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Biomedical subjects

C McKenzie

Publications and source records attributed to C McKenzie.

At least 19 recordsLinked to original sources
PubMed1997

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin.

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.

Adaptation, Ocular↗
PubMed1997

Pancreatic spasmolytic polypeptide protects the gastric mucosa but does not inhibit acid secretion or motility.

The objectives of these studies were to examine whether the trefoil peptide porcine pancreatic spasmolytic polypeptide (PSP) had gastric mucosal protectant properties similar to its human equivalent human spasmolytic polypeptide (hSP) and to confirm the antisecretory and antimotility action of the peptide. PSP and recombinant hSP reduced gastric mucosal damage caused by a combination of subcutaneous indomethacin and restraint stress in the conscious rat. At a dose of 500 micrograms/kg bolus plus 500 micrograms.kg-1.h-1 sc, PSP significantly reduced the total area of damage by 58%. PSP at a dose of 150 micrograms/kg iv had no inhibitory effect on pentagastrin-stimulated gastric acid secretion in the perfused stomachs of anesthetized rats. This lack of antisecretory activity was confirmed in vitro using an isolated stomach preparation from the immature rat. PSP and hSP at concentrations up to 800 nM did not inhibit electrically or chemically evoked contractions of the guinea pig ileum and duodenum in vitro. Thus antisecretory and antimotility actions do not underlie the mucosal protectant properties of PSP. PSP did, however, stimulate cell migration, and this may, at least in part, account for its protectant properties.

Animals↗
PubMed1996

Second licensure for advanced practice: current status.

This article provides a through update of second licensure for advanced practice nurses. The National Council of State Boards of Nursing (NCSBN) has proposed new requirements for legislation and licensure for advanced practice nurses. This proposal could have major repercussions for all advanced practice nurses, depending on whether the state boards of nursing adopt the council's recommendation. A review of the historical aspect and the development of nursing licensure is reported. Both the 1992 and 1995 second licensure proposals are analyzed. Support for and dissent against the proposals by nursing organizations and individuals in the nursing community are included. The current status of the proposal for second licensure by the National Council of State Boards of Nursing is high-lighted.

Humans↗
PubMed1994

Developing and implementing a user-driven departmental database system--implications for the Royal College of Radiologists' COIN proposal.

With the increasing availability of computers, more departments are using word processors in place of typewriters. In the course of typing patient discharge summaries and letters, a large amount of information of potential use for audit or research purposes is entered into the computer but in a form inaccessible for analysis. We have developed a data-base system, based on information entered by departmental staff in the course of their work, rather than by designated data managers. The aim of the system is to replace word-processed clinical summaries. We describe the design, implementation and possible advantages and disadvantages of such a system and implications for the COIN proposal of the Royal College of Radiologists.

Computer Communication Networks↗
PubMed1992

Hepatitis B vaccination: a survey of health care workers' knowledge and acceptance.

The purpose of this survey was to determine methods to improve compliance and knowledge related to Hepatitis B vaccination. A self administered questionnaire was distributed to employees of a large metropolitan hospital. The survey asked for information about the health care workers' acceptance of Hepatitis B vaccination and knowledge of appropriate follow up after a significant blood exposure occurs. According to the results, 45% of employees at risk for contracting HBV have not received the vaccination. Findings related to the methods of follow up used by employees after a blood exposure indicate a lack of knowledge about HBV. The results of this survey support the need for further education about the risk of occupationally acquired HBV.

Data Collection↗
PubMed1991

Uterine leiomyosarcoma with massive necrosis diagnosed during gonadotropin-releasing hormone analog therapy for presumed uterine fibroid.

Recurrence of heavy vaginal bleeding and massive necrosis of a uterine leiomyosarcoma are reported in a 41-year-old female who was being treated with GnRH-a for a presumed uterine fibroid. The pathogenic mechanisms of such an event are reviewed and discussed in light of the available literature on the subject of GnRH-a and the treatment of uterine smooth muscle neoplasms.

