Cerebral cortical representation of reflexive and volitional swallowing in humans

The purpose of this study was to compare cerebral cortical representation of experimentally induced reflexive swallow with that of volitional swallow. Eight asymptomatic adults (24-27 yr) were studied by a single-trial functional magnetic resonance imaging technique. Reflexive swallowing showed bilateral activity concentrated to the primary sensory/motor regions. Volitional swallowing was represented bilaterally in the insula, prefrontal, cingulate, and parietooccipital regions in addition to the primary sensory/motor cortex. Intrasubject comparison showed that the total volume of activity during volitional swallowing was significantly larger than that activated during reflexive swallows in either hemisphere (P < 0.001). For volitional swallowing, the primary sensory/motor region contained the largest and the insular region the smallest volumes of activation in both hemispheres, and the total activated volume in the right hemisphere was significantly larger compared with the left (P < 0.05). Intersubject comparison showed significant variability in the volume of activity in each of the four volitional swallowing cortical regions. We conclude that reflexive swallow is represented in the primary sensory/motor cortex and that volitional swallow is represented in multiple regions, including the primary sensory/motor cortex, insular, prefrontal/cingulate gyrus, and cuneus and precuneus region. Non-sensory/motor regions activated during volitional swallow may represent swallow-related intent and planning and possibly urge.     

Isolation of diverse bioactive compounds from Euphorbia balsamifera: Cytotoxicity and antibacterial activity studies

Antibacterial and cytotoxic activities of Euphorbia balsamifera, fractions and pure compounds were evaluated. The cytotoxic assays for HCT116, HePG2 and MCF7 showed a significant IC₅₀: 54.7 and 76.2 µg/mL of non-polar fraction “n-hexane” against HCT116 and HePG2, respectively. Antibacterial results revealed that plant fractions exhibited significant potential against the tested pathogens than the total extract where n-butanol and ethyl acetate fractions showed significant antibacterial activity (P < 0.05) against tested bacterial strains. Isolation and structure determination of compounds from n-hexane and n-butanol fractions were performed. From n-hexane fraction, 29-nor-cycloartanol (1), lanost-8-en-3-ol (2a), cycloartanol (2b) and kampferol-3,4'-dimethyl ether (3) were isolated and structurally identified, along with 24 compounds were tentatively identified by GC–MS. From the polar n-butanol fraction, 4-O-β-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (4), 4-O-α-L-rhamnosyl-(1 → 6)-β-D-glucopyranosyl-2-hydroxy-6methoxy-acetophenone (5), quercetin-3-O-glucopyranoside (6) and isoorientin (7) were assigned. Structures of the obtained compounds were determined by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. Except compounds 1 and 5, all reported compounds announced antibacterial efficiency. Compound 2 showed selectively the highest activity against Enterococcus faecalis (22 ± 0.13 mm), meanwhile 4-O-β-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (4) showed broadly the highest antibacterial activity with MIC of 1.15–1.88 mg/mL against the test Gram-positive and Gram-negative bacteria. Cytotoxic assays indicated that kampferol-3,4'-dimethyl ether (3) exhibited the highest activity with matching IC₅₀ values to doxorubicin; 111.46, 42.67 and 44.90 µM against HCT116, HePG2 and MCF7, respectively, however, it is toxic on retina normal cell line RPE1.     

Novel in vitro perfusion model to study the interaction between coagulation and blood-borne metastasis

The association between cancer and hemostasis has long been studied in cell culture, animal models, and cancer patients developing thrombosis. The variety of biologic mechanisms involved in malignancy and metastasis makes the understanding of the relative importance of each mechanism difficult. We have developed a novel in vitro perfusion model that allows for the isolated study of the interactions between tumor cells and components of the hemostatic system under normal physiologic conditions. Segments of denuded umbilical cord or saphenous vein are cut longitudinally and mounted in a perfusion chamber under sterile conditions. Human breast cancer cells are perfused for 24 h under venous flow conditions with either whole blood (WB), platelet-rich plasma (PRP), platelet-poor plasma (PPP), or serum. Tissue samples are fixed and stained with hematoxylin and eosin as well as with pan-cytokeratin. Morphometric analysis is performed to quantify cancer cell adhesion. With PRP, this model maintains normal human physiologic conditions for the duration of the experiment. It differentiates between previously characterized high and low metastatic breast cancer cell lines. In addition, different vein tissue types do not alter tumor cell attachment. This model appears to be an accurate representation of the pathophysiology of in vivo metastasis. This model may serve as a useful bridge between cell culture studies and animal models. It may be a useful tool to elucidate the role of selected hemostatic systems in blood-borne metastasis and may potentially serve as a screening tool for the development of antimetastatic pharmaceutical agents.     

