Expression Profiling of EMT Transcriptional Regulators ZEB1 and ZEB2 in Different Histopathological Grades of Oral Squamous Cell Carcinoma Patients.

Background: Pakistan has a high burden of oral cancers, with a prevalence rate of around 9%. Oral Squamous Cell Carcinoma (OSCC) accounts for about 90% of oral cancer cases. Epithelial to Mesenchymal Transition (EMT) gets highly stimulated in tumor cells by adopting subsequent malignant features of highly invasive cancer populations. Zinc Finger E-Box binding factors, ZEB1 and ZEB2, are regulatory proteins that promote EMT by suppressing the adherent ability of cells transforming into highly motile cancerous cells. The present study aimed to analyze the expression of EMT regulators, ZEB1 and ZEB2, and their association with the clinicopathological features in different grades of OSCC patients. Methods: Tissue samples were collected for both case and control groups from the recruited study participants. Cancer tissues (cases) were collected from the confirmed OSCC patients, and healthy tissues (controls) were collected from third-molar dental extraction patients. The study participants were recruited with informed consent and brief demographic and clinical characteristics. The case group was further segregated with respect to the histological cancer grading system into well-differentiated (WD), moderately differentiated (MD), and poorly differentiated (PD) squamous cell carcinoma (SCC) groups. RNA was extracted from the tissue samples for expression profiling of ZEB1 and ZEB2 genes through quantitative real-time PCR (qRT-PCR). Results: All of the recruited participants had a mean age of 46.55 ± 11.7 (years), with most of them belonging to Urdu speaking ethnic group and were married. The BMI (kg/m2) of the healthy participants was in the normal range (18-22 kg/m2). However, BMI was found to be reduced with the proliferation in the pathological state of cancer. The oral hygiene of patients was better than the healthy participants, possibly due to the strict oral hygiene practice concerns of consultants. Every recruited OSCC patient had one or multiple addiction habits for more than a year. Patients reported health frailty (46.6%), unhealed mouth sores (40%), swallowing difficulties and white/reddish marks (80%), and restricted mouth opening (64.4%). Furthermore, 82.2% of the recruited patients observed symptoms within 1-12 months, and buccal mucosa was the most exposed tumor site among 55.6% of the patients. Expression profiling of EMT regulators showed gradual over-expressions of ZEB1 (8, 20, and 42 folds) and ZEB2 (4, 10, and 18 folds) in respective histological cancer grades. Conclusion: High expressions of ZEBs have been significantly associated with cancer progression and poor health. However, no association was found between OSCC with other clinicopathological features when compared to healthy controls.

Exploring the Effect of Cetylpyridinium Chloride Addition on the Antibacterial Activity and Surface Hardness of Resin-Based Dental Composites.

The aim of this study was to evaluate the effect of cetylpyridinium chloride (CPC) addition on the antibacterial and surface hardness characteristics of two commercial resin-based dental composites (RBDCs). A total of two hundred and seventy (n = 270) specimens from Filtek Z250 Universal and Filtek Z350 XT flowable RBDCs were fabricated with the addition of CPC at 2 %wt and 4 %wt concentrations to assess their antibacterial activity using the agar diffusion test and direct contact inhibition test, and their surface hardness using the Vickers microhardness test after 1 day, 30 days, and 90 days of aging. A surface morphology analysis of the specimens was performed using a scanning electron microscope (SEM). The RBDCs that contained 2 %wt and 4 %wt CPC demonstrated significant antibacterial activity against Streptococcus mutans up to 90 days, with the highest activity observed for the 4 %wt concentration. Nevertheless, there was a reduction in antibacterial effectiveness over time. Moreover, compared to the control (0 %wt) and 2 %wt CPC groups, the universal RBDCs containing 4 %wt CPC exhibited a notable decrease in surface hardness, while all groups showed a decline in hardness over time. In conclusion, the satisfactory combination of the antibacterial effect and surface hardness property of RBDCs was revealed with the addition of a 2 %wt CPC concentration.

Anti-fungal efficacy of Miswak Extract (Salvadora Persica) and commercial cleaner against Candida albicans on heat cured polymethylmethacrylate denture base.

