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Background: The pathogenesis of inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease is not well understood. This study investigated the roles and regulation of the claudin-1, -2, -3, and -4 isoforms in the pathogenesis of ulcerative colitis, and the potential therapeutic effects of nobiletin. Methods: Colitis was induced in rats by administering dextran sulfate sodium [DSS] in drinking water for seven days. Animals were treated daily with nobiletin [oral, 60 mg/Kg body weight] and studied in four groups, C [non-colitis control], D [DSS-induced colitis], CN [nobiletin-treated non-colitis control], and DN [nobiletin-treated DSS-induced colitis]. On day seven, the animals were sacrificed, and colonic tissues were collected and analyzed. Results: Both macroscopic and microscopic findings suggest the progression of colitis. In the inflamed colon, claudin-1 and -4 proteins were decreased, claudin-2 increased, while the claudin-3 protein remained unchanged. Except for claudin-1, these changes were not paralleled by mRNA expression, indicating a complex regulatory mechanism. Uniform β-actin expression along with consistent quality and yield of total RNA indicated selectivity of these changes. Nobiletin treatment reversed these changes. Conclusions: Altered expression of the claudin isoforms -1, -2, and -4 disrupts tight junctions, exposing the lamina propria to microflora, leading to electrolyte disturbance and the development of ulcerative colitis. Nobiletin with its anti-inflammatory properties may be useful in IBD.

The current practices and shortcomings of engineering students' English language teaching (ELT) syllabi were examined from the perspectives of learners and teachers in English as a foreign language (EFL) context. The syllabi included content that had little impact on students' communicative competence in English (CC-E). Students were generally concerned about their professional communication abilities. In this study, the researchers collected data from ten engineering-focused universities in Bangladesh. These universities' existing ELT syllabi (ELT-S) were examined, seeking the current practices and pitfalls. The study sampled 152 participants from the selected universities. The study followed a mixed-method approach. In the qualitative technique, content analysis, focus group discussion (FGD), and interviews were employed for data collection, while survey questions were used in the quantitative approach. The study's findings revealed that the existing English syllabi of those selected universities required updating and modification to meet the identified professional requirements regarding the type, credit allotment, content, classroom practices, class size, policies, etc. The improvements included redesigning English syllabi, material, and teaching methods to improve engineering students' communicative abilities. A uniform curriculum with at least one English language sessional course per semester in all engineering majors was strongly recommended.

Background: Mutations in NOD2/CARD15 gene have been linked to an increased risk of Crohn's disease (CD). The objective of this study is to determine NOD2/CARD15 gene mutations, and their association with the risk of CD in Arabs in Kuwait. Methods: Four NOD2 gene mutations, including Pro268Ser (SNP5), Arg702Trp (SNP8), Gly908Arg (SNP12), and Leu1007FsinsC (SNP13) were examined in Arab CD patients (n = 103) and control subjects (n = 100). The genomic DNA was isolated and used in polymerase chain reaction (PCR) with four sets of specific primers. The PCR-amplified DNA fragments were sequenced and analyzed for the NOD2 mutations. Logistic regression was used to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI). Results: Of the four genotyped variants, the Arg702Trp (SNP8) and Leu1007FsinsC (SNP13) variants were not informative in our study sample due to minor allele frequency of

