Pharyngeal airway protective reflexes are triggered before the maximum volume of fluid that the hypopharynx can safely hold is exceeded

Aerodigestive reflexes triggered by pharyngeal stimulation can protect the airways by clearing fluid from the pharynx. The objective of this study was to determine the relationship between the maximum capacity of fluid that can safely dwell in the hypopharynx [hypopharyngeal safe volume (HPSV)] before spilling into the larynx and the threshold volumes required to trigger pharyngoglottal closure reflex (PGCR), pharyngo-upper esophageal sphincter contractile reflex (PUCR), and reflexive pharyngeal swallow (RPS). Twenty-five healthy volunteers (mean age 24 yr, 8 males) were studied in the semi-inclined supine position. PGCR, PUCR, and RPS were elicited using techniques of concurrent upper esophageal sphincter manometry and pharyngo-laryngoscopy. The hypopharynx was then anesthetized to abolish RPS. HPSV was determined by infusing water in the pharynx, and perfusion was stopped when the infusate reached the superior margin of the interarytenoid fold. The threshold volumes for triggering PGCR, PUCR, and RPS by slow and rapid injections before pharyngeal anesthesia were 0.18 ± 0.02 and 0.09 ± 0.02 ml; 0.20 ± 0.020 and 0.13 ± 0.04 ml; and 0.61 ± 0.04 and 0.4 ± 0.06 ml, respectively. All of the above volumes were significantly smaller than the HPSV (0.70 ± 0.06 ml, P < 0.01) except for the threshold volume to elicit RPS during slow perfusion, which was not significantly different (P = 0.23). We conclude that pharyngeal aerodigestive reflexes are triggered by both slow and rapid pharyngeal perfusion of water at significantly smaller volumes than the maximum capacity of the hypopharynx to safely hold contents without spilling into the airway. These reflexes thereby aid in prevention of aspiration.     

High Genetic Diversity Detected in Olives beyond the Boundaries of the Mediterranean Sea

Background

Olive trees (Olea europaea subsp. europaea var. europaea) naturally grow in areas spanning the Mediterranean basin and towards the East, including the Middle East. In the Iranian plateau, the presence of olives has been documented since very ancient times, though the early history of the crop in this area is shrouded in uncertainty.

Methods

The varieties presently cultivated in Iran and trees of an unknown cultivation status, surviving under extreme climate and soil conditions, were sampled from different provinces and compared with a set of Mediterranean cultivars. All samples were analyzed using SSR and chloroplast markers to establish the relationships between Iranian olives and Mediterranean varieties, to shed light on the origins of Iranian olives and to verify their contribution to the development of the current global olive variation.

Results

Iranian cultivars and ecotypes, when analyzed using SSR markers, clustered separately from Mediterranean cultivars and showed a high number of private alleles, on the contrary, they shared the same single chlorotype with the most widespread varieties cultivated in the Mediterranean.

Conclusion

We hypothesized that Iranian and Mediterranean olive trees may have had a common origin from a unique center in the Near East region, possibly including the western Iranian area. The present pattern of variation may have derived from different environmental conditions, distinct levels and selection criteria, and divergent breeding opportunities found by Mediterranean and Iranian olives.These unexpected findings emphasize the importance of studying the Iranian olive germplasm as a promising but endangered source of variation.     

Association of Genetic Variants of MTHFR,ENPP1, and ADIPOQ with Myocardial Infarction in Egyptian Patients

The study aimed to investigate the association between MTHFR C677T, ENPP1 K121Q, and ADIPOQ 45 T/G gene polymorphisms and incidence of myocardial infarction (MI) in Egyptian patients. The study included 60 unrelated patients suffering from their first MI and 60 unrelated controls. Patients were recruited from Kasr-El Eini hospital, Cairo University. The previously mentioned polymorphisms were determined in all participants by PCR–RFLP. There was no significant difference in the distribution of genotypes and alleles of MTHFR C677T between groups. In contrast, significant difference was found in the distributions of genotypes and alleles of ENPP1 K121Q and ADIPOQ 45 T/G between MI patients and controls (P = 0.01, P = 0.004, P = 0.009, P = 0.001, respectively). Univariate analysis revealed that 121Q ENPP1 and 45 G ADIPOQ alleles were associated with the increased risk of MI (OR = 3; 95 % CI = 1.45–6.2; P = 0.004 and OR = 5.8; 95 % CI = 1.92–17.54; P = 0.001, respectively). The mutant homozygous genotypes of MTHFR, ENPP1, and ADIPOQ were more prevalent in diabetic hypertensive MI patients than it was among non-diabetic normotensive MI patients. Regarding the coagulation profile, INR (P = 0.009) and PC % (P = 0.022) were significantly different among the three genotypes of MTHFR C677T. The 677 T, 121 Q, and 45G variants were associated with MI in Egyptian patients; however, more studies are needed to determine the possible protective effect for these polymorphisms in our population.     

