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Biomedical subjects

E Smith

Publications and source records attributed to E Smith.

At least 37 records · Page 2Linked to original sources
PubMed2003

Buccal cells as a source of DNA for comparative animal genomic analysis.

The source of DNA of adequate quality and quantity is an important consideration in genome analysis. In many animal and livestock species, easy access to DNA will facilitate the rapid and reliable genotyping of a large number of individual individuals. Here, we describe the use, for the first time, of buccal cells from non-human mammalian species as a source of DNA template for PCR and restriction analysis. The buccal cells from the pig, cow and human, were used to amplify PCR fragments that were scanned SNPs and for comparative genome analysis. The work indicates that buccal cells are also adequate sources of DNA for genome analysis of animals that have been identified as priorities in comparative genomics.

Animals↗
PubMed2003

Twenty-year survey of the epidemiology of hepatitis B in Denmark: effect of immigration.

Implementation of hepatitis B virus (HBV) vaccination is being considered in Denmark. Therefore, a 20 y survey on the epidemiology of HBV infection was performed. All notified cases of acute HBV infection in Denmark from 1982 to 2002 were reviewed retrospectively and all available data from 1970 to 2001 on the prevalence of hepatitis B surface antigen (HBsAg) in different groups of the Danish population were studied. The notified annual incidence of acute HBV infection has declined from more than 200 cases to fewer than 50 cases in 2001. In the indigenous population there has been a similar decline in prevalence of HBsAg carriers, from 0.15 to 0.03%, but owing to immigration of new HBsAg carriers from developing countries the overall number of carriers has not changed. The small effect of immigration on the incidence of acute HBV infections as well as the decreasing prevalence of HBsAg carriers among Danes should be taken into account when planning new vaccination strategies in Denmark.

Adolescent↗
PubMed2003

Arsenic in Australian environment: an overview.

The most common source of elevated As concentrations in the Australian environment are attributable to anthropogenic activities. Mining activities have contributed to the contamination of soil and water primarily in Western Australia and Victoria. However, other anthropogenic activities such as agriculture, forestry and industry have also contaminated soil and water at a localized scale. Currently there are over 1000 As contaminated sites previously used as cattle dips for eradicating cattle ticks. Although As contamination of the environment may be severe enough to limit plant growth there appears to be few other reports identifying the impacts of the contaminants on other organisms, such as fish, mammals and humans. In Australia the impacts of metal/metalloid contamination of the environment are often unnoticed or ignored. However, the impacts of elements such as As may pass unnoticed by the public or regulators due to the perception of the minimal impact a contaminant has on the environment. This paper presents an overview of As in the Australian environment including the sources of As contamination, soil, water and plant As content, and the pathways of exposure.

Agriculture↗
PubMed2003

Expression of NOD2 in Paneth cells: a possible link to Crohn's ileitis.

BACKGROUND AND AIMS: Genetic variation in NOD2 has been associated with susceptibility to Crohn's disease (CD) and specifically with ileal involvement. The reason for the unique association of NOD2 mutations with ileal disease is unclear. To identify a possible link, we tested expression of NOD2 in intestinal tissue of CD patients and controls. PATIENTS AND METHODS: Fifty five specimens of ileum or colon from 21 CD patients, seven ulcerative colitis (UC) patients, and five controls with pathology other than CD or UC were stained for NOD2 using an immunoperoxidase method. RESULTS: Using a monoclonal antibody against NOD2 developed in our laboratory, we detected uniform expression of NOD2 in terminal ileum Paneth cells from controls and patients as well as in metaplastic Paneth cells in the colon. Mechanical purification showed enriched expression of NOD2 mRNA in ileal crypts. In Paneth cells, NOD2 was located in the cytosol in close proximity to the granules that contain antimicrobial peptides. We detected minimal NOD2 in the villous epithelium of the ileum or in the colonic epithelium from both CD patients and controls. CONCLUSIONS: These results suggest a role for NOD2 in the regulation of Paneth cell mediated responses against intestinal bacteria and a plausible mechanism to explain the selective association of NOD2 mutations with ileal disease. The impaired capacity of CD associated mutations to sense luminal bacteria may result in increased susceptibility to certain gut microbes.