AIM: The aim of the study was to compare the antifungal efficacy between commercial cleaner (Corega) and Miswak extract (Salvadora persica) against Candida albicans on heat cured Polymethyl methacrylate (PMMA) acrylic denture base resin. MATERIALS AND METHODS: Forty-eight samples of heat cured PMMA acrylic denture base resin were fabircated in the study. The sterile acrylic resin specimens were immersed in standardized cell suspension of Candida albicans and incubated for 60 min at 370°C for cell adhesion and 2 h at 370°C for biofilm formation. After 24 h biofilm was evaluated by cell viability (CFUs) on SDA and cell counting of Candida albicans under light microscope at 400× magnification. The fungicidal effect of commercial cleaner and Miswak extract on Candida albicans biofilm was then evaluated by colony-forming units on SDA and cell counting under light microscope at 400× magnification. RESULTS: Screening test agar disk-diffusion assay showed mean inhibitory zone of 3 mm for commercial cleaner as compared to Miswak extract, which showed mean inhibitory zone of 2 and 1 mm for different concentrations. Broth microdilution method showed 31 mg/ml MIC and 62.5 mg/ml Minimal Fungicidal Concentration (MFC) values for commercial cleaner as compared to Miswak extract that showed 125 mg/ml MIC and 250 mg/ml MFC values against Candida albicans. A significant difference (p < 0.05) was observed between pre and post treatment of both commercial cleaner and Miswak extract, for CFUs and cell count for Candida albicans. CONCLUSION: Commercial denture cleaner (Corega) showed better antifungal (C albicans) activity than Miswak extract (Salvadora persica) on heat cured PMMA acrylic denture base resin.

Waste Valorization of a Recycled ZnCoFe Mixed Metal Oxide/Ceftriaxone Waste Layered Nanoadsorbent for Further Dye Removal.

Waste valorization of spent wastewater nanoadsorbents is a promising technique to support the circular economy strategies. The terrible rise of heavy metal pollution in the environment is considered a serious threat to the terrestrial and aquatic environment. This led to the necessity of developing cost-effective, operation-convenient, and recyclable adsorbents. ZnCoFe mixed metal oxide (MMO) was synthesized using co-precipitation. The sample was characterized using X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Factors affecting the adsorption process such as pH, the dose of adsorbent, and time were investigated. ZnCoFe MMO showed the maximum adsorption capacity of 118.45 mg/g for ceftriaxone sodium. The spent MMO was recycled as an adsorbent for malachite green (MG) removal. Interestingly, the spent adsorbent showed 94% removal percent for MG as compared to the fresh MMO (90%). The kinetic investigation of the adsorption process was performed and discussed. In addition, ZnCoFe MMO was tested as an antimicrobial agent. The proposed approach opens up a new avenue for recycling wastes after adsorption into value-added materials for utilization in adsorbent production with excellent performance as antimicrobial agents.

Gemifloxacin-transition metal complexes as therapeutic candidates: antimicrobial, antifungal, anti-enzymatic, and docking studies of newly synthesized complexes.

In the era of acquired microbial resistance (AMR), resulting in the ineffectiveness of antibiotics is of keen interest for researchers in current scenarios. Ten novel metal complexes of gemifloxacin have been synthesized by reacting it with essential and trace elements in a 2:1 ratio predetermined conducto-metrically. As these metals are either present in the body or co-administered as metallic supplements can alter the level of antibiotics. Therefore, Metal complexes of Gemifloxacin, an important member of the fluoroquinolone family, were synthesized. The possible coordination of gemifloxacin with these metals has been proposed by the electronic and elemental data obtained through molar conductance, elemental analysis, and spectroscopic techniques like ultraviolet-visible (UV-Vis), infrared (IR), and proton-nuclear magnetic resonance (1H NMR) studies. In the light of these studies, the monoanionic bidentate ligand behavior of gemifloxacin in complexation with metals has been revealed. For in-vitro microbial studies, these newly synthesized complexes were tested against eleven different bacteria including Gram + ve and Gram -ve organisms, and one fungal strain. The results were compared with the parent drug by applying ANOVA through SPSS software version 22. Therefore, it has been found that among all synthesized metal complexes, the G-M01 complex exhibits increased activity against B. subtilis, P. mirabilis, E. coli, K. pneumonia, and C. freundii. Complex G-M02, G-M03, G-M04, and G-M10 show more pronounced activity than Gemifloxacin against S. aureus and M. luteus. Moreover, the binding orientations of the synthesized metal complexes into the binding site of the urease enzyme revealed that all the docked metal complexes oriented away from the Ni bi-center, and the inactivation of urease is due to their interaction with entrance flap residues.

