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1.
J Chem Phys ; 153(16): 164118, 2020 Oct 28.
Article in English | MEDLINE | ID: mdl-33138420

ABSTRACT

Concurrent multiscale techniques such as Adaptive Resolution Scheme (AdResS) can offer ample computational advantages over conventional atomistic (AT) molecular dynamics simulations. However, they typically rely on aphysical hybrid regions to maintain numerical stability when high-resolution degrees of freedom (DOFs) are randomly re-inserted at the resolution interface. We propose an Energy Minimized AT (DOF) Insertion (EMATI) method that uses an informed rather than random AT DOF insertion to tackle the root cause of the issue, i.e., overlapping AT potentials. EMATI enables us to directly couple AT and coarse-grained resolutions without any modifications of the interaction potentials. We exemplify AdResS-EMATI in a system of liquid butane and show that it yields improved structural and thermodynamic properties at the interface compared to competing AdResS approaches. Furthermore, our approach extends the applicability of the AdResS without a hybrid region to systems for which force capping is inadequate.

2.
J Agric Sci ; 156(5): 658-672, 2018 Jul.
Article in English | MEDLINE | ID: mdl-30369629

ABSTRACT

A probabilistic crop forecast based on ensembles of crop model output estimates, presented here, offers an ensemble of possible realizations and probabilistic forecasts of green water components, crop yield and green water footprints (WFs) on seasonal scales for selected summer crops. The present paper presents results of an ongoing study related to the application of ensemble forecasting concepts in crop production. Seasonal forecasting of crop water use indicators (evapotranspiration (ET), water productivity, green WF) and yield of rainfed summer crops (maize, spring barley and sunflower), was performed using the AquaCrop model and ensemble weather forecast, provided by The European Centre for Medium-range Weather Forecast. The ensemble of estimates obtained was tested with observation-based simulations to assess the ability of seasonal weather forecasts to ensure that accuracy of the simulation results was the same as for those obtained using observed weather data. Best results are obtained for ensemble forecast for yield, ET, water productivity and green WF for sunflower in Novi Sad (Serbia) and maize in Groß-Enzersdorf (Austria) - average root mean square error (2006-2014) was <10% of observation-based values of selected variables. For variables yielding a probability distribution, capacity to reflect the distribution from which their outcomes will be drawn was tested using an Ignorance score. Average Ignorance score, for all locations, crops and variables varied from 1.49 (spring barley ET in Groß-Enzersdorf) to 3.35 (sunflower water productivity in Groß-Enzersdorf).

3.
Graefes Arch Clin Exp Ophthalmol ; 254(1): 135-41, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26287265

ABSTRACT

PURPOSE: The purpose was to assess the influence of donor and storage factors on the suitability of organ-cultured corneas for transplantation. METHODS: Data from 1340 donor corneas stored between 2009 and 2015 were analyzed retrospectively. Logistic regression analysis was used to assess the influence of different factors on the suitability of grafts for transplantation. RESULTS: Forty-one percent (553/1340) of corneas were discarded. The leading causes were medical contraindication (20.2 %) and poor endothelial quality (19.3 %). Donor age influenced suitability for transplantation significantly. Corneas from donors aged 80 years and older were more likely to be discarded because of endothelial insufficiency (P < 0.0001). The cause of donor death including infection and multiple organ dsyfunction syndrom (MODS) increased the risk of bacterial or fungal contamination during organ culture (P = 0.007 and P = 0.014, respectively). Prolonged time between death and enucleation was associated with an increased risk of unsuitability for transplantation (P < 0.0001). The amount of time between death and corneoscleral disc excision and duration of storage influenced the suitability for transplantation (P = 0.0007 and P < 0.0001, respectively). CONCLUSION: Donor age, cause of death, storage time, death to enucleation and death to disc excision times influenced transplantation suitability. The percentage of discarded corneas may be reduced by shortening storage time, death to enucleation, and death to corneoscleral disc excision times. Setting a maximum donor age could reduce the percentage of discarded corneas. However, as long as there is a lack of donor corneas, we do not recommend any donor age limit.


