On a concept of genericity for RLC networks

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordA recent definition of genericity for resistor-inductor-capacitor (RLC) networks is that the realisability set of the network has dimension one more than the number of elements in the network. We prove that such networks are minimal in the sense that it is not possible to realise a set of dimension n with fewer than n − 1 elements. We provide an easily testable necessary and sufficient condition for genericity in terms of the derivative of the mapping from element values to impedance parameters, which is illustrated by several examples. We show that the number of resistors in a generic RLC network cannot exceed k + 1 where k is the order of the impedance. With an example, we show that an impedance function of lower order than the number of reactive elements in the network need not imply that the network is non-generic. We prove that a network with a non-generic subnetwork is itself non-generic. Finally we show that any positive-real impedance can be realised by a generic nMathWork

Derivative spectrophotometric analysis of benzophenone (as an impurity) in phenytoin

Three simple and rapid spectrophotometric methods were developed for detection and trace determination of benzophenone (the main impurity) in phenytoin bulk powder and pharmaceutical formulations. The first method, zero-crossing first derivative spectrophotometry, depends on measuring the first derivative trough values at 257.6 nm for benzophenone. The second method, zero-crossing third derivative spectrophotometry, depends on measuring the third derivative peak values at 263.2 nm. The third method, ratio first derivative spectrophotometry, depends on measuring the peak amplitudes of the first derivative of the ratio spectra (the spectra of benzophenone divided by the spectrum of 5.0 μg/mL phenytoin solution) at 272 nm. The calibration graphs were linear over the range of 1-10 μg/mL. The detection limits of the first and the third derivative methods were found to be 0.04 μg/mL and 0.11 μg/mL and the quantitation limits were 0.13 μg/mL and 0.34 μg/mL, respectively, while for the ratio derivative method, the detection limit was 0.06 μg/mL and the quantitation limit was 0.18 μg/mL. The proposed methods were applied successfully to the assay of the studied drug in phenytoin bulk powder and certain pharmaceutical preparations. The results were statistically compared to those obtained using a polarographic method and were found to be in good agreement

Alemtuzumab plus cyclosporine treatment of the autoimmune hemolytic anemia in an adult bowel transplant

An adult male underwent a bowel transplant for tufting enteropathy, receiving alemtuzumab, tacrolimus, and steroids as immunosuppressants. Five years later, he developed an autoimmune hemolytic anemia (AIHA), anti-IgG positive, with reduced reticulocyte count, leukopenia, and thrombocytopenia with antiplatelet antibodies. After an unsuccessful initial treatment with high dose steroids, reduction in tacrolimus dose, and intravenous immunoglobulin (IVIG), a bone marrow biopsy revealed absence of erythroid maturation with precursor hyperplasia. The patient was switched to sirolimus and received four doses of rituximab plus two courses of plasmapheresis, which decreased his transfusion requirements. After a febrile episode one month later, the AIHA relapsed with corresponding decreases in platelet and leukocyte count: cyclosporine A (CsA) was started with a second course of rituximab and IVIG without response, even though repeat bone marrow biopsy did not reveal morphology correlated to an acquired pure red cell aplasia (APRCA). Considering the similarity in his clinical and laboratory findings to APRCA, alemtuzumab was added (three doses over a week) with CsA followed by steroids. The patient was eventually discharged transfusion-independent, with increasing hemoglobin (Hb) levels and normal platelet and leukocyte count. One year later he is still disease-free with functioning graft

