Showing papers by "University of Jordan published in 2010"

Antibiotic prescribing practices by dentists: a review

Abstract: Antibiotics are prescribed by dentists for treatment as well as prevention of infection. Indications for the use of systemic antibiotics in dentistry are limited, since most dental and periodontal diseases are best managed by operative intervention and oral hygiene measures. However, the literature provides evidence of inadequate prescribing practices by dentists, due to a number of factors ranging from inadequate knowledge to social factors. Here we review studies that investigated the pattern of antibiotic use by dentists worldwide. The main defects in the knowledge of antibiotic prescribing are outlined. The main conclusion is that, unfortunately, the prescribing practices of dentists are inadequate and this is manifested by over-prescribing. Recommendations to improve antibiotic prescribing practices are presented in an attempt to curb the increasing incidence of antibiotic resistance and other side effects of antibiotic abuse.

Antiproliferative activity of plant extracts used against cancer in traditional medicine

Abstract: Forty four extracts from sixteen plants used traditionally as anticancer agents were evaluated in vitro for their antiproliferative activity against Hep-2, MCF-7, and Vero cell lines. Plants were fractionated using ethanol, methanol, chloroform, n-hexane, distilled water, and butanol. The antiproliferative activity was measured by MTT assay. TLC was used to identify active fractions. The apoptotic activity of active fractions was determined using TUNEL colorimetric assay. 20 of these extracts demonstrated significant antiproliferative activity against one or more of the cell lines. These extracts were prepared from Ononis hirta, Inula viscosa, Salvia pinardi, Verbascum sinaiticum and Ononis sicula. Methanol fractions of Ononis hirta (aerial parts) and Inula viscosa (flowers) were the most active fractions against MCF-7 cells with IC50 of 27.96 and 15.78 μg/ml respectively and they were less toxic against other cell lines. Other extracts showed lower activity against cancer cell lines. TLC analysis showed the presence of flavonoids and terpenoids in active plants while alkaloids were detected in Ononis hirta (aerial parts) extracts. Ononis hirta (aerial parts) and Inula viscosa (flowers) extracts exerted their antiproliferative activity by inducing apoptosis in cancer cell lines. Further studies are necessary for detailed chemical characterization and more extensive biological evaluation of the most active ingredients.

Preferential effect of synchrotron microbeam radiation therapy on intracerebral 9L gliosarcoma vascular networks.

Abstract: PURPOSE: Synchrotron microbeam radiation therapy (MRT) relies on spatial fractionation of the incident photon beam into parallel micron-wide beams. Our aim was to analyze the effects of MRT on normal brain and 9L gliosarcoma tissues, particularly on blood vessels. METHODS AND MATERIALS: Responses to MRT (two arrays, one lateral, one anteroposterior (2 × 400 Gy), intersecting orthogonally in the tumor region) were studied during 6 weeks using MRI, immunohistochemistry, and vascular endothelial growth factor Western blot. RESULTS: MRT increased the median survival time of irradiated rats (×3.25), significantly increased blood vessel permeability, and inhibited tumor growth; a cytotoxic effect on 9L cells was detected 5 days after irradiation. Significant decreases in tumoral blood volume fraction and vessel diameter were measured from 8 days after irradiation, due to loss of endothelial cells in tumors as detected by immunochemistry. Edema was observed in the normal brain exposed to both crossfired arrays about 6 weeks after irradiation. This edema was associated with changes in blood vessel morphology and an overexpression of vascular endothelial growth factor. Conversely, vascular parameters and vessel morphology in brain regions exposed to one of the two arrays were not damaged, and there was no loss of vascular endothelia. CONCLUSIONS: We show for the first time that preferential damage of MRT to tumor vessels versus preservation of radioresistant normal brain vessels contributes to the efficient palliation of 9L gliosarcomas in rats. Molecular pathways of repair mechanisms in normal and tumoral vascular networks after MRT may be essential for the improvement of such differential effects on the vasculature.

Antimicrobial, cytotoxicity and phytochemical screening of Jordanian plants used in traditional medicine.