Isolation and characterization of human esophageal microvascular endothelial cells: mechanisms of inflammatory activation

Gastroesophageal reflux disease is the most common malady of the esophagus, affecting 7% of the United States population. Histological assessment demonstrates classic inflammatory mechanisms including selective leukocyte recruitment and hemorrhage, suggesting a prominent role for the microvasculature. We isolated and characterized human esophageal microvascular endothelial cells (EC) (HEMEC), examined inflammatory activation in response to cytokines, LPS, and acidic pH exposure, and identified signaling pathways that underlie activation. HEMEC displayed characteristic morphological and phenotypic features including acetylated LDL uptake. TNF-alpha/LPS activation of HEMEC resulted in upregulation of the cell adhesion molecules (CAM) ICAM-1, VCAM-1, E-selectin, and mucosal addressin CAM-1 (MAdCAM-1), increased IL-8 production, and enhanced leukocyte binding. Both acid and TNF-alpha/LPS activation lead to activation of SAPK/JNK in HEMEC that was linked to VCAM-1 expression and U-937 leukocyte adhesion. Expression of constitutive inducible nitric oxide synthase in HEMEC was in marked contrast to intestinal microvascular endothelial cells. In this study, we demonstrate that HEMECs are phenotypically and functionally distinct from lower gut-derived endothelial cells and will facilitate understanding of inflammatory mechanisms in esophageal inflammation.     

Association between SIRT1 Gene Polymorphisms and Breast Cancer in Egyptians

Background

Breast cancer is reported to cause the highest mortality among female cancer patients. Previous studies have explored the association of silent mating-type information regulator 2 homolog 1 (SIRT1) gene expression with prognosis in breast cancer. However, no studies exist, so far, on the role of SIRT1 gene polymorphism in breast cancer risk or prognosis. The present study aimed to assess the association between SIRT1 gene polymorphisms and breast cancer in Egyptians.

Methods

The study comprised 980 Egyptian females divided into a breast cancer group (541 patients) and a healthy control group (439 subjects). SIRT1 gene single nucleotide polymorphisms (SNPs) rs3758391, rs3740051 and rs12778366 were genotyped using real-time polymerase chain reaction (RT-PCR). Allelic and genotypic frequencies were determined in both groups and association with breast cancer and clinicopathological characteristics was assessed.

Results

Breast cancer patients exhibited elevated serum SIRT1 levels which varied among different tumor grades. SIRT1 rs3758391 and rs12778366 TT genotypes were more frequent, exhibited higher SIRT1 levels than CC and CT genotypes and were associated with histologic grade and lymph node status. SIRT1 rs12778366 TT genotype also correlated with negative estrogen receptor (ER) and progesterone receptor (PR) statuses. The T allele frequency for both SNPs was higher in breast cancer patients than in normal subjects. Combined GG and AG genotypes of rs3740051 were more frequent, showed higher serum SIRT1 levels than the AA genotype, and were associated with ER and PR expression. Furthermore, inheritance of the G allele was associated with breast cancer.

Conclusions

Our findings reveal that rs3758391 and rs12778366 polymorphisms of SIRT1 gene are associated with breast cancer risk and prognosis in the Egyptian population.     

Heat resistance of Cronobacter species (Enterobacter sakazakii) in milk and special feeding formula

Aim:  To determine D - and z -values of Cronobacter species ( Enterobacter sakazakii ) in different reconstituted milk and special feeding formula and the effect of reconstitution of powdered milk and special feeding formula with hot water on the survival of the micro-organism.
Methods and Results:  Five Cronobacter species (four C. sakazakii isolates and C. muytjensii ) were heated in reconstituted milk or feeding formula pre-equilibrated at 52–58°C for various times or mixed with powdered milk or feeding formula prior to reconstitution with water at 60–100°C. The D -values of Cronobacter at 52–58°C were significantly higher in whole milk (22·10–0·68 min) than in low fat (15·87–0·62 min) or skim milk (15·30–0·51 min) and significantly higher in lactose-free formula (19·57–0·66 min) than in soy protein formula (17·22–0·63 min). The z -values of Cronobacter in reconstituted milk or feeding formula ranged from 4·01°C to 4·39°C. Water heated to ≥70°C and added to powdered milk and formula resulted in a > 4 log₁₀ reduction of Cronobacter .
Conclusions:  The heat resistance of Cronobacter should not allow the survival of the pathogen during normal pasteurization treatment. The use of hot water (≥70°C) during reconstitution appears to be an effective means to reduce the risk of Cronobacter in these products.
Significance and Impact of the Study:  This study supports existing data available to regulatory agencies and milk producers that recommended heat treatments are sufficient to substantially reduce risk from Cronobacter which may be present in these products.     

