Nutritional Status in Childhood as a Prognostic Factor in Patients with Cystic Fibrosis.

INTRODUCTION: There is a strong association between cystic fibrosis and malnutrition, mainly because of the higher energy needs combined with lower intake. There is also a well-established correlation between good nutritional status and better lung function. To date, however, there are no studies examining nutritional status in childhood and adult lung function. To respond to this need, this innovative study explored the long-term correlations between nutritional status in childhood and lung function in adulthood for the same patient population. METHODS: A retrospective patient file study was conducted to identify putative correlations between nutritional status in childhood and lung function in adulthood. The medical archives at Sheba Medical Center were examined for a period of 31 years between 1986 and 2017 for age, gender, mutations, pancreatic sufficiency or insufficiency (PI/PS), sputum cultures, cystic fibrosis related diabetes, body mass index (BMI) at the age of 10, and FEV1 at 20 and 30 in patients who underwent or did not undergo lung transplantation. RESULTS: The database was composed of the records of sixty-five patients, thirteen of whom underwent lung transplantation. The correlations (R²) between BMI at age of 10 years and FEV1 at the age of 20 and 30 years were 0.35 and 0.28, respectively, p < 0.001. A BMI of lower than - 0.75 at the age of 10 emerged as a risk factor for lung transplantation (OR 3.42 p = 0.023) and had a negative predictive value of 90%. Kaplan-Meier survival curve showed significant lower lung transplantation rate in the group of BMI z score higher than - 0.75 at the age of 10 years. Logistic regression found nutritional at the age of 10 years as a dominant risk factor for lung transplantation. CONCLUSIONS: This study reports a clear, significant and important correlation for the first time between nutritional status in childhood and lung function for the same patients at adulthood. Hence, nutritional status sets a clear trajectory and should be treated aggressively. The findings emphasize the importance of new-born screening and early implementation of nutritional guidelines for cystic fibrosis patients.

Use of prescription opioids before and after an operation for chronic pain (lumbar fusion surgery).

Lumbar fusion surgery is usually prompted by chronic back pain, and many patients receive long-term preoperative opioid analgesics. Many expect surgery to eliminate the need for opioids. We sought to determine what fraction of long-term preoperative opioid users discontinue or reduce dosage postoperatively; what fraction of patients with little preoperative use initiate long-term use; and what predicts long-term postoperative use. This retrospective cohort study included 2491 adults undergoing lumbar fusion surgery for degenerative conditions, using Oregon's prescription drug monitoring program to quantify opioid use before and after hospitalization. We defined long-term postoperative use as ≥4 prescriptions filled in the 7 months after hospitalization, with at least 3 occurring >30 days after hospitalization. Overall, 1045 patients received long-term opioids preoperatively, and 1094 postoperatively. Among long-term preoperative users, 77.1% continued long-term postoperative use, and 13.8% had episodic use. Only 9.1% discontinued or had short-term postoperative use. Among preoperative users, 34.4% received a lower dose postoperatively, but 44.8% received a higher long-term dose. Among patients with no preoperative opioids, 12.8% became long-term users. In multivariable models, the strongest predictor of long-term postoperative use was cumulative preoperative opioid dose (odds ratio of 15.47 [95% confidence interval 8.53-28.06] in the highest quartile). Cumulative dose and number of opioid prescribers in the 30-day postoperative period were also associated with long-term use. Thus, lumbar fusion surgery infrequently eliminated long-term opioid use. Opioid-naive patients had a substantial risk of initiating long-term use. Patients should have realistic expectations regarding opioid use after lumbar fusion surgery.

Evaluation of Rural vs Urban Trauma Patients Served by 9-1-1 Emergency Medical Services.

