Effects of partial or total fish meal replacement by agricultural by-product diets on gonad maturation, sex steroids and vitellogenin dynamics of African catfish (Clarias gariepinus).

The establishment of the first sexual maturation was characterized in African catfish (Clarias gariepinus) in order to study the efficiency of replacement of fish meal (FM) by diets composed of local vegetable ingredients. Four diets were formulated containing decreasing levels of FM (50-0% for diet 1 to diet 4) and increasing proportions of vegetable ingredients (50-100%). Gonadosomatic index (GSI), diameter and percentages of developmental stages of oocytes, plasma sex steroids and vitellogenin dynamics were investigated from February to June using one-year-old fish. Fish were individually tagged, and 12 individuals from each diet were investigated monthly. Replacement of FM with plant ingredients did not affect the GSI neither in males, nor in females. All males were spermiating, and no abnormal gonads were found. In females, GSI and percentages of advanced stages of oocytes decreased during the dry season, indicating seasonal changes in gonad development. Moreover, oocytes were in late exogenous vitellogenesis, but no final maturation stages were observed, whatever the diet. Higher plasma levels of E2 in females and of androgens (T and 11-KT) in both sexes were observed in fish fed diet 4 than in those receiving diet 1 depending on the season. Levels of plasma E2 and ALP (indicator for vitellogenin) in males did not differ among treatments and seasons suggesting no phytoestrogenic activity. The results showed that total replacement of FM by vegetable diets composed of groundnut oilcakes, bean and sunflower meals has no deleterious effect on the onset of sexual maturation in African catfish but, may stimulate the sex steroid production and in turns may potentially exert some positive actions on reproductive success.

Aspects epidemiologiques et anatomopathologiques des cancers dans les centres hospitaliers universitaires (CHU) du Rwanda

Il s'agit d'une etude retrospective realisee dans le but de mesurer la frequence des cancers de toute origine dans les Centres Hospitaliers Universitaires (CHU) du Rwanda durant la periode de 2000 a 2004. Deux milles cinq cents dix sept (2517) patients ont ete retenus pour notre etude et 942 cas de cancers ont ete histologiquement confirmes dans le service d'anatomopathologie. Les tumeurs representent 38;5 des tissus examines dans le laboratoire d'anatomopathologie; dont 20;85 sont des tumeurs malignes. Seuls 30;1 des suspicions de cancers dans les CHU ont ete confirmees par l'histologie. Parmi les cancers diagnostiques; 54;4 surviennent chez des sujets de sexe feminin. L'age moyen est de 44;8 ans. Chez l'homme les cancers les plus frequents sont : les cancers de l'estomac (16;4); le sarcome de Kaposi (11;5); du foie (10;1) et les lymphomes malins non Hodgkiniens (9;1). Chez la femme; les cancers du col uterin constituent la localisation la plus frequente (27;3); precedant les cancers du sein (10;5) et de l'estomac (8;8). Les enfants de moins de 15 ans ont presente 7;7 des cancers diagnostiques et les cancers de l'enfance les plus frequents sont les lymphomes malins non hodgkiniens (33;15) et le nephroblastome (9;84). La frequence des tumeurs malignes observees au laboratoire d'anatomopathologie n'est certainement pas representative de toute la realite cancereuse et la mise en place d'un registre des cancers au Rwanda est necessaire pour la surveillance epidemiologique de cette affection

[Osteogenesis imperfecta in monozygotic twins in Burundi]. / Ostéogenèse imparfaite chez des jumelles monozygotes au Burundi.

Little data is available about osteogenesis imperfecta in Black African children. This defect was diagnosed in monozygotic twins from Rwanda who presented multiple fractures, in particular of the femur, when they began to walk. Osteogenesis imperfecta was confirmed by lower limb deformity, presence of wormian bones in the skull, blue sclera, and tooth defects. In addition to the fact that it is uncommon to encounter this condition in monozygotic twins, this case is interesting for several reasons. Was osteogenesis imperfecta in these patients type I, frequent, or type III, exceptional? More importantly, this case stresses the high prevalence of type III in Black Africa which could constitute a hot-bed in the world.

A technique for identification of cercariae of Schistosoma haematobium, S. curassoni, S. bovis and S. intercalatum.

The chaetotaxy of 84 samples or isolates of Schistosoma spp. from western or central Africa has been studied. Three indices were calculated for cercariae of each sample; their average value, the skewness and kurtosis of each indice was established. Each species (S. haematobium, S. curassoni, S. bovis and S. intercalatum) was discriminated with nine variables. The present work gives information to assess, specific diagnosis with simple calculations easily achieved on a small computer.

Identification of Schistosoma haematobium, S. bovis and S. curassoni by multivariate analysis of cercarial papillae indices.