Subject(s)
Cornea , Corneal Transplantation , Organ Culture Techniques , Organ Preservation , Tissue Donors , Tissue and Organ Procurement , Adolescent , Adult , Age Factors , Aged , Aged, 80 and over , Cause of Death , Eye Banks/methods , Eye Enucleation , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Factors , Tissue and Organ Harvesting
5.
Eye (Lond) ; 29(3): 428-35, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25523205

ABSTRACT

PURPOSE: To investigate the biocompatibility of the new cyanine dye: 3,3'-Di-(4-sulfobutyl)-1,1,1',1'-tetramethyl-di-1H-benz[e]indocarbocyanine (DSS) as a vital dye for intraocular application in an in vivo rat model and to evaluate the effects of this dye on retinal structure and function. METHODS: DSS at a concentration of 0.5% was applied via intravitreal injections to adult Brown Norway rats with BSS serving as a control. Retinal toxicity was assessed 7 days later by means of retinal ganglion cell (RGC) counts, light microscopy, optical coherence tomography (OCT), and electroretinography (ERG). RESULTS: No significant decrease in RGC numbers was observed. No structural changes of the central retina were observed either in vivo (OCT) or under light microscopy. ERGs detected a temporary reduction of retinal function 7 days after injection; this was no longer evident 14 days after injection. CONCLUSIONS: DSS showed good biocompatibility in a well-established experimental in vivo setting and may be usable for intraocular surgery as an alternative to other cyanine dyes. In contrast to indocyanine green, it additionally offers fluorescence in the visual spectrum. Further studies with other animal models are needed before translation into clinical application.


Subject(s)
Basement Membrane/surgery , Biocompatible Materials , Carbocyanines/toxicity , Coloring Agents/toxicity , Epiretinal Membrane/surgery , Retina/drug effects , Animals , Basement Membrane/pathology , Cell Count , Electroretinography/drug effects , Epiretinal Membrane/diagnosis , Female , Intravitreal Injections , Materials Testing , Rats , Rats, Inbred BN , Retina/pathology , Retinal Ganglion Cells/drug effects , Retinal Ganglion Cells/pathology , Staining and Labeling , Tomography, Optical Coherence
6.
Klin Monbl Augenheilkd ; 231(10): 1023-8, 2014 Oct.
Article in German | MEDLINE | ID: mdl-25333241

ABSTRACT

BACKGROUND: Cataract surgery is the most commonly performed surgical procedure in developed countries. The annual number of cataract surgeries in Germany is about 600,000. Acute postoperative endophthalmitis is a very severe and the most dreaded complication of cataract surgery. Various operative and non-operative measures have been suggested to prevent this serious complication. The European Society of Cataract & Refractive Surgeons (ESCRS) study of intracameral cefuroxime was the first prospective, randomised and partially placebo-controlled clinical trial showing the efficacy of antibiotic prophylaxis to prevent endophthalmitis in 2007. The aim of this retrospective study is to investigate a possible reduction of intracameral cefuroxime to prevent postoperative endophthalmitis at the University Eye Hospital Tübingen. PATIENTS AND METHODS: During the period from January 2002 to August 2013, 2 time periods were determined based on the adoption of intracameral cefuroxime injections after cataract surgery. From January 2002 to May 2009 patients received at the end of cataract surgery a subconjunctival administration of 50 mg of mezlocillin and postoperative antibiotic eye drops (gentamicin) without intracameral injection. From June 2009 to August 2013, patients received an intracameral injection of cefuroxime while antibiotic drops (moxifloxacin) were used too. The rates of postoperative infectious endophthalmitis during these 2 periods were calculated. RESULTS: 31 cases of endophthalmitis occurred in 31,386 cataract surgeries. The overall cumulative incidence was 0.99 per 1000 patients. The incidence in the first period without intracameral cefuroxime injection was 1.38 (95 % confidence interval [CI]: 1.03-1.72) per 1000 patients and in the second period 0.44 (95 % CI: 0.34-0.54) per 1000 patients (p < 0.001). CONCLUSION: Intracameral injection of cefuroxime reduces the rate of postoperative infectious endophthalmitis in cataract surgery significantly.


