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Biomedical subjects

J Oswald

Publications and source records attributed to J Oswald.

At least 37 records · Page 2Linked to original sources

Verification of bacterial killing effects of cage wash time and temperature combinations using standard penicylinder methods.

We conducted the present study to evaluate various time and hot-water temperature combinations necessary to kill three common bacterial species in standardized cultures on stainless steel penicylinders, in accordance with methods approved by the Association of Official Analytical Chemists. Exposure for no more than 2 sec to water at 82.2 degrees C killed all three bacterial species, as did exposure for 3 sec to water at 80 degrees C, 4 sec at 77.8 degrees C, and 5 sec at 75.6 degrees C. We conclude that temperatures in the range of 75.6 degrees C to 82.2 degrees C will effectively kill vegetative bacteria in a matter of seconds and that failure to kill these bacteria in cagewash operations, with belt travel times in minutes rather than seconds, is due to other factors that prevent the effective application of sufficiently hot water to the bacterial load.

Animals↗

H19 and Igf2 are expressed and differentially imprinted in neuroectoderm-derived cells in the mouse brain.

Igf2 and H19 are reciprocally imprinted genes that are closely linked and coexpressed in tissues of mesodermal and endodermal origin. Here we report that coexpression of these genes is also found in specific fetal tissues of neuroectodermal origin, that is in the ventral midline region of both the hindbrain and spinal cord. For cells of neuroectodermal origin, complete absence of Igf2 and H19 transcription was previously described. Analysis of allele-specific expression of both Igf2 and H19 in the ventral midline region of the hindbrain shows that H19 is expressed monoallelically, with the paternal allele being silent, whereas Igf2 is expressed biallelically. Furthermore, we observed a strong influence of the parental species background, in that the Mus musculus allele was always expressed at higher levels than the M. spretus allele. This was observed when the M. spretus allele was contributed by the mother or by the father. An analysis of Igf2 methylation by bisulphite genomic sequencing provided no clear answer as to whether Igf2 expression and methylation are linked in a tissue of neuroectodermal origin. Taken together, our results provide novel information on H19 and Igf2 expression and imprinting patterns in the fetal mouse brain. In addition, they indicate that some aspects of Igf2 regulation in cells of neuroectodermal origin do not follow the pattern that exists in mesoderm- and endoderm-derived tissues. Apart from the ventral midline region, H19 and Igf2 were found to be coexpressed in the ectodermally derived Rathke's pouch and in some circumventricular organs of the brain, such as the organum vasculosum of the lamina terminalis (OVLT) and the pineal gland.

Animals↗

Long-term use and tapered dose reduction of intranasal desmopressin in the treatment of enuretic children.

OBJECTIVE: To determine the time taken to achieve complete dryness, the management of desmopressin dosage to reduce the relapse rate, the mean dosage in those responding and any side effects of long-term treatment. PATIENTS AND METHODS: Enuretic children (155, 68% boys and 32% girls, mean age 8 years, range 5-19) were treated with desmopressin and assessed. Treatment (intranasal spray) was started with 20 microg desmopressin and titrated to 40 microg (maximum 50 microg) after 2 days if the child did not become dry within 48 h. The maximum dosage was maintained for at least 4-6 weeks. After 4 weeks of complete dryness, the dosage was reduced by 10 microg initially, and after each additional 4 dry weeks, by a further 10 microg; medication was stopped only after 4 dry weeks at 10 microg. RESULTS: Of the children, 85% responded to intranasal desmopressin therapy; 71% achieved complete dryness with no relapses, remaining dry with no further treatment, 7% achieved dryness after relapses during or after therapy, 7% improved (no more than two wet nights per week) and 15% did not respond to therapy or improved only slightly (> 2 wet nights per week). The mean duration of therapy was 28 weeks, the mean dose of desmopressin was 30 microg and the median follow-up 18 months. There were no significant side-effects. CONCLUSION: This study indicates that rapid titration until dryness within 1-3 days, a long maintenance therapy of at least 4-6 weeks and a slow stepwise reduction of dose decreases the frequency of relapse and improves the outcome.

Administration, Inhalation↗

Loss of the maternal H19 gene induces changes in Igf2 methylation in both cis and trans.

Recent investigations have shown that the maintenance of genomic imprinting of the murine insulin-like growth factor 2 (Igf2) gene involves at least two factors: the DNA (cytosine-5-)-methyltransferase activity, which is required to preserve the paternal specific expression of Igf2, and the H19 gene (lying 90 kb downstream of Igf2 gene), which upon inactivation leads to relaxation of the Igf2 imprint. It is not yet clear how these two factors are related to each other in the process of maintenance of Igf2 imprinting and, in particular, whether the latter is acting through cis elements or whether the H19 RNA itself is involved. By using Southern blots and the bisulfite genomic-sequencing technique, we have investigated the allelic methylation patterns (epigenotypes) of the Igf2 gene in two strains of mouse with distinct deletions of the H19 gene. The results show that maternal transmission of H19 gene deletions leads the maternal allele of Igf2 to adopt the epigenotype of the paternal allele and indicate that this phenomenon is influenced directly or indirectly by the H19 gene expression. More importantly, the bisulfite genomic-sequencing allowed us to show that the methylation pattern of the paternal allele of the Igf2 gene is affected in trans by deletions of the active maternal allele of the H19 gene. Selection during development for the appropriate expression of Igf2, dosage-dependent factors that bind to the Igf2 gene, or methylation transfer between the parental alleles could be involved in this trans effect.

Alleles↗

A modified and improved method for bisulphite based cytosine methylation analysis.

Sequencing of bisulphite modified genomic DNA is the most powerful method to determine methylation patterns in chromosomal DNA. In many experimental systems, the amount of material available for analysis is very small which makes it necessary to perform experiments at extreme levels of sensitivity and reproducibility. In this communication, we present an improved modification of the bisulphite based sequencing method. Our strategy is to perform the bisulphite treatment and subsequent PCR steps on material embedded into agarose beads. This prevents loss of DNA during the experimental procedure and ensures an optimal bisulphite reactivity by maintaining the DNA in the single stranded form. The modification improves previously published protocols in that it facilitates the handling of probes and reproducibly reaches a very high level of sensitivity.

Cell Line↗

Prenatal care utilization in Minnesota. Patterns of concern, areas for improvement.

We conducted an analysis of prenatal care utilization among Minnesota resident mothers for the years 1990 to 1991 to determine why this state ranks poorly in prenatal care use while its infant mortality rate is one of the lowest in the nation. We found that 6% of women began care in the first trimester yet did not receive an adequate number of visits. These women were more likely to deliver preterm, low birthweight infants than women who started care later. Fifteen percent of women had records missing important data, and these women also had higher rates of poor pregnancy outcomes. Our findings have implications for maternal outreach and follow-up efforts and suggest potential benefits from private and public health collaborations. In addition, efforts to improve the quality of data reporting should begin immediately.

Adolescent↗

[Anti-arrhythmia effectiveness of potassium-magnesium-aspartate infusion].

In 21 patients with ventricular arrhythmias we analysed the effect of an intravenous infusion of potassium-magnesium-aspartate. It could be demonstrated that the frequency of ventricular ectopic beats significantly declined 1 hour after starting the medication. The maximum effect occurred at the 6th and 7th hour and continued until the 10th hour after starting the medication.

Anti-Arrhythmia Agents↗

[Nevi of the face].

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Facial Neoplasms↗