Silver nanoparticle-induced developmental inhibition of Drosophila melanogaster accompanies disruption of genetic material of larval neural stem cells and non-neuronal cells.

A few studies had determined the effects of silver nanoparticles on the development of Drosophila melanogaster. However, none had addressed its genotoxic effects on specific larval cells of the fly in details. This study was conducted to determine the effects of silver nanoparticle on the development of D. melanogaster with simultaneous evaluation of its genotoxic potential on specific larval cell types that play important roles in immunological defenses as well as growth and development. Five male and five female flies were maintained in standard Drosophila melanogaster culture medium containing varying concentrations of silver nanoparticles, i.e., 25, 50, 100, 200, and 300 mg/l with control culture medium containing no nanoparticle. Total time needed for stage-specific development, population yield, and genotoxic effects on third instar larval polytene chromosomes, hemocytes, and neuroblasts was determined. Body pigmentation of pupae and young adults was examined visually. In comparison with control, silver nanoparticles dose dependently inhibited the metamororphosis and population yields of pupae and young adults of Drosophila melanogaster. Every concentration of the nanoparticles inhibited pupa to adult conversion, with huge reduction under the influence of nanoparticle concentration of 100 mg/ml and above. Developmental inhibition was accompanied by dose-dependent and significant structural aberrations of larval polytene chromosomes and deformities of hemocytes and neuroblasts. Pupae and young adults also exhibited gradual discoloration of body with the increase in exposure to nanoparticle concentration.

Mycobacterium tuberculosis and non-tubercular mycobacterium infection in women with unexplained infertility from eastern India.

BACKGROUND: Genital tuberculosis (GTB) is an important cause of female infertility, especially in developing countries. The positive results of polymerase chain reaction (PCR) in endometrial GTB in the absence of tubal damage raise the possibility of the detection of sub-clinical or latent disease, with doubtful benefits of treatment. OBJECTIVE: This study aims to evaluate the Mycobacterium tuberculosis (MTB) and Non-tubercular Mycobacterium (NTM) infection by using Real-PCR technique in the menstrual blood samples of 120 unexplained infertile women. MATERIALS AND METHODS: In this cross-sectional study, 120 infertile women with unexplained infertility aged 20-35 yr old and normal hysterosalpingography findings were taken. Menstrual blood in the first 12 hr of menstruation containing the endometrial tissues from each participant was tested for MTB and NTM by Real-Time PCR. RESULTS: Among the selected 120 patients, only two were found to be positive for MTB infection. All remaining participants were negative for MTB infection. All participants were negative for NTM infection at the endometrium. CONCLUSION: Although, studies have indicated that PCR is a useful method in diagnosing early GTB disease in infertile women with no demonstrable evidence of tubal or endometrial involvement, our study showed that GTB is not the major problem in women with unexplained infertility.

Impacts of dietary exposure to sodium or potassium salts of nitrate and nitrite on the development of Drosophila melanogaster.

The effects of four food additives, namely sodium nitrite (NaNO2), sodium nitrate (NaNO3), potassium nitrite (KNO2), and potassium nitrate (KNO3), on animal development were evaluated by using Drosophila melanogster, a model organism. Adult male and female flies were allowed to breed in culture medium, each containing one of 4 concentrations, i.e.10, 20, 30 or 40 mM of the above mentioned salts. The concentration of 40 mM, NaNO2 and KNO2 completely arrested the development of the flies. Of the different concentrations of the four salts tested, exposure of flies to 30 mM NaNO2 exhibited only significant delays in the initial appearances of third instar larvae, pupae and young adults, along with huge reduction in the number of pupae and young adults compared to controls. Rearrangements like inversions, deletion looping, regional shrinking, as well as highly enlarged puffing, etc. were also observed in the polytene chromosomes of the third instar larvae exposed to 30 mM NaNO2. Developmental outcomes of the flies exposed to varying concentrations of NaNO3 and KNO3 did not differ significantly from the controls. Owing to the extensive genetic homology between Drosophila and human and the successful uses of this fly as models in developmental and toxicological studies, we speculate that the experimental results exhibited by this organism in our study strongly advocate for abstaining from the dietary use of NaNO2 and KNO2 during human pregnancies to avoid possible negative developmental outcomes.