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Biomedical subjects

S M Meyer

Publications and source records attributed to S M Meyer.

At least 19 recordsLinked to original sources
PubMed2001

A formative evaluation of a Web-based tutorial.

Lecturers of the Department of Nursing Science of the University of Pretoria (UP) were requested to participate in an informal evaluation of a software program. The software evaluated were developed as a tutorial by the author of this article. The content of the tutorial concerns the current issues of the new education and training dispensation in South Africa, and specifically how to compile unit standards to meet the requirements of the South African Qualifications Authority (SAQA) and the National Qualifications Framework (NQF). The purpose of the evaluation was to assess the quality of the software. Participants were provided with a questionnaire, as well as criteria for the evaluation of software as presented in literature and information on the Web. The feedback has been useful and suggestions made by the participants have been used to improve and add to the product.

Education, Nursing↗
PubMed2001

The adoption of technology in higher/nursing education.

This is a review article on the adoption of technology in higher education. Higher education in general is looked at. Nursing Education is also higher education and therefore it will not be addressed separately, but mentioned in some instances. The article presents a look into how students and lecturers experience change, as well as barriers they perceive in the integration and adoption of technology. Some suggestions are made to the adoption process as well as the necessity for personnel development in information technology. The role that Information Technology personnel play in the adoption and integration process of technology is also discussed.

Computer-Assisted Instruction↗
PubMed1998

Visualization and molecular analysis of actin assembly in living cells.

Actin filament assembly is critical for eukaryotic cell motility. Arp2/3 complex and capping protein (CP) regulate actin assembly in vitro. To understand how these proteins regulate the dynamics of actin filament assembly in a motile cell, we visualized their distribution in living fibroblasts using green flourescent protein (GFP) tagging. Both proteins were concentrated in motile regions at the cell periphery and at dynamic spots within the lamella. Actin assembly was required for the motility and dynamics of spots and for motility at the cell periphery. In permeabilized cells, rhodamine-actin assembled at the cell periphery and at spots, indicating that actin filament barbed ends were present at these locations. Inhibition of the Rho family GTPase rac1, and to a lesser extent cdc42 and RhoA, blocked motility at the cell periphery and the formation of spots. Increased expression of phosphatidylinositol 5-kinase promoted the movement of spots. Increased expression of LIM-kinase-1, which likely inactivates cofilin, decreased the frequency of moving spots and led to the formation of aggregates of GFP-CP. We conclude that spots, which appear as small projections on the surface by whole mount electron microscopy, represent sites of actin assembly where local and transient changes in the cortical actin cytoskeleton take place.

Actin Cytoskeleton↗
PubMed1998

A new structural class of proteasome inhibitors that prevent NF-kappa B activation.

The multicatalytic proteinase or proteasome is a highly conserved cellular structure that is responsible for the ATP-dependent proteolysis of many proteins involved in important regulatory cellular processes. We have identified a novel class of inhibitors of the chymotrypsin-like proteolytic activity of the 20S proteasome that exhibit IC50 values ranging from 0.1 to 0.5 microgram/mL (0.1 to 1 microM). In cell proliferation assays, these compounds inhibit growth with an IC50 ranging from 5 to 10 micrograms/mL (10-20 microM). A representative member of this class of inhibitors was tested in other biological assays. CVT-634 (5-methoxy-1-indanone-3-acetyl-leu-D-leu-1-indanylamide) prevented lipopolysaccharide (LPS), tumor necrosis factor (TNF)-, and phorbol ester-induced activation of nuclear factor kappa B (NF-kappa B) in vitro by preventing signal-induced degradation of I kappa B-alpha. In these studies, the I kappa B-alpha that accumulated was hyperphosphorylated, indicating that CVT-634 did not inhibit I kappa B-alpha kinase, the enzyme responsible for signal-induced phosphorylation of I kappa B-alpha. In vivo studies indicated that CVT-634 prevented LPS-induced TNF synthesis in a murine macrophage cell line. In addition, in mice pretreated with CVT-634 at 25 and 50 mg/kg and subsequently treated with LPS, serum TNF levels were significantly lower (225 +/- 59 and 83 +/- 41 pg/mL, respectively) than in those mice that were treated only with LPS (865 +/- 282 pg/mL). These studies suggest that specific inhibition of the chymotrypsin-like activity of the proteasome is sufficient to prevent signal-induced NF-kappa B activation and that the proteasome is a novel target for the identification of agents that may be useful in the treatment of diseases whose etiology is dependent upon the activation of NF-kappa B.