Geographic heterogeneity of the AML1-ETO fusion gene in Iranian patients with acute myeloid leukemia

Background:

The human AML1 gene, located on chromosome 21, can be fused to the AML1- eight-twenty-one (ETO) oncoprotein on chromosome eight, resulting in a t(8;21)(q22;q22) translocation. Acute myeloid leukemia (AML) associated with this translocation is considered a distinct AML with a favorable prognosis. Due to the various incidences of the translocation, which is associated with geographic diversities, investigation of molecular epidemiology is important to increase the awareness of physicians and hematologists regarding the frequency this chromosomal aberration.

Methods:

The patients were classified according to the French–American–British classification into eight groups: M0–M7. Determination of the prevalence of the AML1-ETO fusion gene was accomplished by TaqMan real-time PCR. Bone marrow samples from 113 patients with newly-diagnosed, untreated AML -M1, -M2, and -M4, and 20 healthy controls admitted to the Ghaem Hospital in Mashhad, Iran were studied.

Results:

The AML1-ETO fusion gene was detected up 50% of the M2 subgroup and absent in the M1 and M4 subtypes and healthy controls. Comparison of the prevalence of the t(8;21) translocation with results of previous studies showed that it varies between countries. This result may be due to geographic or ethnic differences, or both.

Conclusions:

The relatively high prevalence of the t(8;21) translocation in Iran was similar to that found in other Asian countries. It was closely associated with female gender, relatively young age, and FAB-M2 subtype. Its distribution varied considerably with geographic area. Therefore, further studies are needed to provide epidemiological data important for the establishment of optimal therapeutic strategies applicable to patients of each region. Key Words: Acute myeloid leukemia, AML1-ETO, M2, Prevalence, t(8;21)     

Association of long non-coding RNAs NEAT1, and MALAT1 expression and pathogenesis of Behçet's disease among Egyptian patients

Behçet''s disease (BD) is a chronic inflammatory disease. Immunological defects have been shown to play a significant role in the progression of BD. The serum levels of two long non-coding RNAs (lncRNAs), NEAT1 and MALAT1, were examined in patients with BD to identify their role in the disease pathogenesis. Both lncRNAs were mentioned as essential regulators of innate immune responses and have a crucial role in inflammatory diseases. Fifty patients with BD and a similar number of control individuals were involved in our study. At enrollment, data was collected from patients and controls, and the disease severity in active cases was determined using the Behçet''s Disease Current Activity Form (BDCAF). Levels of the two studied biomarkers in the serum, NEAT1 and MALAT1, were investigated by quantitative RT-PCR (qRT-PCR). NEAT1 levels were significantly turned down in BD patients (fold changes = 0.77, p = 0.0001) and correlated negatively with the BDCAF (r = −0.41; p = 0.003). On the other hand, the MALAT1 levels were significantly up-regulated in BD patients (fold changes = 2.65, p = 0.003). Serum levels of NEAT1 were significantly decreased in patients with active states than in stationary cases (0.387 versus 1.99, respectively; p = 0.01) and compared with controls (p = 0.001). Also, NEAT1 levels were significantly increased in patients with stationary states compared to controls (p = 0.03). There was a positive association between NEAT1 and MALAT1 levels among BD patients (r = 0.29, p = 0.04). Our findings demonstrate a possible role of NEAT1 and MALAT1 in the pathogenesis of BD.     