Subject(s)
Antibiotic Prophylaxis/statistics & numerical data , Cataract Extraction/statistics & numerical data , Cefuroxime/administration & dosage , Endophthalmitis/epidemiology , Endophthalmitis/etiology , Endophthalmitis/prevention & control , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Aged , Anti-Bacterial Agents/administration & dosage , Antibiotic Prophylaxis/methods , Causality , Comorbidity , Endophthalmitis/diagnosis , Female , Germany/epidemiology , Humans , Incidence , Longitudinal Studies , Male , Retrospective Studies , Risk Assessment , Treatment Outcome
7.
Ophthalmologe ; 110(10): 941-7, 2013 Oct.
Article in German | MEDLINE | ID: mdl-24046168

ABSTRACT

After introduction of vitreoretinal surgery more than 40 years ago, further development of the procedure involved a continuous reduction of potential toxic effects by irrigating solutions, endoillumination or mechanical manipulation. Recently, additional efforts were made to prevent neurodegeneration via pharmacological intervention. Taurine as additive for irrigating solutions can be considered as an example for neuroprotectants in vitreoretinal surgery. Approval of neuroprotective agents demands an increased effort for preclinical and clinical evaluation. To date, only few neuroprotective substances are used in clinical routine in the context of vitreoretinal surgery, however, experimental data suggest a high potential of various neuroprotective agents. The following article gives an overview of current neuroprotective approaches feasible for vitreoretinal surgery and a critical analysis of their clinical relevance.


Subject(s)
Neuroprotective Agents/administration & dosage , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Premedication/methods , Retinal Diseases/surgery , Vitreoretinal Surgery/adverse effects , Vitreoretinal Surgery/methods , Humans , Intravitreal Injections , Ophthalmic Solutions/administration & dosage , Taurine/administration & dosage
8.
Internist (Berl) ; 54(4): 485-90, 2013 Apr.
Article in German | MEDLINE | ID: mdl-23460391

ABSTRACT

We report a case of nearly fatal ventricular tachyarrhythmia type Torsade de pointes caused by medication-induced prolongation of QTc duration (methadone, ondansetron, escitalopram). The etiology, pathophysiology, and trigger mechanisms of such malignant arrhythmias are discussed. In order to prevent similar iatrogenic complications in the future, we networked the qtdrug database with our medication interaction control program and installed an automatic electronic warning system for the physicians in charge in case of a digitally recorded prolonged QTc duration.


Subject(s)
Decision Support Systems, Clinical , Drug Therapy, Computer-Assisted/methods , Medical Order Entry Systems/organization & administration , Methadone/adverse effects , Ondansetron/adverse effects , Torsades de Pointes/chemically induced , Torsades de Pointes/prevention & control , Adult , Analgesics, Opioid/adverse effects , Antidepressive Agents/adverse effects , Antidepressive Agents, Second-Generation/adverse effects , Citalopram/adverse effects , Drug Therapy, Combination/adverse effects , Humans , Male
9.
Water Sci Technol ; 65(7): 1258-64, 2012.
Article in English | MEDLINE | ID: mdl-22437024

ABSTRACT

We have investigated how different approaches for water footprint (WF) calculations lead to different results, taking sugar beet production and sugar refining as examples. To a large extent, results obtained from any WF calculation are reflective of the method used and the assumptions made. Real irrigation data for 59 European sugar beet growing areas showed inadequate estimation of irrigation water when a widely used simple approach was used. The method resulted in an overestimation of blue water and an underestimation of green water usage. Dependent on the chosen (available) water quality standard, the final grey WF can differ up to a factor of 10 and more. We conclude that further development and standardisation of the WF is needed to reach comparable and reliable results. A special focus should be on standardisation of the grey WF methodology based on receiving water quality standards.


Subject(s)
Models, Theoretical , Water Supply , Water , Agriculture , Beta vulgaris , Food-Processing Industry
10.
Oncogene ; 31(47): 4912-22, 2012 Nov 22.
Article in English | MEDLINE | ID: mdl-22266866

