Occupational exposure of midwives to nitrous oxide on delivery suites.

AIMS: To compare environmental and biological monitoring of midwives for nitrous oxide in a delivery suite environment. METHODS: Environmental samples were taken over a period of four hours using passive diffusion tubes. Urine measurements were taken at the start of the shift and after four hours. RESULTS: Environmental levels exceeded the legal occupational exposure standards for nitrous oxide (100 ppm over an 8 hour time weighted average) in 35 of 46 midwife shifts monitored. There was a high correlation between personal environmental concentrations and biological uptake of nitrous oxide for those midwives with no body burden of nitrous oxide at the start of a shift, but not for others. CONCLUSIONS: Greater engineering control measures are needed to reduce daily exposure to midwives to below the occupational exposure standard. Further investigation of the toxicokinetics of nitrous oxide is needed.

Preliminary screening of some traditional Zulu medicinal plants for antineoplastic activities versus the HepG2 cell line.

Aqueous and methanol extracts of nine traditional Zulu medicinal plants, Cissus quandrangularis L., Cyphostemma flaviflorum (Sprague) Descoings, Cyphostemma lanigerum (Harv.) Descoings ex Wild & Drum, Cyphostemma natalitium (Szyszyl.) J. v. d. Merwe, Cyphostemma sp., Rhoicissus digitata (L. F.) Gilg & Brandt, Rhoicissus rhomboidea (E. Mey. Ex harv.) Planch, Rhoicissus tomentosa (Lam.) Wild & Drum, R. tridentata (L. F.) Wild & Drum and Rhoicissus tridentata (L. F.) Wild & Drum subsp. cuneifolia (Eckl. & Zeyh.) N. R. Urton, all belonging to the Vitaceae family, were evaluated to determine their therapeutic potentials as antineoplastic agents. The antiproliferative activity in vitro against HepG2 cells was determined. Twenty-two of the twenty-seven crude plant extracts showed activities ranging from 25% to 97% inhibition of proliferation when compared with the control which showed no inhibitory activity. Higher degrees of growth inhibition were found in aqueous root extracts in comparison with the methanol extracts of the same plant parts. The results show potential antineoplastic activity, indicating some scientific validation for traditional usage.

Preliminary screening of some traditional zulu medicinal plants for anti-inflammatory and anti-microbial activities.

Aqueous and methanolic extracts from different parts of nine traditional Zulu medicinal plants, of the Vitaceae from KwaZulu-Natal, South Africa were evaluated for therapeutic potential as anti-inflammatory and anti-microbial agents. Of the twenty-nine crude extracts assayed for prostaglandin synthesis inhibitors, only five methanolic extracts of Cyphostemma natalitium-root, Rhoicissus digitata-leaf, R. rhomboidea-root, R. tomentosa-leaf/stem and R. tridentata-root showed significant inhibition of cyclo-oxygenase (COX-1). The extracts of R. digitata-leaf and of R. rhomboidea-root exhibited the highest inhibition of prostaglandin synthesis with 53 and 56%, respectively. The results suggest that Rhoicissus digitata leaves and of Rhoicissus rhomboidea roots may have the potential to be used as anti-inflammatory agents. All the screened plant extracts showed some degrees of anti-microbial activity against gram-positive and gram-negative microorganisms. The methanolic extracts of C. natalitium-stem and root, R. rhomboidea-root, and R. tomentosa-leaf/stem, showed different anti-microbial activities against almost all micro-organisms tested. Generally, these plant extracts inhibited the gram-positive micro-organisms more than the gram-negative ones. Several plant extracts inhibited the growth of Candida albicans while only one plant extract showed inhibitory activity against Saccharomyces cerevisiae. All the plant extracts which demonstrated good anti-inflammatory activities also showed better inhibitory activity against Candida albicans.

Screening of Zulu medicinal plants for prostaglandin-synthesis inhibitors.