Adult↗
PubMed1990

Permethrin metabolism in pyrethroid-resistant adults of the horn fly (Muscidae: Diptera).

The in vivo metabolism of topically applied 14C-permethrin was determined for adults of pyrethroid-resistant and -susceptible horn flies, Haematobia irritans (L.) at 1, 2, and 6 h after treatment. At 1 and 2 h after treatment, resistant horn flies had significantly higher internal levels of radioactivity (permethrin plus metabolites) compared with adults of the susceptible strain. Analysis of the internal extracts by thin-layer chromatography indicated no differences in the levels of permethrin. However, significantly higher levels of metabolites that co-chromatograph with 3-(2'- or 4'-hydroxyphenoxy)benzyl (1RS) cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate at 1 and 2 h after treatment and (1RS) cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid at 1 h after treatment. These results demonstrate that an enhanced penetration and metabolism are present during the early phases of permethrin intoxication. Enhanced metabolism may contribute to the ability of resistant horn flies to survive in the presence of pyrethroids.

Animals↗
PubMed1988

Role of cystourethrography in the preoperative evaluation of stress urinary incontinence in women.

Thirty-two women with stress urinary incontinence and 27 control continent patients with pelvic relaxation underwent a detailed clinical and urodynamic evaluation of the lower urinary tract. All patients underwent a standard chain urethrocystographic evaluation to detect anatomic pathology of the lower urinary tract. Urethrocystographic study included an evaluation of the posterior and anterior urethral angle, funneling of the proximal urethra on straining, the position of the urethrovesical junction and flattening of the bladder base. No differences were seen in the incidence of radiographic findings in women with pelvic relaxation with or without stress urinary incontinence. All five cystographic criteria were similar in the continent and stress incontinence patients. Static urethrocystography cannot differentiate women with and without stress urinary incontinence from among those with pelvic relaxation and thus should not be relied upon in the evaluation of women with urinary incontinence.

Adult↗
PubMed1986

First-trimester fetal diagnosis for haemoglobinopathies: report on 200 cases.

First-trimester prenatal diagnosis by DNA analysis was found to be possible in 224 (80%) of 281 families at risk of having a child with beta-thalassaemia major. 200 prenatal diagnoses, mainly for beta-thalassaemia or sickle-cell anaemia, were made by means of chorionic villus sampling and fetal DNA analysis. The overall fetal loss rate was 6.7%, the majority being in the first half of the programme. There was one misdiagnosis. Prenatal diagnosis was also carried out successfully for both pairs of twins in two pregnancies. Comparison of these results with 53 prenatal diagnoses made with DNA prepared from amniotic fluid suggests that the first-trimester procedure is more reliable. If further experience confirms that chorionic villus sampling has an acceptably low risk for both mother and fetus it will largely replace other methods for prenatal diagnosis of the haemoglobin disorders and other single-gene conditions.

Amniotic Fluid↗
PubMed1983

Lymphoma-like presentation of acute monocytic leukaemia.

Four patients in whom a diagnosis of acute monocytic leukaemia (M5) was subsequently made presented with extramedullary disease clinically resembling lymphoma. In all patients histological sections were initially misinterpreted as showing malignant lymphoma or anaplastic carcinoma. The diagnosis of M5 leukaemia was subsequently made on the basis of morphological and cytochemical studies of peripheral blood and bone marrow. The histological diagnosis of the soft tissue lesions of M5 leukaemia (monocytic sarcoma) is difficult, although features such as abundant cytoplasm and the presence of some reniform nuclei are helpful. If there is no peripheral blood or bone marrow involvement and only fixed paraffin-embedded tissues are available, demonstration of lysozyme by an immunoperoxidase technique may confirm the diagnosis but results are not invariably positive. An early diagnosis of M5 leukaemia has therapeutic implications since the disease evolves through a progressive leukaemia phase and systemic therapy is essential.

Adolescent↗