Insulin in Combination with N-Acetylcysteine Protects Hypoxia-Induced Toxicity in 661W Cells

Background: Proliferative diabetic retinopathy (PDR) is the leading cause of blindness among working-age adults. Photoreceptors are the most numerous and metabolically demanding cells in the retina thus oxygen is essential for retinal function. It has been reported that photoreceptors found in rat retina are specifically vulnerable to hypoxia. Hypoxia-induced metabolic stress leads to photoreceptor atrophy and retinopathy. Furthermore, photoreceptor cell death is known to occur mainly through apoptosis. However, the protection of hypoxia-induced-cytotoxicity in cone photoreceptor cells has not been investigated extensively. The aim of this study was to determine whether co-treatment of insulin and the N-Acetyl-L-Cysteine (NAC) (a free radical scavenger) efficiently protects against hypoxia-induced cytotoxicity in 661W cells. Methods: 661W, an immortalized mouse cone photoreceptor cells, were cultured at 5% CO2 at 37˚C in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% FBS, penicillin (100 units/mL), and streptomycin (100μg/mL). Cobalt (II) Chloride hexahydrate (CoCl2) was used to induce hypoxia. Insulin was suspended in sterile water, and NAC was diluted in the culture medium. For recovery experiment, cells were pretreated with CoCl2 for 24hrs, and then followed by replacing of medium with insulin (100nM) and NAC (3mM) alone, or with a combination of the two reagents for another 24hrs. Cell viability was determined by MTT assay in a 96 well culture plate. Morphological changes of the cells were observed and photographed under phase-contrast microscope and protein expression was measured by Western blot analysis. Statistical analysis was undertaken using independent two-tailed Students’ t-test and determined with SPSS Statistics software. Results: Treatment with CoCl2 significantly inhibited cell proliferation, reduced the number of viability cells, and induced apoptosis, initiated (poly (ADP-ribose) polymerase (PARP) cleavage, and increased caspase 3 activation. In addition, CoCl2 treatment led to oxidative stress, autophagy, and ubiquitination in the 661W cells. All of these effects, including cell proliferations were significantly reversed by the combination treatment of Insulin and NAC. In contrast, treatment with Insulin alone did not result in a similar protective effect and NAC partially protects against hypoxia induced toxicity. Conclusion: Hypoxia induces significant apoptosis, oxidative stress, and protein ubiquitination in 661W cone photoreceptors. A combination treatment of Insulin and NAC completely reversed such hypoxia-induced cytotoxicity. Additional research on a combination therapy employing insulin and NAC may provide a novel and promising therapeutic strategy for hypoxia-mediated cone photoreceptor cell damage

Highlights from International Conference on Cancer Health Disparities 2021

The first International Conference on Cancer Health Disparities (ICCHD) was held on August 13-14, 2021, in Harlingen, TX, USA. This two-day ICCHD-2021 was organized by the University of Texas Rio Grande Valley, School of Medicine (UTRGV-SOM). About 200 national and international delegates from 10 countries attended this hybrid meeting in person and through online digital platforms. The event delegates were representatives from National Institutes of Health (NIH), Cancer Prevention and Research Institute of Texas (CPRIT), and the City of Harlingen, in addition to clinicians, faculty, researchers, scientists, bioinformaticians, geneticists, bioethicists, and others. Under the theme of Cancer Health Disparities, this event featured a number of special talks and showcased the work done by researchers from a broad array of disciplines (academia, community, and health care) to identify gaps and/or solutions to multi-faceted heath and health disparity issues impacting minority and underserved populations across the country and worldwide. The conference was comprised of six sessions: Session 1: Introduction to the conference and tackling cancer health disparities; Session 2: Elimination of cancer health disparities; Session 3: Cancer cellular and molecular biology; Session 4: Diversity and Inclusion in cancer research: Session 5: Poster and oral presentations, and Early career investigator talks; Session 6: An award ceremony and closing remarks. This conference report summarizes the meeting’s content, discussions, and conclusions

Limitations of microscopy to differentiate Plasmodium species in a region co-endemic for Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi

