Biomedical subjects
D Conway
Publications and source records attributed to D Conway.
Inclusion of Vpr accessory gene in a plasmid vaccine cocktail markedly reduces Nef vaccine effectiveness in vivo resulting in CD4 cell loss and increased viral loads in rhesus macaques.
We compared the immunogenicity of plasmid vaccines containing multiple human immunodeficiency virus (HIV) antigens and found that covaccination with plasmids expressing HIV-1 14 kDa vpr gene product profoundly reduces antigen-specific CD8-mediated cytotoxic T-cell activity (CTL). Interestingly, Th1 type responses against codelivered antigens (pGag-Pol, pNef, etc.) encoded by the plasmid vaccines were suppressed. This suggested that vpr might compromise CD8 T-cell immunity in vivo during infection. A pilot primate vaccine study was designed to test the hypothesis to compare the following groups: unvaccinated controls, animals vaccinated without simean immunodeficiency virus (SIV)-Nef antigen plasmid, and animals covaccinated with the identical plasmid antigen and a plasmid construct encoding SIV Vpr/Vpx. Animals were subsequently challenged intrarectally with pathogenic SIVmac251 after the final vaccination of a multiple immunization protocol. Control animals were all infected and exhibited high viral loads and rapid CD4+ T-cell loss. In contrast, the Nef plasmid-vaccinated animals were also infected but exhibited preservation of CD4+ T-cells and a multilog reduction in viral load compared with controls. Animals covaccinated multiple times with the Nef vaccine and pVpr/Vpx plasmid suffered rapid and profound loss of CD4+ T-cells. These results have important implications for the design of multicomponent and particle vaccines for HIV-1 as well as for our understanding of HIV/SIV pathogenesis in vivo.
The ECG and left ventricular hypertrophy in primary care hypertensives.
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Use of intraoperative cytologic assessment of mandibular marrow scrapings to predict resection margin status in patients with squamous cell carcinoma.
PURPOSE: This study assessed the feasibility of intraoperative microscopic assessment of mandibular bone resection margins in patients undergoing segmental resection of mandible for treatment of squamous cell carcinoma. PATIENTS AND METHODS: This prospective pilot study involved 7 consecutive patients undergoing segmental resection of mandible as part of surgical treatment of oral squamous cell carcinoma. Cytologic examination of smear/touch preparations of 35 bone marrow scrapings, including simulated positive margins, was performed. RESULTS: "Malignant" excision margins produced a high cell yield, and it was easy to assign samples to malignant or benign categories on microscopic examination. All the simulated positive margins were easily identified. No false positive results were found. CONCLUSION: Cytologic examination of bone excision margin scrapings is a rapid, inexpensive, and accurate technique. This study confirms its feasibility and accuracy in cases of mandibular resection for squamous cell carcinoma.
Neuromuscular monitoring in intensive care patients: milliamperage requirements for supramaximal stimulation.
We investigated the effects of peripheral oedema on the supramaximal current required for neuromuscular monitoring of critically ill patients. We studied 32 sedated patients who had not needed a neuromuscular blocking drug. The presence of oedema over the volar aspect of both wrists was assessed by a blinded observer and graded (grade 0, no oedema; grade 1, mild oedema; grade 2, gross oedema). The supramaximal current was derived by applying an incrementally increasing current over the ulnar nerve and measuring the amplitude of the electromyographic (EMG) response of the first dorsal interosseous muscle. The supramaximal current was that current above which there was no significant increase in EMG amplitude. It was 40 mA in the absence of oedema. This current was significantly increased in the presence of grade 1 oedema (60 mA, Mann-Whitney test, P<0.01) and grade 2 oedema (82.5 mA, Mann-Whitney test, P<0.01). In the presence of oedema, the required supramaximal current decreased significantly after the application of pressure over the stimulating electrodes (Wilcoxon signed rank test, P<0.05). Supramaximal current in critically ill patients is increased in the presence of peripheral oedema. We recommend that nerve stimulators used for neuromuscular monitoring in the ICU are capable of delivering a stimulus current of at least 100 mA.
Atrial fibrillation and stroke: more concepts and controversies.
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Case book: palpitations.
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Re: Newton J.P. et al. Masseteric hypertrophy?: preliminary report. Br J Oral Maxillofac Surg 1999; 37: 405-408.
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Ecthyma gangrenosum as a manifestation of Pseudomonas sepsis in a previously healthy child.
We present a case of Pseudomonas aeruginosa sepsis heralded by ecthyma gangrenosum in a previously healthy 15-month-old child. Pseudomonas infection and its uncommon skin manifestation are rarely encountered in an immunocompetent child. This case highlights the critical importance of identifying ecthyma gangrenosum to institute optimal antimicrobial therapy.
Allelic recombination and linkage disequilibrium within Msp-1 of Plasmodium falciparum, the malignant human malaria parasite.