Adolescent↗
PubMed2003

Optimum physical-chemical pre-treatment of copper damascene wastewater.

Chemical and mechanical polishing (CMP) of copper damascene circuits will typically produce copper levels in excess of regulatory limits in wastewater with a unique process chemistry, including high solids. Physical-chemical methods were investigated to determine the optimum treatment depending upon pre-treatment and/or water reuse requirements. Jar test studies revealed that an alum dose of 150-200 mg/L together with anionic polymer aid provided a good removal of turbidity. If the treatment objective is simply solids and copper reduction for discharge to a sewer system, then solids removal can combined with precipitation of copper hydroxide for relatively inexpensive pre-treatment. The presence of peroxide from the process solution, however, may make it difficult to achieve copper values below 5 mg/L, depending on the associated process conditions. If the objective is to remove solids and recover copper, which may also allow recovery of water for reuse, then solids removal by alum and polymer can be followed by ion exchange by a strong acid cation resin. As with precipitation, however, effective copper removal by ion exchange requires pre-treatment of peroxide by chemical reduction. The exchange of dissolved aluminum also reduces the capacity of the resin for copper.

Alum Compounds↗
PubMed2003

Pond treatment and effluent reuse of sewage from an oil production site in an arid coastal environment.

A pond system consisting of two lines each of an anaerobic followed by facultative and maturation ponds is used to treat site sewage from oil and gas production operations in an arid coastal environment. The performance of the pond system was evaluated together with the suitability of treated effluent for reuse in local irrigation. Effluent from the pond system by-and-large satisfies criteria for irrigation of non-food crop plants with respect to chemical parameters. The primary problem is coliform bacteria levels which are an order of magnitude higher than preferred values. First-order decay rate constants for each pond were calculated from a mass balance model that assumes complete mixing and incorporates the considerable evaporation that occurs in this setting. While the anaerobic ponds of both lines exhibit suitable performance, rate calculations indicate that the facultative and maturation ponds of the East Line are performing better than the West. A tracer study of the facultative and maturation ponds indicates that some short-circuiting is occurring in the West Line. A field experiment of coliform transport in irrigated soil gives indications of short- and long-term risks associated with reuse of the effluent.

Agriculture↗
PubMed2002

An integrated computational pipeline and database to support whole-genome sequence annotation.

We describe here our experience in annotating the Drosophila melanogaster genome sequence, in the course of which we developed several new open-source software tools and a database schema to support large-scale genome annotation. We have developed these into an integrated and reusable software system for whole-genome annotation. The key contributions to overall annotation quality are the marshalling of high-quality sequences for alignments and the design of a system with an adaptable and expandable flexible architecture.

Animals↗
PubMed2002

Biosorption of organochlorine pesticides using fungal biomass.

Cladosporium strain AJR(3)18501 was tested for its ability to sorb the organochlorine pesticide (OCP) p,p'-DDT from aqueous media. When p,p'-DDT was added to distilled water, ethanol or 1-propanol solutions in excess of its solubility, p,p'-DDT was sorbed onto the fungal biomass. Increasing the amount of p,p'-DDT in solution by changing the medium composition increased sorbent uptake: p,p'-DDT uptake by the fungal biomass was 2.5 times greater in 25% 1-propanol (17 mg of p,p'-DDT g(-1) dry weight fungal biomass) than in distilled water. When p,p'-DDT was dissolved in 25% 1-propanol (12 mg x l(-1)), rapid p,p'-DDT sorption occurred during the first 60 min of incubation. p,p'-DDT in solution was reduced to 2.5 mg x l(-1) with the remaining p,p'-DDT recovered from the fungal biomass. A number of environmental parameters were tested to determine their effect on p,p'-DDT biosorption. As arsenic (As) is prevalent at DDT-contaminated cattle dip sites, its effect on p,p'-DDT uptake was determined. The presence of As [As(III) or As(V) up to 50 mg x l(-1)] did not inhibit p,p'-DDT uptake and neither As species could be sorbed by the fungal biomass. Changing the pH of the medium from pH 3 to 10 had a small effect on p,p'-DDT sorption at low pH indicating that an ion exchange process is not the major mechanism for p,p'-DDT sorption. Other mechanisms such as Van der Waals forces, chemical binding, hydrogen bonding or ligand exchange may be involved in p,p'-DDT uptake by Cladosporium strain AJR(3)18501.

