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Biomedical subjects

M M Jackson

Publications and source records attributed to M M Jackson.

At least 19 recordsLinked to original sources
PubMed2001

Urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP-9) expression and activity during early embryo development in the cow.

Several extracellular matrix (ECM)-degrading proteinases are hypothesised to play important roles during early mammalian development. In particular, urokinase-type plasminogen activator (uPA) and matrix metalloproteinase 9 (MMP-9) are expressed in peri-implantation mouse, sheep, and pig embryos and are implicated in the implantation process. These proteinases are not expressed in early (pre-blastocyst) mouse, sheep or pig embryos. The aim of this study was to establish the gene expression and proteolytic activity of uPA and MMP-9 in in vitro-produced (IVP) cow embryos. Using RT-PCR, mRNA transcripts for uPA and MMP-9 were detected during the first 7 days of development. To investigate the activity of these proteinases, conditioned media from various stages of development (days 2, 3, 4, 5 and 7) were assayed for uPA activity by chromogenic assay and MMP-9 activity by gelatin zymography. Both uPA and MMP-9 activities were detected in the media samples indicating the production and secretion of these proteinases. This pattern of proteinase expression is novel in comparison to the mouse where uPA and MMP-9 are only expressed from the blastocyst stage onwards. The results of this study suggest that these ECM proteinases have a role prior to implantation in the cow, in contrast to that exhibited by mouse, sheep and pig embryos.

Animals↗
PubMed2001

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 are key regulators of extracellular matrix degradation by mouse embryos.

Embryo implantation in humans and rodents is a highly invasive yet tightly controlled process involving extracellular matrix (ECM) degradation. Matrix metalloproteinase 9 (MMP-9) has been implicated as the major facilitator of this ECM degradation. MMP-9 is expressed by the embryo's trophoblast cells, whereas tissue inhibitor of metalloproteinases 3 (TIMP-3) is expressed by the maternal uterine cells immediately adjacent to the trophoblast. We examined the functional roles of MMP-9 and TIMP-3 during in vitro ECM degradation by mouse embryos. Blastocysts were treated with either MMP-9 antisense or sense oligonucleotides and incubated on an ECM gel. The extent of ECM degradation exhibited by the blastocysts due to proteinase secretion was quantified. Embryos exposed to MMP-9 antisense oligonucleotides exhibited reduced ECM-degrading activity as compared with controls, and this reduced activity was correlated with the level of MMP-9 secreted by the embryos. The functional role of TIMP-3 was then examined by incubating blastocysts on an ECM gel that had been impregnated with various amounts of TIMP-3. In a dose-dependent manner, increases in TIMP-3 resulted in a reduction in ECM degradation and were correlated with diminished MMP-9 activity. These results provide important functional evidence that in vitro ECM degradation is regulated by embryo-derived MMP-9 and ECM-derived TIMP-3.

Animals↗
PubMed1999

Pathogens, old and new: an update for cardiovascular nurses.

Infectious diseases remain the major cause of death throughout the world, and this is not likely to change in the foreseeable future. However, there are steps that can be taken to combat them, including both the recognition of and interventions against emerging infectious diseases. This article will provide general information about emerging infectious organisms, mechanisms of resistance to antimicrobial agents, and comments on a variety of prevention strategies. In addition, the reader is directed to a number of comprehensive references for additional information.

Bacterial Infections↗
PubMed1999

The healthcare marketplace in the next millennium and nurses' roles in infection prevention and control.

For the past several years, constant changes in the health care marketplace have been dominated by the demand to manage costs. This has resulted in declining numbers of hospitals, hospital beds, and occupancy rates, along with increasing severity of illness in the patients who are hospitalized. It has long been known that infection prevention and control activities reduce risks for morbidity and mortality in patients and caregivers. Infection risk reduction activities are integral to nursing care delivery in any health care setting; however, the increasing stresses on care providers and declining staff-to-patient ratios compromise these priorities. Nurses share responsibility for infection risk reduction with other health care personnel who all need to work together with infection control professionals (ICPs) to develop and use prevention and control strategies based on scientific evidence.

Education, Nursing↗
PubMed1997

A practical approach to designing and performing a focused study.

Designing and performing focused studies is part of the regular work of infection surveillance, prevention, and control, and the methodology of a prevalence survey used in this practice forum will be familiar to many infection control professionals. A practical example of a focused study to evaluate cost savings from extending intravenous catheter site and administration set change frequency from 72 hours to 96 hours illustrates the steps required. Suggested references for additional information are included at the end of the article.

Catheterization, Peripheral↗
PubMed1996

Pulmonary tuberculosis in a homeless person.