Importance: Despite a large rural US population, there are potential differences between rural and urban regions in the processes and outcomes following trauma. Objectives: To describe and evaluate rural vs urban processes of care, injury severity, and mortality among injured patients served by 9-1-1 emergency medical services (EMS). Design, Setting, and Participants: This was a preplanned secondary analysis of a prospective cohort enrolled from January 1 through December 31, 2011, and followed up through hospitalization. The study included 44 EMS agencies transporting to 28 hospitals in 2 rural and 5 urban counties in Oregon and Washington. A population-based, consecutive sample of 67 047 injured children and adults served by EMS (1971 rural and 65 076 urban) was enrolled. Among the 53 487 patients transported by EMS, a stratified probability sample of 17 633 patients (1438 rural and 16 195 urban) was created to track hospital outcomes (78.9% with in-hospital follow-up). Data analysis was performed from June 12, 2015, to May 20, 2016. Exposures: Rural was defined at the county level by 60 minutes or more driving proximity to the nearest level I or II trauma center and/or rural designation in the Centers for Medicare & Medicaid Services ambulance fee schedule by zip code. Main Outcomes and Measures: Mortality (out-of-hospital and in-hospital), need for early critical resources, and transfer rates. Results: Of the 53 487 injured patients transported by EMS (17 633 patients in the probability sample), 27 535 were women (51.5%); mean (SD) age was 51.6 (26.1) years. Rural vs urban sensitivity of field triage for identifying patients requiring early critical resources was 65.2% vs 80.5%, and only 29.4% of rural patients needing critical resources were initially transported to major trauma centers vs 88.7% of urban patients. After accounting for transfers, 39.8% of rural patients requiring critical resources were cared for in major trauma centers vs 88.7% of urban patients. Overall mortality did not differ between rural and urban regions (1.44% vs 0.89%; P = .09); however, 89.6% of rural deaths occurred within 24 hours compared with 64% of urban deaths. Rural regions had higher transfer rates (3.2% vs 2.7%) and longer transfer distances (median, 97.4 km; interquartile range [IQR], 51.7-394.5 km; range, 47.8-398.6 km vs 22.5 km; IQR, 11.6-24.6 km; range, 3.5-97.4 km). Conclusions and Relevance: Most high-risk trauma patients injured in rural areas were cared for outside of major trauma centers and most rural trauma deaths occurred early, although overall mortality did not differ between regions. There are opportunities for improved timeliness and access to major trauma care among patients injured in rural regions.

Association Between Initial Opioid Prescribing Patterns and Subsequent Long-Term Use Among Opioid-Naïve Patients: A Statewide Retrospective Cohort Study.

BACKGROUND: Long-term efficacy of opioids for non-cancer pain is unproven, but risks argue for cautious prescribing. Few data suggest how long or how much opioid can be prescribed for opioid-naïve patients without inadvertently promoting long-term use. OBJECTIVE: To examine the association between initial opioid prescribing patterns and likelihood of long-term use among opioid-naïve patients. DESIGN: Retrospective cohort study; data from Oregon resident prescriptions linked to death certificates and hospital discharges. PARTICIPANTS: Patients filling opioid prescriptions between October 1, 2012, and September 30, 2013, with no opioid fills for the previous 365 days. Subgroup analyses examined patients under age 45 who did not die in the follow-up year, excluding most cancer or palliative care patients. MAIN MEASURES: Exposure: Numbers of prescription fills and cumulative morphine milligram equivalents (MMEs) dispensed during 30 days following opioid initiation ("initiation month"). OUTCOME: Proportion of patients with six or more opioid fills during the subsequent year ("long-term users"). KEY RESULTS: There were 536,767 opioid-naïve patients who filled an opioid prescription. Of these, 26,785 (5.0 %) became long-term users. Numbers of fills and cumulative MMEs during the initiation month were associated with long-term use. Among patients under age 45 using short-acting opioids who did not die in the follow-up year, the adjusted odds ratio (OR) for long-term use among those receiving two fills versus one was 2.25 (95 % CI: 2.17, 2.33). Compared to those who received < 120 total MMEs, those who received between 400 and 799 had an OR of 2.96 (95 % CI: 2.81, 3.11). Patients initiating with long-acting opioids had a higher risk of long-term use than those initiating with short-acting drugs. CONCLUSIONS: Early opioid prescribing patterns are associated with long-term use. While patient characteristics are important, clinicians have greater control over initial prescribing. Our findings may help minimize the risk of inadvertently initiating long-term opioid use.