Aqueous and ethanolic extracts of 39 plants used in traditional Zulu medicine to treat headache or inflammatory diseases were screened for prostaglandin-synthesis inhibitors. Extracts were tested in an in vitro assay for cyclooxygenase inhibitors. In general, ethanolic extracts caused higher inhibition than aqueous extracts. Two-thirds of the plants screened had high inhibitory activity. The highest inhibition was obtained with ethanolic extracts of Bidens pilosa, Eucomis autumnalis, Harpephyllum caffrum, Helichrysum nudifolium, Leonotis intermedia, L. leonorus, Ocotea bullata, Rumex saggitatus, Solanum mauritianum, Synadenium cupulare and Trichilia dregeana.

Plants used for stress-related ailments in traditional Zulu, Xhosa and Sotho medicine. Part 1: Plants used for headaches.

The usage and indications of possible therapeutic and harmful effects of 96 plants reported to be used for headaches in traditional Zulu, Xhosa and Sotho medicine are reviewed. Although few pharmacological studies have been undertaken on the plants used, related usage by other ethnic groups and known properties in related plants indicate significant possible analgesic, decongestant, anti-inflammatory, antispasmodic or sedative properties. Observations made by healers indicate an acute awareness of some of the potentially toxic compounds likely to be found in the plants. Most of the medicines are snuffed or inhaled. Both the routes of administration and the plants used merit further investigation.

Preparation and reactivities of anti-porcine CD44 monoclonal antibodies.

Five monoclonal antibodies (MoAbs) were raised against porcine soluble CD44. The MoAbs recognized the same antigen on the surface of porcine lymphocytes as was recognized by anti-human CD44 MoAb Hermes-1, but identified five different epitopes. They bound to most porcine leucocytes but not to red cells. The epitopes were susceptible to treatment with papain or bromelain, whereas trypsinization of porcine leucocytes only reduced the antigen density. The epitopes seem to be co-expressed among various lymphoid tissues. The MoAbs also cross-reacted to various degrees with leucocytes of humans, dogs, sheep, cattle, goats and horses, suggesting that the corresponding epitopes are differentially conserved among species.

Subsets of null and gamma delta T-cell receptor+ T lymphocytes in the blood of young pigs identified by specific monoclonal antibodies.

Rat monoclonal antibodies (mAb) against isolated pig Null T cells were derived using a novel two-colour cytofluorometric assay. One (MAC320) identified all blood CD2-sIg- 'Null' cells (present at up to approximately 6 x 10(6)/ml). Another type (MAC319 and MAC318) identified a subset comprising approximately 60% or approximately 30% of the Null cell population. This percentage appears genetically determined. This subset partially overlapped with a gamma delta T-cell receptor+ (TcR+) population which consisted of approximately 40% of Null T cells. The antibodies did not react with other leucocyte or lymphocyte populations. In non-reducing conditions, MAC320 precipitated two molecules at approximately 270,000-280,000 MW in SDS-PAGE; the larger of which was also precipitated by MAC319 (and MAC318, which binds to the same epitope). Under reducing conditions, MAC320 immunoprecipitated two or three polypeptide chains at approximately 130,000-160,000 MW; MAC319 precipitated only the largest of these polypeptides. The large MAC319+ MAC320+ molecule on one subset is removed by bromelain treatment; the smaller MAC319- MAC320+ molecule on the remaining Null cells is not bromelain sensitive. Several properties of this new antigen complex specific to pig Null T cells show that it is distinct from the ruminant T19 complex.

Observations on the use of some known and suspected toxic Liliiflorae in Zulu and Xhosa medicine.

The usage as well as some of the known family chemical characteristics of Xhosa and Zulu traditional medicinal plants belonging to various families of the superorder Liliiflorae are related to some of the clinical effects of Xhosa medicine observed by Solleder in 1972. Symptoms and effects of some fatal cases of human and animal poisoning are tabled. Fewer cases of acute poisoning appear to take place than might be expected. If hospital staff were seen to be more understanding in their attitude towards herbal medicine, tracing and eventually discouraging the use of harmful plants and practices might be easier.