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Biomedical subjects

J Beekman

Publications and source records attributed to J Beekman.

6 recordsLinked to original sources
PubMed2003

Immunohistochemical changes induced by repeated footshock stress: revelations of gender-based differences.

As a growing literature has proven, adverse experiences, particularly when severe and persistent, play a pivotal role in the development of neuronal dysfunctions and psychopathology. In the present study, the neurochemical changes induced by acute and repeated footshock exposure were investigated at the molecular and cellular level, using c-fos and phospho-ERK1/2 immunoreactivity and gene expression arrays. Marked gender-related differences were found following both acute and prolonged footshock exposure. Acute aversive conditioning resulted in significant immunohistochemical changes that might be critically involved in the modulation of fear-related responses, especially in males. Prolonged footshock exposure, on the contrary, was associated with sustained hypothalamic-pituitary-adrenal axis hyperactivity, differential gender-related patterns of cortical-limbic activity, and abnormal neuronal plasticity, especially in medial prefrontocortical regions. These data may provide additional insights into the understanding of the neural circuits underlying the effects of acute and repeated footshock exposure as well as clarify some of the mechanisms involved in the development of stress-related neuronal abnormalities.

Animals↗
PubMed2001

Molecular typing of HLA-A, -B, and DRB using a high throughput micro array format.

The goal of this study was to develop a DNA micro array procedure for molecular human leukocyte antigen (HLA) typing of a large number of samples. DNA was isolated from peripheral blood samples and polymerase chain reaction (PCR) amplified for HLA-A, -B, and -DRB. Amplified DNA samples were spotted on silane-treated glass slides using a micro array spotter. The spotter was capable of spotting multiple slides with up to 9216 samples per slide or 2304 samples in quadruplicate. The allele specific oligo nucleotide probes for HLA-A, -B, and -DRB were labeled with the fluorescent dye Cy3, while a control probe, to quantitate the total amount of PCR product in a sample, was labeled with Cy5. Each slide was hybridized with a mixture of an allele specific Cy3 probe plus the control Cy5 probe. Following hybridization and wash, the amount of probe hybridizing to each DNA sample on the slide was measured with a micro array scanner. A computer program was used for image analysis, to calculate the average Cy3/Cy5 ratios and to identify the positive and negative samples. In turn, this information was used to determine the HLA phenotype of each sample. There was very good concordance between the results obtained for all three loci using Cy-labeled probes as compared with those previously obtained by chemiluminescent detection of alkaline phosphatase labeled probes. This methodology has the potential of greatly simplifying HLA molecular typing of large number of samples.

Alleles↗
PubMed2000

Design and validation of immunological tests for the detection of Porcine endogenous retrovirus in biological materials.

The present study details the design and demonstrates function for a series of reagents and methods to allow the detection of exposure to antigens specific for Porcine endogenous retrovirus (PERV). The detection of PERV is carried out by the means of a variety of immunological screening methods including, indirect immunofluorescence, Western blotting and enzyme linked immunosorbent assay (ELISA) for the detection of antibodies in serum specific for PERV gag and env antigens. Alternatively, PERV-specific antisera for gag and env can be used to detect viral antigen in serum or other samples. PERV env peptides with potential specificity for the known PERV types are also described. Antisera against the peptides can be used to detect PERV antigens directly or to characterise viral type. Using electron microscopy coupled with labelled PERV-gag-specific antisera it was possible to visualise PERV virions.

Amino Acid Sequence↗
PubMed1991

Low-dose isradipine once daily effectively controls 24-h blood pressure in essential hypertension.

In one study of 10 patients with mild-to-moderate hypertension, equivalent total daily doses (13 +/- 2 mg) of isradipine given twice daily and a modified-release formulation of isradipine (isradipine MR) given once daily were found to control adequately 24 h ambulatory blood pressure compared with placebo (P less than .001 for each v placebo). In another study of 22 patients with essential hypertension, 5 and 10 mg isradipine MR once daily has been shown to reduce the average 24 h blood pressure by 11 +/- 1/6 +/- 1 mm Hg (P less than .001) and 13 +/- 2/9 +/- 1 mm Hg (P less than .001), respectively, compared with placebo. There was no loss of efficacy with isradipine MR during the 24 h observation period with either dose. In conclusion, low-dose isradipine MR once daily is an effective first-line treatment in essential hypertension.

Antihypertensive Agents↗
PubMed1985

Serodiagnosis of lungworm infection in calves using ELISA.

Soluble antigens were prepared from adult Dictyocaulus viviparus worms and from parasitic larval stages. Circulating antibody titres against these antigens were determined during experimental and field challenge studies. Stage-specific responses were found in vaccinated and non-vaccinated calves after challenge infection. Titre-values are probably correlated with the number of larvae reaching the lungs and the number of larvae developing into later larval resp. adult stages. The ELISA-technique appeared to be useful for diagnosis of lungworm infection level in cattle herds and has been applied in a sero-epidemiological survey in the Netherlands.

Animals↗