Fatty acid nitroalkenes - Multi-target agents for the treatment of sickle cell disease

Sickle cell disease (SCD) is a hereditary hematological disease with high morbidity and mortality rates worldwide. Despite being monogenic, SCD patients display a plethora of disease-associated complications including anemia, oxidative stress, sterile inflammation, vaso-occlusive crisis-related pain, and vasculopathy, all of which contribute to multiorgan dysfunction and failure. Over the past decade, numerous small molecule drugs, biologics, and gene-based interventions have been evaluated; however, only four disease-modifying drug therapies are presently FDA approved. Barriers regarding effectiveness, accessibility, affordability, tolerance, and compliance of the current polypharmacy-based disease-management approaches are challenging. As such, there is an unmet pharmacological need for safer, more efficacious, and logistically accessible treatment options for SCD patients. Herein, we evaluate the potential of small molecule nitroalkenes such as nitro-fatty acid (NO2-FA) as a therapy for SCD. These agents are electrophilic and exert anti-inflammatory and tissue repair effects through an ability to transiently post-translationally bind to and modify transcription factors, pro-inflammatory enzymes and cell signaling mediators. Preclinical and clinical studies affirm safety of the drug class and a murine model of SCD reveals protection against inflammation, fibrosis, and vascular dysfunction. Despite protective cardiac, renal, pulmonary, and central nervous system effects of nitroalkenes, they have not previously been considered as therapy for SCD. We highlight the pathways targeted by this drug class, which can potentially prevent the end-organ damage associated with SCD and contrast their prospective therapeutic benefits for SCD as opposed to current polypharmacy approaches.

Comparison of Pain Control and Analgesic Consumption With or Without Infiltration of Bupivacaine at Port Sites after Laparoscopic Cholecystectomy

Pain management is an essential component of all surgical procedures. Analgesics are used for this purpose but there are some complications in using them. Local anesthetics like bupivacaine can be used to reduce postoperative pain as well as analgesics consumption. The objective of this study is to observe the result of infiltration of bupivacaine at port sites and to compare the postoperative pain relief with that of opioids and NSAID administration following laparoscopic cholecystectomy for chronic calculus cholecystitis. This is a cross sectional study was conducted over one year in the Department of Surgery of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2018 to August 2019. Here total 40 patients were enrolled by purposive sampling. They were divided in two groups. One group received bupivacaine while other did not. A numerical pain scale was used as tool. Data will be recorded by peer reviewed interview and observation based semi structured data collection sheet. Data analysis was done by SPSS version 23.0. P-value was significant at (p<0.05) and determined by chi square test. Written informed consent was taken from the patient. The mean Numerical Rating Scale (NRS) score of pain at 6 hour was 2.55±0.6 in Group I and 6.8±1.15 in Group II. The mean NRS score of pain at 12 hour was 4.1±1.21 in Group I and 7.95±0.6 in Group II. The mean time of 1st analgesic administration was 13.85±1.57 hours in Group I and 2.75±0.72 hours in Group II. The mean repeat dose of analgesic was in 22±2.29 hours in Group I and 9.5±1.15 hours in Group II. In Group I one third patients (30.0%) single dose analgesic required in 1st 12 hours while in Group II almost 90.0% patients needed analgesics in 1st 12 hours. In Group I, total doses of analgesics required were 2 in 75.0% patients while in Group II at least 3 doses of analgesics were needed. In Group I only one patient needed analgesic in first 6 hours (5.0%) while in Group II, all the patients (100.0%) needed analgesics. The difference was statistically significant (p<0.05) between two groups. The patients receiving bupivacaine at port sites will experience less pain at postoperative period and will need less analgesic medications.

Demographic Characteristics of Patients with Breast Cancer in Bangladesh: A Single-Centre Study

We performed this study to investigate the socio-demographic factors of breast cancer patients of Bangladesh. This cross-sectional study was conducted in the Department of General Surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2018 to September 2019 for a period of one (1) year. All consecutive cases of breast carcinoma admitted in hospital and attended at outpatient department during the study period were selected as study population. Total 50 patients were selected. The mean age of the study patients was 51.1. Maximum number (70.0% cases) of breast cancer was belonged in 4th to 5th decade aged group. 70.0% breast cancer patients were housewives. The most of the breast carcinoma was reported in the urban people which were 78.0% cases. The percentage of educated study population was 80.0%. On religious background, 86.0% cases of breast cancer patients were Muslim. Most of breast cancer patients were sporadic in origin 94.0% cases, had no family history of breast cancer. Breast cancer was mostly distributed in pre-menopausal aged group with 82.0% cases. Ninety percent (90.0%) of the study population was come from middle class socio-economic group. In western countries, incidence of breast cancer is more in elderly aged menopause women with high socio-economic class. In this study the breast carcinoma was most prevalent among educated urban Muslim pre-menopausal housewives of age group 4th to 5th decade and most of them belonged to middle socio-economic class. The socio-demographic factors of breast cancer patients in Bangladesh are disparate from western countries in age standard, social class group and menstrual status.