Adenosine Triphosphatases↗
PubMed1998

Contrasting the original Malcolm Baldrige National Quality Award and the Health Care Pilot Award.

In recent years, interest in establishing a separate health care category for the Malcolm Baldrige National Quality Award has grown. A 1995 pilot study evaluated a new set of award criteria specifically designed for the health care industry. The article discusses the similarities and differences between the two awards, including the factors that make quality management in the health care industry more complex.

Awards and Prizes↗
PubMed1996

Direct in vivo effects of nitric oxide on the coronary circulation.

To determine the direct in vivo effects of nitric oxide (NO) on the coronary circulation, we infused NO-saturated saline (1.0 +/- 0.1 mmol/l) into the coronary arteries of anesthetized dogs and measured changes in coronary blood flow velocity (CBFV) with a Doppler catheter, changes in coronary artery size with quantitative angiography, and transmural myocardial perfusion with radioactive microspheres. Boluses of NO (1-8 micromol) caused a stepwise increase in CBFV (3.1 +/- 0.3 x basal CBFV at 8 micromol) similar to that caused by adenosine (2.6 +/- 0.3 x basal CBFV, maximal dose). Continuous subselective infusions (0.1, 1.0, and 4.0 micromol/min) caused dose-dependent increases in CBFV (2.2 +/- 0.3 x basal CBFV at 4.0 micromol/min) and in epicardial artery diameter (+ 15 +/- 6% diam). Left main infusions (8 micromol/min) caused a stepwise increase in CBFV and in the endocardial-to-epicardial flow ratio without affecting systemic hemodynamics. Brief infusion of NO (2 min) did not significantly reduce acetylcholine-mediated endothelial NO release. Therefore, despite rapid metabolism, direct intra-arterial infusion of NO can be given at a rate sufficient to overwhelm metabolic elimination, providing direct evidence that NO is a potent in vivo coronary vasodilator. Moreover, the enhanced subendocardial vasodilator response to direct NO infusion suggests increased regional sensitivity to NO.

Animals↗
PubMed1995

The hazards of chloroquine self prescription in west Africa.

We report a severe accidental chloroquine poisoning in a West African adult. This intoxication results from the widespread practice in Senegal of taking mild doses of chloroquine for a few days (i.e. 300 mg x 3 for 3 or 5 days) following the onset of any fever suspected of being a malaria attack. To our knowledge, this practice and this kind of poisoning have not been reported before. The present clinical case demonstrated that self-medication can be the cause of severe chloroquine poisoning responsible for arrhythmia (torsades de pointes). In this clinical case, no diazepam was administered. However, there were no further problems and the patient was discharged three days after admission to the intensive care unit.

Aged↗
PubMed1992

Efficacy and safety of lodoxamide 0.1% vs cromolyn sodium 4% in patients with vernal keratoconjunctivitis.

A multicenter, double-masked, parallel-group clinical study compared the efficacy and safety of lodoxamide 0.1% ophthalmic solution and cromolyn sodium 4% ophthalmic solution in 120 patients with vernal keratoconjunctivitis. On various follow-up visits, the clinical efficacy of lodoxamide 0.1% was statistically superior to cromolyn sodium 4% in alleviating four of the primary symptoms (itching, tearing, foreign-body sensation, and discomfort) and five of the primary signs (Trantas' dots, palpebral conjunctival changes, bulbar conjunctival hyperemia, erythema/swelling of the eyelids and periorbital tissues, and epithelial disease). At no time during the study was cromolyn sodium 4% statistically superior to lodoxamide 0.1% in demonstrating improvements in clinical signs and symptoms of vernal keratoconjunctivitis. The physician's clinical judgment of patients' response to treatment showed lodoxamide 0.1% effected a greater and earlier improvement than cromolyn sodium 4%. Both drugs were safe for topical ophthalmic use when used four times daily for up to 28 days.

