Genetic manipulation studies in Oreochromis niloticus L.

The results of a study aimed at the identification of treatment optima for triploidy induction in recently fertilised Oreochromis niloticus eggs by altering the intensity, duration and timing of application of pressure, heat and cold shocks are reported. Preliminary, but not directly comparable, trials suggested the following treatments to be close to the individual agent optima. Pressure; 8,000 p.s.i. 2 mins, duration applied 9 mins, after fertilisation (a.f.); heat: 41 *C, 3.5 mins, duration applied 5 mins. a.f.; cold: 9 *C. 30 mins, duration applied 7 mins. a-f. In a directly comparable trial in which the eggs of eight different females were separately exposed to the optimum shocks listed above, individual triploid yields were more variable following cold shocks and mean triploid yields were, therefore, higher following pressure and heat shock. The effects of triploidy on sexual development and maturation in female and male fish were examined in successive age groups (4 - 10 months). Significant differences in ovary weight and OSI were found between 3n and 2n females. But 3n males showed normal testis development and some of them could produce aneuploid sperm. The testis weight and OSI of such males were not significantly different compared to 2n. Comparative performance of growth, biochemical composition and endocrine profiles of normal diploids and pressure, heat and cold shocked triploids was investigated. 3n females were not significantly different in growth rate and proximate nutrition parameters compared to the 2n controls but were found to be functionally and endocrinologically sterile. 3n males showed no significant differences in growth or proximate nutrition parameters but were genetically sterile despite showing normal 2n endocrinological profiles and secondary sexual characteristics. Evidence is presented for successful suppression of first cleavage in O. niloticus and thereby the production of mitotic gynogenetics. The optimal parameters for UV irradiation of milt were 300 - 310 pW/cm> for 2 min at 4-C. The optimal pressure shock W.S 9000 p.s.i. for 2 mins at 28 *C at 40 - SO mins a.f. and that for heat was 41 *C for 3.5 mins at 27.5 - 30 mins. a.f. Isozyme analysis of putative mitotic gynogenetic survivors at ADA' locus confirmed homozygosity, therefore, restoration of diploidy occurred by inhibition of first mitosis. Subsequently gene-centromere recombination frequency estimated at six enzyme loci further revealed no recombination between the respective gene and centromere at all the loci. In contrast, recombination frequency in meiotic gynogenetic progeny was 0 - 100* (mean y = 0.41) which suggesting that this probably a reflection of the relative position of the various loci to centromere on their respective chromosomes. Production of heterozygous clones of O. niloticm was successfully carried out by crossbreeding between viable mitotic gynogenetic female and male sibs. At the same time, homozygous clones of the fish was produced by gynogenetic reproduction (retention of 2nd polar body) using optimal pressure/heat shock treatments. The outbred (OCL) and inbred (ICL) nature of two types of clonal lines were checked and identified at ADA' marker locus. A model for the large scale production of such clonal lines is presented. The effect of inbreeding on various phenotypic characters of two types of gynogenetics (meiotic and mitotic) in comparison to full sib controls was investigated. The coefficient of variation values of growth, meristic and all reproductive train were lowest in control, intermediate in meiotic and highest in mitotic gynogenetic group. This study revealed that the expansion of variation in such performance train in both type of gynogenetics was possibly the result of phenotypic expression of unmasked homozygous recessive and deleterious genes due to increasing levels of homozygosity (F value). Mendelian mode of ted body colour inheritance was studied in Egyptian red O. niloOcus and Thai ted tilapia attains. Cross-breeding between ted a ted and ted x wild parents resulted in mostly all red coloured progenies and in some red x wild crosses progenies were also segregated into red and wild types. The F. red hybrids mated infer se and back-crossed to wild type, the progeny phenotype segregated closely into approximating the expected 3 red: 1 wild and 1 red : 1 wild ratios respectively. These results demonstrate that red body colour in two mutant attains of tilapia is controlled by a single autosomal dominant "R" gene. But both the red strains contain differing proportion of heterozygotes (Rr). In order to produce pure breeding strains, it will be important to identify heterozygotes so that the “r" gene can be culled in some way. In this case. Mendelian test-cross technique has been proposed on the light of the present study as a means of probable solution. The possible implications of above results of genetic manipulation study in the aquaculture of Oreochromis spp. are discussed