The C-terminal, cysteine-rich 19kDa domain of merozoite surface protein-1 (MSP-1) of Plasmodium falciparum is a target of the host's humoral immunity and thus a malaria vaccine candidate. Although variation in the 19kDa domain is limited among parasite isolates, tertiary structure-dependent intramolecular associations between the 19kDa domain and other parts of MSP-1 are suggested to be involved in immune evasion by allowing competitive binding of protective and non-protective antibodies directed to their epitopes, which are conformationally in close proximity but separated at the primary structure. Since allelic recombination can account for the major variability of the Msp-1 gene, we examined whether linkage disequilibrium occurs between polymorphic loci in the 5'- and the 3'-region, the latter encoding the 19kDa domain. From 184 Thai field isolates, we selected 69 isolates with a single allelic type in six variable blocks of Msp-1 as determined by PCR-based allelic typing. All the isolates showed no evidence of recombination in blocks 6 to 16, whereas recombination was apparent in blocks 2 to 6. Sequencing of the 3'-region revealed two potential recombination sites in block 17. Strong linkage disequilibrium was seen between polymorphic loci in the 5'- and 3'-regions. The strength of this disequilibrium did not correlate with distance between loci. We discuss the possible role of epistatic selection on particular association types (haplotypes) of Msp-1.
Population pressure and land resources in Nepal: a revisit, twenty years later.
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Bad representation in the media.
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Consequences of migration and remittances for Mexican transnational communities.
"Our aims in this paper are to broaden explanation of remittance expenditures and to evaluate the positive contributions of remittances, return migrants, or circulating sojourners. Specifically focusing on the situation in ¿home' communities, we illustrate the multifaceted consequences of remittances and migration, emphasizing positive nonmonetary and social impacts." Data are from ethnographic research carried out in 1992-1993 in Santa Ana del Valle, Oaxaca, Mexico.
Preeclampsia: is induction of labor more successful?
OBJECTIVE: To test the hypothesis that preeclamptic women are more readily inducible than are nonpreeclamptic women, regardless of cervical condition. METHODS: One hundred eighty-three preeclamptic women and 461 nonpreeclamptic women requiring labor induction were studied prospectively. Patients were categorized by Bishop score, parity, gestational age, and method of induction. Outcome variables were success of induction and cesarean delivery rates. RESULTS: Failed induction was significantly more common in the preeclamptic group (8.2% versus 1.7%; odds ratio [OR] 5.06; 95% confidence interval [CI] 1.97, 13.28), as was cesarean delivery (28% versus 16%; OR 2.09; 95% CI 1.36, 3.18). When controlled by logistic regression for Bishop score, parity, method of induction, epidural anesthesia, macrosomia, and gestational age, a fourfold higher risk of failed induction and a twofold higher risk of cesarean delivery were found in the preeclamptic group. CONCLUSIONS: Induction of labor in preeclamptic women has a higher risk of failure and consequently of cesarean delivery than in nonpreeclamptic women. The vast majority of patients achieve vaginal delivery.
Outer membrane characteristics of Campylobacter jejuni grown in chickens.
A type of in vivo phenotype of Campylobacter jejuni was obtained by maintaining bacteria in the peritoneal cavities of chickens for one week. These bacteria, which had not been subcultured on laboratory media, were used to prepare outer membranes for comparison with C. jejuni grown in vitro. Flagella with subunits of 65 kDa and a single porin with a protein subunit of 49 kDa were expressed constitutively; however, outer membrane proteins of 55, 35 and 20 kDa, and intermediate-chain lipopolysaccharide were only expressed by bacteria maintained in chickens.
Ecopolitical battles at the Tarai frontier of Nepal: an emerging human and environmental crisis.
"In Nepal, the drama of human and environmental ills is increasingly being played out in the form of peasants' ecopolitical battles over common land access and control, such as in the Tarai frontier, a region bordering the Gangetic Plain of India. This is a complex battle, pitting peasants' day-to-day survival against environmental security on one front, and against the Nepalese State and its dominant class interests on the other. This article critically dissects this raging battle to gain a clear understanding of its complexities as well as its diverse roots."
Novel anti-silicone surface-associated antigen antibodies (anti-SSAA(x)) may help differentiate symptomatic patients with silicone breast implants from patients with classical rheumatological disease.
The frequency of novel autoreactive antibodies to silicone surface associated antigens (anti-SSAA(x)) was measured in healthy control patients, symptomatic patients with breast implants, asymptomatic patients with breast implants, and control patients with classical rheumatological diseases. The frequencies of elevated anti-SSAA(x) antibodies in 310 symptomatic breast implant patients were 17.4% anti-SSAA(fn), 12.9% anti-SSAA(col1), and 7.4% anti-SSAA(col3) and 7.1% anti-SSAA(fbgn) [Normal (n = 173) = 0.6% for all four tests] (p < .005). In 11 asymptomatic breast implant patients, the frequencies of elevated values for the same anti-SSAA's were 0%, 9%, 0%, and 0% respectively, while in 50 patients with rheumatoid arthritis, the frequencies were 4%, 0%, 6% and 2% respectively. The anti-SSAA(x) profile for symptomatic patients with breast implants was different than the profile for control healthy patients (p < .005 on all eight tests) but differed significantly by two measures, anti-SSAA(fbgn) and anti-SSAA(col3), from the profile for the 19 patients with systemic lupus erythematosus. We conclude that anti-SSAA(x) antibodies levels in symptomatic patients with breast implants are elevated, that the antibodies are associated with symptoms, and that they differ both qualitatively and quantitatively from healthy controls, asymptomatic patients with breast implants, and symptomatic patients with classical rheumatological diseases.