Reproducibility of swallow-induced cortical BOLD positive and negative fMRI activity

Functional MRI (fMRI) studies have demonstrated that a number of brain regions (cingulate, insula, prefrontal, and sensory/motor cortices) display blood oxygen level-dependent (BOLD) positive activity during swallow. Negative BOLD activations and reproducibility of these activations have not been systematically studied. The aim of our study was to investigate the reproducibility of swallow-related cortical positive and negative BOLD activity across different fMRI sessions. We studied 16 healthy volunteers utilizing an fMRI event-related analysis. Individual analysis using a general linear model was used to remove undesirable signal changes correlated with motion, white matter, and cerebrospinal fluid. The group analysis used a mixed-effects multilevel model to identify active cortical regions. The volume and magnitude of a BOLD signal within each cluster was compared between the two study sessions. All subjects showed significant clustered BOLD activity within the known areas of cortical swallowing network across both sessions. The cross-correlation coefficient of percent fMRI signal change and the number of activated voxels across both positive and negative BOLD networks were similar between the two studies (r ≥ 0.87, P < 0.0001). Swallow-associated negative BOLD activity was comparable to the well-defined "default-mode" network, and positive BOLD activity had noticeable overlap with the previously described "task-positive" network. Swallow activates two parallel cortical networks. These include a positive and a negative BOLD network, respectively, correlated and anticorrelated with swallow stimulus. Group cortical activity maps, as well as extent and amplitude of activity induced by volitional swallowing in the cortical swallowing network, are reproducible between study sessions.     

Mechanism of resistance of Bacillus subtilis spores to chlorhexidine

Chlorhexidine diacetate (CHA) was rather more sporicidal at 20C to ureadithreitol-sodium lauryl sulphate (UDS)-treated spores of Bacillus subtilis NCTC 8236 than to urea-dithiothreitol (UDT)-treated or normal (untreated) spores. UDS spores adsorbed more CHA from solution than did the other two forms. No differences in hydrophobicity, as determined by hydrophobic interaction chromatography (HIC) or bacterial adherence to hydrocarbon (BATH), could be detected between the three spore types. Germinating spores took up much less CHA than did outgrowing spores. Germinating cells were considerably more hydrophobic, as measured by the BATH technique, than outgrowing cells or normal spores. Chlorhexidine diacetate increased the apparent hydrophobicity of the two latter forms, but this effect could be partially reversed by subsequent exposure to a non-ionic surfactant.     

Yeast Cell Microcapsules as a Novel Carrier for Cholecalciferol Encapsulation: Development,Characterization and Release Properties

In this study Saccharomyces cerevisiae yeast cells was used as a novel vehicle for encapsulation of vitamin D₃. The effects of initial cholecalciferol concentration (100,000 and 500,000 IU/g yeast), yeast cell pretreatment (plasmolysis with NaCl) and drying method (spray or freeze drying) on microcapsules properties were investigated. It was found that the vitamin concentration and drying method had significant influence on encapsulation efficiency (EE) and size of yeast microcapsules. Furthermore, EE values were more increased by the plasmolysis treatment. The highest EE was obtained for plasmolysed and spray dried yeast cells prepared using initial cholecalciferol concentration of 2.5 mg per gram of yeast cells (76.10?±?6.92%). The values of mean particle size were 3.43–7.91 μm. The presence of cholecalciferol in yeast microcapsules was confirmed by X-ray diffraction (XRD) and Fourier transform-infrared (FT-IR) analyses. The in vitro cholecalciferol release from yeast microcapsules in phosphate buffer saline solution (PBS) followed a controlled release manner consistent with a Fickian diffusion mechanism. In addition, the release studies in simulated gastrointestinal tract showed sustained release of cholecalciferol in the stomach condition and significant release in intestinal medium.     

Introducing a novel method based on the imperialistic competitive algorithm to determine fluorine intermolecular potential from ab initio calculations and calculation of some properties via MD simulations

In this work, the possibility of obtaining an accurate site-site potential model suitable for use in molecular dynamics (MD) simulations of fluorine from ab initio calculations has been explored. The exploration was made on ab initio calculations. To reduce the ab initio pair potentials into a site-site potential, a higher significance was assigned to the configuration which is more stable. For this purpose, the imperialistic competitive algorithm (ICA) was implemented as a powerful optimisation tool. The calculated second virial coefficients were compared to the experimental values to test the quality of the presented intermolecular potential. The relative error for the calculated second virial coefficient ranged from 0.1 to 5.6%. MD simulations were used to evaluate the ability of the proposed intermolecular potential function. The relative error for the MD simulations ranged from 0.5 to 5.2%. The results are in good agreement with experimental data.