Carotid Body Tumors: Surgical Management and Review of Patients Over 10 Years

Background: Carotid body tumours (CBTs) are rare but highly vascular neoplasms originating in the paraganglionic cells of the carotid bifurcation. Exact etiology of these tumors is not known. Male and female distributions are equal except at high altitude where females appear to predominate. Diagnosis of a chemodectoma usually begins with a color flow duplex scan. Magnetic resonance angiography are also useful, especially to evaluate bilateral disease. Conventional Arteriography with CT Angiography are valuable, especially in larger tumours, and are regarded as the best tools for diagnosis. The treatment of choice for carotid body tumours is surgical removal. Shamblin's classification system is used to categorize carotid body tumours based on their size and the difficulty of surgical resection. Results: It was observed that majority of the patients in this study were females numbering 35(79.45%) whereas there were 9 (20.43%) males. commonest age group involved was of patients 50 to 59 years of age. Surgery was done in all 44 (100%) patients with complete resection in 41 (93.07%) and incomplete in 3 (6.81%) patients. 10 (23%) were Shamblin grade 1, 29 (66%) grade 2 and 5 (11%) grade 3. ECA repair was done in 4 (9.08%) of patients, ICA repair in 2 (4.54%), ECA ligation in 2 (4.54%) and vascular graft was used in 1 (2.27%) of patients. 7 (15.89%) had transient cranial nerve palsy most commonly involving hypoglossal nerve. 3 (6.81%) had permanent cranial nerve palsy. In 6 (13.62%) patients there was local wound infection .There was post op stroke in 2 (4.54%) of patients. No operative mortality was seen.43 (97.61%) patients were proved to be paraganglionomas on HPE while 1 (2.27%) patients had inconclusive biopsy on Histopathological examination. Conclusion: Although rare, Carotid body tumor is still a pathology that we encounter in our experience and it should be kept in mind as a differential diagnosis for painless lateral neck masses

Insights into the Conserved Regulatory Mechanisms of Human and Yeast Aging

Aging represents a significant biological process having strong associations with cancer, diabetes, and neurodegenerative and cardiovascular disorders, which leads to progressive loss of cellular functions and viability. Astonishingly, age-related disorders share several genetic and molecular mechanisms with the normal aging process. Over the last three decades, budding yeast Saccharomyces cerevisiae has emerged as a powerful yet simple model organism for aging research. Genetic approaches using yeast RLS have led to the identification of hundreds of genes impacting lifespan in higher eukaryotes. Numerous interventions to extend yeast lifespan showed an analogous outcome in multi-cellular eukaryotes like fruit flies, nematodes, rodents, and humans. We collected and analyzed a multitude of observations from published literature and provide the contribution of yeast in the understanding of aging hallmarks most applicable to humans. Here, we discuss key pathways and molecular mechanisms that underpin the evolutionarily conserved aging process and summarize the current understanding and clinical applicability of its trajectories. Gathering critical information on aging biology would pave the way for future investigation targeted at the discovery of aging interventions

Rapid assessment of avoidable blindness and cataract surgery coverage among forcibly displaced Myanmar Nationals (Rohingya refugees) in Cox's Bazar, Bangladesh.

AimTo determine the prevalence and causes of blindness, vision impairment and cataract surgery coverage among Rohingya refugees aged ≥ 50 years residing in camps in Cox's Bazar, Bangladesh.MethodsWe used the Rapid Assessment of Avoidable Blindness (RAAB) methodology to select 76 clusters of 50 participants aged ≥ 50 years with probability proportionate to size. Demographic and cataract surgery data were collected using questionnaires, visual acuity was assessed per World Health Organization criteria and examinations were conducted by torch, and with direct ophthalmoscopy in eyes with pinhole-corrected vision ResultsWe examined 3,629 of 3800 selected persons (95.5%). Age and sex adjusted prevalence of blindness (3/60 to ≤6/60), moderate visual impairment (MVI; >6/60 to ≤6/18), and early visual impairment (EVI; >6/18 to ≤6/12) were 2.14%, 2.35%, 9.68% and 14.7% respectively. Cataract was responsible for 75.0% of blindness and 75.8% of SVI, while refractive error caused 47.9% and 90.9% of MVI and EVI respectively. Most vision loss (95.9%) was avoidable. Cataract surgical coverage among the blind was 81.2%. Refractive error was detected in 17.1% (n = 622) of participants and 95.2% (n = 592) of these did not have spectacles. In the full Rohingya cohort of 76,692, approximately 10,000 surgeries are needed to correct all eyes impaired (ConclusionThe prevalence of blindness was lower than expected for a displaced population, in part due to few Rohingya being ≥60 years and the camp's good access to cataract surgery. We suggest the United Nations High Commissioner for Refugees include eye care among recommended health services for all refugees with long-term displacement

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

Azithromycin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatory actions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19. Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospital with COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients were randomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once per day by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatment groups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment and were twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants and local study staff were not masked to the allocated treatment, but all others involved in the trial were masked to the outcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) were eligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was 65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomly allocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall, 561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days (rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median 10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days (rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, no significant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilation or death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24). Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or other prespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restricted to patients in whom there is a clear antimicrobial indication. Funding UK Research and Innovation (Medical Research Council) and National Institute of Health Research