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Biomedical subjects

D Armstrong

Publications and source records attributed to D Armstrong.

At least 73 records · Page 4Linked to original sources
PubMed2001

Neonatal outcome following maternal opiate use in late pregnancy.

OBJECTIVE: To determine the neonatal outcome in the form of use of morphine and triclofos to treat the neonatal abstinence syndrome following maternal opiate use in late pregnancy. METHODS: Retrospective case study of 51 pregnancies associated with maternal opiate use between January 1992 and December 1997. RESULTS: There were 51 pregnancies which resulted in 51 live births. In the third trimester 22 women took methadone only, 19 women used heroin and 10 women stopped opiate use during pregnancy. Babies of methadone using mothers were less likely to be treated with morphine or triclofos than heroin using women. Morphine, triclofos use was more common in high dose methadone users compared with low users. CONCLUSIONS: Successful methadone substitution compared with continued heroin use results in reduced morphine and triclofos use in the babies exposed.

Analgesics, Opioid↗
PubMed2001

Effect of Antioxidants on Radical-initiated Peroxidation of Retinal Homogenate.

Purpose: To compare the effect of antioxidants on radical-initiated peroxidation of retinal homogenate.Methods: Lipid peroxides in bovine retinal homogenate were induced by 5 mM FeNO(3) (Fe), 25 mM 2, 2'-azobis(2, 4'-dimethylvaleronitrile) (lipid-soluble, AMVN) or 50 mM 2, 2'-azobis (2-amidinoprpane) dihydrochloride (water-soluble, AAPH) and the preventive effects of antioxidants were measured. Phosphatidylcholine hydroperoxide (PC-OOH) was analyzed with high performance liquid chromatography (HPLC) as the endpoint biomarker.Results and Conclusion: Troglitazone, an oral hypoglycemic agent, inhibited PC-OOH production by Fe and AMVN. Therefore, it may be effective for protecting against oxidative stress on the inner surface plasma membranes and subcellular organelle. Quercetin has radical scavenging effects on both sides of the membrane, because it prevents PC-OOH production by AMVN or AAPH. These results demonstrate the usefulness of an in vitro screening test that can accurately and rapidly determine the capacity of an antioxidant against lipid peroxidation or oxidative stress. (Jpn Ophthalmol Soc 104:466-70, 2000)

Journal Article↗
PubMed2001

Guidelines for reporting clinical features in cases with MECP2 mutations.

An international group recommends that papers relating phenotypes to genotypes involving mutations in the X chromosome gene MECP2 should provide a minimum data set reporting the range of disturbances frequently encountered in Rett Syndrome. A simple scoring system is suggested which will facilitate comparison among the various clinical profiles. Features are described which should prompt screening for MECP2 mutations.

Chromosomal Proteins, Non-Histone↗
PubMed2001

Substance P immunoreactivity in the enteric nervous system in Rett syndrome.

Rett syndrome is associated with profound mental retardation and motor disability in girls. It has a characteristic clinical phenotype which includes abnormalities of the autonomic nervous system. Feeding impairment and severe constipation are two symptoms of this autonomic dysfunction. Substance P, an important peptide in the autonomic nervous system, is decreased in the cerebrospinal fluid of Rett syndrome. We have demonstrated that substance P immunoreactivity is significantly decreased in Rett syndrome brain-stem and may be related to the autonomic dysfunction. In this study, we have continued the investigation of substance P in the enteric nervous system. We immunohistochemically examined the normal developing bowel in 22 controls (ages, 14 gestational weeks to 31 years) using formalin fixed tissue, with antibodies to substance P, tyrosine hydroxylase and vasoactive intestinal peptide. We compared the immunoreactivity of normal controls with 14 cases of Rett syndrome (ages, 5-41 years) and observed that the expression of substance P, tyrosine hydroxylase and vasoactive intestinal peptide immunoreactivity in the bowel in Rett syndrome was not significantly different from that of controls. This suggests that the feeding impairment and constipation in Rett syndrome relate to dysfunction of the autonomic nervous system originating outside of the bowel, in the brain-stem, as suggested by our previous study.

