Applied surgical methods and outcomes in crooked nose rhinoplasty.

OBJECTIVE: In this retrospective and multicentric study, we investigated applied surgical methods in rhinoplasty for crooked nose deformity. PATIENTS AND METHODS: The retrospective data for 300 crooked nose deformity cases (191 males and 109 females) were used in our study. Classification of the initial deformities was performed as (1) I-shaped crooked nose deformity, (2) C-shaped crooked nose deformity, (3) Reverse C-shaped crooked nose deformity, and (4) S-shaped crooked nose deformity. As an operation technique, L-strut septoplasty was performed. The applied surgical methods in rhinoplasty to correct the crooked nose are evaluated and classified. RESULTS: Our results showed that initial deformities in crooked nose patients were I-shaped crooked nose deformity (34%), C-shaped crooked nose deformity (28%), Reverse C-shaped crooked nose deformity (21.3%), and S-shaped crooked nose deformity (16.7%). L-strut septoplasty was performed, and the results of the applied methods to correct the crooked nose were evaluated and classified. It was noticed that more than one procedure was applied to each case: (1) double-side lateral osteotomy (86.6%), (2) wedge bone resection on one side of the osteotomy (7.3%), (3) single-side lateral osteotomy (6%), (4) symmetric spreader grafts (56%), (5) asymmetric spreader grafts (10.6%), (6) shaving of the transverse wing of dorsal septum (8%), (7) correction of deviated dorsal septum (16.3%), (8) displaced anterior nasal spine (12.6%), (9) clocking suture (dorsal septal rotation suture) (9%), (10) dorsal septal scoring and splinting graft (8.3%), and equalizing lateral cruses (12.6%). CONCLUSIONS: I-shaped and C-shaped crooked nose deformities were mainly detected in crooked nose deformity patients. Correcting the crooked nose, double-side lateral osteotomy, and symmetric spreader grafts were the most applied techniques to correct the crooked nose. Other rhinoplasty techniques were also applied to these patients; more than one technique was needed.

Septal extension graft use in the treatment of alar collapse.

OBJECTIVE: In our study, we showed that the septal extension graft (SEG) technique, which we applied for nasal projection in rhinoplasty surgery, increases the tension of the lateral cartilage (LC) and alar structures. We also demonstrated that nasal congestion could be treated by applying this technique in patients with nasal obstruction due to bilateral dynamic alar collapse. PATIENTS AND METHODS: This study was conducted retrospectively on 23 patients with nasal obstruction due to alar collapse. Bilateral dynamic nasal collapse and (+) Cottle test was present in all patients. Nasal lateral wall tissue was also found flaccid on nasal palpation and collapsed to the extent of obstruction on deep inspiration. Standard septal extension graft (SEG) and tongue-in-groove techniques were applied to all patients. RESULTS: Septal cartilage was used for SEG in all patients. No complaints of nasal obstruction on deep inspiration were noted by the patients at six months postoperative follow-up, and Cottle tests were negative. The patients' mean respiratory score was 152 postoperatively, compared to 66.5 preoperatively. This difference was statistically significant using the Wilcoxon signed ranks test (p<0.001). In evaluating postoperative cosmetic appearance due to nasal tip projection (NTP) and cephalic rotation changes, 16 men and four women reported that it was better, while two men felt that there was no change. One woman reported that her cosmetic appearance was worse than before; a revision surgery was performed for her at seven months postoperatively. CONCLUSIONS: This method is effective for patients with bilateral nasal collapse and thick-short columella. With the applied surgery, the caudal edge of the LC diverges from the septum, alar region tension and resistance increase, the columella increases in length, nasal projection increases, and the vestibule cross-sectional area is enlarged. In this way, a significant increase in nasal vestibular volume was obtained.

The intranasal trigeminal system: roles in rhinitis (allergic and non-allergic).

The aim of this paper is to review intranasal trigeminal system and associated reflexes. The literature survey was performed on PubMed, ProQuest Central database of Kirikkale University and Google Scholar. The intranasal trigeminal system and associated reflexes play an important role in humans in both health and disease, including in rhinitis of non-allergic and mixed type. The intranasal trigeminal nerve provides sensory perception to the lining of the nose, supplying information on how patent the nasal airway is and responding to various chemical signals. The reflexes known to exist within the intranasal trigeminal system are nasobronchial reflex, trigemino-cardiac reflex, nasogastric reflex, and nasal cycle. The intranasal trigeminal system and its reflexes play a vital role in normal human physiology. Alterations in how this system operates may underlie multiple forms of rhinitis and more research is needed to fully understand the mechanisms involved.

