFA) is the fear of cardiac-related stimuli and sensations because of their perceived negative consequences. Although HFA is common to a wide variety of persons who experience chest pain and distress, it often is unrecognized and misdiagnosed, particularly in cardiology and emergency room patients without and with heart disease. To address these concerns, this article reports on the development and preliminary psychometric evaluation of the Cardiac Anxiety Questionnaire (CAQ) designed to measure HFA. In Study 1, 188 cardiology patients completed the CAQ. Item and factor analyses indicated a three-factor solution pertaining to heart-related fear, avoidance, and attention. Reliability analysis of the 18-item CAQ revealed good internal consistency of the total and subscale scores. In Study 2, 42 patients completed the CAQ and several other anxiety-related questionnaires to assess its convergent and divergent properties. Although preliminary validity results are promising, further psychometric study is necessary to cross-validate the CAQ, examine its test-retest reliability, and confirm the stability of the factor structure. Taken together, the CAQ appears to assess HFA, and may therefore be a useful instrument for identifying patients with elevated HFA without and with heart disease.

Coronary Angiography↗