Adolescent↗
PubMed2001

Infectious morbidity in critically ill patients with cancer.

Infection frequently complicates the course of cancer treatment and often adversely affects the outcome. Patients have a greater tendency for acquiring infections caused by opportunistic microorganisms. Agents with low virulence potential may lead to invasive and often life-threatening infections because of altered host immune function. The immune dysfunction may be caused by the underlying malignancy, by antineoplastic chemotherapy, or by invasive procedures during supportive care.

Agranulocytosis↗
PubMed2001

Zoonoses.

Explore the source record for details and available documents.

Animals↗
PubMed2001

The SNRPN promoter is not required for genomic imprinting of the Prader-Willi/Angelman domain in mice.

In mice and humans, the locus encoding the gene for small nuclear ribonucleoprotein N (SNRPN/Snrpn), as well as other loci in the region are subject to genomic imprinting. The SNRPN promoter is embedded in a maternally methylated CpG island, is expressed only from the paternal chromosome and lies within an imprinting center that is required for switching to and/or maintenance of the paternal epigenotype. We show here that a 0.9-kb deletion of exon 1 of mouse Snrpn did not disrupt imprinting or elicit any obvious phenotype, although it did allow the detection of previously unknown upstream exons. In contrast, a larger, overlapping 4.8-kb deletion caused a partial or mosaic imprinting defect and perinatal lethality when paternally inherited.

Angelman Syndrome↗
PubMed2001

Ig heavy chain CDR3 size diversities are similar after conventional peripheral blood and ex vivo expanded hematopoietic cell transplants.

It is largely unknown whether the immune repertoire can be reconstituted successfully after high-dose chemotherapy and transplantation using ex vivo expanded hematopoietic stem cell (HSC) grafts. It is critically important for the transplant outcome that immune repertoire reconstitution progresses after ex vivo expanded HSC graft transplants at least as efficiently as that seen after conventional HSC transplants. Previously, we showed that the T cell receptor V beta (TCRVB) third complementarity determining region (CDR3) diversification after ex vivo expanded bone marrow (BM) HSC graft transplants was similar to that seen after conventional peripheral blood stem cell transplants (PBSCTs). In the present study, the CDR3 diversity of the six immunoglobulin (Ig) heavy chain variable region gene (V(H)) families was examined in five breast cancer patients who were transplanted with ex vivo expanded BM HSCs as the only source of stem cells. For comparison, 12 healthy adults and four conventional PBSCT recipients were also studied. Using both CDR3 fingerprinting and single strand conformation polymorphism (SSCP) methodologies, it is shown that the contribution of the V(H) families to the overall repertoire among healthy adults is highly variable and not always proportional to V(H) family member size. After both ex vivo expanded HSC transplants and conventional PBSCTs, the V(H) CDR3 repertoires were limited in size diversity at 6 weeks post transplant. By 6 months, however, V(H) families displayed a repertoire diversity that was as complex as that seen in healthy adults. No difference was seen between ex vivo expanded HSC graft transplant recipients and conventional PBSCT recipients in V(H) repertoire diversity. In one patient there was a follow-up analysis 12 months after ex vivo expanded graft transplant, and the diversity of the V(H) families was maintained. In all patients, the amino acid size of the CDR3 regions fell within adult limits at all time points post transplant. These results indicate that B cell repertoire regeneration after ex vivo expanded hematopoietic cell graft transplants is similar to that seen after conventional PBSCT.

Adult↗
PubMed2001

Whanaungatanga - a process in the treatment of Măori with alcohol- and drug-use related problems.

Măori, the indigenous people of New Zealand have advocated that culturally-based care requires goals and processes specifically defined within their ethnocultural context. Positive cultural identity and pride have been posited as integral to achieving wellbeing for Măori. A sample of Măori in treatment for alcohol- and drug-use associated problems was reported to believe that a sense of belonging to an iwi ("tribe") could contribute to the recovery process. Data relating to "tribal" affiliation, cultural self-identity and upbringing of that sample is presented. The key concepts of whănau ("family") and whănaungatanga ("relationships") in the treatment process for Măori are explored and the implications of their utility discussed. The findings highlight the complexity of providing treatment that is cognizant of ethnocultural factors.