Is G. cambogia a promising treatment? Effects on cultured nasal epithelial cells.

OBJECTIVE: The purpose of this study is to assess the effects of applying Garcinia cambogia to cultured human nasal epithelial cells. MATERIALS AND METHODS: A cell culture was set up consisting of human primary nasal epithelial cells harvested during septorhinoplasty from volunteers. The cells came from individuals with no history of rhinosinusitis. One assay for assessing cytotoxicity in cell culture utilizes MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). This method allows visualization of fragmented DNA, condensation of nuclei and changes to the external cellular membrane or cytoskeleton. Our study employed this method. Nasal epithelial cells at 37°C were exposed in culture to G. cambogia for a period of 24 hours. Afterwards an MTT assay was used in conjunction with confocal microscopy to assess evidence of toxicity. The proliferative capability of the nasal epithelial cells was also evaluated by inducing a scratch injury to cultured cells followed by light microscopic examination. RESULTS: Testing for cytotoxicity in this manner indicates that G. cambogia does not appear harmful to cultured nasal epithelial cells when applied directly. The cells exposed to this plant extract were still fully viable 24 hours afterwards. There was no increase in viability at the level of statistical significance. It was noted, however, that proliferation did increase slightly within the exposure period. The MTT assay and confocal microscopy confirm these findings. Under confocal microscopic examination, a compact morphology with unaltered nuclear and cytoskeletal appearances was observed. Thus, there is no evidence suggesting viability is impaired or that cytotoxicity occurs. Ordinary light microscopic examination showed the area denuded of cells had become re-covered completely within 24 hours in the cultures where G. cambogia had been applied. The result suggests that exposure to G. cambogia has no significant effect in terms of stimulating or inhibiting cellular proliferation. CONCLUSIONS: G. cambogia may offer clinical benefit as a supplementary topical treatment for inflammation of the nose and sinuses, as seen in chronic and acute rhinosinusitis, or nasal polyps. The plant appears to increase nasal epitheliocytic proliferation slightly, as revealed by the MTT assay. There were no indications of a cytotoxic effect on epithelial cells of the nose.

Do products containing menthol exacerbate allergic rhinitis? A narrative review.

The aim of this paper is to review whether products containing menthol exacerbate allergic rhinitis. A literature survey was performed on PubMed, Google and Google Scholar concerning allergic rhinitis (AR). Allergic rhinitis is an inflammatory condition of the nasal mucosa characterized by wheeze, congestion, nasal pruritus and discharge, or any combination thereof. Menthol is a naturally occurring phytochemical, with the formula C10H20O. The L-isomeric form creates the typical odor of peppermints and causes a sensation of coolness when applied to the skin or mucosae. Inhaling menthol vapor is known to affect the respiratory system in a number of different ways. The cooling agent, menthol, is also recognized as a trigger for asthma, AR and urticaria. The menthol molecule stimulates the TRPM8 receptor and may stimulate histamine release in a dose-dependent manner from RBL-2H3 cell cultures. The addition of menthol to products produces symptomatic relief in some patients by providing an impression of freer nasal air flow. It does this by stimulating cold receptors on branches of the fifth cranial nerve. Menthol is capable of provoking allergic hypersensitivity reactions and disorders, including asthma, AR and urticaria. It may also trigger an anaphylactic response. The use of menthol-containing products is best avoided in cases where an allergic disorder exists.

Mechanisms and solutions for nasal drug delivery - a narrative review.

The aim of this paper is to review mechanisms and solutions for nasal drug delivery. Literature survey was performed via PubMed, Google Scholar, Google, and ProQuest Central database of Kirikkale University. The nasal lining presents a large area of endothelium of variable permeability and with a rich vascular supply. Advantages of this route include eliminating first-pass metabolism and being easily accessible. The nasal route enables some agents which are otherwise difficult to administer to enter the systemic circulation, for example, low molecular mass compounds with high polarity, peptides, or proteins. There are three principal factors that influence the extent to which drugs can be absorbed through the nasal lining, namely the physico-chemical characteristics of the drug molecule itself, the action of the mucociliary system within the nose, and the presence of any factors increasing nasal absorption. A key factor limiting the use of the intranasal route of administration is insufficient absorption through the nasal mucosa. A number of drugs in development cannot be administered intranasally because their bioavailability following nasal administration is too low. There has been considerable research focus on methods to enhance absorption via the nasal mucosa. In this chapter, we review the literature related to this problem and discuss potential solutions.