Recent acquisition of Helicobacter pylori by Baka Pygmies

Both anatomically modern humans and the gastric pathogen Helicobacter pylori originated in Africa, and both species have been associated for at least 100,000 years. Seven geographically distinct H. pylori populations exist, three of which are indigenous to Africa: hpAfrica1, hpAfrica2, and hpNEAfrica. The oldest and most divergent population, hpAfrica2, evolved within San hunter-gatherers, who represent one of the deepest branches of the human population tree. Anticipating the presence of ancient H. pylori lineages within all hunter-gatherer populations, we investigated the prevalence and population structure of H. pylori within Baka Pygmies in Cameroon. Gastric biopsies were obtained by esophagogastroduodenoscopy from 77 Baka from two geographically separated populations, and from 101 non-Baka individuals from neighboring agriculturalist populations, and subsequently cultured for H. pylori. Unexpectedly, Baka Pygmies showed a significantly lower H. pylori infection rate (20.8%) than non-Baka (80.2%). We generated multilocus haplotypes for each H. pylori isolate by DNA sequencing, but were not able to identify Baka-specific lineages, and most isolates in our sample were assigned to hpNEAfrica or hpAfrica1. The population hpNEAfrica, a marker for the expansion of the Nilo-Saharan language family, was divided into East African and Central West African subpopulations. Similarly, a new hpAfrica1 subpopulation, identified mainly among Cameroonians, supports eastern and western expansions of Bantu languages. An age-structured transmission model shows that the low H. pylori prevalence among Baka Pygmies is achievable within the timeframe of a few hundred years and suggests that demographic factors such as small population size and unusually low life expectancy can lead to the eradication of H. pylori from individual human populations. The Baka were thus either H. pylori-free or lost their ancient lineages during past demographic fluctuations. Using coalescent simulations and phylogenetic inference, we show that Baka almost certainly acquired their extant H. pylori through secondary contact with their agriculturalist neighbors

Role of vasopressin in the treatment of anaphylactic shock in a child undergoing surgery for congenital heart disease: a case report

<p>Abstract</p> <p>Introduction</p> <p>The incidence of anaphylactic reactions during anesthesia is between 1:5000 and 1:25000 and it is one of the few causes of mortality directly related to general anesthesia. The most important requirements in the treatment of this clinical condition are early diagnosis and maintenance of vital organ perfusion. Epinephrine administration is generally considered as the first line treatment of anaphylactic reactions. However, recently, new pharmacological approaches have been described in the treatment of different forms of vasoplegic shock.</p> <p>Case presentation</p> <p>We describe the case of a child who was undergoing surgery for ventricular septal defect, with an anaphylactic reaction to heparin that was refractory to epinephrine infusion and was effectively treated by low dose vasopressin infusion.</p> <p>Conclusion</p> <p>In case of anaphylactic shock, continuous infusion of low-dose vasopressin might be considered after inadequate response to epinephrine, fluid resuscitation and corticosteroid administration.</p

Antrum Approach Planning for Removal of Impacted Tooth Using Cone-Beam Computed Tomography

Due to the great number of structures in the maxillofacial region, cone-beam computed tomography (CBCT) is an important procedure in presurgical planning for removal of impacted teeth. Most of the information provided by this imaging technique cannot be visualized in conventional radiographs. In addition, CBCT reduces patient exposure to radiation in comparison with helical computed tomography and provides dental practitioners with easy access. We report the clinical case of a patient who underwent a surgical procedure for removal of an impacted maxillary premolar. CBCT-assisted presurgical treatment was used, enabling a more conservative surgical access, a less traumatic and less time consuming procedure than conventional surgical intervention

CD40-targeted adenoviral GM-CSF gene transfer enhances and prolongs the maturation of human CML-derived dendritic cells upon cytokine deprivation

Vaccination with autologous leukaemia-derived dendritic cells (DC) presents an adjuvant treatment option for chronic myeloid leukaemia (CML). Here, we show that high-efficiency CD40-targeted adenoviral gene transfer of GM-CSF to CML-derived DC induces long-lived maturation in the absence of exogenous cytokines and may thus ensure protracted stimulation of CML-specific T cells upon vaccination

Single-Nucleotide Polymorphism Genotyping Identifies a Locally Endemic Clone of Methicillin-Resistant Staphylococcus aureus

We developed, tested, and applied a TaqMan real-time PCR assay for interrogation of three single-nucleotide polymorphisms that differentiate a clade (termed ‘t003-X’) within the radiation of methicillin-resistant Staphylococcus aureus (MRSA) ST225. The TaqMan assay achieved 98% typeability and results were fully concordant with DNA sequencing. By applying this assay to 305 ST225 isolates from an international collection, we demonstrate that clade t003-X is endemic in a single acute-care hospital in Germany at least since 2006, where it has caused a substantial proportion of infections. The strain was also detected in another hospital located 16 kilometers away. Strikingly, however, clade t003-X was not found in 62 other hospitals throughout Germany nor among isolates from other countries, and, hence, displayed a very restricted geographical distribution. Consequently, our results show that SNP-typing may be useful to identify and track MRSA clones that are specific to individual healthcare institutions. In contrast, the spatial dissemination pattern observed here had not been resolved by other typing procedures, including multilocus sequence typing (MLST), spa typing, DNA macrorestriction, and multilocus variable-number tandem repeat analysis (MLVA)