BackgroundIn areas co-endemic for multiple Plasmodium species, correct diagnosis is crucial for appropriate treatment and surveillance. Species misidentification by microscopy has been reported in areas co-endemic for vivax and falciparum malaria, and may be more frequent in regions where Plasmodium knowlesi also commonly occurs. MethodsThis prospective study in Sabah, Malaysia, evaluated the accuracy of routine district and referral hospital-based microscopy, and microscopy performed by an experienced research microscopist, for the diagnosis of PCR-confirmed Plasmodium falciparum, P. knowlesi, and Plasmodium vivax malaria. ResultsA total of 304 patients with PCR-confirmed Plasmodium infection were enrolled, including 130 with P. knowlesi, 122 with P. falciparum, 43 with P. vivax, one with Plasmodium malariae and eight with mixed species infections. Among patients with P. knowlesi mono-infection, routine and cross-check microscopy both identified 94 (72%) patients as “P. malariae/P. knowlesi”; 17 (13%) and 28 (22%) respectively were identified as P. falciparum, and 13 (10%) and two (1.5%) as P. vivax. Among patients with PCR-confirmed P. falciparum, routine and cross-check microscopy identified 110/122 (90%) and 112/118 (95%) patients respectively as P. falciparum, and 8/122 (6.6%) and 5/118 (4.2%) as “P. malariae/P. knowlesi”. Among those with P. vivax, 23/43 (53%) and 34/40 (85%) were correctly diagnosed by routine and cross-check microscopy respectively, while 13/43 (30%) and 3/40 (7.5%) patients were diagnosed as “P. malariae/P. knowlesi”. Four of 13 patients with PCR-confirmed P. vivax and misdiagnosed by routine microscopy as “P. malariae/P. knowlesi” were subsequently re-admitted with P. vivax malaria. ConclusionsMicroscopy does not reliably distinguish between P. falciparum, P. vivax and P. knowlesi in a region where all three species frequently occur. Misdiagnosis of P. knowlesi as both P. vivax and P. falciparum, and vice versa, is common, potentially leading to inappropriate treatment, including chloroquine therapy for P. falciparum and a lack of anti-relapse therapy for P. vivax. The limitations of microscopy in P. knowlesi-endemic areas supports the use of unified blood-stage treatment strategies for all Plasmodium species, the development of accurate rapid diagnostic tests suitable for all species, and the use of PCR-confirmation for accurate surveillance

Integration of Structural Constraints into TSP Models

International audienceSeveral models based on constraint programming have been proposed to solve the traveling salesman problem (TSP). The most efficient ones, such as the weighted circuit constraint (WCC), mainly rely on the Lagrangian relaxation of the TSP, based on the search for spanning tree or more precisely "1-tree". The weakness of these approaches is that they do not include enough structural constraints and are based almost exclusively on edge costs. The purpose of this paper is to correct this drawback by introducing the Hamiltonian cycle constraint associated with propagators. We propose some properties preventing the existence of a Hamiltonian cycle in a graph or, conversely, properties requiring that certain edges be in the TSP solution set. Notably, we design a propagator based on the research of k-cutsets. The combination of this constraint with the WCC constraint allows us to obtain, for the resolution of the TSP, gains of an order of magnitude for the number of backtracks as well as a strong reduction of the computation time

Adhesion formation after intracapsular myomectomy with or without adhesion barrier.

Objective: To show the prevention of adhesion formation by placing an absorbable adhesion barrier after intracapsular myomectomy. Design: Prospective blinded observational study. Setting: University-affiliated Hospitals. Patient(s): Patients R18 years old with single or multiple uterine fibroids removed by laparoscopic or abdominal intracapsular myomectomy. Intervention(s): A total of 694 women undergoing laparoscopic or abdominal myomectomy were randomized for placement of oxidized regenerated cellulose absorbable adhesion barrier to the uterine incision or for control subjects without barriers. The presence of adhesions was assessed in 546 patients who underwent subsequent surgery. MainOutcomeMeasure(s): Theprimaryandsecondaryoutcomesoftheanalysiswerethepresenceandseverityof adhesions for four groups: laparotomy with barrier, laparotomy without barrier, laparoscopy with barrier, and laparoscopy without barrier. Result(s): Therewasahigherrateofadhesionsinlaparotomywithoutbarrier(28.1%)comparedwithlaparoscopy with no barrier (22.6%), followed by laparotomy with barrier (22%) and laparoscopy with barrier (15.9%). Additionally, the type of adhesions were different, filmy and organized were predominant with an adhesion barrier, and cohesive adhesions were more common without an adhesion barrier. Conclusion(s): Oxidized regenerated cellulose reduces postsurgical adhesions. Cohesive adhesions reduction was noted in laparoscopy

Reproducible doxycycline-inducible transgene expression at specific loci generated by Cre-recombinase mediated cassette exchange

Comparative analysis of mutants using transfection is complicated by clones exhibiting variable levels of gene expression due to copy number differences and genomic position effects. Recombinase-mediated cassette exchange (RMCE) can overcome these problems by introducing the target gene into pre-determined chromosomal loci, but recombination between the available recombinase targeting sites can reduce the efficiency of targeted integration. We developed a new LoxP site (designated L3), which when used with the original LoxP site (designated L2), allows highly efficient and directional replacement of chromosomal DNA with incoming DNA. A total of six independent LoxP integration sites introduced either by homologous recombination or retroviral delivery were analyzed; 70–80% of the clones analyzed in hamster and human cells were correct recombinants. We combined the RMCE strategy with a new, tightly regulated tetracycline induction system to produce a robust, highly reliable system for inducible transgene expression. We observed stable inducible expression for over 1 month, with uniform expression in the cell population and between clones derived from the same integration site. This system described should find significant applications for studies requiring high level and regulated transgene expression and for determining the effects of various stresses or oncogenic conditions in vivo and in vitro