1-Propanol↗
PubMed2002

Delayed transient sciatic nerve palsy after total hip arthroplasty.

Sciatic nerve palsy after total hip arthroplasty is a well-known complication, but delayed sciatic nerve palsy is rare. We report such a case with profound clinical manifestations and well-documented electrophysiologic changes. We found no helpful guidance to managing delayed palsy in the literature. We also are unaware of any previous cases reported in which nearly full recovery has occurred.

Arthroplasty, Replacement, Hip↗
PubMed2002

Gene expression, cell localization, and evolution of rodent submandibular gland androgen-binding protein.

A small dimeric androgen-binding protein (Abp) secreted by mouse (Mus) submandibular salivary glands has been hypothesized to function in mate-selection. The alpha-subunit (Abpa) evolves rapidly under natural selection. However, cellular site(s) of synthesis, mode of function, and patterns of evolution of this biologically important protein are otherwise unknown. We used a radiolabeled riboprobe and in situ hybridization to mouse (Mus) Abpa mRNA to localize Abpa synthesis to submandibular gland acinar cells. We next used a quantitative fluorescent thermal cycler (real-time PCR) to determine relative expression levels (normalized with a constitutively expressed ribosomal gene [S15/rig; rat insulinoma gene]) in male, female, and sexually immature European striped field mice (Apodemus agrarius). We hypothesized that gender or age-related differences might occur in production of a salivary protein related to sexual selection, but found no significant differences within our sample. Finally, we also used reverse transcription-PCR of mRNAs isolated from submandibular salivary glands to determine the Abpa allele in the striped wood mouse and compare it to published information on the homologue in Mus musculus domesticus.

Amino Acid Sequence↗
PubMed2001

[Tuberculosis among children in Denmark, 1990-1999].

INTRODUCTION: During a century with a decreasing incidence of tuberculosis (TB) in Denmark, the last 15 years have seen an increase. We describe the epidemiology of TB in children in Denmark with the focus on the impact of immigration. MATERIALS AND METHODS: Data from the national TB surveillance of 1990-1999 were analysed. The variables were age, gender, nationality, TB location(s), and the results of microscopy and culture. RESULTS: Three hundred and forty-nine children below 15 years of age were found, representing 8% of all notified cases of TB. Of these, 268 children (78%) were immigrants. The number of children increased over time, as did the proportion of immigrants (p < 0.0001). The median age was four years in the native Danes and nine years in the immigrant children (p < 0.001). The mean annual incidence of TB in the children was 3.9 per 10(5); 45.8 per 10(5) in the immigrants and 0.92 per 10(5) in the native Danes. The incidence increased from 2.0 in 1990 to 5.3 per 10(5) in 1999. Forty-nine per cent of the immigrants were Somalis, 13% were Pakistanis. The mean annual TB incidence was 581 per 10(5) in Somalis and 78 per 10(5) in Pakistanis. The incidence increased with age in children from Pakistan and Somalia and decreased in native Danes. Seventy-seven per cent of native Danes and 65% of immigrants had pulmonary TB +/- other locations (p < 0.05). Sixty-seven per cent of immigrant children with extrapulmonary TB had TB in the glands, 9% had TB in the bones, and another 9% had TB in the digestive system, proportions that were 38% (p < 0.05), 8%, and 0%, respectively, in native Danes. DISCUSSION: Immigration has had an impact on the incidence of TB, as well as on the pattern of TB location in children in Denmark. The incidence was 48 times higher in immigrant than in native Danish children.

Child↗
PubMed2001

A novel contractile phenotype with cardiac transgenic expression of the human P2X4 receptor.

