The microRNAs of Caenorhabditis elegans

MicroRNAs (miRNAs) are an abundant class of tiny RNAs thought to regulate the expression of protein-coding genes in plants and animals. In the present study, we describe a computational procedure to identify miRNA genes conserved in more than one genome. Applying this program, known as MiRscan, together with molecular identification and validation methods, we have identified most of the miRNA genes in the nematode Caenorhabditis elegans. The total number of validated miRNA genes stands at 88, with no more than 35 genes remaining to be detected or validated. These 88 miRNA genes represent 48 gene families; 46 of these families (comprising 86 of the 88 genes) are conserved in Caenorhabditis briggsae, and 22 families are conserved in humans. More than a third of the worm miRNAs, including newly identified members of the lin-4 and let-7 gene families, are differentially expressed during larval development, suggesting a role for these miRNAs in mediating larval developmental transitions. Most are present at very high steady-state levels-more than 1000 molecules per cell, with some exceeding 50,000 molecules per cell. Our census of the worm miRNAs and their expression patterns helps define this class of noncoding RNAs, lays the groundwork for functional studies, and provides the tools for more comprehensive analyses of miRNA genes in other species.     

Reliability of anthropological measurements in determining vertical dimension of occlusion in Saudi population: A cross sectional study

BackgroundRange of techniques have been described in traditional prosthodontics to establish Vertical dimension of occlusion (VDO). Experienced clinicians agree that there is no one single method, which is universally accepted record VDO precisely and consistently. Many facial and body landmarks have been proposed in the literature correlating to the VDO. Presence of so many methods to determine VDO further leads to confusion in the minds of clinicians. There is always a need for a research to both substantiate the findings in the literature and check reliability of such correlations in local population. Such correlation between the anthropological measurements and VDO would give clinician an evidence based approach to establish VDO during prosthetic rehabilitation. Hence this study was planned to check reliability of various anthropometric measurements in measuring VDO in a cross section of Saudi population.Material and methodTotal of 500 subjects selected for the study following an inclusion and exclusion criteria. Anthropological readings such as Index finger, Little finger, Thumb finger, Distance between Inner canthus of left eye to outer canthus of right eye and Outer canthus of the right eye to corner of mouth (rima oris) were recorded using digital Vernier caliper. The data were analyzed statistically.ResultsStrong positive correlation was observed between VDO and anthropological landmarks selected in the study. Pearson’s correlation test showed VDO in males has strong coefficient correlation with Index finger (r = 0.7341) and in females strong coefficient correlation with Little finger. (r = 0.5827).ConclusionIn Saudi Males, VDO could be correlated to the index finger measurements followed by Thumb finger. In Saudi females subjects, VDO correlated with little finger measurements followed by outer canthus of the eye to corner of the mouth reading. It is always appropriate to use one or more methods to approximate the measurements of VDO initially and then use the other methods to test the appropriateness of the dimensions initially established.     

Whole-genome sequencing of Egyptian multidrug-resistant Klebsiella pneumoniae isolates: a multi-center pilot study

European Journal of Clinical Microbiology & Infectious Diseases - Multidrug-resistant (MDR) Klebsiella pneumoniae is a common infectious pathogen. We performed whole-genome sequencing (WGS) of...     

Association of Exosomal miR-34a with Markers of Dyslipidemia and Endothelial Dysfunction in Children and Adolescents with T1DM

