A GFP-lacZ Bicistronic Reporter System for Promoter Analysis in Environmental Gram-Negative Bacteria

Here, we describe a bicistronic reporter system for the analysis of promoter activity in a variety of Gram-negative bacteria at both the population and single-cell levels. This synthetic genetic tool utilizes an artificial operon comprising the gfp and lacZ genes that are assembled in a suicide vector, which is integrated at specific sites within the chromosome of the target bacterium, thereby creating a monocopy reporter system. This tool was instrumental for the complete in vivo characterization of two promoters, Pb and Pc, that drive the expression of the benzoate and catechol degradation pathways, respectively, of the soil bacterium Pseudomonas putida KT2440. The parameterization of these promoters in a population (using β-galactosidase assays) and in single cells (using flow cytometry) was necessary to examine the basic numerical features of these systems, such as the basal and maximal levels and the induction kinetics in response to an inducer (benzoate). Remarkably, GFP afforded a view of the process at a much higher resolution compared with standard lacZ tests; changes in fluorescence faithfully reflected variations in the transcriptional regimes of individual bacteria. The broad host range of the vector/reporter platform is an asset for the characterization of promoters in different bacteria, thereby expanding the diversity of genomic chasses amenable to Synthetic Biology methods

An Information Theoretic, Microfluidic-Based Single Cell Analysis Permits Identification of Subpopulations among Putatively Homogeneous Stem Cells

An incomplete understanding of the nature of heterogeneity within stem cell populations remains a major impediment to the development of clinically effective cell-based therapies. Transcriptional events within a single cell are inherently stochastic and can produce tremendous variability, even among genetically identical cells. It remains unclear how mammalian cellular systems overcome this intrinsic noisiness of gene expression to produce consequential variations in function, and what impact this has on the biologic and clinical relevance of highly ‘purified’ cell subgroups. To address these questions, we have developed a novel method combining microfluidic-based single cell analysis and information theory to characterize and predict transcriptional programs across hundreds of individual cells. Using this technique, we demonstrate that multiple subpopulations exist within a well-studied and putatively homogeneous stem cell population, murine long-term hematopoietic stem cells (LT-HSCs). These subgroups are defined by nonrandom patterns that are distinguishable from noise and are consistent with known functional properties of these cells. We anticipate that this analytic framework can also be applied to other cell types to elucidate the relationship between transcriptional and phenotypic variation

Rhinocerebral mucormycosis treated with 32 gram liposomal amphotericin B and incomplete surgery: a case report

Background: Mucormycosis (or zygomycosis) is the term for infection caused by fungi of the order Mucorales. Mucoraceae may produce severe disease in susceptible individuals, notably patients with diabetes and leukemia. Rhinocerebral mucormycosis most commonly manifests itself in the setting of poorly controlled diabetes, especially with ketoacidosis

Oculogyric crisis in a patient taking metoclopramide

Yaran Koban, Metin Ekinci, Halil Huseyin Cagatay, Zeliha Yazar Department of Ophthalmology, Faculty of Medicine, Kafkas University, Kars, Turkey Abstract: Oculogyric crisis is an acute dystonic reaction of the ocular muscles characterized by bilateral dystonic elevation of visual gaze lasting from seconds to hours. This reaction is most commonly explained as an adverse reaction to drugs such as antiemetics, antipsychotics, antidepressants, antiepileptics, and antimalarials. Although the incidence of metoclopramide-induced acute dystonic reactions has been reported as 25% in children, there have been few published cases on oculogyric crisis in general. It is important to be able to recognize this ocular side effect because, without a thorough patient history, symptoms can be confused with other diseases such as versive seizures, paroxysmal tonic upward gaze, and encephalopathy. In this paper, we report a case of oculogyric crisis induced by metoclopramide. Keywords: oculogyric crisis, dystonic reactions, metoclopramid

Comparison of the effect of W-shaped and linear skin incisions on scar visibility in bilateral external dacryocystorhinostomy

Metin Ekinci,1 Halil Hüseyin Çağatay,1 Gokcen Gokce,2 Erdinç Ceylan,3 Sadullah Keleş,4 Özgür Çakici,5 Mehmet Ersin Oba,1 Zeliha Yazar1 1Department of Ophthalmology, University of Kafkas, 2Department of Ophthalmology, Sarikamis Military Hospital, Sarikamis, Kars, 3Ophthalmology Clinic, Erzurum Training and Research Hospital, 4Department of Ophthalmology, University of Atatürk, Erzurum, 5Department of Ophthalmology, University of Mugla Sitki Kocman, Muğla, Turkey Background: The aim of this study was to compare the effect of W-shaped skin (WS) and linear skin (LS) incisions on cutaneous scar tissue formation in patients who have undergone bilateral external dacryocystorhinostomy. Methods: Sixteen patients (14 females and two males) with acquired bilateral nasolacrimal duct obstruction were included in this prospective, interventional comparative study. LS incision was applied to one side and WS skin incision to the other side. The skin incisions were assessed 6 months after each procedure by the patients themselves and by two ophthalmologists who were unaware of the skin incision shape and side. Scar tissue that was not recognized under the same light conditions and in the same room from a 100 cm distance was recorded as grade 1. Minimally visible scar tissue was assessed as grade 2, moderately visible scar tissue as grade 3, and easily visible scar tissue as grade 4. Results: The mean scar assessment scores recorded by the first ophthalmologist were 2.50±0.82 for the LS group and 1.25±0.45 for the WS group (P<0.001). The second ophthalmologist’s assessment scores were 2.25±0.86 for the LS group and 1.25±0.45 for the WS group (P<0.001). The mean patient self-assessment score for the incision scars was 2.44±1.03 for the LS group and 1.56±0.73 for the WS group (P<0.001). Conclusion: Compared with LS incision, WS incision resulted in less cutaneous scar tissue formation in patients who have undergone bilateral external dacryocystorhinostomy. Keywords: external dacryocystorhinostomy, skin, W-shaped incision, linear incisio