Hematopoietic stem cell regeneration through paracrine regulation of the Wnt5a/Prox1 signaling axis

The crosstalk between the BM microenvironment (niche) and hematopoietic stem cells (HSCs) is critical for HSC regeneration. Here, we show that in mice, deletion of the Fanconi anemia (FA) genes Fanca and Fancc dampened HSC regeneration through direct effects on HSCs and indirect effects on BM niche cells. FA HSCs showed persistent upregulation of the Wnt target Prox1 in response to total body irradiation (TBI). Accordingly, lineage-specific deletion of Prox1 improved long-term repopulation of the irradiated FA HSCs. Forced expression of Prox1 in WT HSCs mimicked the defective repopulation phenotype of FA HSCs. WT mice but not FA mice showed significant induction by TBI of BM stromal Wnt5a protein. Mechanistically, FA proteins regulated stromal Wnt5a expression, possibly through modulating the Wnt5a transcription activator Pax2. Wnt5a treatment of irradiated FA mice enhanced HSC regeneration. Conversely, Wnt5a neutralization inhibited HSC regeneration after TBI. Wnt5a secreted by LepR⁺CXCL12⁺ BM stromal cells inhibited β-catenin accumulation, thereby repressing Prox1 transcription in irradiated HSCs. The detrimental effect of deregulated Wnt5a/Prox1 signaling on HSC regeneration was also observed in patients with FA and aged mice. Irradiation induced upregulation of Prox1 in the HSCs of aged mice, and deletion of Prox1 in aged HSCs improved HSC regeneration. Treatment of aged mice with Wnt5a enhanced hematopoietic repopulation. Collectively, these findings identified the paracrine Wnt5a/Prox1 signaling axis as a regulator of HSC regeneration under conditions of injury and aging.

Hes1 deficiency causes hematopoietic stem cell exhaustion

The transcriptional repressor Hairy Enhancer of Split 1 (HES1) plays an essential role in the development of many organs by promoting the maintenance of stem/progenitor cells, controlling the reversibility of cellular quiescence, and regulating both cell fate decisions. Deletion of Hes1 in mice results in severe defects in multiple organs and is lethal in late embryogenesis. Here we have investigated the role of HES1 in hematopoiesis using a hematopoietic lineage‐specific Hes1 knockout mouse model. We found that while Hes1 is dispensable for steady‐state hematopoiesis, Hes1‐deficient hematopoietic stem cells (HSCs) undergo exhaustion under replicative stress. Loss of Hes1 upregulates the expression of genes involved in PPARγ signaling and fatty acid metabolism pathways, and augments fatty acid oxidation (FAO) in Hes1^f/fVav1Cre HSCs and progenitors. Functionally, PPARγ targeting or FAO inhibition ameliorates the repopulating defects of Hes1^f/fVav1Cre HSCs through improving quiescence in HSCs. Lastly, transcriptome analysis reveals that disruption of Hes1 in hematopoietic lineage alters expression of genes critical to HSC function, PPARγ signaling, and fatty acid metabolism. Together, our findings identify a novel role of HES1 in regulating stress hematopoiesis and provide mechanistic insight into the function of HES1 in HSC maintenance.

Dye-sensitized InGaN nanowire arrays for efficient hydrogen production under visible light irradiation

Solar water splitting is a key sustainable energy technology for clean, storable and renewable source of energy in the future. Here we report that Merocyanine-540 dye-sensitized and Rh nanoparticle-decorated molecular beam epitaxially grown In0.25Ga0.75N nanowire arrays have produced hydrogen from ethylenediaminetetraacetic acid (EDTA) and acetonitrile mixture solution under green, yellow and orange solar spectra (up to 610 nm) for the first time. An apparent quantum efficiency of 0.3% is demonstrated for wavelengths 525-600 nm, providing a viable approach to harness deep-visible and near-infrared solar energy for efficient and stable water splitting.

Factors associated with thiopurine non-adherence in patients with inflammatory bowel disease

BACKGROUND

Medication non-adherence seems to be a particular problem in younger patients with inflammatory bowel disease (IBD) and has a negative impact on disease outcome.

AIMS

To assess whether non-adherence, defined using thiopurine metabolite levels, is more common in young adults attending a transition clinic than adults with IBD and whether psychological co-morbidity is a contributing factor. We also determined the usefulness of the Modified Morisky 8-item Adherence Scale (MMAS-8) to detect non-adherence.