Cellulose-based activated carbon/layered double hydroxide for efficient removal of Clarithromycin residues and efficient role in the treatment of stomach ulcers and acidity problems.

The terrible rise of antibiotic residues which possesses a serious threat to the ecological and aquatic environments. So, the development of highly cost-effective, highly operation-convenient and recyclable adsorbents was a must. In our study, we utilized the ternary layered double hydroxide (CoZnAl LDH) as an efficient adsorbent and nano-carrier for Clarithromycin (CLA) residues for their biodegradability and biocompatibility. Also, we enhanced the removal efficiency of the synthesized ternary LDH using cellulose-based activated carbon which was obtained using the hydrothermal carbonization method followed by chemical activation via static air converting the cellulose derivative (hydroxy ethyl cellulose HEC) into highly porous activated carbon that played an important role in the adsorption process. Full characterization of the synthesized activated carbon (AC) and the adsorbents before and after the adsorption processes were carried out using different techniques. The differences between the two adsorbents were investigated in a comparative study in terms of factors affecting the adsorption process like pH, the dose of adsorbent, time, and temperature. The adsorption isotherm was investigated at pH 10 with high regression coefficient (R2) of 0.99 showing maximum adsorption capacity (qmax) of 61.5 mg/g for (CLA) using LDH as adsorbent, whereas, the investigation using the modified LDH (LDH-AC) with high regression coefficient (R2) of 0.99 shows maximum adsorption capacity (qmax) of 495 mg/g for (CLA). Kinetic studies were estimated. The thermodynamic parameters such as ΔS°, ΔG° and ΔH° were estimated showing that the adsorption processes undergo exothermic and spontaneous routes. The safety and cytotoxicity of the modified, synthesized LDH (LDH-AC) were investigated besides the investigation of the gastroprotective efficacy against generated stomach ulcers. (LDH-AC) showed significant reduction for the generated ulcer in addition to the enhancement of the gastro protective efficacy revealing the safe use of LDH-AC/CLA for biological purposes like ulcer reduction and the enhancement of the ulcer inhibition.

Understanding the physicochemical properties of Zn-Fe LDH nanostructure as sorbent material for removing of anionic and cationic dyes mixture.

In our work, the removal of cationic and anionic dyes from water was estimated both experimentally and computationally. We check the selectivity of the adsorbent, Zn-Fe layered double hydroxide (LDH) toward three dyes. The physical and chemical properties of the synthesis adsorbent before and after the adsorption process were investigated using X-ray photoelectron spectroscopy, energy dispersive X-ray, X-ray diffraction, FT-IR, HRTEM, and FESEM analysis, particle size, zeta potential, optical and electric properties were estimated. The effect of pH on the adsorption process was estimated. The chemical stability was investigated at pH 4. Monte Carlo simulations were achieved to understand the mechanism of the adsorption process and calculate the adsorption energies. Single dye adsorption tests revealed that Zn-Fe LDH effectively takes up anionic methyl orange (MO) more than the cationic dyes methylene blue (MB) and malachite green (MG). From MO/MB/MG mixture experiments, LDH selectively adsorbed in the following order: MO > MB > MG. The adsorption capacity of a single dye solution was 230.68, 133.29, and 57.34 mg/g for MO, MB, and MG, respectively; for the ternary solution, the adsorption capacity was 217.97, 93.122, and 49.57 mg/g for MO, MB, and MG, respectively. Zn-Fe LDH was also used as a photocatalyst, giving 92.2% and 84.7% degradation at concentrations of 10 and 20 mg/L, respectively. For visible radiation, the Zn-Fe LDH showed no activity.

Association between Interleukin-1ß Gene Polymorphism and Chronic Periodontitis.

