Construction of a swine artificial chromosome: a novel vector for transgenesis in the pig

A de novo SAC was constructed by making use of YAC technology and a humanized yeast strain. The construct (about 310 kb) contained pig centromeric DNA and the Neo gene. The construct was introduced into a pig cell line by yeast-mammalian cell fusion and G418 resistant clones were obtained. One clone was characterized by FISH and shown to contain an episomally located microchromosome containing YAC, Neo and pig centromere sequences. FISH analysis over time showed that the SAC was mitotically stable for at least 34 generations in the absence of selection. The size of the SAC was determined by confocal microscopy of the SAC and shown to be approximately 7 Mb, which is about 25-fold greater than the size of the original YAC. From its behavior in pulsed field gel electrophoresis, FISH analysis of stretched DNA fibers, and its appearance under scanning confocal microscopy, it was concluded that the SAC is a circularized and multimerized derivative of the original YAC. Possible applications as vectors for animal transgenesis are discussed.     

“Neurologist's contribution to the diagnosis of sine materia respiratory insufficiency: case report”

Background

Obstructive sleep apnea (OSA) and arterial hypertension (AH) are common and underrecognized medical disorders. OSA is a potential risk factor for the development of AH and/or may act as a factor complicating AH management. The symptoms of excessive daytime sleepiness (EDS) are considered essential for the initiation of continuous positive airway pressure (CPAP) therapy, which is a first line treatment of OSA. The medical literature and practice is controversial about the treatment of people with asymptomatic OSA. Thus, OSA patients without EDS may be left at increased cardiovascular risk.

Case presentation

The report presents a case of 42year old Asian woman with symptoms of heart failure and angina like chest pain upon admission. She didnt experience symptoms of EDS, and the Epworth Sleepiness Scale was seven points. Snoring was reported on direct questioning. The patient had prior medical history of three unsuccessful pregnancies complicated by gestational AH and preeclampsia with C-section during the last pregnancy. The admission blood pressure (BP) was 200/120mm Hg. The patients treatment regimen consisted of five hypotensive medications including diuretic. However, a target BP wasnt achieved in about one and half month. The patient was offered to undergo a polysomnography (PSG) study, which she rejected. One month after discharge the PSG study was done, and this showed an apnea-hypopnea index (AHI) of 46 events per hour. CPAP therapy was initiated with a pressure of 11H₂0cm. After 2months of compliant CPAP use, adherence to pharmacologic regimen and lifestyle modifications the patients BP decreased to 134/82mm Hg.

Conclusions

OSA and AH are common and often underdiagnosed medical disorders independently imposing excessive cardiovascular risk on a diseased subject. When two conditions coexist the cardiovascular risk is likely much greater. This case highlights a possible clinical phenotype of OSA without EDS and its association with resistant AH. Most importantly a good hypotensive response to medical treatment in tandem with CPAP therapy was achieved in this patient. Thus, it is reasonable to include OSA in the differential list of resistant AH, even if EDS is not clinically obvious.     

Ragweed presence in Trieste: clinical and aerobiological data

Summary Studies on ragweed have been carried out in the province of Trieste (Northern Italy) in which it is becoming widespread. The floristic records, the increasing amount of airborne pollen monitored and the relevant skin reactivity are reported. This phenomenon, though still at the beginning, is actually showing an upward trend due to man's intervention over wider and wider areas which as a consequence become suitable for the settlement of these anthropophitic species. The aerobiological data are compared to the skin reactivities of allergic subjects.     

Structure elucidation and hepatotoxicity evaluation against HepG2 human cells of neo-clerodane diterpenes from Teucrium polium L

Seven neo-clerodanes (teupolins VI–XII) and eleven known compounds were isolated and characterized from leaf extracts of Teucrium polium L., a medicinal plant used in traditional and herbal medicine for its hypolipidemic, hypoglycemic, antioxidant and antiproliferative properties. The structures of these compounds were elucidated by 1D (¹H, ¹³C and DEPT) and 2D (COSY, TOCSY, HSQC, HMBC) NMR experiments and by mass spectrometry analysis. The complete stereostructure of each compound was defined with a NOESY experiment. Because the overexploitation of herbal remedies containing T. polium extracts has resulted in several cases of hepatitis, the hepatotoxic activity of pure metabolites against the human hepatoblastoma cancer cell line HepG2 was assessed by the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) test. All of the compounds showed low toxicity values at the highest concentration tested (200 μM).     

Anti-PlGF inhibits growth of VEGF(R)-inhibitor-resistant tumors without affecting healthy vessels

Novel antiangiogenic strategies with complementary mechanisms are needed to maximize efficacy and minimize resistance to current angiogenesis inhibitors. We explored the therapeutic potential and mechanisms of alphaPlGF, an antibody against placental growth factor (PlGF), a VEGF homolog, which regulates the angiogenic switch in disease, but not in health. alphaPlGF inhibited growth and metastasis of various tumors, including those resistant to VEGF(R) inhibitors (VEGF(R)Is), and enhanced the efficacy of chemotherapy and VEGF(R)Is. alphaPlGF inhibited angiogenesis, lymphangiogenesis, and tumor cell motility. Distinct from VEGF(R)Is, alphaPlGF prevented infiltration of angiogenic macrophages and severe tumor hypoxia, and thus, did not switch on the angiogenic rescue program responsible for resistance to VEGF(R)Is. Moreover, it did not cause or enhance VEGF(R)I-related side effects. The efficacy and safety of alphaPlGF, its pleiotropic and complementary mechanism to VEGF(R)Is, and the negligible induction of an angiogenic rescue program suggest that alphaPlGF may constitute a novel approach for cancer treatment.     

ApoE-dependent sterol efflux from macrophages is modulated by scavenger receptor class B type I expression

Macrophages express a number of proteins involved in sterol efflux pathways, including apolipoprotein E (apoE) and scavenger receptor class B type I (SR-BI). We have investigated a potential interaction between these two sterol efflux pathways in modulating overall macrophage sterol flux. We utilized an experimental system in which we increased expression of each of these proteins to a high physiologic range in order to perform our evaluation. We show that in apoE-expressing cells, a 4-fold increase in SR-BI expression leads to reduction of sterol and phospholipid efflux. SR-BI-mediated reduction in sterol efflux was only observed in cells that expressed endogenous apoE. In J774 cells that did not express apoE, a similar increase in SR-BI level led to increased sterol efflux. The divergent response of sterol efflux after increased SR-BI was maintained in the presence of a number of structurally diverse extracellular sterol acceptors. Increased SR-BI expression also enhanced sterol efflux to exogenously added apoE. Investigation of a potential mechanism for reduced efflux in apoE-expressing cells indicated that SR-BI expression reduced macrophage apoE by accelerating the degradation of newly synthesized apoE. This led to decreased secretion of apoE and reduced the fraction of apoE sequestered on the cell surface. Thus, enhanced SR-BI expression in macrophages can reduce the cellular level and secretion of apoE by accelerating degradation of the newly synthesized protein. This reduction of endogenous apoE is accompanied by reduced sterol efflux from macrophages.