The use of DNA markers in the pre-clinical diagnosis of familial adenomatous polyposis in families in South Africa

No Abstract

Strengthening impact assessment: a call for integration and focus

We suggest that the impact assessment community has lost its way based on our observation that impact assessment is under attack because of a perceived lack of efficiency. Specifically, we contend that the proliferation of different impact assessment types creates separate silos of expertise and feeds arguments for not only a lack of efficiency but also a lack of effectiveness of the process through excessive specialisation and a lack of interdisciplinary practice. We propose that the solution is a return to the basics of impact assessment with a call for increased integration around the goal of sustainable development and focus through better scoping. We rehearse and rebut counter arguments covering silo-based expertise, advocacy, democracy, sustainability understanding and communication. We call on the impact assessment community to rise to the challenge of increasing integration and focus, and to engage in the debate about the means of strengthening impact assessment

Books

Technology in blood transfusion Clinical Haemotology. Vol. 3 No. 2. Blood Transfusion: The Impact of New Technologies. Ed. by Marcela Contreras. pp. x + 482. illustrated. R22,SO. Kent: Harcourt Brace Jovanovich. 1990.Oncology International Classification of Diseases for Oncology. 2nd ed. Ed. By C. Percy, V. van Holten and C. Muir. pp. xiv + 144. Geneva: WHO. 1990.Chronic fatigue syndrome Chronic Fatigue Syndrome: The Stnlggle for Health. Ed. by Jay A. Goldstein. pp. xiv + 177. illustrated. Beverley Hills: Chronic Fatigue Syndrome Institute. 1990. Respiratory medicineRespiratory Medicine. Ed. by R. A. L. Brewis, G. J. Gibson and D. M. Geddes. pp. xxi + 1559. illustrated. R85. London: Bailliere, Tindall. 1990.Cardiac hypertrophy and failure Research in Cardiac Hypertrophy and Failure. Ed. by B. Swynghedauw. pp. xvi + 696. illustrated. £65. London: John Libbey. 1990.Reconstructive surgery in gynaecology Reconstructive Surgery in Gynaecology. Red. deur P. G. Knapstein, V. Friedberg and B-U. Sevin. pp. xii + 281. illustrated. DM 298. Smttgart: Georg Thieme Verlag. 1990.Menslike anatomie Basiese Menslike Anatomie. Red. deur Linda de Jager. pp. 204, illustrated. Wetton: Juta. 1990. GIFT: from basics to clinics GIFr: From Basics to Clinics. Red. deur G. L. Capitanio, R. H. Asch, L. de Cecco and S. Croce. New York: Serono Symposia Publications from Raven Press.Environmental health Environmental Health Criteria. No. 88: Polychlorinated Dibenzopara-dioxins and Dibenzofurans. pp. 409. illustrated. Geneva: WHO. 1989.Genetic engineering Reshaping Life: Key Issues in Genetic Engineering. 2nd ed. Ed. by G. J. V. Nossal and Ross L. Coppel. pp. xii + 179. Australia: Cambridge University Press. 1989.Doctor-patient communication Talking With Patients: A Basic Clinical skin. Ed. by Philip R. Myerscough. pp. I + 148. illustrated. Oxford: Oxford University Press. 1989.

Determinants of Persistence and Tolerance of Carnivores on Namibian Ranches: Implications for Conservation on Southern African Private Lands

Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large carnivores. Cheetahs (Acinonyx jubatus), leopards (Panthera pardus) and brown hyaenas (Hyaena brunnea) were widely distributed on Namibian farmlands, spotted hyaenas (Crocuta crocuta) had a narrower distribution, and wild dogs (Lycaon pictus) and lions (Panthera leo) are largely limited to areas near source populations. Farmers were most tolerant of leopards and least tolerant of lions, wild dogs and spotted hyaenas. Several factors relating to land use correlated consistently with carnivore-presence and landowner tolerance. Carnivores were more commonly present and/or tolerated where; wildlife diversity and biomass were higher; income from wildlife was higher; income from livestock was lower; livestock biomass was lower; in conservancies; game fencing was absent; and financial losses from livestock depredation were lower. Efforts to create conditions whereby the costs associated with carnivores are lowest, and which confer financial value to them are likely to be the most effective means of promoting carnivore conservation. Such conditions are achieved where land owners pool land to create conservancies where livestock are replaced with wildlife (or where livestock husbandry is improved) and where wildlife generates a significant proportion of ranch income. Additional measures, such as promoting improved livestock husbandry and educational outreach efforts may also help achieve coexistence with carnivores. Our findings provide insights into conditions more conducive to the persistence of and tolerance towards large carnivores might be increased on private (and even communal) lands in Namibia, elsewhere in southern and East Africa and other parts of the world where carnivore conservation is being attempted on private lands

Benefits of wildlife-based land uses on private lands in Namibia and limitations affecting their development

