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Biomedical subjects

B Christiansen

Publications and source records attributed to B Christiansen.

At least 19 recordsLinked to original sources
PubMed2001

Meeting the challenge of tobacco use within the Medicaid population.

The Wisconsin Medicaid Program, which purchases health care for Wisconsin's low income residents, has entered into a number of partnerships designed to systematically address tobacco use by Medicaid recipients. With the help of Wisconsin HMOs, a chart audit established an overall tobacco use prevalence of 45.7%, about double that of the general population. A direct survey of Medicaid recipients confirmed a rate of 45.0%. The chart audit also revealed a dramatic under-utilization of currently available Medicaid smoking cessation benefits. Plans are now being made to increase this utilization on a statewide basis. In addition, a partnership with the Wisconsin Women's Health Foundation and the Bureau of Family and Community Health Program within the Division of Public Health has resulted in a pilot project to address tobacco use by low income, pregnant women. Finally, a partnership with a specialized HMO serving those with disabilities and the Mental Health Association in Milwaukee County plans to address tobacco use by those with chronic and persistent mental illness.

Adolescent↗
PubMed2000

Haloperidol reinstates latent inhibition impaired by hippocampal lesions: data and theory.

The effect of haloperidol administration on the impairment of latent inhibition produced by aspirative lesions of the hippocampus was examined in the rat eyeblink response preparation. During the preexposure phase, rats with hippocampal or control lesions were either exposed to a tone or allowed to sit in the training apparatus. During the conditioning phase, the tone was paired with an airpuff to the eye after the rats were injected with either saline or haloperidol. Although saline-injected rats with hippocampal lesions did not show latent inhibition, the phenomenon was reinstated in rats that received haloperidol injections. A possible locus of the interaction between hippocampal lesions and haloperidol is the nucleus accumbens. The reported data are well described by a neural network model of classical conditioning. This study contributes to the understanding of the neurophysiology of latent inhibition as well as the neuropsychological bases of schizophrenia.

Animals↗
PubMed1999

Neuropsychological functioning and MRI signal hyperintensities in geriatric depression.

OBJECTIVE: The purpose of this study was to examine the relationship between signal hyperintensities--a probable marker of underlying pathology--on T2-weighted magnetic resonance brain scans and neuropsychological test findings in elderly depressed and normal subjects. METHOD: Elderly subjects with a DSM-III-R diagnosis of major depression (N=41) and normal elderly comparison subjects (N=38) participated in a magnetic resonance imaging study (1.0-T) of signal hyperintensities in periventricular, deep white matter, and subcortical gray matter. Hard copies of scans were rated in random order by research psychiatrists blind to diagnosis; the modified Fazekas hyperintensity rating scale was used. Cognitive performance was independently assessed with a comprehensive neuropsychological battery. Clinical and demographic differences between groups were assessed by t tests and chi-square analysis. Relationships between neuropsychological performance and diagnosis and hyperintensities and their interaction were analyzed by using analysis of covariance, with adjustment for age and education. RESULTS: Elderly depressed subjects manifested poorer cognitive performance on several tests than normal comparison subjects. A significant interaction between hyperintensity location/severity and presence/absence of depression on cognitive performance was found: depressed patients with moderate-to-severe deep white matter hyperintensities demonstrated worse performance on general and delayed recall memory indices, executive functioning and language testing than depressed patients without such lesions and normal elderly subjects with or without deep white matter changes. CONCLUSIONS: Findings validate cognitive performance decrements in geriatric depression and suggest possible neuroanatomic vulnerabilities to developing particular neuropsychological dysfunction in depressed subjects.

Aged↗
PubMed1999

Hygienic monitoring of environmental surroundings in office-based ambulatory surgery units--an instrument for infection control.

Out-patient operations cause lower costs and they are a method the patients are less burdened with than it is the case with usual operating methods. Avoiding nosocomial infections is regarded as another advantage. The rate of infection can be given by a carefully kept nosocomial infection surveillance. Ambulatory surgery units have difficulties in keeping these statistics because they often do not take over the after-treatment of this patients. Out-patient operations in surgeries must guarantee the same standard of hygiene which can usually be found in hospitals. Hospital epidemiologists, health authorities and professional associations have published corresponding guidelines with organizational/functional and structural requirements. These requirements, however, are only met by few ambulatory practices. Surgery holders justify the non-observance of the guidelines by supposing that the spectrum of germs in their office differs from that in a hospital and that there aren't any pathogens. The standard of hygiene in ambulatory surgery units is not controlled regularly. Therefore the hygienic conditions and the microbial burden of five surgeries that carry out out-patient operations under general anaesthesia were determined within the scope of microbial monitoring of the surroundings. Only two surgeries achieved a standard of hygiene which is comparable with that of a hospital. Up to 42% of the taken samples were sterile. The other three surgeries did not meet the requirements. The microbial burden in these surgeries was distinctly higher. The spectrum of detected microorganisms was very wide and there were pathogens too. Hygienic controls and monitoring of the surroundings should be carried out regularly as a measure to guarantee the production and maintenance of quality. Thus the actually achieved hygienic standard in the surgeries can be controlled and improved if necessary. Ambulatory surgeries should be liable to similar hygienic controls as hospitals.