Iatrogenic superior mesenteric vein injury: the perils of high ligation.

PURPOSE: The purpose of this review is to highlight the perils and pitfalls associated with high vascular ligation during right colectomies for adenocarcinoma and to identify the various mechanisms of injury to the superior mesenteric vein (SMV) and its tributaries. METHODS: This is a retrospective chart review of 304 right colectomies (159 open and 145 laparoscopic) performed over a period of 10 years (1 June 2006-31 May 2016) for right-sided colonic adenocarcinoma in an academic medical center. RESULTS: During a 10-year study period, we encountered five cases in which significant damage to the SMV and its tributaries occurred. This accounts for a total of 1.6 % of all right colectomies performed for colonic adenocarcinoma. CONCLUSIONS: Iatrogenic superior mesenteric vein injury is a rare, severe, and underreported complication of both open and laparoscopic right colectomy for colonic adenocarcinoma. We identified several mechanisms of injury such as anatomic misperception, excessive traction and pulling on the venous system, extensive tumor involvement of the mesentery, and uncontrolled suturing attempts at hemostasis. We believe that increased awareness of this complication with profound understanding of vascular anatomy and the different mechanisms of injury will allow surgeons to avoid this often devastating complication.

Genome-wide association study of lung function phenotypes in a founder population.

BACKGROUND: Lung function is a long-term predictor of mortality and morbidity. OBJECTIVE: We sought to identify single nucleotide polymorphisms (SNPs) associated with lung function. METHODS: We performed a genome-wide association study (GWAS) of FEV1, forced vital capacity (FVC), and FEV1/FVC in 1144 Hutterites aged 6 to 89 years, who are members of a founder population of European descent. We performed least absolute shrinkage and selection operation regression to select the minimum set of SNPs that best predict FEV1/FVC in the Hutterites and used the GRAIL algorithm to mine the Gene Ontology database for evidence of functional connections between genes near the predictive SNPs. RESULTS: Our GWAS identified significant associations between FEV1/FVC and SNPs at the THSD4-UACA-TLE3 locus on chromosome 15q23 (P = 5.7 × 10(-8) to 3.4 × 10(-9)). Nine SNPs at or near 4 additional loci had P < 10(-5) with FEV1/FVC. Only 2 SNPs were found with P < 10(-5) for FEV1 or FVC. We found nominal levels of significance with SNPs at 9 of the 27 previously reported loci associated with lung function measures. Among a predictive set of 80 SNPs, 6 loci were identified that had a significant degree of functional connectivity (GRAIL P < .05), including 3 clusters of ß-defensin genes, 2 chemokine genes (CCL18 and CXCL12), and TNFRSF13B. CONCLUSION: This study identifies genome-wide significant associations and replicates results of previous GWASs. Multimarker modeling implicated for the first time common variation in genes involved in antimicrobial immunity in airway mucosa that influences lung function.

Human leukocyte antigen-G expression in differentiated human airway epithelial cells: lack of modulation by Th2-associated cytokines.

BACKGROUND: Human leukocyte antigen (HLA)-G is a nonclassical class I antigen with immunomodulatory roles including up-regulation of suppressor T regulatory lymphocytes. HLA-G was recently identified as an asthma susceptibility gene, and expression of a soluble isoform, HLA-G5, has been demonstrated in human airway epithelium. Increased presence of HLA-G5 has been demonstrated in bronchoalveolar lavage fluid recovered from patients with mild asthma; this suggests a role for this isoform in modulating airway inflammation though the mechanisms by which this occurs is unclear. Airway inflammation associated with Th2 cytokines such as IL-4 and IL-13 is a principal feature of asthma, but whether these cytokines elicit expression of HLA-G is not known. METHODS: We examined gene and protein expression of both soluble (G5) and membrane-bound (G1) HLA-G isoforms in primary differentiated human airway epithelial cells collected from normal lungs and grown in air-liquid interface culture. Cells were treated with up to 10 ng/ml of either IL-4, IL-5, or IL-13, or 100 ng/ml of the immunomodulatory cytokine IL-10, or 10,000 U/ml of the Th1-associated cytokine interferon-beta, for 24 hr, after which RNA was isolated for evaluation by quantitative PCR and protein was collected for Western blot analysis. RESULTS: HLA-G5 but not G1 was present in dAEC as demonstrated by quantitative PCR, western blot and confocal microscopy. Neither G5 nor G1 expression was increased by the Th2-associated cytokines IL-4, IL-5 or IL-13 over 24 hr, nor after treatment with IL-10, but was increased 4.5 ± 1.4 fold after treatment with 10,000 U/ml interferon-beta. CONCLUSIONS: These data demonstrate the constitutive expression of a T lymphocyte regulatory molecule in differentiated human airway epithelial cells that is not modulated by Th2-associated cytokines.