ABSTRACT

The Ras association domain family 1 isoform A (RASSF1A) is a tumor suppressor whose inactivation is implicated in the development of many human cancers, including breast carcinomas. Little is known about the tumor-suppressive function of RASSF1A in breast tissue and whether its inactivation is mechanistically involved in the initiation and progression of breast tumors. Here, we show that RASSF1A inhibits breast cancer growth in vivo, and suppresses estrogen receptor (ERα) expression and function. Reconstitution of RASSF1A in MCF7 cells led to decreased ERα levels and reduced sensitivity to estrogen (E2). Concomitantly, we observed decreased expression of Id1 as well as the E2-responsive genes Bcl-2 and c-Myc that cooperatively contribute to the immortalization and transformation of breast epithelial cells. This downregulation was associated with induction of cell-cycle arrest and senescence that constitute early barriers to cancer initiation and progression. Knockdown of ERα showed that downregulation of ERα suffices to increase senescence and inhibit expression of Bcl-2, c-Myc and Id1. However, enforced expression of ERα only partially rescued RASSF1A-mediated growth inhibition and senescence, suggesting that suppression of ERα expression and activity is not the only mechanism by which RASSF1A inhibits growth and survival of breast cancer cells. Ectopic expression of Bcl-2, c-Myc and Id1 had little or no effect on RASSF1A-mediated growth arrest, indicating that RASSF1A acts dominantly over these oncogenes. Mechanistically, RASSF1A was found to suppress ERα expression through Akt1. It also transiently inhibited ERα-induced Ras-MAPK activity after exposure of cells to E2. Together, our data show that RASSF1A acts as a tumor suppressor in ERα+ mammary epithelial cells, in part through inhibiting ERα expression and activity. These findings suggest that RASSF1A has a key role in suppressing the transformation of human breast epithelial cells and ERα+ breast cancer initiation.


Subject(s)
Breast Neoplasms/metabolism , Estrogen Receptor alpha/genetics , Gene Expression Regulation, Neoplastic , Signal Transduction , Tumor Suppressor Proteins/physiology , Animals , Apoptosis , Breast Neoplasms/pathology , Cell Cycle Checkpoints , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Proliferation , Cell Survival , Cellular Senescence , Estradiol/analogs & derivatives , Estradiol/pharmacology , Estrogen Antagonists/pharmacology , Estrogen Receptor alpha/metabolism , Estrogens/pharmacology , Female , Fulvestrant , Gene Expression , Humans , MCF-7 Cells , Mice , Mice, Inbred NOD , Mice, SCID , Neoplasm Transplantation , Proteolysis , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism
11.
Klin Monbl Augenheilkd ; 228(10): 900-4, 2011 Oct.
Article in German | MEDLINE | ID: mdl-21656461

ABSTRACT

BACKGROUND: Behçet's disease is a systemic vasculitis disorder of unknown aetiology. Ocular involvement, especially with vasculitis, is detected in up to 80 % of the cases. Anterior segment involvement such as cataract is also seen in the follow-up of patients who are then treated surgically. In this study, we aimed to analyze the outcomes of cataract surgery in patients with Behçet's disease retrospectively. PATIENTS AND METHODS: The records of 9 patients (12 eyes) with Behçet's disease who underwent phacoemulsification with IOL implantation in 11 eyes and extracapsular cataract extraction (ECCE) with IOL implantation in one eye between June 2001 and September 2009 were evaluated retrospectively. The visual outcome and complications were analysed. RESULTS: The mean follow-up was 33.8 months (range 3 to 88 months). The mean preoperative LogMAR BCVA was 1.15 ± 0.53 (95 % CI: 0.81 - 1.49) and increased to 0.36 ± 0.32 (95 % CI: 0.15 - 0.56) at last medical visit (p < 0.001). The most frequent postoperative complication was posterior capsular opacification, which developed in 2 eyes (17 %). Other complications were mild fibrinous reaction in 1 eye (8 %). CONCLUSIONS: The outcomes of cataract surgery in patients with Behçet's disease were satisfactory. The great majority of the patients regained and retained a good visual outcome and had fewer postoperative complications.


Subject(s)
Behcet Syndrome/surgery , Lenses, Intraocular , Adult , Anti-Inflammatory Agents/administration & dosage , Azathioprine/administration & dosage , Cataract Extraction/methods , Female , Humans , Immunosuppressive Agents/administration & dosage , Interferon alpha-2 , Interferon-alpha/administration & dosage , Male , Middle Aged , Perioperative Care , Postoperative Complications/etiology , Prednisolone/administration & dosage , Recombinant Proteins/administration & dosage , Retrospective Studies , Young Adult
12.
Ophthalmologe ; 106(1): 11-5, 2009 Jan.
Article in German | MEDLINE | ID: mdl-19139900

ABSTRACT

For the last 8 years vital dyes have been used to visualize preretinal semitransparent structures in the eye during vitroretinal surgery. However, indocyanine green (ICG), which was the first commonly used dye, proved to be partly toxic to retinal cells and the retinal pigment epithelium in various in vitro and in vivo studies. Therefore, an intensive search for new and safer dyes was started. At present three dyes, trypan blue, patent blue and brilliant blue are predominantly used for vitreoretinal surgery, in addition to ICG. In this article an overview of preclinical biocompatibility studies for common vital dyes is presented. Additionally, a systematic approach for testing of new candidate dyes for vitreoretinal surgery will be proposed.