Ambulatory Surgical Procedures↗
PubMed1998

Microbiological investigations to validate the preparation of corneal transplants.

The globe and cornea are colonized by microorganisms and cannot be removed as sterile products. Antiseptic measures and storage of the cornea in medium containing antibiotics lead to an obvious reduction of the microbial flora. Unfortunately there is the possibility of secondary microbial contamination during the preparation. Large amounts of bacteria or resistant bacteria can ruin attempts to reduce the microbial flora. To validate the whole process of preparation we investigated the contamination of removed globes, environment, materials, instruments and media for each sequence of operation and eliminated sources of contamination. Recommendations are given to ensure a virtually sterile product at the end of preparation.

Bacteria↗
PubMed1997

Down-regulation of tissue specific tumor necrosis factor-alpha in the liver and lung after burn injury and endotoxemia.

Burn injury and endotoxin lead to the development of a systemic inflammatory response. Because tumor necrosis factor-alpha (TNF-alpha) is a component of the proinflammatory response, we have determined the effect of burn injury and endotoxin in a murine model of thermal on tissue specific TNF-alpha levels in the liver and lung. Male mice were divided into four groups and injected with endotoxin (ETX) (2.5 mg/kg intraperitoneally) or saline (CNTL) or subjected to a 16% full-thickness scald burn (B), or ETX administration 72 hours after burn injury (B+ETX). Animals were killed at 0 to 24 hours after ETX or CNTL, 0 to 72 hours after B, and 72 to 96 hours after B+ETX (ETX administration 72 hours after B). TNF-alpha mRNA by Northern blot and protein analysis by enzyme-linked immunosorbent assay were determined and protein expressed as nanogram per gram of tissue. Statistical analysis was performed using analysis of variance with significance at p < 0.05. Burn injury did not result in detectable levels of liver or lung TNF protein or mRNA. Endotoxin administration resulted in a near six-fold rise in liver TNF protein compared with controls at 1, 2, and 6 hours after ETX (p < 0.05 to p < 0.001). Liver mRNA remained elevated from 20 minutes to 24 hours after ETX versus CNTL (p < 0.05). Endotoxin injection produced a persistent lung TNF protein elevation reaching significance at 1 and 2 hours (p < 0.001) and a rise in mRNA at 40 minutes to 6 hours (p < 0.05) versus CNTL. The liver showed a trend of reduced mRNA after B+ETX versus ETX (p = NS), whereas protein levels were reduced by 50 to 60% at 1 and 2 hours (p < 0.01). Lung mRNA values after B+ETX were only 40% compared with ETX at nearly all time points (p < 0.001) but were 15 times above CNTL values at 2 hours (p < 0.05). Based on these results, we conclude that burn injury did not cause an increase in liver or lung tissue specific TNF-alpha. However, the presence of a preexisting burn injury dramatically altered the response to endotoxin and the primary point of regulation appears to be at the posttranscriptional level.

Animals↗
PubMed1997

Construction of specific erythromycin resistance mutations in the temperate lactococcal bacteriophage TP901-1 and their use in studies of phage biology.

A method for the construction and isolation of specifically designed mutations of the temperate lactococcal phage TP901-1 has been developed. Two different erm-labeled mutants were isolated. One was shown to be defective in lysogenization and excision. The other, showing normal lysogenization, was used for host range studies.

Bacteriophages↗
PubMed1996

A resolvase-like protein is required for the site-specific integration of the temperate lactococcal bacteriophage TP901-1.

The integration system of the temperate lactococcal phage TP901-1 was characterized in Lactococcus lactis subsp. cremoris LM0230 and MG1363 with the use of deletion derivatives of the integration vector pBC143 (B. Christiansen, M. G. Johnsen, E. Stenby, F. K. Vogensen, and K. Hammer, J. Bacteriol. 176:1069-1076, 1994). The phage-encoded elements necessary for integration were localized on a 2.8-kb NsiI-EcoRI fragment including the phage attachment site, attP. This fragment was DNA sequenced, and sequence analysis revealed three putatively expressed open reading frames, Orf1, Orf2, and Orf3 By the introduction of mutations within the orf1, orf2, and orf3 genes, it was shown that only Orf1 was necessary for the integration process. Furthermore, it was found that Orf1, attP, and a 425-bp region upstream of the orf1 gene are sufficient for integration. Orf1 contains 485 amino acids and is located just upstream of attP. The N-terminal 150 to 180 amino acids of Orf1 showed 38 to 44% similarity to the resolvase group of site-specific integrases, while no similarity to known proteins was found in the C-terminal end. Bacteriophage TP901-1 therefore contains a unique integration system that does not resemble the Int class of site-specific integrases usually found in temperate bacteriophages. The constructed integration vector, pBC170, integrates into the chromosomal attachment site very efficiently and forms stable transformants with a frequency corresponding to 20% of the transformation efficiency.

