The apparent uptake of fluorescently labeled siRNAs by electroporated cells depends on the fluorochrome.

Transfection of mammalian cells with preformed small interfering RNAs (siRNAs) permits a transient and often specific reduction of gene expression. It is possible to rapidly examine the uptake of siRNAs by transfection with fluorescently labeled siRNAs. We examined the apparent uptake of such siRNAs by several leukemic cell lines after electroporation.

Histone acetylation-mediated regulation of genes in leukaemic cells.

Histone deacetylase (HDAC) and histone acetyltransferase (HAT) functions are associated with various cancers, and the inhibition of HDAC has been found to arrest disease progression. Here, we have investigated the gene expression profiles of leukaemic cells in response to the HDAC inhibitor trichostatin A (TSA) using oligonucleotide microarrays. Nucleosomal histone acetylation was monitored in parallel and the expression profiles of selected genes were confirmed by quantitative polymerase chain reaction (PCR).

The importance of age in screening for cancer.

Objective: To derive a rational method of selecting the age range over which screening tests for cancer should be offered (that is, over which they would be most effective in saving life).

Main Outcome Measure: The number of person-years of life that are lost through deaths occurring at each year of age from each of six cancers.

Results: For each cancer the number of years of life lost to age 80, plotted against age at death, showed a rise followed by a fall.

The effects of specific antibody fragments on the 'irreversible' neurotoxicity induced by Brown snake (Pseudonaja) venom.

Brown snake (Pseudonaja) venom has been reported to produce 'irreversible' post synaptic neurotoxicity (Harris & Maltin, 1981; Barnett et al., 1980). A murine phrenic nerve/diaphragm preparation was used to study the neurotoxic effects of this venom and pre- and post-synaptic components were distinguished by varying the temperature and frequency of nerve stimulation.

Vascular endothelial growth factor upregulates constitutive cyclooxygenase 1 in primary bovine and human endothelial cells.

The effect of the angiogenic cytokine vascular endothelial growth factor (VEGF) on nitric oxide synthase (NOS) and cyclooxygenase (COX) expression was examined in human (HUVEC) and bovine (BAE) endothelial cells. VEGF (10 ng/ml) induced constitutive COX-1 expression in both HUVEC and BAE, but not the cytokine-inducible isoform, COX-2, inducible NOS or endothelial NOS. In HUVEC, VEGF (10 ng/ml) increased COX activity, but COX inhibitors had no effect on the proliferative response of endothelial cells to this cytokine.

Suppression by dexamethasone of inducible nitric oxide synthase protein expression in vivo: a possible role for lipocortin 1.

Western blot and densitometric analysis of organ homogenates from lipopolysaccharide (LPS)-treated rats (1-10 mg kg(-1), i.p.) exhibited a strong induction of inducible nitric oxide synthase (iNOS) expression seen at all the doses tested (1, 3, and 10 mg kg(-1), n = 3).

Development of a specific fluoroimmunoassay for ovine albumin.

A fluoroimmunoassay has been developed to measure serum levels of albumin in sheep. It employs ovine albumin labelled with fluorescein as the tracer and a rabbit antiserum raised against ovine albumin. Separation of the antibody bound and free fractions is achieved using a second antiserum directed against the Fc of rabbit immunoglobulin G and, to simplify the assay, the two antisera are premixed prior to use.

First clinical experiences with a new ovine Fab Echis ocellatus snake bite antivenom in Nigeria: randomized comparative trial with Institute Pasteur Serum (Ipser) Africa antivenom.

During the past decade, effective snake antivenoms have become scarce in northern Nigeria. As a result, many patients severely envenomed by the saw-scaled or carpet viper (Echis ocellatus), which is responsible for more than 95% of the snake bites in the region, did not receive effective treatment and mortality and morbidity increased. To combat this crisis, a new monospecific ovine Fab antivenom (EchiTab) is being developed.

Regional proliferative patterns in the colon of patients at risk for hereditary nonpolyposis colorectal cancer.

Unlabelled: Patients from a hereditary nonpolyposis colorectal cancer (HNPCC) kindred (Lynch Type 1 and Type 2) have an increased risk of developing large-bowel cancer. Tumors occur at a young age and are characteristically right-sided. Colonic mucosal proliferation is known to be increased in several groups of patients at risk of colorectal cancer.

Randomized placebo-controlled study of the effects of simvastatin on haemostatic variables, lipoproteins and free fatty acids. The Oxford Cholesterol Study Group.

The Oxford Cholesterol Study is a randomized placebo-controlled trial designed primarily to assess the effects of simvastatin on blood cholesterol levels and side-effects in preparation for a large, long-term trial of the effects of cholesterol-lowering drug therapy on mortality. At present there is only limited evidence from randomized comparisons of the effects of HMG-CoA reductase inhibitors, such as simvastatin, on thrombogenic, as distinct from atherogenic, pathways in coronary heart disease. The present sub-study was carried out to assess the effects of simvastatin on a range of haemostatic variables, as well as on free fatty acids and on lipoprotein fractions not studied in detail previously.

A randomized trial to evaluate the effectiveness of dietary advice by practice nurses in lowering diet-related coronary heart disease risk.

Background: Dietary factors are an important contribution to the high rates of coronary heart disease in the UK. One approach to achieving change is health-promoting advice in primary care.

Aim: To compare the effectiveness of structured dietary advice by practice nurses with standard health education in changing serum cholesterol, weight and diet.