Finding cost-efficient ways of increasing oil production with a low carbon footprint is the new challenge for the petroleum industry that wants to meet the net-zero emission goals by 2050. Smart water injection is an EOR process that increases oil production and delays water breakthrough by wettability alteration. Seawater is a smart water in chalk reservoirs, being especially effective at high temperatures. Different studies have shown that the effectiveness of seawater can be further improved by modifying the ion composition before injection. Carbonated water (CW) has been proposed as a potential EOR fluid. In addition to producing extra oil, the reduction of greenhouse gas (CO2) in the atmosphere can be achieved by using carbonated smart water as an injection fluid. The main mechanism behind increased oil recovery by injecting carbonated water is believed to be oil viscosity reduction and swelling, as the CO2 is transferred from the aqueous phase to the oil phase. Wettability alteration has also been proposed as a possible mechanism, and this hypothesis is further investigated in this study along with other proposed mechanisms. Stevns Klint outcrop chalk was used in this study, this material is recognized as an excellent analogue for North Sea chalk reservoirs. Optimized oil recovery by carbonated water in chalk was investigated at a high temperature (130°C) by flooding carbonated formation water (CFW) and carbonated seawater (CSW), to be compared with high saline formation water (FW) and seawater (SW) flooding. The oil/brine/rock/CO2 interactions were tracked by measuring the pH of the produced water (PW) and by identifying any mineralogical changes by SEM (Scanning Electron Microscope) and EDX (Energy Dispersive X-Ray) analyses. The solubility of CO2 in different brines was measured and compared with simulation data performed by PHREEQC. The diffusion of CO2 from the aqueous phase to the oil phase was analysed to check if enough CO2 can be diffused from the carbonated water into the oil phase. By flooding CSW in both secondary and tertiary modes, a slight increase in the oil recovery was observed and was found to be the best performing brine. The oil recovery was also slightly increased using CFW in tertiary mode after FW which does not behave like smart water for carbonates. The solubility of CO2 was low and increased by increasing pressure and decreasing brine salinity. The acidity of CW did not increase by increasing pressure. No changes in pore surface minerals were observed after CW flooding, confirming limited mineral dissolution. A mass transfer of CO2 from the brine phase to the oil phase was confirmed in the experimental work, but a significant amount of CO2 remained in the brine phase. The main mechanism behind this extra oil observed using CW is most likely not linked to oil swelling and viscosity reduction or mineral dissolution which could affect the porosity and the permeability of the rock system. Wettability alteration is a more likely explanation but needs to be looked further into for confirmation.

In order to provide fundamental stellar spectra that extend into the UV, Hubble Space Telescope’s Space Telescope Imaging Spectrograph targeted 556 stars via proposals GO9088, GO9786, GO10222, and GO13776. Exposures through three low-resolution gratings provide wavelength coverage from 0.2 < λ < 1 μ m at λ /Δ λ ∼ 1000. The UV grating (G230LB) scatters red light that results in unwanted signal, especially in cool stars. We applied scattered-light corrections and flux corrections arising from pointing errors relative to the center of the 0.″2 slit based on Worthey et al. We present 513 fully reduced stellar spectra, fluxed, dereddened, and cross correlated to zero velocity. Because of the broad spectral range, we can simultaneously study H α and Mg ii λ 2800, indicators of chromospheric activity. Their behaviors are decoupled. Besides three cool dwarfs and one giant with mild flares in H α , only Be stars show strong H α emission. Mg2800 emission, however, strongly anticorrelates with temperature such that warm stars show absorption and stars cooler than 5000 K universally show chromospheric emission regardless of dwarf/giant status or metallicity. Transformed to Mg2800 flux emerging from the stellar surface, we find a correlation with temperature with approximately symmetric astrophysical scatter. Previous work had indicated a basal level with asymmetric scatter to strong values. The discrepancy is primarily due to our improved treatment of extinction. We confirm statistically significant time variability in Mg2800 strength for one star.

In this study, we investigated a mechanistic link between Na−H exchanger-1 (NHE-1) and carbonic anhydrase (CA) in experimental colitis induced in the rats by intrarectal administration of trinitrobenzenesulphonic acid (TNBS). Western blot analysis showed CA-I and CA-II as the major isoforms and CA-IV as a minor one in the colon, and they all are expressed as minor isoforms in the ileum. Co-immunoprecipitation and confocal immunofluorescence microscopy showed colocalization of NHE-1 with CA-I and CA-II, but not with CA-IV. TNBS significantly reduced the levels of NHE-1 and CA protein isoforms in the colon, but not in the uninflamed ileum. A similar reduction profile of the expression of CA isozymes was also obtained in ex vivo treatment of normal colon strips with TNF-α. The level of uncoupling as detected by co-immunoprecipitation was significantly more pronounced. A peptide (83 aa) from the NHE-1 C-terminus demonstrated binding of CA-II only, but not of the CA-I or CA-IV isoform. Furthermore, the profile of inflammatory test markers confirmed inflammation in the tissue used. These findings taken together suggest an inflammation-induced uncoupling of CA and NHE-1, which might be a putative mechanism for reducing the activity of NHE-1 in experimental colitis. This uncoupling might lead to an intracellular accumulation of H+, resulting in acidosis and necrosis in the inflamed colon.