The superiority of Dexpanthenol or Vaseline as excipient in nasal formulations.

OBJECTIVE: Dexpanthenol is an ingredient in multiple topical pharmaceutical preparations thanks to its high penetration and localized concentration. It is included in many ointments or lotions for dermatological use, assisting in healing and reducing pruritus. Vaseline is a synthetic product obtained by distilling crude oil. It is commercially available in several grades. The study presented here examined how topically applied agents (dexpanthenol or vaseline) affect nasal epithelial cells in culture. In particular, the study aimed to identify any alterations to epithelial cells which might indicate toxicity. MATERIALS AND METHODS: The nasal epithelial cells used were sourced from mucosal tissue fragments left over the following septorhinoplasty on five patients not suffering from rhinosinusitis. The first step was to dissect the mucosal fragments into smaller pieces on a sterilized Petri dish. These fragments were then placed into the DMEM-F12 cell culture medium, which had been freshly prepared. The dexpanthenol and vaseline were diluted in dimethylsulfoxide (DMSO) to a concentration of 5 mg/mL. The cells in the wells were exposed to varying concentrations of dexpanthenol or vaseline. The actual concentration of the test reagent to which the epithelial cells were exposed ranged from 0.15 mg/mL to 5 mg/mL. The exposure period was 24 hours. The cells were finally examined using a Leica SP5II confocal microscope. The features sought were DNA fragmentation, condensation of the nuclei, changes in the outer membrane, or cytoskeletal abnormality. These features, if present, indicate cytotoxicity. RESULTS: The viability of the cultured nasal epithelial cells was unaltered by a 24-hour exposure to dexpanthenol, nor was the cellular proliferation rate affected at the level of statistical significance. There was evidence of a cytotoxic effect from exposing nasal epithelial cells to vaseline in liquid form for 24 hours. There was a reduction in cellular viability in the plates where the highest dose of vaseline (5 mg/mL) was used. Cellular viability was not affected significantly at any of the doses below 5 mg/mL. CONCLUSIONS: The absence of cytotoxic effects from the application of dexpanthenol to the nasal mucosa indicates that this agent may be safely used within the nose. The cytotoxic effects of liquid vaseline observed in this trial (condensed nuclear chromatin, loss of cellular volume) indicate that this agent may be harmful when used intranasally. For patients who require nasal packing due to nose bleeds or following endoscopic sinus surgical procedures, dexpanthenol should be preferred to vaseline from the point of view of maximizing healing of a nasal injury.

A murine model of acute myeloid leukemia with Evi1 overexpression and autocrine stimulation by an intracellular form of GM-CSF in DA-3 cells.

The poor treatment response of acute myeloid leukemia (AML) overexpressing high-risk oncogenes such as EVI1, demands specific animal models for new treatment evaluations. Evi1 is a common site of activating integrations in murine leukemia virus (MLV)-induced AML and in retroviral and lentiviral gene-modified HCS. Still, a model of overt AML induced by Evi1 has not been generated. Cell lines from MLV-induced AML are growth factor-dependent and non-transplantable. Hence, for the leukemia maintenance in the infected animals, a growth factor source such as chronic immune response has been suggested. We have investigated whether these leukemias are transplantable if provided with growth factors. We show that the Evi1(+)DA-3 cells modified to express an intracellular form of GM-CSF, acquired growth factor independence and transplantability and caused an overt leukemia in syngeneic hosts, without increasing serum GM-CSF levels. We propose this as a general approach for modeling different forms of high-risk human AML using similar cell lines.

TK.007: A novel, codon-optimized HSVtk(A168H) mutant for suicide gene therapy.