Abstract: Antimicrobial activity and cytotoxicity of fifty one extracts of different parts of 14 plants were studied. Ethanol, methanol, aqueous, butanol, and n-hexane extracts were tested against three Gram negative, two Gram positive bacteria, and two fungi. Cytotoxicity and phytochemical screening were determined using MTT and TLC assays, respectively. Of the fifty one extracts, twenty two showed activities against different microorganisms with MICs ranging from 62.5 to 1000 µg/mL. The highest activity (100% inhibition) was for a butanol extract of Rosa damascena receptacles against Salmonella typhimurium and Bacillus cereus (MIC of 62.5 and 250 µg/mL) respectively. Butanol extract of Narcissus tazetta aerial parts and aqueous extract of Rosa damascena receptacles were both active against Candida albicans (MIC of 125 µg/mL). Methicillin-resistant Staphylococcus aureus was inhibited by butanol, aqueous extracts of Rosa damascena receptacles and butanol extract of Inula viscosa flowers (MIC of 500, 500, and 250 µg/mL) respectively. Rosa damascena receptacles and Verbascum sinaiticum flowers ethanol extract showed lowest cytoxicity against Vero cell line (IC50 of 454.11and 367.11). Most toxic was the ethanol extract of Ononis hirta aerial parts (IC50 72.50 µg/mL). Flavonoids and terpenoids were present in all plants. Ononis hirta and Narcissus tazetta contained alkaloids. The results validate the use of these plants and report for the first time bioactivity of Rosa damascena receptacles and further justifies the use of such screening programs in the quest for new drugs.

Effect of ethnomedicinal plants used in folklore medicine in Jordan as antibiotic resistant inhibitors on Escherichia coli

Abstract: Escherichia coli occurs naturally in the human gut; however, certain strains that can cause infections, are becoming resistant to antibiotics. Multidrug-resistant E. coli that produce extended-spectrum β lactamases (ESBLs), such as the CTX-M enzymes, have emerged within the community setting as an important cause of urinary tract infections (UTIs) and bloodstream infections may be associated with these community-onsets. This is the first report testing the antibiotic resistance-modifying activity of nineteen Jordanian plants against multidrug-resistant E. coli. The susceptibility of bacterial isolates to antibiotics was tested by determining their minimum inhibitory concentrations (MICs) using a broth microdilution method. Nineteen Jordanian plant extracts (Capparis spinosa L., Artemisia herba-alba Asso, Echinops polyceras Boiss., Gundelia tournefortii L, Varthemia iphionoides Boiss. & Blanche, Eruca sativa Mill., Euphorbia macroclada L., Hypericum trequetrifolium Turra, Achillea santolina L., Mentha longifolia Host, Origanum syriacum L., Phlomis brachydo(Boiss.) Zohary, Teucrium polium L., Anagyris foetida L., Trigonella foenum-graecum L., Thea sinensis L., Hibiscus sabdariffa L., Lepidium sativum L., Pimpinella anisum L.) were combined with antibiotics, from different classes, and the inhibitory effect of the combinations was estimated. Methanolic extracts of the plant materials enhanced the inhibitory effects of chloramphenicol, neomycin, doxycycline, cephalexin and nalidixic acid against both the standard strain and to a lesser extent the resistant strain of E. coli. Two edible plant extracts (Gundelia tournefortii L. and Pimpinella anisum L.) generally enhanced activity against resistant strain. Some of the plant extracts like Origanum syriacum L.(Labiateae), Trigonella foenum- graecum L.(Leguminosae), Euphorbia macroclada (Euphorbiaceae) and Hibiscus sabdariffa (Malvaceae) did not enhance the activity of amoxicillin against both standard and resistant E. coli. On the other hand combinations of amoxicillin with other plant extracts used showed variable effect between standard and resistant strains. Plant extracts like Anagyris foetida (Leguminosae) and Lepidium sativum (Umbelliferae) reduced the activity of amoxicillin against the standard strain but enhanced the activity against resistant strains. Three edible plants; Gundelia tournefortii L. (Compositae) Eruca sativa Mill. (Cruciferae), and Origanum syriacum L. (Labiateae), enhanced activity of clarithromycin against the resistant E. coli strain. This study probably suggests possibility of concurrent use of these antibiotics and plant extracts in treating infections caused by E. coli or at least the concomitant administration may not impair the antimicrobial activity of these antibiotics.

Beneficial effects of melatonin on obesity and lipid profile in young Zucker diabetic fatty rats.