OBJECTIVES: Periodontitis is a pathological condition of the oral cavity, originating from multiple factors, including microbial, environmental and genetic factors. The vulnerability to several pathologies has been studied with the relationship to genetic polymorphisms, and one of the most prominent is the single nucleotide polymorphisms throughout the genome. The study aimed to find out the association of single nucleotide polymorphism (SNP) of interleukin-1ß +3954 gene with chronic periodontitis (CP) in Pakistan MATERIALS AND METHODS: This case-control study was conducted at Dow University of Health Sciences. DNA was extracted from the blood and amplified by using conventional polymerase chain reaction of respective genes followed by sequencing. Mann-Whitney test accessed the difference of clinical parameters between cases and controls, and Fisher's exact test was applied to access the association of alleles between subjects. Data entered and analyzed using SPSS 21. RESULTS: Significant differences were observed in clinical parameters in cases and controls (p < 0.001). In the IL-1ß +3954 gene, T alleles were significantly higher in cases as compared with controls (p < 0.001). Genotype CC was significantly dominant in the controls and genotype CT and TT in patients (Chi-square = 19.83, p < 0.001). CONCLUSION: Within the study's limits, IL-1ß +3954 gene polymorphism is associated with periodontitis and is expected to be among the several causes of respective pathology in Pakistan's population.

Case-control study for assessment of factors associated with periodontitis among adults attending a university hospital in Karachi, Pakistan.

OBJECTIVE: To compare the physiological and biochemical markers in healthy and periodontitis subjects, and to relate these markers with the periodontal health condition. METHOD: The case-control study was conducted at the Dow University of Health Sciences, Karachi, from April 2017 to March 2018, and comprised systematically healthy controls and periodontitis cases. Periodontal probing depth, clinical attachment loss, oral hygiene indices, educational status and body mass index were recorded for all the subjects. Serum levels of biochemical markers, including calcium, phosphate and interleukin-6, were also measured. Data was analysed using SPSS 16. RESULTS: Of the 150 subjects, 75(50%) each were in the case and control groups. The overall mean age was 31.23±3.7 years (range: 22-42 years). The cases had relatively poor oral hygiene indices and educational status compared to the controls (p<0.05). Serum calcium level was lower, whereas mean body mass index was higher in the cases compared to the controls (p<0.05). No significant difference was found in interleukin-6 and phosphate levels (p>0.05). Clinical attachment loss showed significant correlation (p<0.05). CONCLUSIONS: Low serum calcium and educational levels, higher body mass index and poor oral hygiene were found to be the risk factors for the progression of periodontitis.

Overview of schizophrenia research and treatment in Pakistan.

Mental health is the most neglected health sector in Pakistan, and the majority of citizens have limited or no access to primary and secondary psychiatric services. The incidence of schizophrenia (SCZ) has increased at an alarming rate in Pakistan, relative to that of other psychiatric disorders. While numerous studies have investigated SCZ, few have addressed the issue about the Pakistani population. In the present review, the researchers discuss current data integral to the prevalence, pathophysiology, and molecular genetics of SCZ; treatment approaches to the disease; and patient responses to drugs prescribed for SCZ in Pakistan. Most Pakistani patients exhibit poor responses to antipsychotic drugs. Based on our review, the researchers hypothesize that genetic dissimilarities between Pakistani and Western populations contribute to such poor responses. Consequently, an understanding of such genetic differences and the provision of personalized treatment may simultaneously aid in improving SCZ treatment in Pakistan.

Probiotic potential of Saccharomyces strains isolated from Litchi chinensis (Lychee fruit).

Recently, probiotic yeasts have become an interesting topic of research all over the world. Saccharomyces cerevisiae is well proven probiotic yeast against several gastrointestinal diseases. Current study aimed to explore the probiotic potential and antibacterial properties of Saccharomyces strains isolated from fresh lychee fruits available in local markets of Karachi, Pakistan. Probiotic potential and antibacterial activity of locally isolated probiotic yeast strains (named as S. cerevisiae BEL 1 and S. cerevisiae BEL 9) was studied against gastrointestinal pathogens using standard in vitro screening methods. Comparative analysis was also carried out with commercially available S. boulardii probiotic preparations. Furthermore, for probiotic potential, all the studied yeast strains were exposed to various stress conditions inherent of gastrointestinal tract i.e., thermo tolerance, pH tolerance, bile salts survivability and osmo-tolerance. Isolated strains (BEL 1 and BEL 9) were able to tolerate at the temperatures (40oC and 45oC), moreover survived in the presence of gastric juices, extreme bile salt concentrations (range 0.5%-2%) and different osmotic stress conditions (1M and 1.5 M NaCl). Optimal growth was observed at 37oC. Similar growth pattern and viability of BEL 1 and 9 was found for most of the stress conditions, when compared with the commercially available strains of S. boulardii. Therefore, isolated yeast strains BEL 1 and 9 will be considered as a potential bio-therapeutic agent because of the promising probiotic potential.