Adolescent↗
PubMed2001

Ex vivo-expanded hematopoietic cell graft recipients exhibit T cell repertoire diversity similar to that seen after conventional stem cell transplants.

The feasibility of using ex vivo-expanded hematopoietic progenitor cells to reconstitute hematopoiesis after high-dose chemotherapy is presently being examined. Early studies have shown that myeloid and erythroid hematopoiesis can be successfully reconstituted after high-dose chemotherapy and ex vivo-expanded hematopoietic cell transplantation. The lymphoid reconstitution, however, has not been addressed previously. In this study, we examined the diversity of the T cell receptor V beta chain (TCRBV) repertoires in 5 breast cancer patients who were transplanted with ex vivo-expanded bone marrow mononuclear cells as the only source of hematopoietic graft. Using the TCRBV third complementarity determining region (CDR3) fingerprinting methodology, it is shown that CD4(+) and CD8(+) T cell subsets after ex vivo-expanded hematopoietic cell graft transplants exhibit TCRBV diversities that are similar in complexity when compared to those seen after conventional autologous peripheral blood stem cell transplants (PBSCT). No apparent difference in the extent of CDR3 diversity was found between ex vivo expanded and conventional autologous PBSCT recipients when the CD4(+) and CD8(+) subsets were further separated into CD45RA(+) "naïve" and CD45RO(+) "memory" subsets. The diversity of the CD45RA(+) naïve subsets was as complex as that of the CD45RO(+) memory subsets. These results indicate that T cell repertoire diversification is not further compromised when ex vivo-expanded hematopoietic cells are used instead of autologous peripheral blood stem cells as the only source of graft.

Adult↗
PubMed2001

Symptom relief in gastroesophageal reflux disease: a randomized, controlled comparison of pantoprazole and nizatidine in a mixed patient population with erosive esophagitis or endoscopy-negative reflux disease.

OBJECTIVES: Gastroesophageal reflux disease (GERD) in primary care practice presents symptomatically, and resources to distinguish promptly between erosive esophagitis and endoscopy-negative reflux disease (ENRD) are limited. It is therefore important to determine the roles of proton pump inhibitors and histamine-2-receptor antagonists for first-line symptom-based therapy in patients with erosive esophagitis and ENRD. The aim of this study was to compare pantoprazole 40 mg once daily versus nizatidine 150 mg b.i.d. in a mixed GERD patient population with ENRD or erosive esophagitis (Savary-Miller grades 1-3). METHODS: A 4-wk randomized, double-blind, parallel-group, multicenter study conducted in Canada. Eligible patients had experienced GERD symptoms > or = 4 times weekly for > 6 months. Patients were randomized to pantoprazole 40 mg once daily or nizatidine 150 mg b.i.d.. Endoscopy was performed before randomization and after 4 wk of therapy. RESULTS: Of 220 patients randomized to therapy, 208 were available for a modified intent-to-treat analysis. Erosive esophagitis was present in 125 patients; 35 patients were Helicobacter pylori positive. There was complete symptom relief after 7 days of therapy in 14% of patients on nizatidine and in 40% of those on pantoprazole (p < 0.0001), and after 28 days of treatment in 36% and 63% of patients, respectively (p < 0.0001). After 28 days of treatment, adequate heartburn control was reported by 58% of the nizatidine group and in 88% of the pantoprazole (p < 0.0001); erosive esophagitis healing rates were 44% for nizatidine and 79% for pantoprazole (p < 0.001). Rescue antacid was needed by a greater number of patients using nizatidine than of those using pantoprazole (p < 0.001). H. pylori infection was associated with an increased probability of erosive esophagitis healing. CONCLUSIONS: Pantoprazole once daily was superior to nizatidine b.i.d. in producing complete heartburn relief in a mixed population of GERD patients and in achieving erosion healing. The proportions of patients with complete symptom relief were greater with pantoprazole after 7 days of therapy than with nizatidine after 28 days. The present study data suggest that pantoprazole is a highly effective first-line therapy for the management of gastroesophageal reflux disease in a primary care practice setting.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2001

Prospective study of Candida species in patients at a comprehensive cancer center.