Conditional elimination of infused gene-modified alloreactive T cells, using suicide gene activation, has been shown to be an efficient strategy to abrogate severe graft-versus-host disease (GvHD) in the context of adoptive immunotherapy. To overcome shortcomings of the most widely used suicide gene, wild-type (splice-corrected) herpes simplex virus thymidine kinase (scHSVtk), we generated two new variants: the codon-optimized coHSVtk and, by introducing an additional mutation (A168H), the novel TK.007. We transduced human hematopoietic cell lines and primary T cells with retroviral "sort-suicide vectors" encoding combinations of selection markers (tCD34 and OuaSelect) with one of three HSVtk variants. In vitro we observed higher expression levels and sustained long-term expression of TK.007, indicating lower nonspecific toxicity. Also, we noted significantly improved kinetics of ganciclovir (GCV)-mediated killing for TK.007-transduced cells. In an experimental (murine) allogeneic transplantation model, TK.007-transduced T cells mediated severe GvHD, which was readily abrogated by application of GCV (10 mg/kg). Last, we established a modified allotransplantation model that allowed quantitative comparison of the in vivo activities of TK.007 versus scHSVtk. We found that TK.007 mediates both significantly faster and higher absolute killing at low GCV concentrations (10 and 25 mg/kg). In summary, we demonstrate that the novel TK.007 suicide gene combines better killing performance with reduced nonspecific toxicity (as compared with the frequently used splice-corrected wild-type scHSVtk gene), thus representing a promising alternative for suicide gene therapy.

Retroviral gene transfer into primary human natural killer cells.

Modulation of intracellular signaling pathways or receptor expression in natural killer (NK) cells by genetic manipulation is an attractive possibility in studies of NK cell specificity and function. Moreover, feasible applications of these genetic manipulations in the context of gene and NK cell therapy regimens may be considered. However, efficient gene modification of primary NK cells has been largely hampered by the absence of an efficient gene-transfer protocol.A retrovirus-based easy-to-use transduction protocol that can insert the gene of interest permanently into primary NK cells would be an important tool to advance our studies in NK cell biology and NK cell-mediated therapies. We have recently described a protocol for efficient expansion of NK cells under good manufacturing practice (GMP) conditions from the healthy donors and from patients with hematological malignancies. As the active division of cells is a prerequisite for efficient retroviral insertion, the high rate of expansion in this protocol provides more efficient transduction by retroviral vectors. We hereby present this simple and efficient retroviral vector-based gene-transfer protocol for such ex vivo cultured primary human NK cells.

Differentiation of human embryonic stem cells into osteogenic or hematopoietic lineages: a dose-dependent effect of osterix over-expression.

Enhanced differentiation of human embryonic stem cells (HESCs), induced by genetic modification could potentially generate a vast number of diverse cell types. Such genetic modifications have frequently been achieved by over-expression of individual regulatory proteins. However, careful evaluation of the expression levels is critical, since this might have important implications for the differentiation potential of HESCs. To date, attempts to promote osteogenesis by means of gene transfer into HESCs using the early bone "master" transcription factor osterix (Osx) have not been reported. In this study, we attained HESC subpopulations expressing two significantly different levels of Osx, following lentiviral gene transfer. Both subpopulations exhibited spontaneous differentiation and reduced expression of markers characteristic of the pluripotent phenotype, such as SSEA3, Tra1-60, and Nanog, In order to promote bone differentiation, the cells were treated with ascorbic acid, beta-glycerophosphate and dexamethasone. The high level of Osx, compared to endogenous levels found in primary human osteoblasts, did not enhance osteogenic differentiation, and did not up-regulate collagen I expression. We show that the high Osx levels instead induced the commitment towards the hematopoietic-endothelial lineage-by up-regulating the expression of CD34 and Gata1. However, low levels of Osx up-regulated collagen I, bone sialoprotein and osteocalcin. Conversely, forced high level expression of the homeobox transcription factor HoxB4, a known regulator for early hematopoiesis, promoted osteogenesis in HESCs, while low levels of HoxB4 lead to hematopoietic gene expression.

Safety analysis of ex vivo-expanded NK and NK-like T cells administered to cancer patients: a phase I clinical study.

The chimeric state after allogeneic hematopoietic stem cell transplantation provides a platform for adoptive immunotherapy using donor-derived immune cells. The major risk with donor lymphocyte infusions (DLIs) is the development of graft-versus-host disease (GvHD). Development of new DLI products with antitumor reactivity and reduced GvHD risk represents a challenging task in cancer immunotherapy. Although natural killer (NK) and NK-like T cells are promising owing to their antitumor activity, their low concentrations in peripheral blood mononuclear cells reduces their utility in DLIs. We have recently developed a system that allows expansion of clinical-grade NK and NK-like T cells in large numbers. In this study, the safety of donor-derived long-term ex vivo-expanded human NK and NK-like T cells given as DLIs was investigated as immunotherapy for cancer in five patients following allogeneic stem cell infusion. Infusion of the cells was safe whether administered alone or with IL-2 subcutaneously. No signs of acute GvHD were observed. One patient with hepatocellular carcinoma showed markedly decreased serum alpha-fetoprotein levels following cell infusions. These findings suggest that the use of ex vivo-expanded NK and NK-like T cells is safe and appears an attractive approach for further clinical evaluation in cancer patients.