Amino Acid Sequence↗
PubMed1994

Characterization of the lactococcal temperate phage TP901-1 and its site-specific integration.

The temperate lactococcal phage TP901-1, induced by UV light from Lactococcus lactis subsp. cremoris 901-1, was characterized. The restriction map was found to be circular, and the packaging of TP901-1 DNA was concluded to occur by a headful mechanism. The pac region was localized on the 38.4-kb phage genome. TP901-1 belongs to the class of P335 phages (V. Braun, S. Hertwig, H. Neve, A. Geis, and M. Teuber, J. Gen. Microbiol. 135:2551-2560, 1989). Evidence is presented that the phages TP936-1 (V. Braun, S. Hertwig, H. Neve, A. Geis, and M. Teuber, J. Gen. Microbiol. 135:2551-2560, 1989) and C3-T1 (A. W. Jarvis, V. R. Parker, and M. B. Bianchin, Can. J. Microbiol. 38:398-404, 1992) are very closely related to or are identical to TP901-1. The lytically propagated TP901-1 phages were able to lysogenize both indicator strains Lactococcus cremoris 3107 and Wg2. Lysogenization resulted in site-specific integration of the phage genome into the bacterial chromosome. Only one chromosomal attB site was found in 20 independent lysogens. The attP region of TP901-1 and the attL and attR regions were cloned and sequenced. The results showed a core region of only 5 bp, in which the recombination occurs, followed after a 1-bp mismatch by a 7-bp identical region, TCAAT(T/C)AAGGTAA. This result was further verified by sequencing of the attB region obtained by PCR. An integration vector was constructed with the 6.5-kb EcoRI fragment from TP901-1 containing attP. This vector also functions in the plasmid-free strains, MG1363 and LM0230 with only one specific attB site, strongly indicating a more general use of the TP901-1-based integration vector in lactococci.

Bacteriophages↗
PubMed1994

[Can contact nurses point the way to competence in practice? Nurses as practice mentors in nursing education].

UNLABELLED: The contact nurse is a central person as a carrier of knowledge and experience in nursing practice, which is important that the student nurse has access to. In order to gain insight into the passage of knowledge between 3 contact nurses and their students, I have carried out a qualitative investigation. METHOD: The method chosen is that of participation, open observation and semi-structured interviews. FINDINGS: While guiding the student, the contact nurse made explicit her way of judging specific nursing situations. She appealed to the use of perceptive insight, and made explicit the complexity in an "everyday situation" in nursing practice. Counselling in patient-situations thus reflects the value of the traditional master-apprentice roles. Professional argumentation delving deeper than more down-to-earth judgements, appears to be absent from the investigation. This shows the importance of a greater degree of reflection in the contact nurse's role as a counsellor.

Clinical Competence↗
PubMed1993

The efficacy of low temperature plasma (LTP) sterilization, a new sterilization technique.

The efficacy of low temperature plasma (LTP) sterilization, a newly developed sterilization procedure was tested. Following experiments were carried out: Determination of the most resistant test organism, influence of 10% and 20% defibrinated sheep blood or varying salt concentrations on the efficacy of the sterilization process, influence of the carrier position in the sterilization chamber and in the sterilization pouches, influence of a loaded sterilization chamber, comparative efficacy of EO and LTP, steel carriers with a blood burden of 0%, 5% and 10%, comparative efficacy of EO and LTP, strip carriers in endoscopes, blood burden 0% and 10%, with and without adaptors, evaluation of two bioindicator models. B. pumilus was the test spore that overall seemed to be most resistant to the sterilization procedure. Supplementation of the test suspension with blood or saline crystals resulted in significantly reduced efficacy and has to be avoided in practical operation. The fully loaded sterilization chamber or the position of germ carriers on the shelves had no negative influence on the effectivity of the sterilization process. There were no significant differences between EO and LTP, the blood burden not exceeding 5%. 10% blood burden resulted in a significantly weaker action of LTP. For sterilization of long lumens adaptors containing hydrogen peroxide are necessary. An appropriate bioindicator tube model is introduced.

Aspergillus niger↗