Tuberculosis disproportionately affects certain segments of society, such as the homeless, and can cause extremely serious disease among persons with severely impaired cellular immunity, especially those with HIV infection. Inhalation of droplet nuclei, which are the airborne residual of droplets expelled from an infected host, is the primary means of transmission. Factors associated with transmission in shelters for the homeless include crowding, inadequate ventilation, and poor compliance with drug therapy. One of the greatest challenges to treatment of this infection among the homeless is the provision of adequate follow-up of patients who have begun therapy. Many individuals do not complete their treatment regimen. This creates an environment in which the transmission of tuberculosis, including multi-drug-resistant strains, can occur. Prevention strategies should focus on rapid identification and treatment of persons with active disease and latent tuberculosis infections. Ventilation with good exchange of fresh air or the addition of air cleaning devices may aid in reducing risks of transmission of disease.

Adult↗
PubMed1996

Initial worker evaluation of a new safety syringe.

A prospective evaluation of a new safety syringe requiring a one-step activation was carried out at the University of California, San Diego Medical Center. Only 59.5% of 390 syringes were activated, and user acceptance and satisfaction were unfavorable. The development of safety devices should incorporate passive activation and take end-user satisfaction into consideration.

California↗
PubMed1995

Development of a numeric Health Care Worker Risk-Assessment Scale to evaluate potential for blood-borne pathogen exposures.

BACKGROUND: An attempt to develop a Health Care Worker Risk Assessment Scale to evaluate potential for exposure to blood-borne pathogens was made in late 1989 through 1990. The research questions were as follows: (1) Can a scale be developed to assign weights to variables that influence health care workers' risk of exposure to blood-borne pathogens? (2) If so, what variables would be included? METHODS: A five-round Delphi technique was used with 26 panel members from 15 U.S. states and the United Kingdom who were recognized experts in strategies to reduce health care workers' risk of exposure to blood-borne pathogens. The scale included four elements, each scored up to 40 points. Elements were as follows: (1) potential route of exposure, (2) experience of health care worker and cooperation of patient, (3) prevalence of blood-borne pathogens, and (4) difficulty in managing the situation. A minimum score of 20 indicated an extremely low-risk situation; a maximum score of 160 indicated an extremely high-risk situation. RESULTS: Consensus was achieved among the panel members in identifying the elements that contributed to risk for exposure to blood-borne pathogens and in applying the scale to carefully worded vignettes. This required several modifications of both the scale and the vignettes to ensure consistent interpretation of the terms used. In all vignette situations, the risk-abatement strategy was specific to the situation depicted in the vignette and not to the task itself; the value of a numeric scale is thus questionable. CONCLUSIONS: Even with the participation of 26 expert panelists, we were unable to develop a numeric scale to objectively quantify risk in such a way that risk-reduction strategies could be based on the scale rather than on the specific risk elements in a situation. Instead of attempting to use a scale such as this to quantify risk objectively, educators or clinicians may be better advised to teach health care workers the four scale elements so that health care workers can subjectively use these elements to evaluate and modify their own risk situations.

Blood-Borne Pathogens↗
PubMed1993

Value of molecular epidemiologic analysis in a nosocomial methicillin-resistant Staphylococcus aureus outbreak.

OBJECTIVE: To evaluate two molecular epidemiologic methods used in the analysis of a nosocomial methicillin-resistant Staphylococcus aureus (MRSA) outbreak. DESIGN: Restriction endonuclease analysis of plasmid DNA (REAP) was used in the analysis of 45 MRSA isolates. After termination of the outbreak, isolates were retrospectively analyzed in a blind fashion using the newly described technique of arbitrarily primed polymerase chain reaction (AP-PCR). Molecular analyses were compared with epidemiologic and antimicrobial susceptibility data. SETTING: Tertiary care university hospital. SUBJECTS: Twenty-eight patients and 12 employees infected or colonized with MRSA during a 6-week period. RESULTS: A clonal relationship demonstrated among isolates from burn unit patients and staff was clearly distinguishable from MRSA isolates arising from other hospital wards. The combination of REAP and AP-PCR provided complementary information in several instances. Aggressive measures to isolate infected patients and eradicate colonization from patients and staff terminated the outbreak. CONCLUSIONS: Although traditional epidemiologic methods retain their central role in modern hospital infection control, molecular epidemiologic analysis can significantly enhance the ability of infection control officers to analyze and terminate hospital epidemics. The combination of AP-PCR and REAP may prove to be a particularly informative means of tracking the nosocomial spread of microbial strains and their mobile genetic elements.

Adolescent↗