Subject(s)
Biocompatible Materials , Coloring Agents , Image Enhancement/methods , Ophthalmologic Surgical Procedures/methods , Surgery, Computer-Assisted/methods , Vitreoretinopathy, Proliferative/pathology , Vitreoretinopathy, Proliferative/surgery , Humans
13.
Ophthalmologe ; 106(1): 7-10, 2009 Jan.
Article in German | MEDLINE | ID: mdl-19082605

ABSTRACT

This article reviews the most relevant vital dyes and adjuncts currently available for use in vitreoretinal surgical procedures. The current concepts of intraocular application as well as the staining properties are described, and the issue of biocompatibility is discussed.


Subject(s)
Coloring Agents , Image Enhancement/methods , Ophthalmologic Surgical Procedures/methods , Surgery, Computer-Assisted/methods , Vitreoretinopathy, Proliferative/pathology , Vitreoretinopathy, Proliferative/surgery , Humans
14.
Br J Ophthalmol ; 92(8): 1142-7, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18653608

ABSTRACT

BACKGROUND/AIMS: To evaluate the retinal toxicity of Brilliant Blue G (BBG) following intravitreal injection in rat eyes and examine the biocompatibility and the staining properties in humans. METHODS: BBG was injected into the 11 rat eyes to evaluate toxic effects with balanced salt solution (BSS) serving as control. Retinal toxicity was assessed by retinal ganglion cell (RGC) counts and by light microscopy 7 days later. In addition, BBG was applied during vitrectomy for macular hole (MH) (n = 15) or epiretinal membranes (ERM) (n = 3) in a prospective, non-comparative consecutive series of patients. Before and after surgery, all patients underwent a complete clinical examination including measurement of best corrected visual acuity (VA) and intraocular pressure, perimetry, fundus photography and optical coherence tomography. Patients were seen 1 day before surgery and then in approximately four weeks intervals. RESULTS: No significant reduction in RGC numbers and no morphological alterations were noted. A sufficient staining of the internal limiting membrane (ILM) was seen in patients with MH, while the staining pattern in ERM cases was patchy, indicating that parts of the ILM were peeled off along with the ERM in a variable extent. All MHs could be closed successfully. VA improved in 10 eyes (56%; 8/15 MH patients, 2/3 ERM patients), was unchanged in four eyes (22%; all MH patients) and was reduced in four eyes (22%; 3/15 MH, 1/3 ERM). No toxic effects attributable to the dye were noted during patient follow-up. The ultrastructure of tissue harvested during surgery was unremarkable. CONCLUSION: Brilliant Blue provides a sufficient and selective staining of the ILM. No retinal toxicity or adverse effects related to the dye were observed in animal and human studies. The long-term safety of this novel dye will have to be evaluated in larger patient series and a longer follow-up.


Subject(s)
Benzenesulfonates/toxicity , Coloring Agents/toxicity , Retina/drug effects , Aged , Animals , Cell Count , Epiretinal Membrane/diagnosis , Epiretinal Membrane/pathology , Epiretinal Membrane/surgery , Female , Humans , Male , Middle Aged , Prospective Studies , Rats , Rats, Inbred BN , Retina/pathology , Retina/ultrastructure , Retinal Ganglion Cells/drug effects , Retinal Ganglion Cells/pathology , Retinal Perforations/surgery , Staining and Labeling/methods , Vitrectomy/methods
15.
Br J Ophthalmol ; 92(9): 1265-8, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18586900