Effect of GABA(B) receptor agonist on distension-sensitive pelvic nerve afferent fibers innervating rat colon

Spinal afferents innervating the gastrointestinal tract are the major pathways for visceral nociception. Many centrally acting analgesic drugs attenuate responses of visceral primary afferent fibers by acting at the peripheral site. Gamma-amino butyric acid (GABA), a major inhibitory neurotransmitter, acts via metobotropic GABA(B) and ionotropic GABA(A)/GABA(C) receptors. The aim of this study was to test the peripheral effect of selective GABA(B) receptor agonist baclofen on responses of the pelvic nerve afferent fibers innervating the colon of the rat. Distension-sensitive pelvic nerve afferent fibers were recorded from the S(1) sacral dorsal root in anesthetized rats. The effect of baclofen (1-300 micromol/kg) was tested on responses of these fibers to colorectal distension (CRD; 60 mmHg, 30 s). A total of 21 pelvic nerve afferent fibers was recorded. Mechanosensitive properties of four fibers were also recorded before and after bilateral transections of T(12)-S(3) ventral roots (VR). Effect of baclofen was tested on 15 fibers (7 in intact rats, 4 in rats with transected VR, and 4 in rats pretreated with CGP 54626). In nine fibers (5/7 in intact and 4/4 in VR transected rats), baclofen produced dose-dependent inhibition of response to CRD. Pretreatment with selective GABA(B) receptor antagonist CGP 54626 (1 micromol/kg) reversed the inhibitory effect of baclofen. Results suggest a peripheral role of GABA(B) receptors in the inhibition of mechanotransduction property of distension-sensitive pelvic nerve afferent fibers.     

MicroRNAs as Potential Diagnostic New Biomarkers in Diagnosis of Sepsis in Pediatric Patients

Background:Sepsis is one of the most common causes of multiorgan failure. Sepsis requires the presence of infection with a resultant systemic inflammatory state. Organ dysfunction occurs from the combination of the two processes. Sepsis is the main cause of mortality at intensive care units, with 30-50% mortality rate for all septic episodes. MicroRNA (miRNA) profile data could be beneficial as a specific diagnostic biomarker for sepsis and systemic inflammatory response syndrome (SIRS).Methods:Expression of miRNAs -122, -181b, -223 and -146a levels were assayed by quantitative real time polymerase chain reaction (qRT-PCR) in a prospective case control study, where forty septic cases were compared to 40 healthy controls of matched age and gender. Results:miRNAs -122 and -181b were significantly upregulated during early septic conditions, indicating that they could be sensitive and specific biomarkers for diagnosing sepsis. miRNA-223 and miRNA-146a could also represent highly specific and sensitive diagnostic biomarkers, as they were found to be significantly down-regulated. Serum levels of miRNA-223 could be used to predict poor prognosis with 70% sensitivity and 75% specificity, whereas the other three miRNAs could not predict prognosis.Conclusion:Our study shows that all tested miRNAs can be used for early detection of sepsis, with miRNA-223 being predictive of mortality, hence preventing multi-organ failure and reducing mortality, and predicting poor outcomes, thereby assisting in early categorization of ICU patients for rapid appropriate treatment and medico legal aspects.Key Words: Micrna-223, Systemic inflammatory response syndrome (SIRS), Sepsis, Biomarker     

The Effects of Antidepressants “Fluoxetine and Imipramine” on Vascular Abnormalities and Toll Like Receptor-4 Expression in Diabetic and Non-Diabetic Rats Exposed to Chronic Stress

Several studies reveal that diabetes doubles the odds of comorbid depression with evidence of a pro-inflammatory state underlying its vascular complications. Indeed, little information is available about vascular effects of antidepressant drugs in diabetes. Method: We investigated the effect of chronic administration of fluoxetine “FLU” and imipramine “IMIP” on behavioral, metabolic and vascular abnormalities in diabetic and non-diabetic rats exposed to chronic restraint stress (CRS). Results: Both diabetes and CRS induced depressive-like behavior which was more prominent in diabetic/depressed rats; this was reversed by chronic treatment with FLU and IMIP in a comparable manner. Diabetic and non-diabetic rats exposed to CRS exhibited abnormalities in glucose homeostasis, lipid profile and vascular function, manifested by decreased endothelium-dependent relaxation, increased systolic blood pressure and histopathological atherosclerotic changes. Vascular and metabolic dysfunctions were associated with significant increase in aortic expression of TLR-4, and pro-inflammatory cytokines (TNF-α and IL-1ß). FLU ameliorated these metabolic, vascular and inflammatory abnormalities, while IMIP induced either no change or even worsening of some parameters. Conclusion: FLU has favorable effect over IMIP on metabolic, vascular and inflammatory aberrations associated with DM and CRS in Wistar rats, clarifying the preference of FLU over IMIP in management of comorbid depression in diabetic subjects.