Derivation of human skin fibroblast lines for feeder cells of human embryonic stem cells.

After the first derivations of human embryonic stem cell (hESC) lines on fetal mouse feeder cell layers, the idea of using human cells instead of mouse cells as feeder cells soon arouse. Mouse cells bear a risk of microbial contamination, and nonhuman immunogenic proteins are absorbed from the feeders to hESCs. Human skin fibroblasts can be effectively used as feeder cells for hESCs. The same primary cell line, which can be safely used for up to 15 passages after stock preparations, can be expanded and used for large numbers of hESC derivations and cultures. These cells are relatively easy to handle and maintain. No animal facilities or animal work is needed. Here, we describe the derivation, culture, and cryopreservation procedures of research grade human skin fibroblast lines. We also describe how to make feeder layers for hESC using these fibroblasts.

Lentiviral-mediated HoxB4 expression in human embryonic stem cells initiates early hematopoiesis in a dose-dependent manner but does not promote myeloid differentiation.

The variation of HoxB4 expression levels might be a key regulatory mechanism in the differentiation of human embryonic stem cell (hESC)-derived hematopoietic stem cells (HSCs). In this study, hESCs ectopically expressing high and low levels of HoxB4 were obtained using lentiviral gene transfer. Quantification throughout differentiation revealed a steady increase in transcription levels from our constructs. The effects of the two expression levels of HoxB4 were compared regarding the differentiation potential into HSCs. High levels of HoxB4 expression correlated to an improved yield of cells expressing CD34, CD38, the stem cell leukemia gene, and vascular epithelium-cadherin. However, no improvement in myeloid cell maturation was observed, as determined by colony formation assays. In contrast, hESCs with low HoxB4 levels did not show any elevated hematopoietic development. In addition, we found that the total population of HoxB4-expressing cells, on both levels, decreased in developing embryoid bodies. Notably, a high HoxB4 expression in hESCs also seemed to interfere with the formation of germ layers after xenografting into immunodeficient mice. These data suggest that HoxB4-induced effects on hESC-derived HSCs are concentration-dependent during in vitro development and reduce proliferation of other cell types in vitro and in vivo. The application of the transcription factor HoxB4 during early hematopoiesis from hESCs might provide new means for regenerative medicine, allowing efficient differentiation and engraftment of genetically modified hESC clones. Our study highlights the importance of HoxB4 dosage and points to the need for experimental systems allowing controlled gene expression. Disclosure of potential conflicts of interest is found at the end of this article.

Good manufacturing practice and clinical-grade human embryonic stem cell lines.

Human embryonic stem cell (hESC) lines, after directed differentiation, hold the greatest potential for cell transplantation treatment in many severe diseases. Good manufacturing practice (GMP) quality, defined by both the European Medicines Agency and the Food and Drug Administration, is a requirement for clinical-grade cells, offering optimal defined quality and safety in cell transplantation. Using animal substance-free culture media, feeder cells or feeder-free matrix in derivation, passaging, expansion and cryopreservation procedures, immune reactions against animal proteins in the cells, and infection risk caused by animal microbes can be avoided. It is also possible to apply GMP to animal components if no better options are available. In recent production of GMP-quality hESC lines, feeder cells had been cultured in fetal bovine serum, and the medium supplemented with an animal protein containing a serum replacement component. Using embryos cultured in a GMP laboratory, isolating the inner cell mass mechanically, deriving lines on human feeder cells originally cultured in xeno-free medium in a GMP laboratory, and using xeno-free media for derivation and culture of hESC lines themselves, GMP-quality xeno-free hESC lines could be established today. Human serum is a xeno-free component available today, but many chemically defined media are under development.

NK cell-mediated targeting of human cancer and possibilities for new means of immunotherapy.

