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Tulbaghia is known to have antifungal properties that can be used in the treatment of both human and plant pathogens and is used in traditional medicine in South Africa. Increasing demands for plant material makes it necessary to cultivate this species on a large scale. Unfortunately, cultivation can lead to a reduction in the biological activity of plants making them unsuitable for use. In light of the lack of knowledge regarding the agronomic requirements of this plant, the aim of this study was to determine the effect of several rates and two forms of nitrogenous fertilizer on the yield and biological activity of Tulbaghia violacea. Plants were cultivated in sand while the basic fertilization used was the same as that of garlic (20 kg P ha-1, 75 kg K ha-1), a plant from the same family, containing similar active ingredients. Nitrogen was applied once at the beginning of the trial at rates of 30, 60, 120, and 180 kg ha-1 in the form of either nitrate or ammonium. Vegetative growth was quantified in terms of number of leaves and leaf area as well as root and leaf dry mass, while harvested material was tested for antifungal activity. The results indicated that compared with the untreated control, increasing N-rates in both the nitrate and ammonium forms increased leaf number and leaf area as well as both root and leaf dry mass. However, at a rate above 60 kg ha-1, and especially at 180 kg ha-1, the nitrate form stimulated growth more markedly than the ammonium form, whereas antifungal activity decreased sharply and almost linearly as the application rate was increased. Although growth was not stimulated to the same extent by the ammonium form, it increased the in-vitro antifungal activity at different levels during different times of the growing season. From an ornamental perspective, nitrate is the preferred nitrogenous form but, from a bioactivity perspective, ammonium is recommended. [ABSTRACT FROM AUTHOR]

Abstract: The Livingstone potato (Plectranthus esculentus N.E.Br.) produces a cluster of edible tubers at the base of the stem that are used as a potato substitute in many areas of Africa. No information is available on factors affecting tuberization in this species. Photoperiod is known to influence storage organ formation in a wide range of crops, and pilot trials indicated that it also played a role in tuberization in P. esculentus. The critical photoperiod for tuber induction, as well as the number of short-day cycles required to induce tubers, were investigated in glasshouse trials using in vitro plants. Nine photoperiod treatments (30-min intervals from 10 to 14h of light) were applied in the critical photoperiod experiment. To determine the number of short-day cycles required to induce tuberization, plants were exposed to short days (10h light) for periods ranging from 0 to 20 days at 2-day intervals. Data were collected from both intact plants and sub-apical two-node cuttings made after the experimental treatments were completed. The critical photoperiod for the specific genotype used in this study was between 12.5 and 13h, with cuttings giving a slightly exaggerated result over that of intact plants. It was established that exposure to four short-day cycles was sufficient to induce tuberization in this species. [Copyright &y& Elsevier]

Africa, including South Africa, is faced with a problem of increasing rural poverty that leads to increasing urbanisation, joblessness, crime, food insecurity and malnutrition. Root and tuber crops such as sweet potato and potato, as well as cassava and indigenous potato are important crops for food security. The latter are also important due to their tolerance to marginal conditions. Potato and sweet potato are of great economic value in South Africa, with well-organised marketing chains and, for potato, a large processing industry. There is one cassava starch extraction factory in operation in South Africa. A number of diseases are of importance in potato in South Africa: early blight, late blight, bacterial wilt, scab and virus. Insect pests such as tuber moth and leaf miner are also constraints. In sweet potato the occurrence of viruses and weevils, as well as the availability of healthy planting material are the most important limiting factors in production. African Cassava Mosaic Disease (CMD) caused by a virus, is a problem in growing cassava. Plant biotechnology applications offer a number of sustainable solutions. Basic applications such as in vitro genebanking where large numbers of accessions can be maintained in a small space, meristem cultures to produce virus-free plants and mass propagation of popular cultivars in order to make planting material available for sustainable production. More advanced biotechnology applications that may be of value are molecular marker technology and genetic engineering. The latter can play a role in overcoming virus and potato tuber moth in potato, in resistance to CMD in cassava and possibly in sweet potato to incorporate virus and weevil resistance. [ABSTRACT FROM AUTHOR]