Adolescent↗
PubMed1990

Expression of Ly-6C by T lymphocytes of NOD mice after CD3-complex stimulation. Identification of activated cells during insulitis of prediabetic mice.

Ly-6C is a differentiation antigen that distinguishes T-lymphocyte subsets. In concordance with previous results, splenocytes from NOD mice do not express the epitope recognized by anti-Ly-6C monoclonal antibodies (MoAbs), including MoAb HK1.4 in this study, and cannot be stimulated to proliferate in response to HK1.4. However, when splenocytes from NOD mice were stimulated in vitro with the anti-CD3 MoAb 145-2C11, T lymphocytes expressing Ly-6C were detected after 48 h of stimulation, with as many as 25% of lymphocytes expressing this antigen with prolonged passage in culture. Most of the cells expressing Ly-6C were Thy-1.2+, CD4+, and CD8- and proliferated after stimulation with HK1.4. To further understand the failure of NOD splenocytes to express Ly-6C, freshly isolated cells were stimulated with alpha/beta-interferon (IFN-alpha/beta) and IFN-gamma. Although these lymphokines induced expression of Ly-6A and Ly-6C in splenocytes from C57BL/6J mice and Ly-6A in NOD cells, Ly-6C was not induced on NOD cells. Because Ly-6C expression on splenocytes was a marker of activation via the CD3 T-lymphocyte receptor complex, we also examined expression of Ly-6C on T lymphocytes within islets showing insulitis in vivo. Lymphocytes that were Ly-6C+ were identified within islets on histological sections of pancreas, whereas Ly-6C+ cells in the spleen from the same mouse could not be detected. Our findings imply functional abnormality in expression of Ly-6C in NOD mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Systemic side effects from ophthalmic timolol and their prevention.

Topically applied ophthalmic drugs can occasionally produce adverse systemic effects due to systemic absorption of the drug or impediment of the drug's metabolism. Increasing evidence points to significant adverse systemic effects from topical ocular administration of timolol, a beta-adrenergic blocking agent marketed for the treatment of glaucoma. Various methods to decrease or avoid unwanted systemic effects from eyedrops are discussed, including avoidance of overdosage and how to apply eye medications.

Absorption↗
PubMed1987

Psychiatric side effects from topical ocular timolol, a beta-adrenergic blocker.

Neuropsychiatric side effects have been reported with various systemic betablockers. Data submitted to the National Registry of Drug-Induced Ocular Side Effects appear to indicate similar adverse reactions secondary to topical ophthalmic timolol. One hundred sixty-three of 369 central nervous system cases (44%) reported depression, psychosis, confusion, and hallucinations following topical ophthalmic timolol administration. The psychiatric community should be aware that sudden changes in mental status or onset of common psychiatric conditions, such as depression, may be due to topical ocular timolol. Withdrawal of the drug usually results in disappearance of these effects in 1 to 7 days.

Aged↗
PubMed1985

Adverse ocular reactions possibly associated with isotretinoin.

A total of 261 adverse ocular reactions occurred in 237 patients who received isotretinoin, a commonly used drug in the treatment of severe cystic acne. Blepharoconjunctivitis, subjective complaints of dry eyes, blurred vision, contact lens intolerance, and photodermatitis are reversible side effects. More serious ocular adverse reactions include papilledema, pseudotumor cerebri, and white or gray subepithelial corneal opacities; all of these are reversible if the drug is discontinued. Reported cases of decreased dark adaptation are under investigation. Isotretinoin is contraindicated in pregnancy because of the many reported congenital abnormalities after maternal use (including microphthalmos, orbital hypertelorism, and optic nerve hypoplasia).

Acne Vulgaris↗