Assessment of an ovine antivenom raised against venom from the desert black cobra (Walterinnesia aegyptia).

The desert black cobra (Walterinnesia aegyptia) is an elapid widely distributed throughout the deserts of Saudi Arabia and currently available antivenoms are ineffective in the treatment of its envenoming. Walterinnesia aegyptia venom was assessed for several of its physicochemical, enzymatic and biological characteristics. An antivenom was raised in sheep using a low-dose immunization schedule and digested with papain to provide Fab fragments.

Ornithine decarboxylase activity is a marker of premalignancy in longstanding Helicobacter pylori infection.

Background: Longstanding Helicobacter pylori infection may increase the risk of developing gastric adenocarcinoma. The sequence of chronic active gastritis leading to gastritis with atrophy and subsequent intestinal metaplasia is thought to be a key step in gastric carcinogenesis. Ornithine decarboxylase (ODC) activity is increased in some pre-malignant gastrointestinal conditions and is essential for malignant transformation in vitro.

Incidence of hypertension and non-insulin dependent diabetes mellitus and associated risk factors in a rapidly developing Caribbean community: the St James survey, Trinidad.

Objective: To compare the incidence rates of hypertension and non-insulin dependent diabetes mellitus in relation to ethnicity and other characteristics in a rapidly developing community.

Design: Prospective surveillance of a total community for five years.

Subjects: Cohort of 2491 men and women aged 35 to 69 years (79% response), of African, Indian and "other' (mainly Afro-European) descent.

L-Arginine, nitric oxide, and intestinal secretion: studies in rat jejunum in vivo.

Background: L-Arginine has been shown to induce fluid secretion in human jejunum. Nitric oxide, a derivative of L-arginine is thought to have an important role as an intestinal secretagogue.

Aim: To determine the effect of L-arginine and the nitric oxide synthase inhibitor, nitro L-arginine methyl ester (L-NAME), on fluid and electrolyte movement in rat jejunum.

Improving the palatability of oral rehydration solutions has implications for salt and water transport: a study in animal models.

It is believed that improving the taste of oral rehydration solutions (ORSs) might lead to greater patient acceptability. A pilot trial showed that replacing glucose with sucrose and increasing the citrate concentration at the expense of chloride improves palatability. However, the transport implications of such modifications are not known.

Jejunal water and electrolyte transport in human cryptosporidiosis.

Cryptosporidiosis may have severe clinical consequences in both immunocompromised and immunocompetent individuals. However, pathophysiological mechanisms that are responsible for diarrhea are poorly understood. We performed jejunal perfusion studies in patients with human immunodeficiency virus-related cryptosporidial diarrhea to measure water and electrolyte transport in vivo.

Proteolytic degradation of intestinal mucosal extracellular matrix after lamina propria T cell activation.

Background: Proteoglycans, consisting of glycosaminoglycan (GAG) side chains covalently linked to a protein core, are a major component of the extracellular matrix of the intestinal lamina propria.

Aims: This study investigated the effects of lamina propria T cell activation on the proteoglycan component of the matrix.

Methods: The high degree of sulphation of GAGs means that they are polyanionic and thus can be visualised in tissue sections by means of colloidal-gold labelled cationic probes.

Determination of T-lymphocyte subsets on site in rural Tanzania: results in HIV-1 infected and non-infected individuals.

With the FACSCount flow cytometer, counts of CD4, CD8 and CD3 lymphocytes and CD4/CD8 ratios were performed in a rural hospital in Tanzania. A total of 168 subjects (21 HIV-1 seropositive and 147 HIV-1 seronegative) were tested as part of a population-based serosurvey and AIDS education programme; 134 other subjects were hospitalized patients who had signs and symptoms suggestive of AIDS (69 HIV-1 seropositive and 65 HIV-seronegative). Mean values for the 147 HIV-1 seronegative subjects from the local population were 980 CD4 cells (95% CI 930, 1031), 598 CD8 cells (560, 635) and CD4/CD8 ratio 1.

Influence of endothelial mediators on the vascular smooth muscle and circulating platelets and blood cells.

The vascular endothelium regulates the tone of the underlying smooth muscle and the reactivity of blood elements such as platelets and neutrophils by the release of mediators, in particular nitric oxide, prostacyclin and endothelin-1. The first two of these are potent vasodilators which also inhibit platelet and neutrophil aggregation and adhesion, while endothelin-1 is the most potent mammalian vasoconstrictor peptite yet found. There are also interactions between these mediators.

Measurement of lipocortin 1 levels in murine peripheral blood leukocytes by flow cytometry: modulation by glucocorticoids and inflammation.

1. Lipocortin 1 (LC1) immunoreactivity in murine peripheral blood leukocytes was quantified by use of a flow cytometric technique associated with a permeabilisation protocol with saponin. Using specific antisera raised against the whole protein or against its N-terminus peptide, cell-associated LC1-like immunoreactivity was easily detected in circulating neutrophils and monocytes, whereas very low levels were found in lymphocytes.

Evidence for specific annexin I-binding proteins on human monocytes.

Recombinant human annexin I and a monoclonal antibody specific for this protein (mAb 1B) were used to investigate surface binding of this member of the annexin family of proteins to peripheral blood monocytes. Flow cytometric analysis demonstrated trypsin-sensitive, saturable binding of annexin I to human peripheral blood monocytes but not to admixed lymphocytes. A monoclonal antibody that blocks the anti-phospholipase activity of annexin I also blocked its binding to monocytes.