Gamma radiation as a green method to enhance the dielectric behaviour, magnetization, antibacterial activity and dye removal capacity of Co-Fe LDH nanosheets.

Nowadays, improving the physico-chemical properties of nanomaterials to enhance their performance towards various applications is urgent. Accordingly, gamma irradiation (GI) has evolved and attracted wide attention as a promising green technique to meet this need. In the current study, a Co-Fe LDH was used as a model 2D nanomaterial and was irradiated by GI (dose = 100 kGy). The sample was characterized via XRD, FTIR, FESEM, HRTEM, hydrodynamic size, zeta potential, and BET surface area measurements. The results showed that after irradiation, the surface area of the sample increased from 83 to 89 m2 g-1. Moreover, irradiation increased its dielectric constant, dielectric loss and AC conductivity. In addition, the sample showed superparamagnetic behavior, where its saturation magnetization increased from 1.28 to 52.04 emu g-1 after irradiation. Furthermore, the adsorption capacity of the irradiated LDH towards malachite green (MG) and methylene blue (MB) as model wastewater pollutants was also studied. The exposure of LDH to GI enhanced its adsorption capacity for MG from 44.73 to 54.43 mg g-1. The Langmuir-Freundlich, Sips, and Baudu models were well suited for both MG and MB adsorption among the six fitted isotherm models. The pseudo-first and second order models fit the adsorption kinetics better than the intraparticle diffusion model for both dyes. The interaction of MB and MG with the LDH surface was further investigated in dry and aqueous solution using Grand canonical Monte Carlo and molecular dynamics simulations. These two techniques provided insight into the adsorption mechanism, which is vital to understand the adsorption process by the LDH nanosheets and their possible use in practical applications. Moreover, the Co-Fe LDH showed good antibacterial activity against both Gram-positive and Gram-negative bacteria strains. Furthermore, due to its magnetic property, the Co-Fe LDH could be simply recovered from water by magnetic separation at a low magnetic field after the adsorption process.

Post-translational Serine/Threonine Phosphorylation and Lysine Acetylation: A Novel Regulatory Aspect of the Global Nitrogen Response Regulator GlnR in S. coelicolor M145.

Soil-dwelling Streptomyces bacteria such as S.coelicolor have to constantly adapt to the nitrogen (N) availability in their habitat. Thus, strict transcriptional and post-translational control of the N-assimilation is fundamental for survival of this species. GlnR is a global response regulator that controls transcription of the genes related to the N-assimilation in S. coelicolor and other members of the Actinomycetales. GlnR represents an atypical orphan response regulator that is not activated by the phosphorylation of the conserved aspartate residue (Asp 50). We have applied transcriptional analysis, LC-MS/MS analysis and electrophoretic mobility shift assays (EMSAs) to understand the regulation of GlnR in S. coelicolor M145. The expression of glnR and GlnR-target genes was revisited under four different N-defined conditions and a complex N-rich condition. Although, the expression of selected GlnR-target genes was strongly responsive to changing N-concentrations, the glnR expression itself was independent of the N-availability. Using LC-MS/MSanalysis we demonstrated that GlnR was post-translationally modified. The post-translational modifications of GlnR comprise phosphorylation of the serine/threonine residues and acetylation of lysine residues. In the complex N-rich medium GlnR was phosphorylated on six serine/threonine residues and acetylated on one lysine residue. Under defined N-excess conditions only two phosphorylated residues were detected whereas under defined N-limiting conditions no phosphorylation was observed. GlnR phosphorylation is thus clearly correlated with N-rich conditions. Furthermore, GlnR was acetylated on four lysine residues independently of the N-concentration in the defined media and on only one lysine residue in the complex N-rich medium. Using EMSAs we demonstrated that phosphorylation inhibited the binding of GlnR to its targets genes, whereas acetylation had little influence on the formation of GlnR-DNA complex. This study clearly demonstrated that GlnR DNA-binding affinity is modulated by post-translational modifications in response to changing N-conditions in order to elicit a proper transcriptional response to the latter.