Since most nosocomial systemic yeast infections arise from the endogenous flora of the patient, we prospectively evaluated the species stratification and antifungal susceptibility profile of Candida spp. associated with heavy colonization and systemic infection in patients at Memorial Sloan-Kettering Cancer Center in New York. A total of 349 Candida isolates were obtained from 223 patients during the later half of 1998. Cancer was the most common underlying disease, occurring in 91% of the patients, including 61.8% with organ and 23.7% with hematological malignancies; 4.4% of the patients had AIDS. Candida albicans was the predominant species (67.3%); among 114 non-albicans Candida spp., C. glabrata (45.6%) was the most frequent, followed by C. tropicalis (18.4%), C. parapsilosis (16.6%), and C. krusei (9.6%). The overall resistance to triazole-based agents among all yeast isolates was 9.4 and 10.8% for fluconazole and itraconazole, respectively. A total of 5% of C. albicans strains were resistant to triazole antifungals, whereas 30.8 and 46.2% of C. glabrata strains were resistant to fluconazole (MIC > or = 64 microg/ml) and itraconazole (MIC > or = 1 microg/ml), respectively. A significant association was observed between prior treatment with triazole and isolation of fluconazole-resistant C. albicans (P = 0.005, OR 36), although this relationship was not seen in C. glabrata isolates (P = 0.4). This study reinforces the importance of periodic, prospective surveillance of clinical fungal isolates to determine appropriate prophylactic, empiric, and preemptive antifungal therapy for the highly susceptible patient population.

Antifungal Agents↗
PubMed2001

TBARS and cardiovascular disease in a population-based sample.

BACKGROUND: Oxygen radicals might play a crucial role in the pathogenesis of various diseases, including atherosclerosis. Thiobarbituric acid reaction substances (TBARS), a biomarker of oxidative stress, have been proposed as a summary measure of total circulating oxidation. However, there is no strong indication that circulating levels of TBARS are increased in patients with atherosclerosis. DESIGN: We evaluated the relation between TBARS and cardiovascular disease (CVD) in a cross-sectional random sample of white men and women from Buffalo, New York. METHODS: Logistic regression was used to estimate the risk associated with high levels of TBARS. The area under the ROC curve was used to evaluate the discriminating power of TBARS. RESULTS: After adjusting for age and gender, TBARS levels were significantly higher in those with prevalent CVD (OR= 1.73, 95% CI=1.32-2.38), compared to those without a CVD diagnosis. These OR were almost 50% higher after correcting for measurement error (ME) (OR=1.93, 95% CI=1.07-3.40). The area under the ROC curve was 0.69 (95% CI=0.62-0.77) and when corrected for ME reached 0.80 (95% CI=0.65-0.89). CONCLUSIONS: Our results indicate that elevated levels of TBARS were associated with increase risk of the prevalence of CVD, but this effect was no longer significant after adjusting for glucose.

Adult↗
PubMed2001

Removal of basiliximab by plasmapheresis.

Basiliximab is a chimeric monoclonal antibody directed against the alpha chain of interleukin-2 (IL-2) receptors. Given its expected volume of distribution (plasma volume), therapeutic plasmapheresis may be expected to lower serum Basiliximab levels. A 20-mg dose of Basiliximab was given before plasmapheresis. Blood and pheresis fluid samples were obtained to monitor Basiliximab levels. A total of three blood samples were drawn: the first was obtained 4 hours before, the second sample immediately before commencement, and the third 2 hours after cessation of plasmapheresis. A fourth sample was obtained from the removed plasma. There was an appreciable reduction in Basiliximab concentration levels after plasmapheresis. From the change in serum concentration after plasmapheresis, approximately 64.6% of circulating Basiliximab was removed. Plasmapheresis removes substantial amounts of Basiliximab. Therefore, supplemental Basiliximab should be given after plasmapheresis to maintain the desired duration of IL-2R saturation.