An imprinted locus epistatically influences Nstr1 and Nstr2 to control resistance to nerve sheath tumors in a neurofibromatosis type 1 mouse model.

Cancer is a complex disease in which cells acquire many genetic and epigenetic alterations. We have examined how three types of alterations, mutations in tumor suppressor genes, changes in an imprinted locus, and polymorphic loci, interact to affect tumor susceptibility in a mouse model of neurofibromatosis type 1 (NF1). Mutations in tumor suppressor genes such as TP53 and in oncogenes such as KRAS have major effects on tumorigenesis due to the central roles of these genes in cell proliferation and cell survival. Imprinted genes expressed from only one parental chromosome affect tumorigenesis if their monoallelic expression is lost or duplicated. Because imprinted loci are within regions deleted or amplified in cancer, the parental origin of genomic rearrangements could affect tumorigenesis. Gene polymorphisms can vary tumor incidence by affecting rate-limiting steps in tumorigenesis within tumor cells or surrounding stroma. In our mouse model of NF1, the incidence of tumors mutant for the tumor suppressor genes Nf1 and Trp53 is strongly modified by a linked imprinted locus acting epistatically on two unlinked polymorphic loci, Nstr1 and Nstr2. This interaction of an imprinted locus and polymorphic susceptibility loci has profound implications for human mapping studies where the parental contribution of alleles is often unknown.

Caspase-dependent and -independent cell death of Jurkat human leukemia cells induced by novel synthetic ceramide analogs.

Ceramide metabolism has emerged as a potential target for anticancer therapy. Here, the potential usefulness of two novel synthetic ceramide analogs as anti-leukemic drugs was investigated. Compounds AD2646 and AD2687 were able to dose-and time-dependently decrease the viability of Jurkat leukemic cells. This was accompanied by an accumulation of endogenous ceramide owing to perturbed ceramide metabolism. Cytotoxicity involved caspase activation but also necrotic-like features, as evidenced by phosphatidylserine externalization, membrane permeability, hypodiploidy, caspase processing and only partial protection from cell death by a pan-caspase inhibitor. Ceramide analogs also induced cell death in Jurkat mutants that are deficient in cell death signaling proteins, including FADD, caspase-8 and 10, and RIP. While overexpression of Bcl-xL did not suppress ceramide accumulation, it conferred robust protection from caspase activation and cell death. Altogether, these novel ceramide analogs are able to kill leukemic cells through distinct pathways implicating caspase activation and mitochondrial events, and represent a new group of bioactive molecules with potential applications in anticancer therapy.

Preimplantation diagnosis of a lysosomal storage disorder by in situ enzymatic activity: 'proof of principle' in acid sphingomyelinase-deficient mice.