METHODS

Seventy young adults [51% (36) male] and 74 [62% (46) male] adults were included. Psychological co-morbidity was assessed using the Hospital Anxiety Depression Scale (HADS) and self-reported adherence using the MMAS-8.

RESULTS

Twelve percent (18/144) of the patients were non-adherent. Multivariate analysis [OR, (95% CI), P value] confirmed that being young adult [6.1 (1.7-22.5), 0.001], of lower socio-economic status [1.1 (1.0-1.1), <0.01] and reporting higher HADS-D scores [1.2 (1.0-1.4), 0.01] were associated with non-adherence. Receiver operator curve analysis of MMAS-8 scores gave an area under the curve (95% CI) of 0.85 (0.77-0.92), (P < 0.0001): using a cut-off of <6, the MMAS-8 score has a sensitivity of 94% and a specificity of 64% to predict thiopurine non-adherence. Non-adherence was associated with escalation in therapy, hospital admission and surgeries in the subsequent 6 months of follow up.

CONCLUSIONS

Non-adherence to thiopurines is more common in young adults with inflammatory bowel disease, and is associated with lower socio-economic status and depression. The high negative predictive value of MMAS-8 scores <6 suggests that it could be a useful screen for thiopurine non-adherence.

Imaging slit-coupled surface plasmon polaritons using conventional optical microscopy

We develop a technique that now enables surface plasmon polaritons (SPPs) coupled by nano-patterned slits in a metal film to be detected using conventional optical microscopy with standard objective lenses. The crux of this method is an ultra-thin polymer layer on the metal surface, whose thickness can be varied over a nanoscale range to enable controllable tuning of the SPP momentum. At an optimal layer thickness for which the SPP momentum matches the momentum of light emerging from the slit, the SPP coupling efficiency is enhanced about six times relative to that without the layer. The enhanced efficiency results in distinctive and bright plasmonic signatures near the slit visible by naked eye under an optical microscope. We demonstrate how this capability can be used for parallel measurement through a simple experiment in which the SPP propagation distance is extracted from a single microscope image of an illuminated array of nano-patterned slits on a metal surface. We also use optical microscopy to image the focal region of a plasmonic lens and obtain results consistent with a previously-reported results using near-field optical microscopy. Measurement of SPPs near a nano-slit using conventional and widely-available optical microscopy is an important step towards making nano-plasmonic device technology highly accessible and easy-to-use.

Study on Mycobacterium tuberculosis: the primary drug resistance pattern

The study was carried out to investigate the primary drug resistance pattern of tubercle bacilli isolated from the pulmonary tuberculosis patient attended in Shyamoli TB clinic, Dhaka. Sputum from 961 suspected tuberculous patients were randomly collected and stained by Ziehl-Neelsen (Z.N) stain. 135 were microscopically positive for Acid Fast Bacilli (AFB). Among them 30 patients were excluded from the study as they received antitubercular treatment before. So only 105 microscopically positive cases were cultured on Lowenstein-Jensen (L-J) media and 100 showed pure growth and rest 5 were contaminated with fungus. These 100 cases were studied on 4 antitubercular drugs. Out of these 100 isolates, 91 were M. tuberculosis and rest 9 in the nonchromogen group of mycobacteria other than tuberculosis (MOTT) species. Among 91 M. tuberculosis species, 89 (97.80%) to Isoniazid (INH), 73 (80.21%) to Rifampicin (RMP) and 91 (100%) to Streptomycin (SM) and Ethambutol (ETHM) were sensitive. Of the 9 MOTT species, 4 (44.44%) to SM, 7 (77.78%) to ETHM were sensitive and all (100%) were resistant to INH and RMP. Among the 100 isolates, 27 (18 M. tuberculosis and 9 MOTT) were resistant to 4 drugs either single or in combination. Of the 18 (66.67%) M. tuberculosis species, 16 (59.26%) to RMP, and 2 (7.41%) to RMP and INH were resistant. Of the 9 (33.33%) MOTT species, 4 (14.81%) to RMP and INH, 3 (11.11%) to RMP, INH and SM and 2 (7.41%) to RMP, INH, SM and ETHM were resistant.

The transformation in vitro of peripheral lymphocytes of malnourished children

Children with protein energy malnutrition showed high deranged cellular immunity as evidenced by impairment of lymphocyte transformation after stimulation by phytohaemagglutination (PHA). The proliferative response (PR) to PHA measured by estimating incorporation of tritiated thymidine into newly synthesized DNA. In-vitro proliferative response to PHA was used as a marker for studying the functional characteristics of T lymphocytes of children with different categories of malnutrition. PHA response of peripheral blood lymphocytes obtained from different categories of severely malnourished children were significantly low compared to healthy control children (P < 0.01). The results indicate that cell mediated immunity was grossly depressed in severe malnutrition.