Abstract: The study objective was to investigate the effects of melatonin on obesity and obesity-associated systolic hypertension and dyslipidemia in young male Zucker diabetic fatty (ZDF) rats, an experimental model of the metabolic syndrome. ZDF rats (n = 30) and lean littermates (ZL) (n = 30) were used. At 6 wk of age, both lean and fatty animals were subdivided into three groups (n = 10): naive (N), vehicle-treated (V), and melatonin-treated (M) (10 mg/kg/day) for 6 wk. Vehicle and melatonin were added to the drinking water. Melatonin reduced mean weight gain (51 ± 2/100 g BW) versus N-ZDF group (58 ± 3, P < 0.05) without food intake differences. M-ZDF rats showed an apparent reduction in systolic hypertension that proved not to be statistically significant, and a significant improvement in dyslipidemia, with a reduction in hypertriglyceridemia from 580 ± 40 to 420.6 ± 40.9 mg/dL (P < 0.01). Melatonin raised high-density-lipoprotein (HDL) cholesterol in ZDF (from 81.6 ± 4.9 to 103.1 ± 4.5 mg/dL, P < 0.01) and ZL rats (from 62.8 ± 4.8 to 73.5 ± 4.8 mg/dL, P < 0.05) and significantly reduced low-density-lipoprotein (LDL) cholesterol in ZDF rats from 5.20 ± 0.4 to 4.14 ± 0.3 mg/dL (P < 0.05) but had no effect on total cholesterol levels. To our knowledge, this is the first evidence of a positive effect of melatonin on overweight and lipid pattern of obese Zucker diabetic rats, supporting the proposition that melatonin administration may ameliorate overweight and lipid metabolism in humans. Because these benefits occurred in youth, before advanced metabolic and vascular complications, melatonin might help to prevent cardiovascular disease associated with obesity and dyslipidemia.

Pathophysiological Mechanisms of Dominant and Recessive GLRA1 Mutations in Hyperekplexia

Abstract: Hyperekplexia is a rare, but potentially fatal, neuromotor disorder characterized by exaggerated startle reflexes and hypertonia in response to sudden, unexpected auditory or tactile stimuli. This disorder is primarily caused by inherited mutations in the genes encoding the glycine receptor (GlyR) α1 subunit (GLRA1) and the presynaptic glycine transporter GlyT2 (SLC6A5). In this study, systematic DNA sequencing of GLRA1 in 88 new unrelated human hyperekplexia patients revealed 19 sequence variants in 30 index cases, of which 21 cases were inherited in recessive or compound heterozygote modes. This indicates that recessive hyperekplexia is far more prevalent than previous estimates. From the 19 GLRA1 sequence variants, we have investigated the functional effects of 11 novel and 2 recurrent mutations. The expression levels and functional properties of these hyperekplexia mutants were analyzed using a high-content imaging system and patch-clamp electrophysiology. When expressed in HEK293 cells, either as homomeric α1 or heteromeric α1β GlyRs, subcellular localization defects were the major mechanism underlying recessive mutations. However, mutants without trafficking defects typically showed alterations in the glycine sensitivity suggestive of disrupted receptor function. This study also reports the first hyperekplexia mutation associated with a GlyR leak conductance, suggesting tonic channel opening as a new mechanism in neuronal ligand-gated ion channels.

Distance Bounding Protocols on TH-UWB Radios

Abstract: Relay attacks pose a real threat to the security of wireless communications. Distance bounding protocols have been designed to thwart these attacks. In this paper, we study the way to adapt distance bounding protocols to time-hopping ultra wide band (TH-UWB) radios. Two protocols are proposed which are based on the milestones of the TH-UWB radio: the time-hopping sequence and the mapping code. The security and the different merits of those protocols are analyzed.

Validation of a Self-Excising Marker in the Human Pathogen Aspergillus fumigatus by Employing the β-Rec/six Site-Specific Recombination System

Abstract: Recyclable markers based on site-specific recombination allow repetitive gene targeting in filamentous fungi. Here we describe for the first time functionality of the bacterial recombination system employing β serine recombinase acting on six recognition sequences (β-rec/six) in a fungal host, the human pathogen Aspergillus fumigatus, and its use in establishing a self-excising resistance marker cassette for serial gene replacement.

The effect of malocclusion and self-perceived aesthetics on the self-esteem of a sample of Jordanian adolescents.

Abstract: The aims of this study were to evaluate the effect of normative treatment need, perceived social impact of malocclusion and satisfaction with dental appearance on self-perceived treatment need, self-perceived aesthetics, and self-esteem; the influence of self-perceived need and aesthetics on self-esteem; and whether receipt of orthodontic treatment influences self-esteem. A questionnaire was administered to a random sample of 410 students (195 males and 215 females) aged 14-16 years. Self-esteem was measured using the Global Negative Self-Evaluation (GSE) scale. The Aesthetic and Dental Health Components (AC and DHC) of the Index of Orthodontic Treatment Need (IOTN) were used to assess orthodontic treatment need. Students' AC scores determined their self-perceived dental aesthetics. Spearman correlation coefficient was used to analyse the association between all variables, and multiple stepwise regression analysis to study the effect of independent variables on self-perceived need for treatment, self-perceived aesthetics, and self-esteem. A correlation existed between the students' and examiner's AC scores (P < 0.01); however, students were less critical in evaluating their aesthetic appearance. Students who perceived themselves in need of treatment had a great need for treatment, as assessed by the DHC and the AC of the IOTN (r = 0.421 and 0.489, respectively), were dissatisfied with their dental appearance (r = 0.542) and avoided smiling to hide their teeth (r = 0.457). Students who scored high on the GSE scale perceived a need for orthodontic treatment, evaluated their dental aesthetics poorly, perceived an impact of malocclusion on social acceptance, and had a great normative orthodontic treatment need; the correlation, however, was weak with r values ranging from 0.134 to 0.317. Students who had received orthodontic treatment showed greater self-esteem than those who had not, although the correlation was weak. Dissatisfaction with dental appearance had a strong predictive effect on self-esteem.

Organic matter release by dominant hermatypic corals of the Northern Red Sea

Abstract: Particulate organic matter (POM) and dissolved organic carbon (DOC) release by six dominant hermatypic coral genera (Acropora, Fungia, Goniastrea, Millepora, Pocillopora and Stylophora) were measured under undisturbed conditions by laboratory incubations during four seasonal expeditions to the Northern Red Sea. In addition, the influence of environmental factors (water temperature, light availability and ambient inorganic nutrient concentrations) was evaluated. Particulate organic carbon (POC) and particulate nitrogen (PN) release were always detectable and genus-specific, with Stylophora releasing most POM (6.5 mg POC and 0.5 mg PN m−2 coral surface area h−1) during all seasons. The fire coral Millepora released significantly less POM (0.3 mg POC and 0.04 mg PN m−2 coral surface area h−1) than all investigated anthozoan genera. The average POC:PN ratio of POM released by all coral genera was 12 ± 1, indicating high carbon/low nitrogen content of coral-derived organic matter. POM release showed little seasonal variation, but average values of POC and PN release rates correlated with water temperature, light availability and ambient nitrate concentrations. DOC net release and elevated DOC:POC ratios were detectable for Acropora, Goniastrea and Millepora, revealing maximum values for Acropora (30.7 mg DOC m−2 coral surface area h−1), whilst predominant DOC uptake was observed for Pocillopora, Fungia and Stylophora. Depth-mediated light availability influenced DOC fluxes of Acropora and Fungia, while fluctuations in water temperature and ambient inorganic nutrient concentrations showed no correlation. These comprehensive data provide an important basis for the understanding of coral reef organic matter dynamics and relevant environmental factors.

Inhibition of hormone sensitive lipase and pancreatic lipase by Rosmarinus officinalis extract and selected phenolic constituents