Legislative changes during the 1960s–1970s granted user rights over wildlife to landowners in southern Africa, resulting in a shift from livestock farming to wildlifebased land uses. Few comprehensive assessments of such land uses on private land in southern Africa have been conducted and the associated benefits are not always acknowledged by politicians. Nonetheless, wildlife-based land uses are growing in prevalence on private land. In Namibia wildlife-based land use occurs over c. 287,000 km2. Employment is positively related to income from ecotourism and negatively related to income from livestock. While 87% of meat from livestock is exported $95% of venison from wildlife-based land uses remains within the country, contributing to food security. Wildlife populations are increasing with expansion of wildlife-based land uses, and private farms contain 21–33 times more wildlife than in protected areas. Because of the popularity of wildlife-based land uses among younger farmers, increasing tourist arrivals and projected impacts of climate change on livestock production, the economic output of wildlife-based land uses will probably soon exceed that of livestock. However, existing policies favour livestock production and are prejudiced against wildlife-based land uses by prohibiting reintroductions of buffalo Syncerus caffer, a key species for tourism and safari hunting, and through subsidies that artificially inflate the profitability of livestock production. Returns from wildlife-based land uses are also limited by the failure to reintroduce other charismatic species, failure to develop fully-integrated conservancies and to integrate black farmers sufficiently.TRAFFIC East/Southern Africa and Tom Milliken for instigating this project and the German Federal Ministry for Economic Cooperation and Development and African Wildlife Conservation Fund.http://journals.cambridge.orgam201

Fluorescence of Giemsa and related stains: The CF banding of chromosomes

Since the introduction by Caspersson et al. (1970) of the quinacrine fluorescence method for the identification of human chromosomes, several Giemsa staining techniques have been developed for karyotype analysis. A denser staining of centromere regions of chromosomes was noted after in situ hybridization of mouse chromosomes with satellite DNA, followed by Giemsa staining. Numerous modifications were subsequently reported, all producing densely stained regions of one or both chromosome arms close to the centromere. All these procedures are currently referred to as C-banding. The hematological stains Giemsa and Leishman, which are widely used to demonstrate banding in chromosomes, are extremely heterogenous mixtures. They consist mainly of four dyes, methylene blue, Azure A, Azure B, and eosin Y are not considered to be fluorescent under ultraviolet light. In this report a new microscopic technique is described which allows consecutive fluorescence and bright-field observation of hematological stains. The proposed nomenclature for the striking fluorescence of the Giemsa-stained centromere regions of chromosomes is CF-banding. The main advantage of CF-banding over bright-field is that the C-band polymorphisms are better defined. This is especially an advantage in the identification of C-band chromosome polymorphisms in amniotic fluid cultures. Chromosomes from paternal origin in female fetal chromosomes can be identified more accurately. Furthermore, the fluorescence of the CF-method has a high degree of irradiation resistance, and slides can be stored and re-used.Articl

Regional chromosome mapping of human collagen genes alpha 2(I) and alpha 1(I) (COLIA2 and COLIA1)

For the assignment of the genes for the pro-α2(I) (COLIA2) and the pro-α1(I) (COLIA1) collagens, cDNA and genomic DNA probes were used in in situ hybridization experiments on human prometaphase chromosomes. An improved staining method is reported for the simultaneous identification of chromosomes and the autoradiographic grains after the hybridization procedures. With this procedure more cells with higher resolution could be used for the assignment of genes by in situ hybridization. Statistical analysis of the grains located on respectively 660 and 302 metaphases using pro-α2(I) and proα1(I) DNA probes, confirmed the assignment of these genes to human chromosomes 7 and 17. Analysis of the grain distribution on prometaphase chromosomes showed that the location of the pro-α2(I) collagen gene is in the region 7q21.3-22.1. The location of the pro-α1(I) collagen gene was found to be in band 17q21.31-2205.Articl

Ethylene oxide sterilization: A warning

The original publication is available at http://www.samj.org.za[No abstract available]Publisher’s versio

The gonads of human true hermaphrodites

Gonadal distribution in 409 cases of human true hermaphroditism is reviewed. An ovary was found on the left side of the body in 62.8% of the cases and the testis on the right side in 59.5%. The ovotestis is the most common gonad of the true hermaphrodite; amongst 806 gonads in 406 cases it was found in 44.3%. In this paper we give a detailed description of the morphology of ovotestis, testis and ovary in the true hermaphrodite. In addition we discuss the effects of fetal androgens and Muellerian ihibiting factor on the Wolffian and Muellerian ducts. Correlations between chromosomal complement and gonadal distribution are presented. True hermaphrodites with a 46,XX karyotype most commonly have an ovary on one side and an ovotestis on the other side; those with a Y-chromosome have a testis in 61% of cases. An analysis of the ratio of ovarian and testictular tissue within ovotestes showed a continuum from very little ovarian tissue to a small portion of testicular tissue. Each type of tissue was clearly demarcated, Hypotheses for gonadal induction in the true hermaphrodite should take cognizance of these facts. True hermaphrodites with a 46,XX chromosomal complement were characterized by a male phenotype in 54% of cases. This group may suggest a greater testicular induction ability in the genome as compared to the 46% with a female phenotype.Articl

New findings regarding the aetiology and pathogenesis of true hermaphroditism

The original publication is available at http://www.samj.org.zaNew evidence has become available regarding certain aspects of the aetiology and pathogenesis of true hermaphroditism. It is evident that the presence of a Y-chromosome in the karyotype of the true hermaphrodite predisposes to the formation of a testis on the one side and an ovary or an ovotestis on the other side. The presence of 46,XX-chromosome complement, however, more commonly results in an ovotestis on the one side and an ovary on the other side. The formation of an ovotestis is possibly due to a difference in the presence of H-Y antigen in the cells of the ovarian and the testicular portion. The development of the Mullerian and Wolffian ducts is much more interdependent than has previously been known. No cases have been described where two ducts, both of Wolffian and Mullerian origin, were found next to an ovotestis. In humans, fetal androgen does not change hypothalamic activity to a monophasic pattern or produce male sexual behaviour, according to the evidence found in the true hermaphrodites investigated by us.Publisher’s versio