Competition between the GlnR and PhoP regulators for the glnA and amtB promoters in Streptomyces coelicolor.

Interaction of regulatory networks is a subject of great interest in systems biology of bacteria. Phosphate control of metabolism in Streptomyces is mediated by the two-component system PhoR-PhoP. Similarly, the utilization of different nitrogen sources is controlled by the regulator GlnR. Transcriptomic and biochemical analysis revealed that glnA (encoding a glutamine synthetase), glnR and other nitrogen metabolism genes are under PhoP control. DNA-binding experiments showed that PhoP binds to other nitrogen-regulated genes (SCO0255, SCO01863 and ureA). Using the glnA promoter as model, we observed that PhoP and GlnR compete for binding to the same promoter region, showing GlnR a higher affinity. Using a total of 14 GlnR-binding sites (50 direct repeat units) we established two information-based models that describe the GlnR box as consisting of two 11-nt direct repeats each with clear differences to PHO box. DNA-binding studies with different mutant sequences of glnA promoter revealed that the sequence recognized by GlnR is found in the coding strand whereas that recognized by PhoP is overlapping in the non-coding strand. In amtB promoter PhoP and GlnR boxes are not totally overlapping and both proteins bind simultaneously. PhoP control of nitrogen metabolism genes helps to balance the cellular P/N equilibrium.

Extracting regulator activity profiles by integration of de novo motifs and expression data: characterizing key regulators of nutrient depletion responses in Streptomyces coelicolor.

Determining transcriptional regulator activities is a major focus of systems biology, providing key insight into regulatory mechanisms and co-regulators. For organisms such as Escherichia coli, transcriptional regulator binding site data can be integrated with expression data to infer transcriptional regulator activities. However, for most organisms there is only sparse data on their transcriptional regulators, while their associated binding motifs are largely unknown. Here, we address the challenge of inferring activities of unknown regulators by generating de novo (binding) motifs and integrating with expression data. We identify a number of key regulators active in the metabolic switch, including PhoP with its associated directed repeat PHO box, candidate motifs for two SARPs, a CRP family regulator, an iron response regulator and that for LexA. Experimental validation for some of our predictions was obtained using gel-shift assays. Our analysis is applicable to any organism for which there is a reasonable amount of complementary expression data and for which motifs (either over represented or evolutionary conserved) can be identified in the genome.

A novel GlnR target gene, nnaR, is involved in nitrate/nitrite assimilation in Streptomyces coelicolor.

GlnR is the global transcriptional regulator of nitrogen assimilation in Streptomyces coelicolor. Under nitrogen starvation, GlnR controls the transcription of at least nine genes associated with nitrogen metabolism. In this study, we identified a new GlnR target gene, SCO2958, named nnaR (nitrate/nitrite assimilation regulator). In silico analysis of NnaR revealed the presence of two distinct domains: an N-terminal uroporphyrinogen-III synthase (HemD)-like enzymatic domain and a C-terminal DNA binding domain. Complementation experiments with a haemin auxotroph Escherichia coli ΔhemD mutant strain revealed that NnaR has no HemD activity. Physiological studies of an S. coelicolor nnaR : : Tn5062 mutant showed that NnaR is involved in regulating nitrite reduction. By electrophoretic mobility shift assays the functionality of the NnaR DNA binding domain was confirmed, and it was found that NnaR binds in front of the genes narK (putative nitrate extrusion protein), nirB (nitrite reductase), nirA (putative nitrite/sulphite reductase) and nasA (putative nitrate reductase), which are associated with nitrate/nitrite assimilation. Furthermore, a cooperative binding of NnaR together with GlnR to the nirB promoter was observed, suggesting that NnaR may act as a GlnR co-activator.

The PII protein GlnK is a pleiotropic regulator for morphological differentiation and secondary metabolism in Streptomyces coelicolor.

GlnK is an important nitrogen sensor protein in Streptomyces coelicolor. Deletion of glnK results in a medium-dependent failure of aerial mycelium and spore formation and loss of antibiotic production. Thus, GlnK is not only a regulator of nitrogen metabolism but also of morphological differentiation and secondary metabolite production. Through a comparative transcriptomic approach between the S. coelicolor wild-type and a S. coelicolor glnK mutant strain, 142 genes were identified that are differentially regulated in both strains. Among these are genes of the ram and rag operon, which are involved in S. coelicolor morphogenesis, as well as genes involved in gas vesicle biosynthesis and ectoine biosynthesis. Surprisingly, no relevant nitrogen genes were found to be differentially regulated, revealing that GlnK is not an important nitrogen sensor under the tested conditions.