Insights into the molecular basis for natural killer (NK) cell recognition of human cancer have been obtained in recent years. Here, we review current knowledge on the molecular specificity and function of human NK cells. Evidence for NK cell targeting of human tumors is provided and new strategies for NK cell-based immunotherapy against human cancer are discussed. Based on current knowledge, we foresee a development where more cancers may be subject to treatment with drugs or other immunomodulatory agents affecting NK cells, either directly or indirectly. We also envisage a possibility that certain forms of cancers may be subject to treatment with adoptively transferred NK cells, either alone or in combination with other therapeutic interventions.

Autologous antitumor activity by NK cells expanded from myeloma patients using GMP-compliant components.

Multiple myeloma (MM) is an incurable plasma cell malignancy with poor outcome. The most promising therapeutic options currently available are combinations of transplantation, targeted pharmacotherapy, and immunotherapy. Cell-based immunotherapy after hematopoietic stem-cell transplantation has been attempted, but with limited efficacy. Natural killer (NK) cells are interesting candidates for new means of immunotherapy; however, their potential clinical use in MM has not been extensively studied. Here, we explored the possibility of expanding NK cells from the peripheral blood of 7 newly diagnosed, untreated MM patients, using good manufacturing practice (GMP)-compliant components. After 20 days of culture, the number of NK cells from these patients had expanded on average 1600-fold. Moreover, expanded NK cells showed significant cytotoxicity against primary autologous MM cells, yet retained their tolerance against nonmalignant cells. Based on these findings, we propose that autologous NK cells expanded ex vivo deserve further attention as a possible new treatment modality for MM.

Anti-myeloma activity of endogenous and adoptively transferred activated natural killer cells in experimental multiple myeloma model.

OBJECTIVE: Despite advances in autologous stem cell transplantation and chemotherapy, multiple myeloma (MM) remains an incurable disease. Due to the role of natural killer (NK) cells in host resistance against several tumors, it is of interest to explore the anti-MM activity of NK cells. For this reason, we aimed to determine if NK cells provide anti-MM activity following interleukin-2 (IL-2) administration, and if ex vivo activated and intravenously administered NK cells prolong survival in MM-bearing C57BL/KaLwRij mice. METHODS: The anti-MM effect of IL-2 was tested by intraperitoneal injection into the 5T33MM-inoculated mice. Subsequently, in vivo effector cell depletions were performed by administration of anti-NK1.1 or anti-CD8 monoclonal antibodies. Finally, magnetically separated and activated NK cells from splenocytes of C57BL/KaLwRij mice were adoptively transferred to tumor-bearing mice in conjunction with IL-2 treatment. RESULTS: IL-2 administration into MM-bearing mice significantly prolonged their survival. This effect was diminished by in vivo depletion of NK cells. Adoptive transfer of activated NK cells showed a significant in vivo anti-MM effect that was dependent on cell dose. Biodistribution of the marked adoptively transferred NK cells correlated with MM cells' homing sites. CONCLUSION: These data suggest that activated NK cells have a promising potential in adoptive immunotherapy for MM.

OuaSelect, a novel ouabain-resistant human marker gene that allows efficient cell selection within 48 h.

Efficient selection of gene-modified cells is required for a number of potential gene therapy applications, as well as molecular biology studies. Ideally, a clinical selection regimen would combine high selection speed, efficiency and efficacy, in addition to clinical grade selection techniques and low immunogenicity. To our knowledge, a selection marker satisfying all these features is so far not available. Ouabain is a clinically used cardiac glycoside and selective Na(+)/K(+)-ATPase inhibitor. On the basis of the high sensitivity of human Na(+)/K(+)-ATPase proteins to ouabain, and rapid killing of cells upon exposure, we have screened the ubiquitously expressed Na(+)/K(+)-ATPase alpha1 subunit for mutations that could greatly increase its resistance to ouabain. Two amino-acid substitutions, Q118R and N129D were sufficient to confer a two log greater resistance to ouabain in HeLa, Jurkat, U2OS cells and in primary cells. Furthermore, following transduction of primary lymphocytes with the alpha1(Q118R/N129D) gene, >99% pure populations of gene-modified cells were achieved with a recovery rate of >80% after 48 h of exposure to ouabain. These results identify the human alpha1(Q118R/N129D) (OuaSelect) as a promising selection marker gene for safe, rapid and cost-effective selection in clinical gene therapy and molecular biology research.