BACKGROUND:The Na-H exchanger [NHE] performs an electroneutral uptake of NaCl and water from the lumen of the gastrointestinal tract. There are several distinct NHE isoforms, some of which show an altered expression in the inflammatory bowel diseases (IBD). In this study, we examined a role of NHE-2 in experimental colitis. METHODS:Colitis was induced in male Sprague-Dawley rats by intra-rectal administration of trinitrobenzenesulphonic acid (TNBS). On day 6 post-TNBS, the animals were sacrificed, colonic and ileal segments were taken out, cleaned with phosphate buffered saline and used in this study. RESULTS:There was a significant decrease in the level of NHE-2 protein as measured by ECL western blot analysis and confocal immunofluorescence microscopy. The levels of NHE-2 mRNA and heteronuclear RNA measured by an end-point RT-PCR and a real time PCR were also decreased significantly in the inflamed colon. However, there was no change in the level of NHE-2 protein in response to in vitro TNF-α treatment of uninflamed rat colonic segment. These changes were selective and localized to the colon as actin, an internal control, remained unchanged. Confocal immunofluorescence microscopy revealed co-localization of NHE-2 and NHE-3 in the brush borders of colonic epithelial cells. Inflamed colon showed a significant increase in myeloperoxidase activity and colon hypertrophy. In addition, there was a significant decrease in body weight and goblet cells' mucin staining in the TNBS treated colon. These changes were not conspicuous in the non-inflamed ileum. CONCLUSIONS:These findings demonstrate suppression of NHE-2 expression on the brush borders in the colonic epithelial cells which is regulated transcriptionally. However a role of TNF-α in the regulation of NHE-2 is discounted in the present model of colitis. This decrease in the NHE-2 expression will lead to a loss of electrolyte and water uptake thus contributing to the symptoms associated with IBD.

BACKGROUND: Na+/H+ exchanger (NHE) is responsible for a net uptake of sodium chloride and water from the gastrointestinal tract and maintains electrolyte and water homeostasis. However, its status in human inflammatory bowel disease such as ulcerative colitis (UC) and Crohn’s disease (CD) remains poorly understood.

We have previously shown that antibodies to cholera toxin (CT) reacted with the major outer membrane proteins (MOMPs) from Campylobacter jejuni strains on Western blot. Further, oral immunization with CT significantly protected against challenge with C. jejuni in an adult mouse colonization model of infection. CT and the heat-labile enterotoxin (LT) of enterotoxigenic Escherichia coli are structurally and functionally related. LT and its mutants including the double-mutant LT (R192G/L211A) (dmLT), are powerful mucosal adjuvants. Unlike LT which is reactogenic, dmLT has been shown to be safe for human use. In the current study, we determined whether rabbit anti-dmLT antibodies reacted with MOMPs from C. jejuni strains and whether immunization with dmLT would afford protection against C. jejuni. On Western blot, the MOMPs from C. jejuni 48 (Penner serotype O:19), C. jejuni 75 (O:3) and C. jejuni 111 (O:1,44) were probed with rabbit antibodies to dmLT or LT-E112K (a non-toxic LT mutant), which showed a lack of reaction. Adult BALB/c mice were orally immunized with dmLT and orally challenged with C. jejuni 48 or 111. Protection from colonization with the challenge bacteria was studied by enumerating Campylobacter colonies in feces daily for 9 days. Vaccination produced robust serum and stool antibody responses to dmLT and no antibody responses to C. jejuni MOMP. Vaccinated mice showed reduced colonization and excretion of both challenge strains compared to control mice. However, the differences were not statistically significant. The protective efficacy of the dmLT vaccine varied from 9.1% to 54.5%. The lack of cross-reaction between the MOMP and dmLT suggests that protection is not mediated by cross-reacting antibodies, but may be due to activation of innate immunity. As dmLT is safe for humans, it could be incorporated into a C. jejuni vaccine to enhance its efficacy.

