Occupational stress of nurses in South Africa.

The objective of this study was to examine the construct validity and reliability of the Nursing Stress Indicator (NSI) and to identify differences between occupational stressors of professional and enrolled nurses. A cross-sectional survey design was used. A sample of professional nurses (N = 980) and enrolled and auxiliary nurses (N = 800) in South Africa was used. The NSI was developed as measuring instrument and administrated together with a biographical questionnaire. Five reliable stress factors, namely Patient Care, Job Demands, Lack of Support, Staff Issues, and Overtime were extracted. The most severe stressors for nurses included health risks posed by contact with patients, lack of recognition and insufficient staff. Watching patients suffer, demands of patients and staff issues were also severe stressors for professional nurses. The severity of stressors was higher for professional nurses (compared with enrolled and auxiliary nurses). Organisations that employ nurses should implement programmes to monitor and manage stress, specifically regarding staff issues and job demands.

Growth enhancement and serum replacement in cloning of murine mastocytoma and granulocyte/macrophage precursor cells: two distinct activities present in hemolysates.

In the present study we investigated the serum replacing and enhancing activities of erythrocyte lysates, obtained from different animal species, on the growth of murine mastocytoma cells and normal granulocyte/macrophage precursor cells (CFU-C) present in bone marrow. The soft agar technique for cloning hemopoietic cells in vitro was used to quantitate the growth of these cells in culture. Rat, rabbit, guinea pig, mouse and sheep hemolysates were tested for their capacity to replace or to enhance serum as a growth promoter. All hemolysates except mouse were able to replace serum efficiently when mastocytoma cells were cloned. On the other hand, only rat hemolysate proved to be efficient for cloning normal murine CFU-C. Since increasing the concentration of hemolysates in the soft agar medium did not change these results, the differences in activity are unlikely to reflect quantitative variations. However, hemolysates with little or no serum replacing capacity enhanced the clonal growth of normal CFU-C when added to small amounts (2.5%) of horse serum. Trypsin treatment of rat hemolysate destroyed its serum replacing capacity but not its enhancing activity. No correlation was found between the amount of hemoglobin and the replacing activity of each hemolysate. The data obtained in the present study point to the presence of at least two distinct activities in hemolysate: serum replacing and growth enhancing capacities.

Replacement of serum by hemolysate as growth promoter for murine leukemic and normal hemopoietic progenitor cells in culture.

The present study was undertaken to test whether lysates prepared from rat erythrocytes can replace serum as in vitro growth promoters for murine leukemic and normal hemopoietic progenitor cells (CFU-C). Normal bone marrow and three leukemic cell lines (P-1081, L-1210 and P-815) were used in all the experiments. The soft agar technique for cloning hemopoietic cells was used to quantitate cell proliferation. Addition of hemolysate to the agar medium at a final concentration of 4% promoted the growth of a maximal number of leukemic colonies, similar to the number of colonies obtained when 20% serum was added to the soft agar. As for normal CFU-C, addition of 10% hemolysate or 40% horse serum promoted the growth of comparable numbers of colonies. Rat hemolysate can therefore replace horse serum as a growth promoter of leukemic and normal CFU-C present in culture. It was also shown that rat hemolysate cannot substitute for the colony stimulating factor (CSF) needed for the cloning of CFU-C. However, addition of hemolysate, CSF and serum to the soft agar cultures promoted a potentiated rather than an additive growth of CFU-C.

Hemin stimulating effect on colony formation of leukemic and bone marrow cells.

The hemin enhancing activity on colony formation of leukemic and normal bone-marrow (BM) cells is described. The colony growth of Friend erythroleukemic cells (FL) and mastocytoma cells (M) was markedly enhanced. On the other hand, myeloid leukemic cells (P) and normal bone-marrow cells (BM) were only slightly affected. Inhibition of colony formation was observed with lymphoid leukemic cells (L). For M and BM cells, the horse serum could be replaced by BSA with preservation of hemin enhancing activity.

Contribution of secondaries to the radiation environment on space missions.

Calculations to predict the radiation environment for spacecraft in low earth orbit sometimes ignore the contribution from secondary radiation products. However, the contribution of secondaries, particularly neutrons, on heavy spacecraft or in planetary bodies can be of concern for biological systems. The Shuttle Activation Monitor (SAM) and Cosmic Radiation Effects and Activation Monitor (CREAM) experiments provide valuable data on secondary (as well as primary) radiation effects. Comparisons have been made between induced activity from flight-exposed samples, induced activity in a ground-irradiated sample, and Monte Carlo-derived predictions with and without secondaries. These comparisons show that for a flight-exposed sample, predictions which omit the secondary contribution result in a spectrum that is too low by a factor of 2. The addition of the secondaries results in a predicted spectrum that closely matches the measured data.

Primary care drug therapy training: the solution for PHC nurses?

The priority of the National Health System in South Africa is primary health care (PHC). The approach involves a health system led by PHC services and includes personal and curative services for acute minor ailments delivered by PHC nurses. The nurses are also responsible for the treatment of these ailments with essential drugs according to protocols as proposed in the Essential Drugs List. A before-after experimental research design was used to evaluate the effect of a competency-based primary care drug therapy (PCDT) training programme for PHC nurses in the treatment of acute minor ailments. An experimental group (n = 35) and control group (n = 31) consisting of registered nurses undergoing training in PHC at Gold Fields Nursing College were randomly selected. The results showed a significant increase in prescribing outcomes and medicine utilisation.

Synthetic peptide homologous to the envelope proteins of retroviruses shares a cross-reacting epitope with the CD4 receptor.

A synthetic peptide (CKS-17) homologous to a highly conserved region of the retroviral transmembrane protein p15E was tested for its effect on receptor expression on monocytes. The CKS-17 amino acid sequence is present in several retroviruses including human T-cell lymphotropic virus types I and II and human immunodeficiency virus. The CKS-17 peptide has been previously shown to inhibit monocyte superoxide production, natural killer cell activity, polyclonal B-cell activation, and monocyte-mediated killing by inactivation of interleukin-1. In this study, we demonstrated that the anti-CD4 monoclonal antibody OKT4 binds strongly in vitro to CKS-17-treated human blood monocytes, whereas other antibodies tested were not reactive. This observed binding was the result of direct interaction of OKT4 antibody with the CKS-17 peptide. Moreover, a partial homology was found in amino acid sequence analysis of the CD4 epitope and the CKS-17 peptide.

Biological activities of lipopolysaccharide fractionated by preparative acrylamide gel electrophoresis.

Lipopolysaccharide from a smooth strain of Salmonella minnesota was fractionated into two major fractions and one intermediate fraction by using sodium dodecylsulfate-polyacrylamide gel electrophoresis. On the basis of the study by Hitchcock and Brown, it was deduced that the top fraction was mainly long O-side chain LPS and the bottom fraction was O-side chain-less LPS. The middle fraction was a mixture of both short O-side chain LPS and O-side chain-less LPS. The antigenic properties and biological activities were not altered in this fractionation procedure. Comparison of the biological activities of the top fraction with those of the bottom fraction revealed that the bottom fraction had higher activity in polyclonal B-cell activation and spleen-swelling effect and that there was no significant difference in adjuvant activity, ability to render macrophages cytotoxic, induction of colony-stimulating factor and the ability to induce the Schwartzmann reaction. It was suggested that O-side chain makes no contribution to the latter biological activities including adjuvant activity of S. minnesota LPS.