Objective:Dyslipidemia and endothelial dysfunction are common disorders and major causative factors for atherosclerosis in patients with type 1 diabetes mellitus (T1DM). However, their pathophysiology in young patients with T1DM is still under evaluated. We aimed, for the first time, to assess the expression of exosomal micro-RNA 34a (miR-34a) in serum of children and adolescents with T1DM and correlate this expression with markers of dyslipidemia and endothelial dysfunction.Methods:The study included 120 T1DM patients and 100 control subjects. Assessment of miR-34a was performed using quantitative real-time polymerase chain reaction. Lipid profile was assessed on an automated analyzer and serum endoglin and intracellular adhesion molecule (ICAM) concentrations were measured using immunometric methods.Results:Relative expression of miR-34a and serum endoglin and ICAM concentrations were higher in patients than controls (p=0.001) and in patients with dyslipidemia (42 patients) compared to patients without dyslipidemia (78 patients) (p=0.01). Linear regression analysis revealed a strong independent association between exosomal miR-34a expression and total cholesterol, low-density lipoprotein, serum endoglin and serum ICAM after adjustment for other cofactors. The utility of miR-34a as an indicator for associated dyslipidemia was tested using receiver operator characteristic curve analysis which revealed area under the curve: 0.73 with confidence interval: 0.63-0.83 and p=0.001.Conclusion:This was the first study to show the altered expression of exosomal miR-34a among children and adolescents with T1DM. Moreover, association of miR-34a with markers of dyslipidemia and endothelial dysfunction was identified, suggesting that it could play a role in regulation of lipid metabolism and endothelial function in T1DM.     

Promising roles of erythropoietin and lymphotoxin alpha in critical illness: A pilot study in critically ill children

Background

Several studies proved the anti-inflammatory role of erythropoietin. Little is known about the anti-inflammatory role of lymphotoxin alpha (LT-α). This study was designed to investigate the patterns of erythropoietin (EPO) and LT-α levels in children with acute critical illness.

The Role of Stem Cell Factor in Hyperpigmented Skin Lesions

Background: Skin hyperpigmentation usually results from an increased number, or activity, of melanocytes. The degree of pigmentation of skin depends on the amount and type of melanin, degree of skin vascularity, presence of carotene, and thickness of the stratum corneum. Common causes of hyperpigmentation include post-inflammatory hyperpigmentation, melasma, solar lentigines, ephelides (freckles), and café-au-lait macules. Some skin tumors can be hyperpigmented as basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and malignant melanoma (MM). Stem cell factor (SCF) is a growth factor and its interaction with its receptor, c-kit, is well known to be critical to the survival of melanocytes. Methods: This study was carried out on 60 patients complaining of hyperpigmented skin lesions (20 melasma, 20 solar lentigines, and 20 freckles) and 36 patients with skin tumors (14 BCC, 12 SCC, and 10 MM). Punch skin biopsies were taken from the previous lesions. Immunohistochemical staining of these samples was done using the stem cell factor (SCF). Results: There was positive expression of SCF in all cases of melasma, solar lentigines and freckles with significant increase in the intensity of expression in the lesional areas than the non-lesional ones (P=0.004). There was also a statistically significant increase in the expression of SCF in BCC and melanoma tumor cells. Conclusion: SCF has a great role in skin hyperpigmented disorders and this can be used as a target for the developing of new antipigmentary lines of treatment by inhibiting SCF. SCF can also be involved in the emergence of some skin tumors.     

Gastroretentive Cosolvent-Based In Situ Gel as a Promising Approach for Simultaneous Extended Delivery and Enhanced Bioavailability of Mitiglinide Calcium

Ion cross-linking in situ gels are novel liquid sustained-release drug delivery systems. These systems are unsuitable for poorly water-soluble drugs such as the novel antidiabetic drug mitiglinide calcium (MTG). Thus, our goal was to assess the possibility of using cosolvency approach in formulating gastroretentive in situ gel of the short half-life MTG to simultaneously enhance its bioavailability and sustain its release. MTG in situ gel formulations were developed using propylene glycol as a cosolvent to dissolve MTG in the polymer solution, followed by characterization of viscosity, gel strength, floating ability, and in vitro MTG release and phramacokinetics evaluation. The optimized formulation (composition: 1% gellan gum, 0.75% sodium alginate, 0.75% calcium carbonate, and 7.5% propylene glycol) exhibited reasonable viscosity but on introduction into simulated gastric fluid, it formed firm gel that floated within seconds over the surface and remained buoyant for 24 h. The formula exhibited in vivo sustained release manner of MTG over 24 h and improved the bioavailability of the drug. Thus, cosolvency presents a promising approach to deliver hydrophobic drugs in sustained-release liquid formulations. These formulations will improve diabetic patients' compliance by eliminating the necessity of frequent dosing with a better disease management.