Genetic diagnosis of preimplantation embryos (PGD) can substantially reduce the chance that at-risk couples have children afflicted with inherited diseases. However, PGD requires DNA,which is usually obtained from single cells following embryo biopsy. In addition, PGD requires that the genetic defect(s) causing the disorder be known. We have therefore developed an alternative to PGD, which we term preimplantation enzymatic diagnosis (PED). PED has several advantages over PGD, including the facts that it does not require embryo biopsy and that the gene defect(s) causing the disorder need not be known. We have demonstrated 'proof of principle' for this approach using embryos obtained from a mouse model (ASMKO mice) of acid sphingomyelinase (ASM)-deficient Niemann-Pick disease, an inherited lysosomal storage disorder. For this technique, fluorescently (BODIPY)-conjugated sphingomyelin was used to detect ASM activity in situ. Wild-type, preimplantation embryos degraded the substrate following a short 'pulse-chase' period, resulting in markedly reduced fluorescence compared to ASMKO embryos, which retained the fluorescent substrate. Thus, the two embryo types could be easily distinguished by fluorescent microscopy. The fluorescent sphingomyelin was not toxic to the embryos, and the entire procedure could be accomplished within 48 h without embryo biopsy. We suggest that PED may be useful for the preimplantation diagnosis of lysosomal storage disorders, and perhaps other enzymatic defects where similar in situ assay methods are available.

Susceptibility to astrocytoma in mice mutant for Nf1 and Trp53 is linked to chromosome 11 and subject to epigenetic effects.

Astrocytoma is the most common malignant brain tumor in humans. Loss of the p53 signaling pathway and up-regulation of the ras signaling pathway are common during tumor progression. We have shown previously that mice mutant for Trp53 and Nf1 develop astrocytoma, progressing to glioblastoma, on a C57BL/6J strain background. In contrast, here we present data that mice mutant for Trp53 and Nf1 on a 129S4/SvJae background are highly resistant to developing astrocytoma. Through analysis of F1 progeny, we demonstrate that susceptibility to astrocytoma is linked to chromosome 11, and that the modifier gene(s) responsible for differences in susceptibility is closely linked to Nf1 and Trp53. Furthermore, this modifier of astrocytoma susceptibility is itself epigenetically modified. These data demonstrate that epigenetic effects can have a strong effect on whether cancer develops in the context of mutant ras signaling and mutant p53, and that this mouse model of astrocytoma can be used to identify modifier phenotypes with complex inheritance patterns that would be unidentifiable in humans. Because analysis of gene function in the mouse is often performed on a mixed C57BL/6,129 strain background, these data also provide a powerful example of the potential of these strains to mask interesting gene functions.

Ceramide mediates growth inhibition of the Plasmodium falciparum parasite.

In mammalian cells, ceramide mediates death by chemotherapeutic drugs. We analysed, for the first time, the role of ceramide in inhibiting growth of the malaria-causing parasite Plasmodium falciparum. Added exogenously, ceramide significantly decreased the number of parasites, and this effect was abolished by sphingosine-1-phosphate, a biological antagonist of ceramide action. Ceramide can induce death of cancer cells by decreasing glutathione levels, and in our work it induced dose- and time-dependent depletion of glutathione in P. falciparum parasites. N-acetylcysteine, a precursor of glutathione, abrogated the cytotoxic effect of ceramide. Thus, ceramide can mediate growth inhibition of P. falciparum parasites by decreasing glutathione levels. The antimalarial drugs artemisinin and mefloquine induced the death of P. falciparum parasites by sphingomyelinase-generated ceramide and by decreasing parasite glutathione levels. Altogether, ceramide was identified as a signalling molecule capable of inducing growth inhibition of P. falciparum malarial parasites.

Electron microscope and biochemical observations of the surface active phospholipids on the articular surfaces and in the synovial fluid of the temporomandibular joint: a preliminary investigation.

PURPOSE: The goal of this article is to investigate the surface-active phospholipids located on the articular surfaces and in the temporomandibular joint (TMJ) synovial fluid (SF) by means of electron microscopy and biochemical analysis. MATERIALS AND METHODS: Synovial fluids and articular cartilage samples taken from 6 normally functioning TMJs were studied. The osmiophilic lining of human TMJ articular surfaces has been studied by using special nondestructive fixation procedures. To study the SF, negative staining technique has been used. In addition, thin-layer chromatography has been used to identify the phospholipids extracted from synovial fluid of human TMJs. RESULTS: In the SF, granular bodies were identified with diameter of between 170 and 280 nm. Their diameter decreased dramatically when exposed to phospholipase-A(2). The amorphous and highly osmophilic material on the articular surface include membrane-bound vesicles (270 nm in diameter) with lamellated pattern surrounding the amorphous-dense core. Biochemical extraction revealed phosphatidylcholine as the major component of the polar lipids. CONCLUSIONS: This preliminary study presents findings that suggest that phospholipids present in the TMJ may provide an efficient boundary lubrication that enables the disc to slide down the slope of the eminence on joint function.