Natural radioactivity and chemical concentrations in Egyptian groundwater.

Measurements of natural radioactivity in drinking water have been performed in many parts of the world, mostly for assessment of the doses and risk resulting from consuming water. A study of the radionuclide and chemical components in groundwater from Beni Suef Governate, Egypt has been carried out. Fifty water samples were analyzed by gamma ray spectroscopy to determine the 226Ra, 232Th, and 40K concentrations; major elements, pH, alkalinity, and conductivity were also measured. The specific activity values ranged from 0.008 to 0.040 Bq/l for 226Ra, from 0.003 to 0.019 Bq/l for 232Th, and from 0.025 to 0.344 Bq/l for 40K. The annual ingestions of these radionuclides, using local consumption rates (average over the whole population) of 1.5 l day(-1), were estimated to be 8.59, 4.86, and 83.47 Bq year(-1) for 226Ra, 232Th, and 40K, respectively. The estimated values and weighted means of these radionuclides compare well with the world average. The estimated effective doses from drinking water were found to be 2.4 µSv year(-1) (226Ra), 1.1 µSv year(-1) (232Th), and 0.51 µSv year(-1) (40K). Contribution of these radionuclides to the committed effective dose from 1 year consumption of drinking water is estimated to be only 4%.

Natural radioactive nuclides and chemical components in the groundwater of Beni Suef Governate, Middle Egypt.

Measurements of natural radioactivity in drinking water have been performed in many parts of the world, mostly for assessment of the doses and risk resulting from consuming water. A study of the radionuclide and chemical components in groundwater from Beni Suef Governate, Egypt has been carried out. Fifty water samples were analysed by gamma-ray spectroscopy to determine the (226)Ra, (232)Th and (40)K concentrations; major elements, pH, alkalinity and conductivity were also measured. The activity concentration values ranged from 0.008 to 0.040 Bq l(-1) for (226)Ra, from 0.003 to 0.019 Bq l(-1) for (232)Th and from 0.025 to 0.344 Bq l(-1) for (40)K. The annual ingestion of these radionuclides, using local consumption rates (averaged over the whole population) of 1.5 l d(-1), was estimated to be 8.59, 4.86 and 83.47 Bq y(-1) for (226)Ra, (232)Th and (40)K, respectively. The estimated effective doses from drinking water were found to be 2.4 microSv y(-1) ((226)Ra), 1.1 microSv y(-1) ((232)Th) and 0.5 microSv y(-1) ((40)K). The contribution of these radionuclides to the committed effective dose from a year's consumption of drinking water is therefore estimated to be only 4% of the WHO value (0.1 mSv y(-1)). The moderate pH value is the most important parameter, and there was no observed correlation between natural radioactivity and electrical conductivity or concentrations of major ions.

Assessment of natural radioactivity and radon exhalation rate in Sannur cave, eastern desert of Egypt.

Activity concentrations of 238U, 232Th and 40K in rocks and soil samples collected from Sannur cave, Beni Suef governorate, eastern desert of Egypt, were determined using the high-resolution gamma spectrometry technique. The results show that the concentrations of the naturally occurring radionuclides are the following: 238U ranged from 8.51 +/- 1.23 to 20.66 +/- 2.12 Bq kg(-1), 232Th ranged from 7.69 +/- 1.02 to 22.73 +/- 1.60 Bq kg(-1) and 40K ranged from 185.74 +/- 0.42 to 2084.70 +/- 23.30 Bq kg(-1). The radium equivalent activity (Raeq), the absorbed dose rate (D), and the external hazard index (Hex) were also calculated and compared to the international recommended values. The radon concentration and radon exhalation rate from the rock and soil samples were measured using the Can technique. The average value of annual effective dose for cave workers is 1.98 mSv y(-1), while for visitors it is 2.4 microSv per visit. The radon exhalation rate varies from 0.21 +/- 0.03 to 1.28 +/- 0.02 Bq m(-2) h(-1). A positive correlation has been observed between uranium content and radon exhalation rate.