Genetic and epigenetic risks of intracytoplasmic sperm injection method

Pregnancies achieved by assisted reproduction technologies, particularly by intracytoplasmic sperm injection （ICSI） procedures, are susceptible to genetic risks inherent to the male population treated with ICSI and additional risks inherent to this innovative procedure. The documented, as well as the theoretical, risks are discussed in the present review study. These risks mainly represent thatconsequences of the genetic abnormalities underlying male subfertility （or infertility） and might become stimulators for the development of novel approaches and applications in the treatment of infertility. In addition, risks with a polygenic background appearing at birth as congenital anomalies and other theoretical or stochastic risks are discussed. Recent data suggest that assisted reproductive technology might also affect epigenetic characteristics of the male gamete, the female gamete, or might have an impact on early embryogenesis. It might be also associated with an increased risk for genomic imprinting abnormalities.

VL30 retrotransposition signals activation of a caspaseindependent and p53-dependent death pathway associated with mitochondrial and lysosomal damage

The impact of long terminal repeat （LTR） retrotransposition on cell fate is unknown. Here, we investigated the effect of VL30 retrotransposition on cell death in SV40-transformed mouse SVTT1 cells. Transfection of a VL30 retrotransposon decreased the clonogenicity of SVTT1 by 17-fold, as compared to parental NIH3T3 cells. Correlated levels of retrotransposition frequency and cell death rates were found in retrotransposition-positive SVTT1 cloned cells, exhibiting DNA fragmentation, nuclear condensation, multinucleation and cytoplasmic vacuolization. Analysis of activation of effector caspases revealed a caspase-independent cell death mechanism. However, cell death was associated with p53 induction and concomitant upregulation of PUMAa and Bax and downregulation of Bcl-2 and Hsp70 protein expression. Moreover, we found partial loss of colocalization of large T-antigen （LT）/p53 and p53 translocation to mitochondria, leading to mitochondrial outer membrane permeabilization （MOMP） accompanied by lysosomal membrane permeabilization （LMP）. Interestingly, treatment with the antioxidant N-acetylcysteiue abolished cell death, suggesting the involvement of mitochondrial-derived reactive oxygen species, and resulted in an increase of retrotransposition frequency. Importantly, the induction of cell death was VL30 retrotransposon-specilic as VL30 mobilization was induced; in contrast, mobilization of the non-LTR L1 （LINE-1, long interspersed nuclear element-1）, B2 and LTR MusD retrotransposons decreased. Our results provide, for the first time, strong evidence that VL30 retrotransposition mediates cell death via mitochondrial and lysosomal damage, uncovering the role of retrotransposition as a nuclear signal activating a mitochondrial-lysosomal crosstalk in triggering cell death.

In vitro activities of acetonic extracts from leaves of three forage legumes(Calliandra calotyrsus,Gliricidia sepium and Leucaena diversifolia) on Haemonchus contortus

Objective:To assess ovicidal activity of three acetonic extracts from the leaves of three forage legume,Calliandra calotyrsus(C.calotyrsus),Gliricidia sepium(G.sepium) and Leucaena diversifolia(L.diversifolia) in vitro on Haemonchus contortus(H.contortus).Methods:Eggs were exposed for 24 hours to five different concentrations(0.075,0.15,0.3,0.6 and 1.25 mg/mL) of acetonic extracts at room temperature(24℃).Distilled water and 0.4%Tween were used in the bioassay as negative controls.Results:The later did not affect embryonation and egg hatching of H.contortus.Conversively,significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL).The acetonic extract of G.sepium was found to be more active(2.9%and 0.0% for embryonation and egg hatching,respectively) than the other substances 16.5%and 33.5%, respectively for C.calothyrsus,33.7%and 33.3%,respectively for L diversifolia.Conclusions: These results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out.

Physico-Chemical and Bacteriological Quality of the Vegetable Watering Water in the Dschang Town, Cameroon

Market gardening, in the swampy lowlands of the Dschangcity, plays an important role in terms of providing employment, and supply the city with fresh products. However, waterborne diseases, which occur in the city, are both attributed to the bad quality of drinking water and sanitation practices. This work aims to characterize watering waters of crop, to assess the health risks associated with the use of these waters. Water from eleven streams and five wells used to irrigate crops were sampled and analyzed once a week for a month. Analyses focused on physico-chemical parameters (temperature, suspended matter, pH, electrical conductivity, COD, BOD5, NO-3 , Al, Fe, Cu, Ni), parasitological (helminthes eggs) and bacteriological (total coliforms, fecal coliforms, fecal streptococcus). The results show that, the physico-chemical quality of well waters generally approaches the WHO standards of crop watering water. The physico-chemical of streams waters and bacteriological quality of wells and streams waters are bad, according to WHO guide. These bad quality waters could contaminate crops, some of which are eaten raw, which is surely a cause of the outbreak of waterborne diseases in the city. The waters from streams are more affected. The pretreatment of the water before use for irrigation of vegetables is highly recommended.