ABSTRACT

AIM: To assess whether low concentrations of a fluorescent dye such as Rhodamine 6G would help the unaided human eye visualise the vitreous and the internal limiting membrane (ILM) under standard halogen illumination. MATERIAL/METHODS: The UV/Vis absorption (E) and fluorescence (I) spectra of Rhodamine 6G in water were measured and compared with Indocyanine Green (ICG). Surgery was performed in two rhesus monkeys and consisted of standard pars plana vitrectomy with halogen light source used for illumination. Rhodamine 6G was diluted in balanced salt solution (BSS). A few drops of the dye in a concentration of 0.1% (307 mOsm) were applied over the posterior pole in the air-filled globe and washed out by irrigation after 1 min. Immediately after surgery, the globes were enucleated, fixated and prepared for histological evaluation. RESULTS: In contrast to ICG, both the maximum of the absorption and emission of Rhodamin 6G are very much within the spectral sensitivity of the human eye. The Rhodamine 6G-BSS itself appears red in colour. Using a dye concentration of 0.1%, there was no visible red-staining of the ILM as such. As the dye was irrigated out with BSS, a marked green fluorescence of the fluid within the vitreous cavity was noted. With halogen illumination through a standard 20-gauge light pipe, the dye provided a sufficient green fluorescence to identify and safely remove the ILM and to clearly differentiate areas of peeled from non-peeled ILM. During light microscopy, eyes revealed a peeled ILM demarcation with no signs of acute retinal toxicity. CONCLUSION: The findings indicate that a fluorescent dye can be used for ILM peeling. Assuming that the fluorophore provides a high enough fluorescence quantum yield after adsorption to the ILM, much lower dye concentrations could be used compared with absorbent dyes, thereby minimising toxic effects.


Subject(s)
Bruch Membrane/surgery , Coloring Agents , Fluorescent Dyes , Indocyanine Green , Rhodamines , Vitreous Body , Animals , Bruch Membrane/metabolism , Macaca mulatta , Microscopy, Polarization/methods
16.
Cell Death Differ ; 12(4): 317-25, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15678149

ABSTRACT

Deregulation of apoptosis signalling is commonly found in cancer and results in resistance to cytotoxic therapies. Immunotherapy is a promising strategy to eliminate resistant cancer cells. The transfer of T-lymphocytes during allogeneic stem cell transplantation is clinically explored to induce a 'graft-versus-tumor' effect (GvT). Cytotoxic T-lymphocytes (CTL), which are major effectors of GvT, eliminate cancer cells by inducing apoptosis via multiple parallel pathways. Here, we study in vitro and in vivo the susceptibility of murine cancer cells engineered to express single antiapoptotic genes to CTL-mediated cytotoxicity. Interestingly, we find that single inhibitors of caspase activation, such as BCL-XL or dominant-negative mutants of FADD and caspase-9, protect cancer cells against antigen-specific CTL in vitro. Moreover, expression of BCL-XL impairs the growth suppression by adoptively transplanted CTL of established tumours in vivo. Hence, apoptosis defects that provide protection to cytotoxic cancer therapies can confer crossresistance to immunotherapy by tumour-reactive CTL.


Subject(s)
Adoptive Transfer , Apoptosis/physiology , T-Lymphocytes, Cytotoxic/transplantation , Animals , Apoptosis/genetics , Caspases/metabolism , Enzyme Activation/physiology , HLA-A2 Antigen/genetics , HLA-A2 Antigen/immunology , Mice , Mice, Transgenic , Mitochondria/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Cytotoxic/metabolism , Time Factors , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics , bcl-X Protein
17.
Mol Ther ; 4(3): 273-9, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11545619

ABSTRACT

Murine leukemia virus (MuLV) can be pseudotyped with a variant of the human immunodeficency virus (HIV) envelope gene encoding the surface glycoprotein gp120-SU and a carboxy-terminally truncated transmembrane (TM) protein with only seven cytoplasmic amino acids. MuLV/HIV-1 pseudotyped retroviral vectors selectively target gene transfer to human cells expressing both CD4 and CXCR4. To apply this vector system to gene therapy of human diseases, we generated a stable packaging cell line, FLY-HIV-87, expressing the MuLV gag and pol genes and the C-terminally truncated variant of the HIV-1 envelope gene, but no retroviral vector genome. Production of infectious vector particles was tested after the introduction of different vector genomes and was in the range of 5x10(5) IU/ml. The vector particles could be concentrated up to 25-fold. Specific and efficient gene transfer into CD4/CXCR4 expressing cell lines and stimulated primary human CD4+ peripheral blood lymphocytes was achieved. Thus the packaging cell line FLY-HIV-87 is highly suitable for gene therapy of disorders of human T-helper cells.


