Histology of the male reproductive system of the prawn Macrobrachium lanchesteri (Crustacea: Decapoda)

The testis of the 'freshwater prawn Macrobrachium Ianchesteri consists of numerous branching lobules, bound by thin limiting membranes. There is very little inter-lobular space with indistinct blood sinuses and the lobules are filled with germ cells in different stages of development. The different regions of the vas deferens of the prawn viz., anterior vas deferens (AVD), mid vas deferens (MVD) and posterior vas deferens (PVO) , indicate structural variations reflecting the specific role of each region, in spenn transport, spermatophore formation and ejaculation. The nature of the glandular epithelium and presence of secretory material in the lumen suggest that packaging of sperms into a spermatophore is initiated in the AVO itself. The epithelial cells of the inner margin of the AVD and MVD are highly columnar. fonning a 'typhlosole'-like region. The histology of the MVD differs from that of the A VD in the presence of prominent circular and longitudinal muscle layers. Presence of copious secretory material in the MVD indicates further packaging of the sperms. Extensive muscle layers and reduced secretory activity are characteristic of the PVO. The male hormone-producing tissue. the androgenic gland, is situated mesially in the curvature of the ampulla, the distal end of the PVD. The histology of the gland confirms its secretory role

Regulation of ovigericity in a fresh water prawn macrobrachium lanchesteri (de Man)

Summary The intermoult duration of ovigerous Macrobrachium lanchesteri, between the pre-spawning and the post-parturial moults, is significantly long, twice that of the adult non-ovigerous females. This intermoult duration is independent of mating, fertilization of eggs, presence/absence of eggs held in the brood as well as eyestalk principles. The possible role of specific endogenous factor(s) probably elaborated by the ovary, in the maintenance of the long intermoult duration as well as ovigericity of this prawn, is projected

Studies on the neurosecretion of thoracic ganglion in relation to reproduction of femaleMacrobrachium lanchesteri (de Man)

The changes in the histology of thoracic ganglion in females ofMacro-brachium lanchesteri, prior to spawning and post parturial moult, have been described. Based on the differences in size, cell inclusions and differential staining with CHP, four distinct types of neurosecretory cells have been identified in the ganglion. The activity of these cells has been correlated with the ovarian condition of the prawn and evidence for the elaboration of a gonad-stimulating hormone (GSH), by the ganglion has been derived. The, probable regulation of ovarian maturation during a normal ovarian cycle and that during the ovigerous condition ofM. lanchesteri have been illustrated

The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden