Hassan Hajjhussein - Academia.edu (original) (raw)

Papers by Hassan Hajjhussein

International Journal of Environment, Agriculture and Biotechnology, 2021

Snake melon (Cucumis melo var. flexuosus) is a member of the melon family. It is a seasonal fruit... more Snake melon (Cucumis melo var. flexuosus) is a member of the melon family. It is a seasonal fruit that is high in water and low in calories, fat, and cholesterol. It is a high-yielding crop that has a short shelflife, which results in the loss of a high percentage of the annual yield. In order to reduce the percentage of lost crop, we proposed several new recipes for making pickled snake melon by adding functional foods to enhance the flavor and nutritional values of the pickled snake melon product while evaluating consumer acceptance using sensory evaluation. The different samples of snake melon pickles were analyzed for their sensory attributes (color, odor, texture, taste, saltiness, sourness, and overall acceptability) using a Likert scale ranging from 1 "least liked" to 5 "most liked". While none of the tested recipes were preferred over the control, four of the new recipes were similar to the control in overall acceptability indicating a clear potential for incorporating functional foods to increase diversification of snake melon pickles and in essence increase the potential for snake melon consumption while reducing crop loss.

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Journal of Current Opinion in Crop Science, Jun 23, 2021

Neuropharmacology, 2008

Phosphodiesterase-10A (PDE10A), -1B (PDE1B), -4B (PDE4B), and -4A (PDE4A) are important regulator... more Phosphodiesterase-10A (PDE10A), -1B (PDE1B), -4B (PDE4B), and -4A (PDE4A) are important regulators of signal transduction in striatum due to their catalysis of cyclic AMP and cyclic GMP. The typical antipsychotic drug haloperidol and the atypical antipsychotic drug clozapine are thought to regulate cyclic nucleotide signaling in striatum. Since this brain region is essential in mediation of both therapeutic and extrapyramidal side effects, it was of interest to determine whether chronic treatment for 21 days with haloperidol (1 mg/kg) or clozapine (20 mg/kg) affected PDE expression in rat striatum. This was accomplished using SDS-PAGE/immunoblotting and real-time RT-PCR. Both antipsychotic drugs increased PDE10A and did not change PDE4A. By contrast, PDE1B was increased by haloperidol treatment, but not clozapine treatment, while PDE4B was increased by clozapine, but not haloperidol. In all cases, changes in protein expression were accompanied by corresponding changes in mRNA, and only were observed with chronic treatment. Up-regulation of PDEs may represent compensatory responses to haloperidol and clozapine treatments, due to altered cyclic nucleotide signaling, and that different patterns of effects produced by these drugs may be associated with their mechanisms of action.

Journal of Receptors and Signal Transduction, 2013

Abstract A cluster of hydrophobic amino acids at the cytoplasmic end of trans-membranal helix III... more Abstract A cluster of hydrophobic amino acids at the cytoplasmic end of trans-membranal helix III (TM-III) is a common feature among class-A of G protein-coupled receptors (GPCR). We mutagenized alanine 159(3.53) to glutamic acid and isoleucine160(3.54) to arginine (A159E/I160R) in TM-III of the human β(1)-adrenergic receptor (β(1)-AR) to disrupt the function of the hydrophobic cluster. Structurally, the combined mutations of A159E/I160R caused an almost 90° tilt in the rotation of Arg156(3.50) in the E/DRY motif of TM-III and displaced Tyr166(3.60) in intracellular loop 2. The A159E/I160R β(1)-AR was uncoupled from G(s) as determined by cyclic AMP/adenylyl cyclase assays and by FRET-based proximity measurements between the β(1)-AR and G(s)α. Isoproterenol induced β-arrestin trafficking in cells expressing both the wild-type β(1)-AR and the A159E/I160R β(1)-AR. Isoproterenol markedly increased the phosphorylation of ERK1/2 in cells expressing the WT β(1)-AR and this effect was dependent on the activation of the G(s)-cyclic AMP-dependent protein kinase → Rap → B-raf axis. However, in cells bearing the A159E/I160R β(1)-AR, isoproterenol failed to increase the phosphorylation of ERK(1/2). These results indicate that mutations in the G(s)α-binding pocket of the GPCR interfered with receptor coupling to G(s) and with its downstream signaling cascades.

Brain Research, 2007

NMDA receptor-induced cAMP and cGMP are selectively hydrolyzed by PDE4 and PDE2, respectively, in... more NMDA receptor-induced cAMP and cGMP are selectively hydrolyzed by PDE4 and PDE2, respectively, in rat primary cerebral cortical and hippocampal cultures. Because cAMP levels regulate the expression of PDE4 in rat primary cortical cultures, we examined the manner in which NMDA receptor activity regulates the age-dependent increase in the expression of PDE4A observed in vivo and in vitro. Inhibiting the activity of NR2B subunit with ifenprodil blocked NMDA receptorinduced cGMP synthesis and increased NMDA receptor-induced cAMP levels in a manner that reduced PDE4 activity. Therefore, NR1/NR2B receptor-induced cGMP signaling is involved in an acute cross-talk regulation of NR1/NR2A receptor-induced cAMP levels, mediated by PDE4. Chronic inhibition of NMDA receptor activity with MK-801 reduced PDE4A1 and PDE4A5 expression and activity in a time-dependent manner; this effect was reversed by adding the PKA activator dbr-cAMP. Inhibiting GABA receptors with bicuculline increased NMDA receptorinduced cAMP synthesis and PDE4A expression in cultures treated between DIV 16 and DIV 21 but not in cultures treated between DIV 8 and DIV 13. This effect was due to a high tone of NMDA receptor-induced cGMP in younger cultures, which negatively regulated the expression of PDE4A by a PKG-mediated process. The present results are consistent with behavioral data showing that both PDE4 and PDE2 are involved in NMDA receptor-mediated memory processes.

Phosphodiesterase (PDE)-2 is a component of the nitric-oxide synthase (NOS)/guanylyl cyclase sign... more Phosphodiesterase (PDE)-2 is a component of the nitric-oxide synthase (NOS)/guanylyl cyclase signaling pathway in the brain. Given recent evidence that pharmacologically induced changes in NO-cGMP signaling can affect anxiety-related behaviors, the effects of the PDE2 inhibitors (2-(3,4-dimethoxybenzyl)-7-det-5-methylimidazo-[5,1-f][1,2,4]triazin-4(3H)-one) (Bay 60-7550) and 3-(8-methoxy-1-methyl-2-oxo-7-phenyl-2,3-dihydro-1H-benzo[e]-[1,4]diazepin-5-yl)benzamide (ND7001), as well as modulators of NO, were assessed on cGMP signaling in neurons and on the behavior of mice in the elevated plus-maze, hole-board, and open-field tests, well established procedures for the evaluation of anxiolytics. Bay 60-7550 (1 M) and ND7001 (10 M) increased basal and N-methyl-D-aspartate- or detanonoate-stimulated cGMP in primary cultures of rat cerebral cortical neurons; Bay

Coronaviruses

In Lebanon, with COVID-19 cases escalating and national efforts exhausted in the containment of t... more In Lebanon, with COVID-19 cases escalating and national efforts exhausted in the containment of the pandemic, calls were made for increased awareness, scientific literacy, and the debunking of false information. This article sheds light on the positive role that a private University can play in spreading scientifically-authenticated, health-related, awareness through the community. The Lebanese International University (LIU) has 9 campuses distributed across all Lebanese Governorates with an extensive communications platform that takes advantage of LIU’s website, University Management System, several Facebook pages with thousands of followers, and many WhatsApp groups. LIU has over 34,000 undergraduate and graduate students, in addition to a little over a thousand faculty and staff members. The University capitalized on this extensive network to play a positive role in delivering authenticated health-related information to the University’s greater community. A health committee compr...

Journal of Chemical Education

Communications in Computer and Information Science

Cell Signal, 2011

ß1-adrenergic receptors (ß1-AR) are internalized in response to agonists and then recycle back fo... more ß1-adrenergic receptors (ß1-AR) are internalized in response to agonists and then recycle back for another round of signaling. The serine 312 to alanine mutant of the ß1-AR (S312A) is internalized but does not recycle. We determined that WT ß1-AR and S312A were internalized initially to an early sorting compartment because they colocalized by N 70% with the early endosomal markers rab5a and early endosomal antigen-1 (EEA1). Subsequently, the WT ß1-AR trafficked via rab4a-expressing sorting endosomes to recycling endosomes. In recycling endosomes WT ß1-AR were colocalized by N 70% with the rab11 GTPase. S312A did not colocalize with either rab4a or rab11, instead they exited from early endosomes to late endosomes/lysosomes in which they were degraded. Rab11a played a prominent role in recycling of the WT ß1-AR because dominant negative rab11a inhibited, while constitutively active rab11a accelerated the recycling of the ß1-AR. Next, we determined the effect of each of the rab11-interacting proteins on trafficking of the WT ß1-AR. The recycling of the ß1-AR was markedly inhibited when myosin Vb, FIP2, FIP3 and rabphillin were knocked down. These data indicate that rab11a and a select group of its binding partners play a prominent role in recycling of the human ß1-AR.

Turkish Journal of Agriculture - Food Science and Technology

In light of recent news reporting the use of banned colorants in Lebanese-made pickled turnips ex... more In light of recent news reporting the use of banned colorants in Lebanese-made pickled turnips exported to the European Union (EU) by the Rapid Alert System of Food and Feed (RASFF), The Lebanese Consumer Protection Association tested samples of pickled turnips being sold to the public and confirmed the use of rhodamine B. Many products were pulled off the market and were replaced with new products that were supposed to be free of any banned colorants. We selected 5 different brands of pickled turnips and tested them for pH, salinity, nitrites, and colorants. We tested the salinity using two methods: evaporation and titration. The concentration of nitrites was tested by absorbency method. The presence of colorants was determined using TLC and absorbency method. We determined that the newly released pickled turnips comply with the rules and regulations adopted by the Lebanese Standards Institution (LIBNOR) and the international standards according to the Codex Alimentarius.