Health Science University

About: Health Science University is a based out in . It is known for research contribution in the topics: Population & Medicine. The organization has 9559 authors who have published 8727 publications receiving 200292 citations.

Antitumour activity of melatonin in a mouse model of human prostate cancer: relationship with hypoxia signalling

Abstract: Melatonin is known to exert antitumour activity in several types of human cancers, but the underlying mechanisms as well as the efficacy of different doses of melatonin are not well defined. Here, we test the hypothesis whether melatonin in the nanomolar range is effective in exerting antitumour activity in vivo and examine the correlation with the hypoxia signalling mechanism, which may be a major molecular mechanism by which melatonin antagonizes cancer. To test this hypothesis, LNCaP human prostate cancer cells were xenografted into seven-wk-old Foxn1nu/nu male mice that were treated with melatonin (18 i.p. injections of 1 mg/kg in 41 days). Saline-treated mice served as control. We found that the melatonin levels in plasma and xenografted tissue were 4× and 60× higher, respectively, than in control samples. Melatonin tended to restore the redox imbalance by increasing expression of Nrf2. As part of the phenotypic response to these perturbations, xenograft microvessel density was less in melatonin-treated animals, indicative of lower angiogenesis, and the xenograft growth rate was slower (P < 0.0001). These changes were accompanied by a reduced expression of Ki67, elevated expression of HIF-1α and increased phosphorylation of Akt in melatonin than saline-treated mice. We conclude that the beneficial effect of melatonin in reducing cancer growth in vivo was evident at melatonin plasma levels as low as 4 nm and was associated with decreased angiogenesis. Higher HIF-1α expression in xenograft tissue indicates that the antitumour effect cannot be due to a postulated antihypoxic effect, but may stem from lower angiogenesis potential.

Exclusive breastfeeding and associated factors among mothers in Gozamin district, northwest Ethiopia: a community based cross-sectional study.

Abstract: Exclusive breastfeeding is defined as feeding infants only breast milk, be it directly from breast or expressed, except drops or syrups consisting of vitamins, mineral supplements or medicine. Exclusive breastfeeding is one of the essential actions for infant development and survival. However, the prevalence of exclusive breastfeeding in Ethiopia has been estimated at 52% which is far less than the World Health Organization (WHO) recommendations. Moreover, there are inconsistencies among estimates in different districts of the country. Therefore, this study aimed to assess the prevalence and associated factors of exclusive breastfeeding among mothers in Gozamin district, northwest Ethiopia. Using the simple random sampling technique, seven kebeles (lowest administrative units) were selected as the primary sampling unit of the district. Sample mother-infant pairs were then selected using the systematic random sampling technique that involved our moving from house to house in each village. Data were collected from 506 mother-infant pairs using interviews. Factors associated with exclusive breastfeeding were determined using logistic regression. The measure of association used was the odds ratio, and statistical tests with p-values of less than 0.05 were considered as statistically significant. In this study, the prevalence of exclusive breastfeeding among mothers was 74.1% (95% CI 70.80, 79.10). For government employee mothers, the odds of exclusive breastfeeding were reduced by half compared to housewives (AOR 0.49, 95% CI 0.26, 0.94). Mothers who did not receive breastfeeding counseling after delivery were 0.43 times less likely to practice exclusive breastfeeding compared with mothers who received the services (AOR 0.43, 95% CI 0.25, 0.72). Mothers who gave birth at health institutions were more likely to practice exclusive breastfeeding. Even though the estimated prevalence is relatively high, more effort to meet WHO recommendations is still necessary. Therefore, we suggest health institutions encourage hospital birthing and increase breastfeeding counseling after delivery, and employers needs to give longer maternity leave to improve exclusive breastfeeding practice.

Association of spinothalamic lamina I neurons and their ascending axons with calbindin-immunoreactivity in monkey and human.

Abstract: The calbindin-immunoreactivity of spinothalamic (STT) lamina I neurons and their ascending axons was examined in two experiments. In the first experiment, lamina I STT neurons in macaque monkeys were double-labeled for calbindin and for retrogradely transported WGA∗HRP following large (n=2) or small (n=1) injections that included the posterior thalamus. Most, but not all (78%) of the contralateral retrogradely labeled lamina I STT cells were positive for calbindin. Calbindin-immunoreactivity was not selectively associated with any particular anatomical type of lamina I STT cell; 82% of the fusiform cells, 78% of the pyramidal cells and 67% of the multipolar cells were double-labeled. In the second experiment, oblique transverse sections from upper cervical spinal segments of three macaque monkeys, one squirrel monkey and five humans were stained for calbindin-immunoreactivity. In each case, a distinct bundle of fibers was densely stained in the middle of the lateral funiculus. This matches the location of anterogradely labeled ascending lamina I axons observed in prior work in cats and monkeys, and it matches the location of the classically described ‘lateral spinothalamic tract’ in humans. This bundle had variable shape across cases, an observation that might have clinical significance. These findings support the view that lamina I STT neurons are involved in spinal cordotomies that reduce pain, temperature and itch sensations.