In vitro anthelminthic efficacy of Dichrocephala integrifolia(Asteraceae)extracts on the gastro-intestinal nematode parasite of mice:Heligmosomoides bakeri(Nematoda,Heligmosomatidae)

Objective:To evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia(D.integrifolia)against the eggs(fresh and embryonnated),the first and second larval stages of Heligmosomoides bakeri.In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae(L1 and L2).Methods:Dried extracts were diluted in distilled water to obtain five different concentrations:625,1 250,2500,3750 and 5000μg/mL.Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h.Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h.Distilled water(placebo)and 1.5%DMSO were used as negative controls.Results:Distilled water,and1.5%DMSO had no effect on embryonation,hatching and larval survival.Aqueous extracts of D.integrifolia showed a weak activity against all stages of the parasite at all concentrations tested.On the contrary,the ethanolic extract of D.integrifolia inhibited the embryonation of 87.5%of fresh eggs,the hatching of 81.1%of embryonated eggs and induced the mortality of 98.1%and 98%of L1 and L2 larvae respectively at 5000μg/mL.Conclusions:The results of the present study indicate that the ethanolic extracts of D.integrifolia contained compounds with ovicidal and larvicidal properties.In spite of these results,in vivo tests,studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.

A preliminary analysis of some epidemiological factors involved in porcine cysticercosis in Bafut and Santa subdivisions,North West Region of Cameroon

Objective:To examine the magnitude and some risk factors of porcine eysticercosis in Bafut and Santa,two sub-divisions noted for pig farming in the North West Region of Cameroon.Methods: A total of 499 pigs in 300 households were examined by tongue inspection and serologically by Ag-ELISA.Information was sought on the age and sex of the animals,prevailing husbandry systems,types of feed,the state of each pen and the state of toilets.Futhermore,a questionnaire was administered to the farmers to determine their awareness on taeniasis/cysticercosis and related factors.Results:The prevalence of the disease was significantly higher in Santa(10.2%) than in Bafut(4.2%),although there was a higher level of awareness in both localities(62.3%).Age of pigs,traditional rearing systems(roaming,tethered,earth floor pen,raised floor pen),faecal disposal in the environmenl and poor sanitation significantly influenced the seroprevalence of porcine cysticercosis in both localities.Most farmers(79.7%) used a combination of concentrate, grass and kitchen waste to feed pigs.Financial loss from porcine cysticercosis was estimated at 346 900 CFA representing 2%of total income.Conclusions:Control measures advanced here include sensitization campaigns,periodic examination and treatment of infected pigs by veterinarians,improved husbandry systems,proper use of standard latrines regularly inspected by sanitary officers,and sound hygienic and sanitary practices.

Assessment of the Roles of Cathepsins B, H and L in the Progression of Colorectal Cancer

Cysteine cathepsins are important regulators and signaling molecules of an unimaginable number of biological processes, while they concurrently play an essential role in cancer progression, invasion and metastasis. The purposes of our study were to: a) compare the expression levels of cathepsins B, H and L in the supernatants of colon cancer tissues from 74 patients versus the corresponding enzymic expressions of supernatants in the adjacent normal colorectal tissues;and b) correlate our results to the grade of the malignancy by using an enzyme-linked immunosorbent assay (ELISA). The findings indicated that cathepsins B, H and L of all malignant tissues exhibited significantly higher expression levels than their corresponding controls. Furthermore, cathepsin B expression levels doubled in all tumor samples and this increase remained quite steady with tumor stage advancement, in contrast to cathepsin H expression which rose significantly as malignancy progressed. Specifically, cathepsin H concentration was higher than the corresponding control: 155% in B1 stage and 204.44% in D stage. Among the three investigated proteases, cathepsin L has shown the highest increase, which in D stage stood 261.03% higher than the corresponding control. The results at hand suggested that cysteine protease H and L expression levels could be of critical value in the diagnosis and progression of colon cancer.

Phytoplankton Dynamics of Mokolo and Mopa Ponds in Bertoua City (East-Cameroon)

This study aims to improve the understanding of algal community’s dynamics in response to different environmental factors in two dam ponds (Mokolo and Mopa) in the city of Bertoua (East-Cameroon). Physicochemical and biological analyzes were carried out monthly by direct sampling at the surface and using Van Dorn bottle at 1 m depth. The organisms were collected using transparent glass vials of about 500 ml and fixed with 2.5 ml of a lugol solution, then analyzed using the Utermôhl method. Physicochemical analyzes show low transparency (<75 cm) of the ponds despite their shallow depth (≤150 cm), high levels of dissolved oxygen (>60%), BOD5 (>30 mg/L) and chlorophyll “a” (>30 μg/L). These data made it possible to categorize the Mokolo and Mopa ponds as hypereutrophic with nitrogen as the limiting factor for eutrophication. Biological data show quite diversified ponds with 138 species identified in Mokolo Pond and strongly dominated by Diatoms with 2951 ind. representing 46% of the total abundance. In Mopa Pond, 147 species were identified, mainly represented by Chlorophyceae with 3629 ind. representing 52% of the total abundance. Azpeitia africana (Mokolo) and Eresmophaera gigas (Mopa) were the most represented taxa during the study. This study will have deduced that the structure and dynamics of algal communities are under the control of different factors or processes that interact simultaneously, namely ascending factors or bottom-up corresponding to nutrient resources and sunlight and descending factors or top-down that are exerted by grazing and active physiological substances produced by other algae that are known to influence phytoplankton.