Subject(s)
CD4 Antigens/metabolism , Leukemia Virus, Murine/genetics , Leukemia Virus, Murine/metabolism , T-Lymphocytes, Helper-Inducer/metabolism , T-Lymphocytes, Helper-Inducer/virology , Virus Assembly , Cell Line , Cells, Cultured , Fibronectins/metabolism , Flow Cytometry , Genetic Therapy/methods , Genetic Vectors/genetics , Humans , Leukemia Virus, Murine/growth & development , Organ Specificity , Phytohemagglutinins/pharmacology , Protamines/metabolism , T-Lymphocytes, Helper-Inducer/drug effects , T-Lymphocytes, Helper-Inducer/immunology , Transduction, Genetic
18.
Acad Med ; 76(4 Suppl): S131-3, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11299186

ABSTRACT

The Generalist Partners Program (GPP) provides all University of Wisconsin Medical School students with a comprehensive generalist core curriculum through early clinical experiences, interactive faculty presentations, and small-group discussions during the first two years of medical school. The GPP is the first component of a comprehensive, longitudinal generalist curriculum offered during all four years of medical education. Faculty members from family medicine, general internal medicine, and general pediatrics work together to develop the learning goals and provide the curriculum for the GPP courses. Each of the 145 entering first-year medical students is matched with a community-based physician, the generalist practice partner, and the students participate in early clinical experiences at this site throughout their first two years of medical education. Students' clinical experiences are presented and discussed in case-based small-group sessions led by the school's generalist faculty. A core lecture series on professionalism, communication skills, evidence-based medicine, and the organization of the health care system supplements the early clinical experiences.


Subject(s)
Curriculum , Education, Medical, Undergraduate , Humans , Models, Educational , Primary Health Care , Program Evaluation , Wisconsin
19.
J Virol ; 75(6): 3038-42, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11222732

ABSTRACT

Peptides derived from the heptad repeats of human immunodeficiency virus (HIV) gp41 envelope glycoprotein, such as T20, can efficiently inhibit HIV type 1 (HIV-1) entry. In this study, replication of HIV-1 was inhibited more than 100-fold in a T-helper cell line transduced with a retrovirus vector expressing membrane-anchored T20 on the cell surface. Inhibition was independent of coreceptor usage.


Subject(s)
HIV Envelope Protein gp41/physiology , HIV-1/physiology , Peptide Fragments/physiology , T-Lymphocytes, Helper-Inducer/virology , Amino Acid Sequence , Cell Line , Cell Membrane/metabolism , Enfuvirtide , Genetic Vectors , HIV Envelope Protein gp41/chemistry , HIV Envelope Protein gp41/genetics , HIV Envelope Protein gp41/metabolism , Humans , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/genetics , Peptide Fragments/metabolism , Retroviridae/genetics , Transduction, Genetic , Virus Replication
20.
Assist Inferm Ric ; 19(2): 112-9, 2000.
Article in Italian | MEDLINE | ID: mdl-11107366

ABSTRACT

Care of central venous catheter (CVC) in patients undergoing bone marrow transplantation (BMT) raises significant problems related to the high risk of local infections, to the immunodeficient status, which in itself is a predisposing factor for systematic blood stream infections. Although frequent changes of CVC dressing might theoretically reduce the incidence of infections, they are also accompanied by significant skin toxicity and patient discomfort. No study has yet addressed these points. The objective of this study was to compare two different time interval protocols for CVC dressing, in order to assess the effects on local infections and toxicity. In a multicentre study, 339 bone marrow transplant (BMT) patients with a tunnelled CVC (group A, 230 pts) or a non tunnelled one (Group B, 169 patients) were randomly allocated to receive CVC dressing changes every 5 or 10 days if belonging to group A or 2 or 5 days if in group B. Transparent impermeable polyurethane dressings were used for all patients. The rate of local infection at the site of CVC insertion was assessed by microbiological assay every 10 days, while severity of skin toxicity was measured according to the ECOG scale. Sixty-five per cent of enrolled patients were finally evaluable. Patients (in both groups) receiving CVC dressing changes at longer intervals did not show a significant increase in the rate of local infections, while those who received dressing every two days had a significant increase in local skin toxicity. Longer intervals were accompanied by a reduction in costs. The results of this study demonstrate that the increase in time interval between CVC dressing changes in BMT patients did not increment the risk of local infections, while significantly reducing patients discomfort and costs.


Subject(s)
Bone Marrow Transplantation , Catheterization, Central Venous/adverse effects , Catheterization, Central Venous/nursing , Infection Control/methods , Skin Care/methods , Skin Care/nursing , Clinical Nursing Research , Clinical Protocols , Drug Therapy/methods , Drug Therapy/nursing , Humans , Nursing Assessment , Time Factors
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