The notion that smooth muscle function is altered in inflammation is prompted by clinical observations of altered motility in patients with inflammatory bowel disease (IBD). While altered motility may reflect inflammation-induced changes in intrinsic or extrinsic nerves to the gut, changes in gut hormone release and changes in muscle function, recent studies have provided in vitro evidence of altered muscle contractility in muscle resected from patients with ulcerative colitis or Crohn’s disease. In addition, the observation that smooth muscle cells are more numerous and prominent in the strictured bowel of IBD patients compared with controls suggests that inflammation may alter the growth of intestinal smooth muscle. Thus, inflammation is associated with changes in smooth muscle growth and contractility that, in turn, contribute to important symptoms of IBD including diarrhea (from altered motility) and pain (via either altered motility or stricture formation). The involvement of smooth muscle in this context may be as an innocent bystander, where cells and products of the inflammatory process induce alterations in muscle contractility and growth. However, it is likely that intestinal muscle cells play a more active role in the inflammatory process via the elaboration of mediators and trophic factors, including cytokines, and via the production of collagen. The concept of muscle cells as active participants in the intestinal inflammatory process is a new concept that is under intense study. This report summarizes current knowledge as it relates to these two aspects of altered muscle function (growth and contractility) in the inflamed intestine, and will focus on mechanisms underlying these changes, based on data obtained from animal models of intestinal inflammation.

Background The COVID-19 pandemic has affected people globally, causing widespread illness and functional limitations. Methods This cross-sectional study aimed to investigate the association between COVID-19 symptoms and the functional status of COVID-19 survivors at Bangabandhu Sheikh Mujib Medical University (BSMMU) in Bangladesh. A total of 244 COVID-19 survivors were enrolled in the study, and their symptoms and functional status were assessed using standardized questionnaires. The post-COVID-19 functional status scale (PCFS) was used to assess the entire range of functional outcomes. Results Among the participants 57.4% were male and 42.6% were female. The mean (SD) age of the patients was 44.6 ±14.7 years where 37.7% were from the 20-35 years age group. The mean duration of suffering from COVID-19 was 15.9 ±6.1 days where 61.5 % of the patients had a duration of suffering of 11-20 days. Out of the 244 patients, 40 patients had no functional limitation (grade 0 functional status in the PCFS scale) while 100 had negligible functional limitation and 14 had severe functional limitation. We found patients who were suffering from multi-symptoms were statistically significant with PCFS scale grade 4, whereas grade 1 was found to be statistically significant with only respiratory distress. There was a significant association between the duration of COVID-19 symptoms and post-COVID-19 functional status for patients who experienced symptoms for 14 days or more (p Conclusions Considering the negative impact of COVID-19 symptoms on functional status, comprehensive care and support are required for COVID-19 survivors.

Background The COVID-19 pandemic has affected people globally, causing widespread illness and functional limitations. Methods This cross-sectional study aimed to investigate the association between COVID-19 symptoms and the functional status of COVID-19 survivors at Bangabandhu Sheikh Mujib Medical University (BSMMU) in Bangladesh. A total of 244 COVID-19 survivors were enrolled in the study, and their symptoms and functional status were assessed using standardized questionnaires. The post-COVID-19 functional status scale (PCFS) was used to assess the entire range of functional outcomes. Results Among the participants 57.4% were male and 42.6% were female. The mean (SD) age of the patients was 44.6 ±14.7 years where 37.7% were from the 20-35 years age group. The mean duration of suffering from COVID-19 was 15.9 ±6.1 days where 61.5 % of the patients had a duration of suffering of 11-20 days. Out of the 244 patients, 40 patients had no functional limitation (grade 0 functional status in the PCFS scale) while 100 had negligible functional limitation and 14 had severe functional limitation. We found patients who were suffering from multi-symptoms were statistically significant with PCFS scale grade 4, whereas grade 1 was found to be statistically significant with only respiratory distress. There was a significant association between the duration of COVID-19 symptoms and post-COVID-19 functional status for patients who experienced symptoms for 14 days or more (p Conclusions Considering the negative impact of COVID-19 symptoms on functional status, comprehensive care and support are required for COVID-19 survivors.