Caractéristiques socio-économiques et techniques de l'apiculture dans les hautes terres de l'ouest du Cameroun

Socio-economic and Technical Characteristics of Beekeeping in the Western Highlands of Cameroon. Between April 1998 and August 2000, a survey was carried out to assess socio-economic and technical characteristics of beekeeping in the Western Highlands Cameroon (LN 3-5° ; LE 8-20°). A total of 39 beekeepers were investigated through both interviews and a structure questionnaire. The main results were as followed : - Beekeepers are still essentially male (97.0 %) aged 18 to 58 with an average of 38 years old. All of them are educated. Many beekeepers (52.0 %) have received training with at least 5 years experience in beekeeping. The purpose of the activity is to improve household income. - The average number of hives per beekeeper is 42 varying from 2 to 300. Improved hives are used by 43.3 % of the beekeepers, but traditional types of hive are still more frequently used. - Colonisation of hives is based only on capturing of natural swam between September and March, the most favourable period of the year for this region, using different types ofbait, wax being the most frequently used. Hive colonisation rate is relatively low (64.4 %), being higher for traditional hives compared to improved ones (78.5 and 43.3 % respectively). - Honey, the major hive product exploited is harvested once a year (from March to July) with an average of 6 to 10 liters of honey per colony and per year. The gain is estimated to 10 500 - 10 750 and 18 750 - 19 000 FCFA per hive and per year respectively for traditional and improved hives. The major constraints to beekeeping in the surveilled area are lack of training, bee's enemies and diseases. However, the majority of beekeepers would like to continue the activity and wish to improve their technicity, increase the number of hives and become professionals

Histological and ultrastructural alterations of rat thyroid gland after short-term treatment with high doses of thyroid hormones

The aim of the present study was to investigate histological alterations of rat thyroid gland after short-term treatment with supraphysiological doses of thyroid hormones. Rats from experimental groups were treated with triiodothyronine (T3) or thyroxine (T4) during five days. In both treated groups, thyrocyte height was reduced and follicular lumens were distended. Progressive involutive changes of the thyroid parenchyma were apparent, including follicular remodeling (fusion) and death of thyrocytes. Morphological changes confirmed by quantitative analysis were more pronounced in the T4-treated group. Our results demonstrate that thyrotoxicosis, whether induced by T3 or T4, leads to different grades of thyroid tissue injury, including some irreversible damages. These changes might be explained at least in part by lack of trophic and cytoprotective effects of the thyroid stimulating hormone. Since the period required for morphophysiological recovery may be unpredictable, findings presented here should be taken into consideration in cases where the thyroid hormones are used as a treatment for thyroid and non-thyroid related conditions. Keywords: Light microscopy, Electron microscopy, Thyroid gland, Thyroid hormones, Wistar rat