Plectranthus esculentus N.E.Br. is a member of the family Lamiaceae, to which many aromatic plants such as the mints and sages belong. It differs from most members of the family in that it produces tuberous subterranean organs at the base of the stem, which can weigh as much as 1.8 kg per tuber. These organs are often used by local people as a food source. Storage organs in plants can be modified roots (carrot and sweet potato), stems (potato), or composed of leave bases (onion). In the case of P. esculentus, there is a difference of opinion as to the exact ontogenetic origin of these organs, and whether they are roots, rhizomes, underground stems or root tubers. According to our observations, these tuberous, positively geotropic organs develop from axillary buds at the base of the stem, and even axillary buds along aerial parts of the stem. Their branching pattern follows the decussate phyllotaxis of the species, and flowering of some tubers has been observed. Anatomical studies show the presence of both primary and secondary vascular bundles arranged in a ring of vascular tissue. Therefore, these organs are true stem tubers. [Copyright &y& Elsevier]

Photodynamic diagnosis is of increasing interest for diagnosis in oncology. It is based on a more intense incorporation of a fluorescent dye in tumours compared to normal tissue. As a feasibility study we investigated the effectiveness of oral application of 5-aminolevulinic acid for photodynamic diagnosis of human primary mammary tumours. The study included 16 patients with palpable breast tumours. Aminolevulinic acid was administered at a concentration of 40 mg kg[SUP-1] bodyweight 150-420 min prior to tumourectomy. Intraoperatively blue light (405 nm) was applied to the operation site. Sections of the excised tumour and some lymph nodes were prepared and analysed with a fluorescent microscope. All primary mammary tumour tissues showed significantly higher fluorescence intensity than surrounding normal mammary tissue. Fluorescence of the mammary tumours could also be discriminated macroscopically and intraoperatively. Fluorescence intensity in nonmetastatic lymph node tissue was higher in 2 out of 3 patients than in primary tumour tissue. By photodynamic diagnosis using aminolevulinic acid we were able to reliably distinguish primary mammary tumours from normal mammary tissue microscopically and macroscopically in all our patients. We suggest that photodynamic diagnosis with aminolevulinic acid for breast tumours should be further investigated and developed for intraoperative use and may well be a simple tool for better intraoperative diagnosis and recognition of tumour margins. We hypothesize that lymph node metastasis of breast tumours will not be detectable by this method. [ABSTRACT FROM AUTHOR]

A case of Ollier's disease is demonstrated. Large osteolytic lesions in the left femur and hemipelvis visible on the roentgenograms represent enchondromas. On CT and MRI studies numerous fine translucencies are demonstrated in the surrounding bone, corresponding to multiple cartilaginous foci. These findings may be considered pathognomonic for enchondromatosis (Ollier's disease). In addition, the nature of Ollier's disease and its predilection for malignant transformation are considered. The major differential diagnostic entity in this case was probably fibrous dysplasia. [ABSTRACT FROM AUTHOR]

PLECTRANTHUS ESCULENTUS IS AN INDIGEnous African plant, belonging to the Lamiaceae family, that produces edible tubers. The species is widespread throughout Africa and is used as a potato substitute, being eaten raw, boiled, or cooked as a vegetable. Chemical analysis of the raw tubers gave crude protein, crude lipid and crude carbohydrate values of 13.5, 0.6 and 81.4 g per 100 g, respectively. The tubers contained 140.3, 50.4 and 0.17 mg per 100 g of Ca, Fe and vitamin A, respectively, indicating that the tubers can be a potential source of elements and compounds which are often deficient in the diet of rural South Africans. The levels of seven of the eight essential amino acids are higher than the FAO recommended values, with isoleucine being slightly lower. These concentrations are higher than those of other root and tuber crops such as the Irish potato, sweet potato, taro and cassava, and indicate that this vegetable as a food item can assist in alleviating malnutrition. [ABSTRACT FROM AUTHOR]

A 38-year-old female is described, who was admitted with increasing respiratory distress, cough and visible blood stasis in the jugular veins. The most likely diagnosis in this young women taking oral contraceptives was pulmonary embolism, however, a ventilation-perfusion lung scan was normal. Echocardiography showed a dilated right ventricle and increased systolic pulmonary pressure. Despite administration of oxygen and intravenous heparin the patient died in circulatory collapse before further investigations could be initiated. Post-mortem examination revealed diffuse adenocarcinoma of the stomach (linitis plastica) with metastasis to local lymphnodes, lymphangiosis carcinomatosa of the liver, pancreas and spleen and tumour cell masses within the lumen of small pulmonary arteries leading to variable occlusions of the vessels. Fibrocellular intimal proliferation was found, leading to further obstruction and increased resistance to flow through the pulmonary vascular bed and to subacute cor pulmonale. [ABSTRACT FROM AUTHOR]