Antibodies, Monoclonal↗
PubMed2001

Patients' responses to risk information about the benefits of treating hypertension.

BACKGROUND: The medical profession is often presented with information on the value of treatment in terms of likely risk reduction. If this same information was presented to patients--so enabling them to give proper informed consent--would this affect their decision to be treated? AIM: To examine patients' choice about treatment in response to different forms of risk presentation. DESIGN OF STUDY: Postal questionnaire study. SETTING: The questionnaire was sent to 102 hypertensive patients and 207 matched non-hypertensive patients aged between 35 and 65 years in a UK general practice. METHODS: Patients were asked the likelihood, on a four-point scale, of their accepting treatment for a chronic condition (mild hypertension) on the basis of relative risk reduction, absolute risk reduction, number needed to treat, and personal probability of benefit. RESULTS: An 89% response rate was obtained. Of these, 92% would accept treatment using a relative risk reduction model, 75% would accept treatment using an absolute risk reduction model, 68% would accept treatment using a number needed to treat model, and 44% would accept treatment with a personal probability of benefit model. CONCLUSION: Many patients may prefer not to take treatment for mild hypertension if the risks were fully explained. However, given that the form of the explanation has a strong influence on the patient's decision, it is not clear how decision-making can be fully shared nor what should constitute informed consent to treatment in this situation.

Adult↗
PubMed2001

[Retinal hazard from blue light emitting diode].

PURPOSE: To compare the effect of exposure time from a blue(460 nm) light emitting diode(LED) on the morphology of the outer retina and determine conditions where damage occurs. MATERIALS AND METHODS: Young adult rhesus monkeys were anesthetized, and received blue LED exposure from a modified slit-lamp. A 3 mm beam of 0.85 mW was imaged onto the retina through a lens positioned before the cornea and exposure damage was determined at time intervals for 12 to 90 min. Fundus photography, fluorescein angiography(FAG), retinal tomography(HRT), and s-cone electororetinogram(S-ERG) were recorded at baseline, 2, and 30 days. RESULTS: Two days after 40 min exposure, there was a grey, discolored region, which was over-fluorescent in FAG, and an incresse in HRT and S-ERG corresponding to the site which was exposed to LED light. In histological examination at 30 days, the LED had caused produced a marked disruption of the disks of photoreceptor cells, damaged retinal pigment epithelium(RPE) apical villi, and a loss of RPE melanin after 90 min exposure. CONCLUSION: A threshold level was found around 40 min. This morphological damage may impair function and continuous exposure to blue light is potentially dangerous to vision.

Animals↗
PubMed2001

Effect of creatine on performance of militarily relevant tasks and soldier health.

PURPOSE: Determine the short-term effects of creatine supplementation on performance of military tasks, thermoregulation, and health risks. METHODS: Male military personnel were randomly assigned to a creatine (CR; N = 8) or a placebo (CON; N = 8) supplementation group. Testing was conducted at baseline, after a 6-day load phase (20 g/d), and after 4 weeks of taking 6 g/d. Measurements included body composition, liver/kidney function tests, core body temperatures during a 10-mile march and 5-mile run, and performance on physical tasks. RESULTS: Serum and urine creatine increased significantly in the CR group. Body mass and number of pull-ups performed increased significantly in the CR group but not the CON group by week 4. No significant differences between the CR and CON groups were found for other performance measures, body composition, core body temperature, or other biochemical measures. CONCLUSION: Creatine supplementation increased body mass and pull-up performance but did not cause acute health problems. Creatine did not increase core temperature compared with placebo under the environmental conditions of the study, and it is unlikely that creatine will enhance the overall readiness or performance of soldiers.

Adult↗