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Biomedical subjects

M J Ryan

Publications and source records attributed to M J Ryan.

159 records · Page 9Linked to original sources
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Toxicity of diethanolamine. 1. Drinking water and topical application exposures in F344 rats.

Toxicology studies of diethanolamine were conducted in male and female F344 rats for 13 weeks' duration to characterize and compare effects of exposure in the drinking water with those caused by topical application. Doses of diethanolamine ranged from 160 to 5000 ppm in the drinking water study (equivalent to daily doses of 25-440 mg kg-1 in males and 15-240 mg kg-1 in females) and from 32 to 500 mg kg-1 in the topical application study. Dose-dependent toxic effects due to exposure to diethanolamine included hematological changes (a poorly regenerative, microcytic anemia), as well as toxic responses in the kidney (increased weight, tubular necrosis, decreased renal function, and/or tubular mineralization), brain and spinal cord (demyelination), testis (degeneration of the seminiferous tubules) and skin (site of application: ulceration, inflammation, hyperkeratosis and acanthosis). A no-observed-adverse-effect level was not achieved for hematological changes, nephropathy or hyperkeratosis of the skin. Differences in dose-response between the drinking water and topical application exposures were attributed largely to the limited dermal absorption of this chemical.

Administration, Oral↗
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The issue of anti-D: an integrated seamless approach from recognition of need to bedside administration.

BACKGROUND: The appropriate and timely administration of Anti-D immunoglobulin to Rhesus (D) negative women who have delivered Rhesus (D) positive babies is a vital part of obstetric care. Anti-D has an especially high profile in Ireland because of the tragic inadvertent transmission of Hepatitis C to Irish women in past decades. AUDIT: We have reviewed our policy and procedures pertaining to the administration of Anti-D for sensitising events during pregnancy and postnatally, in the Mid-Western Health Board in 1999/2000. As a result, major changes were made in the storage, issue, recording and administration of Anti-D. New procedures in the transfusion laboratory and in the maternity hospital have been accepted by scientists and midwives and supported by haematology and obstetric medical staff. The pharmacy and haematology laboratory no longer have a role in this programme. IMPLEMENTATION OF MULTI-DISCIPLINARY CHANGE MANAGEMENT: As a result of these changes, the storage, issuing and tracking of Anti-D has become the responsibility of the hospital blood bank. Measurement offoeto-maternal haemorrhage (FMH) is now the responsibility of bio medical scientists in blood bank, utilising both flow cytometry (increasingly recognised as the gold standard method) and the Kleihauer method (Kleihauer-Betke). The programme has moved from a doctor-administered IV Anti-D Ig, to a midwife-administered IM preparation. Prescription remains the responsibility of the doctor. These changes are facilitated by the protocol guided issue of the appropriate dose of Anti-D Ig by bio medical scientists to midwives. The issue of the Anti-D Ig occurs simultaneously with issue of results of mother and baby's serology testing and estimation of volume of FMH. These major changes have been guided by audit and needs assessment and require close liaison between medical, nursing and laboratory scientific staff in haematology, transfusion and obstetrics. CRITICAL INCIDENT AUDIT-CASE REPORT: Before new procedures became official policy, a critical incident audit allowed us to pilot our protocol and to revise it using draft new procedures. In this critical incident we describe successful management of a patient with a large foeto-maternal haemorrhage. This incident supported the need for the procedural enhancements already underway. This critical incident re-emphasised the need for the planned systems improvements to be introduced quickly.

Adult↗
PubMedDate not supplied

Hypercholesterolemia causes mechanical weakening of rabbit atheroma : local collagen loss as a prerequisite of plaque rupture.

Hypercholesterolemia may render atherosclerotic plaques prone to rupture. To test this hypothesis, catheters with matrix-covered balloons were implanted into the aorta of rabbits fed standard or 0. 5% cholesterol chow (n=70). In 1 month, fibrous plaques developed around the balloon. Time-dependent accumulation of cholesteryl esters and free cholesterol was detected in the plaques of the cholesterol-fed group only. The pressure needed to rupture the plaque by balloon inflation was used as an index of plaque strength. Three months after the catheter implantation, the breaking pressure was 2.1 times lower (P<0.05) in cholesterol-fed rabbits. It was accompanied by collagen loss, as measured by plaque hydroxyproline content, but not with deficiency of collagen cross-linking. Sirius red staining showed preservation of collagen originally covering the balloon and accumulation of nascent collagen in the lesions of standard chow-fed rabbits. In the cholesterol-fed group, both mature and new collagen underwent degradation predominantly in the plaque shoulders. Collagen breakdown was associated with local accumulation of foamy macrophages. Gel zymography demonstrated relative enhancement of gelatinolytic activity at 92 and 72 kDa, as well as caseinolytic activity at 57, 45, and 19 kDa in the lipid-laden plaques. Lipid accumulation in the plaque was also associated with a loss of smooth muscle cells, the cellular source of the collagen fibers. The remaining smooth muscle cells showed increased collagen synthesis, although it was insufficient to counterbalance collagen degradation and cell loss. Thus, we have obtained direct evidence that hypercholesterolemia is accompanied by enhanced local collagen degradation, which is potentially responsible for plaque weakening.

Animals↗
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Rumors of disease in the global village: outbreak verification.

Emerging infectious diseases and the growth of information technology have produced new demands and possibilities for disease surveillance and response. Increasing numbers of outbreak reports must be assessed rapidly so that control efforts can be initiated and unsubstantiated reports can be identified to protect countries from unnecessary economic damage. The World Health Organization has set up a process for timely outbreak verification to convert large amounts of data into accurate information for suitable action. We describe the context and processes of outbreak verification and information dissemination.

Communicable Disease Control↗
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Healthy communities: good mission, good sense. Holistic approach is the key.

Catholic healthcare's mission is keeping people healthy, and providers must listen closely to determine their needs in these fast-paced, stressful times. In a society preoccupied with technology and acute care, which has the least overall impact on people's health, providers must implement more preventive strategies. The shift to promoting community health will require diverse, creative approaches. Catholic facilities must offer holistic healing, becoming community resources for children and the elderly. Religious institutes also must prepare for the laity's increasing role in the ministry. Providers must develop initiatives that define Catholic healthcare, such as the Welfare-to-Work Program in St. Louis, which offers women employment opportunities and benefits as a starting point to gain control of their lives. With increased school collaboration, nurses can help children develop good health habits. The guiding vision must be the health of the whole person and the community. Catholic providers must restore public trust and confidence by emphasizing person-centered healthcare. Only by becoming an integral part of the community can Catholic healthcare make a difference in people's lives.

Catholicism↗
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Developing cryopreservation protocols to secure fungal gene function.

Protocols that involve a freezing process are frequently used for the preservation of fungi, but there have been few studies to assess the physiological and genetic stability of isolates after preservation. In this study, the effects of cryopreservation and lyophilisation on the viability, physiology and genetic stability of isolates of Metarhizium anisopliae, Fusarium oxysporum and Serpula lacrymans were examined. It was found that preservation regime influenced the characters of some of the test isolates. Secondary metabolite profiles and extracellular enzyme production can be affected by preservation. Polymorphism's were detected after PCR fingerprinting in replicates of 2 isolates of Metarhizium that had been preserved by cryopreservation and lyophilisation. The results indicated a need to improve existing preservation protocols. Research is being undertaken to develop novel cryopreservation regimes for recalcitrant micro-organisms. Biochemical and molecular techniques will be used to assess the effectiveness of preservation.

Cell Survival↗