Abstract: Rosmarinus officinalis L. (Rosemary) has been long claimed to have hypogylcemic-hypolipidemic dual effects in folkloric medicine. In an effort to explain rosemary's claimed benefits, numerous published studies have investigated an array of pharmacologic activities of the plant including anti-inflammatory, anticarcinogenic and metabolic effects. The question remained, however, as how rosemary would target both plasma lipids and glucose levels simultaneously. A newer mechanism has been suggested, in which targeting the hormone sensitive lipase (HSL) would be the common link between the two metabolic effects. In fact, HSL has been extensively studied for its effects on the metabolic switch between glucose and free fatty acids (FFAs) as an energy source. The current manuscript summarizes a significant amount of work that was undertaken to identify plant species native to Jordan with potential HSL and pancreatic lipase (PL) inhibitory activities. Our results demonstrated in vitroinhibitory effects of R. officnalis on both HSL and PL in a dose dependent manner. Interestingly, the rosemary extract had an IC50 for PL that was several fold lower than the IC50 for HSL, indicating a higher affinity to the former enzyme (13.8 and 95.2 μg/mL for PL and HSL, respectively). In addition, we have compared the inhibitory activities of purified constituents found in rosemary to the parent plant [rosmarinic acid (RA), chlorogenic acid (CA), caffeic acid (CaA) and gallic acid (GA)]. Our results showed that all the tested compounds (RA, CA, CaA, and GA) were able to inhibit the PL and HSL activities in a dose dependent manner, but with different potencies. PL and HSL IC50 values were calculated for each compound and GA was found to be the most potent (IC50 10.1 and 14.5 for PL and HSL, respectively). Further work is necessary to determine whether our in vitro findings would correlate with the in vivo effects. Nonetheless, our results are a first step in fully understanding the long claimed hypoglycemic-hypolipidemic dual effects of rosemary. Simultaneous targeting of both HSL and PL is likely to open the door for a new era in our continuous battle against DM type 2 and its cardiovascular complications. Currently, we are working on identifying the most active constituents of the plant to evaluate a structure-activity relationship which would pave the road for future therapeutic use. Key words: Rosmarinus officinalis, Rosemary, obesity, diabetes mellitus, pancreatic lipase, hormone sensitive lipase, phenolic compounds, rosmarinic acid.

Narghile (water pipe) smoking among university students in Jordan: prevalence, pattern and beliefs

Abstract: Background and objectives: Narghile is becoming the favorite form of tobacco use by youth globally. This problem has received more attention in recent years. The aim of this study was to investigate the prevalence and pattern of narghile use among students in three public Jordanian universities; to assess their beliefs about narghile's adverse health consequences; and to evaluate their awareness of oral health and oral hygiene. Methods: The study was a cross-sectional survey of university students. A self-administered, anonymous questionnaire was distributed randomly to university students in three public Jordanian universities during December, 2008. The questionnaire was designed to ask specific questions that are related to smoking in general, and to narghile smoking in specific. There were also questions about oral health awareness and oral hygiene practices. Results: 36.8% of the surveyed sample indicated they were smokers comprising 61.9% of the male students and 10.7% of the female students in the study sample. Cigarettes and narghile were the preferred smoking methods among male students (42%). On the other hand, female students preferred narghile only (53%). Parental smoking status but not their educational level was associated with the students smoking status. Smokers had also significantly poor dental attendance and poor oral hygiene habits. Conclusion: This study confirmed the spreading narghile epidemic among young people in Jordan like the neighboring countries of the Eastern Mediterranean region. Alarming signs were the poor oral health awareness among students particularly smokers.

Loss of CHSY1, a secreted FRINGE enzyme, causes syndromic brachydactyly in humans via increased NOTCH signaling

Abstract: We delineated a syndromic recessive preaxial brachydactyly with partial duplication of proximal phalanges to 16.8 Mb over 4 chromosomes. High-throughput sequencing of all 177 candidate genes detected a truncating frameshift mutation in the gene CHSY1 encoding a chondroitin synthase with a Fringe domain. CHSY1 was secreted from patients' fibroblasts and was required for synthesis of chondroitin sulfate moieties. Noticeably, its absence triggered massive production of JAG1 and subsequent NOTCH activation, which could only be reversed with a wild-type but not a Fringe catalytically dead CHSY1 construct. In vitro, depletion of CHSY1 by RNAi knockdown resulted in enhanced osteogenesis in fetal osteoblasts and remarkable upregulation of JAG2 in glioblastoma cells. In vivo, chsy1 knockdown in zebrafish embryos partially phenocopied the human disorder; it increased NOTCH output and impaired skeletal, pectoral-fin, and retinal development. We conclude that CHSY1 is a secreted FRINGE enzyme required for adjustment of NOTCH signaling throughout human and fish embryogenesis and particularly during limb patterning.