The P2X4 receptor is a newly identified receptor expressed in the heart cell. Its function was elucidated with cardiac transgenic (TG) expression of the receptor by using the myocardium-specific a-myosin heavy chain promoter. The presence of the transgene was determined by polymerase chain reaction by using primers specific to the receptor and the vector linker region, by Southern blotting of the genomic DNA, and by immunoblotting and immunohistochemistry of both isolated cardiac myocytes and intact hearts. In intact heart study, the P2X4 receptor TG mouse exhibited significantly elevated basal cardiac contractility with greater rates of contraction and relaxation, left ventricular developed pressure, and cardiac output compared with nontransgenic (NTG) animals but showed no evidence of hypertrophy or heart failure. The TG heart also showed a greater increase of cardiac contractility in response to the P2X receptor agonist 2-methylthioATP, consistent with overexpression of a functional P2X4 receptor with consequent increase in the receptor-mediated response. In isolated cardiac cell study, the TG heart cell showed a similar level of basal contraction amplitude as the NTG heart cell while exhibiting a threefold greater increase in contractility during stimulation by 2-methylthioATP. Thus, an increased responsiveness of the overexpressed P2X4 receptor to endogenous ATP is responsible for the enhanced basal cardiac performance in the intact TG heart. The sustained enhanced contractile function with no associated heart pathology in the P2X4 receptor TG mouse suggests a novel physiologic role of the P2X4 receptor, that of stimulating the cardiac contractility.

Adenosine Triphosphate↗
PubMed2001

[HIV infection among young people in Denmark 1990-1999].

INTRODUCTION: The aim of the study was to describe the spread of HIV among young people below 25 years of age in Denmark and further to estimate the risk of acquiring HIV in heterosexuals in Denmark by means of a simple model. MATERIAL AND METHODS: Data from the mandatory national HIV surveillance were analysed. The risk of acquiring HIV was estimated by a simplified mathematical model with estimates of HIV prevalence, risk of transmission per sexual act, and number of sex partners. RESULTS: A total of 266 persons below 25 years of age had HIV infection: 127 men (48%) and 139 women (52%). The most dominant mode of transmission was sexual: 55% were infected heterosexually and 29% homosexually. One hundred and fourteen persons (43%) were foreigners, 87% of whom had been infected outside Denmark. A decreasing trend was found over the years in the number of first-time identified HIV infected persons, overall as well as in Danes, p < 0.01. The annual rate of HIV detection in women aged 20-24 years was calculated to be 2.5 per 10(5) Danish women. DISCUSSION: The spread of HIV among young Danes seems limited when the data on cases diagnosed over the last decade were analysed, and the general risk of acquiring HIV through unprotected intercourse is very low--regardless of changes in partner. Sub-groups of heterosexuals at high-risk may exist, and if so these should be identified.

Adult↗
PubMed2001

Cortactin potentiates bone metastasis of breast cancer cells.

Gene amplification of the chromosome 11q13 in breast cancer and squamous carcinomas in the head and neck results in frequent overexpression of cortactin, a prominent substrate of Src-related tyrosine kinases in the cell cortical areas. To investigate the role of cortactin in tumor progression, we analyzed MDA-MB-231 breast cancer cells overexpressing green fluorescent protein-tagged murine cortactin (GFP-cortactin) and a cortactin mutant deficient in tyrosine phosphorylation under the control of a retroviral vector. Injection of MDA-MB-231 cells overexpressing GFP-cortactin into nude mice through cardiac ventricles caused bone osteolysis at a frequency approximately 85% higher than that of cells expressing the vector alone, whereas injection of cells overexpressing the mutant deficient in tyrosine phosphorylation induced 74% fewer osteolytic metastases as compared with the control group. Interestingly, the cells expressing either GFP-cortactin or the mutant did not show significant differences in growth in vitro or when injected m.f.p. in vivo. On the other hand, the cells overexpressing GFP-cortactin but not the mutant acquired a >60% enhanced capability for transendothelial invasion and endothelial cell adhesion. These data suggest that cortactin contributes to tumor metastasis by enhancing the interaction of tumor cells with endothelial cells and the invasion of tumor cells into bone tissues.

Animals↗