Nitrosation of Nigerian medicinal plant preparations under 'chemical' and 'simulated' gastric conditions.

Preparations of some tropical plants of medicinal importance, collected from the savannah vegetational belt of Nigeria, were nitrosated and analysed for volatile N-nitrosamines formed under chemical and simulated gastric conditions. N-Nitrosamines were determined on a Thermal Energy Analyser following gas chromatographic separation. Mean concentrations of N-nitrosodimethylamine (NDMA) in the range of 7 to 58 ppb and N-nitrosodiethylamine (NDEA) in the range of 23 to 26 ppb were formed in 31 and 7%, respectively, of the preparations using artificial gastric juice (simulated gastric condition). Under chemically optimal conditions, relatively high levels of NDMA (72-2008 ppb), NDEA (23-1528 ppb) and N-nitrosopyrrolidine (20-405 ppb) were formed in 100, 75 and 32% of the preparations, respectively; N-nitrosomethylethylamine, N-nitrosodibutylamine and N-nitrosomorpholine were formed in fewer preparations. These findings suggest that the endogenous formation of N-nitroso compounds from precursors present in medicinal plants might be another source of human exposure to environmental carcinogens in Nigeria and other developing countries.

Aflatoxin contamination of Nigerian foods and feedingstuffs.

Human foods and animal feeds, and ingredients used for their preparation or formulation in Nigeria, were surveyed between 1988 and 1991 for the presence of the fungal metabolite and animal carcinogen aflatoxin. Groundnut and groundnut-containing materials were the most heavily contaminated, the highest value (1862 ppb) being found in a groundnut cake sample. This mycotoxin was also detected occasionally, but to a lesser extent, in some grains and cereals that are of nutritional importance in human foods and the livestock industry in Nigeria. The toxicological implications of this finding are discussed in relation to human health and animal production.

The choice of adjuvants in Mycoplasma vaccines.

The use of adjuvants in vaccine production is an important aspect of potent vaccines. This investigation was concerned with finding the most efficient adjuvants for use in Mycoplasma vaccines produced in Nigeria. Four different vaccines were produced from the Gladysdale strain of Mycoplasma mycoides subspecies mycoides. They differed depending on the type of adjuvants used. Each vaccine was used to vaccinate eight cattle using a dose of 1 ml. Two other groups of eight cattle were used as controls. One of the two groups received 1 ml dose of inactivated Gladysdale vaccine without adjuvant while the second group received 1 ml dose of saline. The number of cattle that had the peak complement fixing (CF) antibody titres of 1/80 in each group of cattle was four for vaccine containing aluminium hydroxide gel, eight for vaccine containing liquid paraffin, one for vaccine containing sodium alginate and one for vaccine without adjuvant. Seven cattle from the group vaccinated with vaccine containing Freund's incomplete adjuvant had peak CF antibody titres of 1/80 or higher. The two groups vaccinated with vaccine containing liquid paraffin and Freund's incomplete adjuvant survived challenge at 6 months post vaccination. Freund's incomplete adjuvant and liquid paraffin containing 10% Arlacel A are the most efficient adjuvants.

Socio-economic impact of rinderpest in Nigeria.

The recurrence of rinderpest in Nigeria since September 1980 and widespread epizootics in 1983-84 claimed almost half a million cattle, and impaired the health of another million and a half which survived. Losses caused by rinderpest were aggravated by complicating diseases and the widespread drought of 1983. The losses were estimated to amount to 1.5 billion naira ($2.0 billion). Many cattle owners became bankrupt when they lost all their cattle due to disease, or sold them at low prices for salvage. Many cattle owners were forced to give up the trade of tending cattle. No development of cattle or economic emancipation of their owners is possible as long as this scourge continues to inflict severe economic losses.

Depuis sa résurgence en septembre 1980 et surtout pendant la grande épizootie de 1983-1984, la peste bovine a tué près d'un demi-million de bovins au Nigéria. En outre, la santé d'un million et demi d'animaux ayant survécu à la maladie a été gravement affectée. Les pertes causées par la peste bovine ont été aggravées par des maladies intercurrentes et par la sécheresse qui a sévi dans le pays en 1983. Le montant des pertes a été estimé à 1,5 milliard de naira (2 milliards de dollars US). De nombreux éleveurs se sont trouvés privés de ressources après avoir perdu tous leurs animaux du fait de la maladie ou après les avoir vendus à bas prix pour éviter une ruine complète. Beaucoup d'entre eux ont dû renoncer à leur activité. Tout développement de l'élevage et toute émancipation économique des éleveurs sont impossibles aussi longtemps que ce fléau continuera à infliger de lourdes pertes économiques.

Desde su reactivación en Septiembre de 1980 y principalmente durante la gran epizootia de 1983-1984, la peste bovina mató a casi medio millón de bovinos en Nigeria. Quedó gravemente afectada además la salud de un millón y medio de animales que sobrevivieron a la enfermedad. Las pérdidas causadas por la peste bovina se han agravado por enfermedades intercurrentes y por la sequía que azotó el país en 1983. Se ha estimado el importe de las pérdidas en 1.500 millones de naira (2.000 millones de dólares US). Muchos ganaderos han quedado privados de recursos después de perder todos los animales por la enfermedad o de venderlos a bajo precio para evitar la ruina completa, habiendo tenido que renunciar a su actividad muchos de los mismos. Mientras que este azote siga inflingiendo onerosas pérdidas económicas será imposible cualquier fomento ganadero y cualquier emancipación económica de los ganaderos.

Role of veterinary public health in the environmental pollution in Nigeria.

Veterinary public health has a part to play in the environmental pollution control programme. However there is a need to conduct research surveys to draw a line of demarkation where a public health hazard could be considered as well a problem of environmental pollution. In the developed countries some of these diseases have been successfully dealth with by the rigourous enforcement of law pertaining to hygiene, sanitation, quarantine, compulsory vaccination etc. In the developing countries by contrast this has so far not been possible due to the scarcity of funds for control programme and of inadequacy of law enforcement and monitoring agencies.

Observations on the ovaries of zebu cattle in Northern Nigeria.

A morphological study was carried out on ovaries of 236 local zebu cattle. Ovaries from 189 of the cattle were found to be abnormal grossly. Histological observations indicated changes due to old age. The findings are discussed in relation to the occurrence of low reproductive efficiency in cattle in Northern Nigeria.