The disposition of cercarial papillae of 68 pre-identified Schistosoma species was established. All the cercariae originated from Africa and Madagascar and were either obtained from natural or experimental infections, and belonged to three species Schistosoma haematobium, S. bovis and S. curassoni. Discriminant analysis was based on nine characters: average values, skewness and kurtosis of three cercarial indices (AD, AL and U) for each sample or isolate. AD, AL correspond respectively to the relative distance between dorsal and lateral papillae. U corresponds to the total number of tail stem papillae. With the exception of two cases of the 68 (one of them corresponding to cercariae shed by a non-African experimentally infected snail), the method enabled discrimination of S. haematobium, S. bovis and S. curassoni.

[Morphology of the tegument of Schistosoma intercalatum; comparison of three stocks from Cameroon, Zaire and Gabon]. / Morphologie des téguments de Schistosoma intercalatum; comparaison de trois souches provenant du Cameroun, du Zaïre et du Gabon.

The study of the teguments of male Schistosoma intercalatum with SEM shows two different morphological types: a) Type Cameroon (Edea) (consistent with the previous studies by Kuntz et al.). b) Type Zaïre (Kisangani) similar to type Gabon (Libreville).

[Chaetotaxy of the cercaria of Paramphistomum sp., a parasite of cattle in Vendée]. / Chétotaxie de la cercaire de Paramphistomum sp. parasite du bétail en Vendée.

The cercaria was shed by an Anisus rotundatus experimentally infected with a parasite of Bos taurus in Vendée (France). This Trematode was identified as Paramphistomum cervi. The snail natural host is unknown. The chaetotaxy of the cercaria differs from that of other European species of Paramphistomum and particularly from P. leydeni and P. daubneyi both species which occur in Vendée. The morphology of the adult precludes any relationship with P. ichikawai also present in Vendée. Therefore it very likely represents a species which was synonymised with P. cervi or a new species.

[Morphology of the teguments of Schistosoma haematobium; comparison with S. curassoni, S. bovis and S. intercalatum]. / Morphologie des téguments de Schistosoma haematobium; comparison avec S. curassoni, S. bovis et S. intercalatum.

Study by SEM of the anterior dorsal teguments of male Schistosoma haematobium from infected rodents. Only paired males, at least hundred days post infection, display a typical morphology. Differentiation from other closely related species obtained experimentally from rodents is possible: bovis: no spines on the tubercles; haematobium: tubercles 10 to 15 microns wide with closely packed spines; curassoni: tubercles over 15 microns wide, with large, closely packed spines; intercalatum: tubercles under 10 microns wide, with scattered spines. It is suggested that the three haematobium genotypes A, B and D are slightly different: A: pointed spines, numerous small additional spines between the tubercles; B: pointed spines, no small additional spines between the tubercles; D: blunt spines. Moreover, the lengths of the prepatent periods in the molluscs of the three S. haematobium genotypes are possibly different: A 72-86 days, B 38-46 days, D 55-58 days. The differentiation of A, B and D is supported by limited data and conclusions on this particular aspect are presented only as a working hypothesis.

Relationships between cercarial indices of Schistosoma haematobium, S. bovis and S. curassoni from Senegal and the isoenzyme genotypes of the adult worms.

S. haematobium and S. curassoni appear to consist of three and two G6PDH genotypes respectively whereas only a single genotype has been observed in S. bovis. This genotype corresponds to one of those exhibited by S. curassoni, but the two species may be distinguished using the AcP enzyme system. The antero-dorsal cercarial indices for S. haematobium gave a mean of 0.78 ranging from 0.67 +/- 0.03 to 0.90 +/- 0.11; S. curassoni gave a mean of 1.11, ranging from 1.00 +/- 0.05 to 1.23 +/- 0.14 and S. bovis a mean of 1.30 within the range 1.01 +/- 0.25 to 1.67 +/- 0.18. From these data it is apparent that there is some correlation between antero-dorsal Cl and enzyme genotype: nevertheless the variation in Cl is somewhat greater than that observed in enzyme genotypes. Generally, Cl values lower than 0.90 can be considered to be due to S. haematobium, those above 1.15 to be S. bovis and intermediate values of 0.90-1.15 indicate S. curassoni.

[Morphology of the teguments of Schistosoma bovis; variations linked to the vertebrate host; comparison with S. curassoni]. / Morphologie des téguments de Schistosoma bovis; variations selon l'hote vertébré; comparaison avec S. curassoni.

S. E. M. study of the dorsal anterior one third of male Schistosoma bovis and of the anterior ventral border of the gynaecophoric duct. S. bovis was previously described as possessing spineless tubercles. This is so in specimens obtained from experimentally infected rodents, but in cattle, on the contrary, when conditions are favourable, teguments have spiny tubercles. Two morphological types have been observed: the first in Bos taurus from Sardinia, the second in domestic (Bos indicus) and wild (Hippotragus equinus and Damaliscus korrigum) bovids from Senegal, Tchad and Centrafrican Republic.