Antimalarial activities of dermaseptin S4 derivatives.

The hemolytic antimicrobial peptide dermaseptin S4 was recently shown to exert antimalarial activity. In this study, we attempted to understand the underlying mechanism(s) and identify derivatives with improved antimalarial activity. A number of dermaseptin S4 derivatives inhibited parasite growth with a 50% inhibitory concentration (IC(50)) in the micromolar range. Among these, the substituted S4 analog K(4)K(20)-S4 was the most potent (IC(50) = 0.2 microM), while its shorter version, K(4)-S4(1-13)a, retained a considerable potency (IC(50) = 6 microM). Both K(4)K(20)-S4 and K(4)-S4(1-13)a inhibited growth of the parasites more at the trophozoite stage than at the ring stage. Significant growth inhibition was observed after as little as 1 min of exposure to peptides and proceeded with nearly linear kinetics. The peptides selectively lysed infected red blood cells (RBC) while having a weaker effect on noninfected RBC. Thus, K(4)K(20)-S4 lysed trophozoites at concentrations similar to those that inhibited their proliferation, but trophozoites were >30-fold more susceptible than normal RBC to the lytic effect of K(4)K(20)-S4, the most hemolytic dermaseptin. The same trend was observed with K(4)-S4(1-13)a. The D isomers of K(4)K(20)-S4 or K(4)-S4(1-13)a were as active as the L counterparts, indicating that antimalarial activity of these peptides, like their membrane-lytic activity, is not mediated by specific interactions with a chiral center. Moreover, dissipation of transmembrane potential experiments with infected cells indicated that the peptides induce damage in the parasite's plasma membrane. Fluorescence confocal microscopy analysis of treated infected cells also indicated that the peptide is able to find its way through the complex series of membranes and interact directly with the intracellular parasite. Overall, the data showed that dermaseptins exert antimalarial activity by lysis of infected cells. Dermaseptin derivatives are also able to disrupt the parasite plasma membrane without harming that of the host RBC.

Structure-activity relationship study of antimicrobial dermaseptin S4 showing the consequences of peptide oligomerization on selective cytotoxicity.

To understand how peptide organization in aqueous solution might affect the activity of antimicrobial peptides, the potency of various dermaseptin S4 analogs was assessed against human red blood cells (RBC), protozoa, and several Gram-negative bacteria. Dermaseptin S4 had weak antibacterial activity but potent hemolytic or antiprotozoan effects. K(4)K(20)-S4 was 2-3-fold more potent against protozoa and RBC, yet K(4)K(20)-S4 was more potent by 2 orders of magnitude against bacteria. K(4)-S4 had similar behavior as K(4)K(20)-S4, but K(20)-S4 and analogous negative charge substitutions were as active as dermaseptin S4 or had reduced activity. Binding experiments suggested that potency enhancement was not the result of increased affinity to target cells. In contrast, potency correlated well with aggregation properties. Fluorescence studies indicated that K(20)-S4 and all negative charge substitutions were as aggregated as dermaseptin S4, whereas K(4)-S4 and K(4)K(20)-S4 were clearly less aggregated. Overall, the data indicated that N-terminal domain interaction between dermaseptin S4 monomers is responsible for the peptide's oligomerization in solution and, hence, for its limited spectrum of action. Moreover, bell-shaped dose-response profiles obtained with bacteria but not with protozoa or RBC implied that aggregation can have dramatic consequences on antibacterial activity. Based on these results, we tested the feasibility of selectivity reversal in the activity of dermaseptin S4. Tampering with the composition of the hydrophobic domains by reducing hydrophobicity or by increasing the net positive charge affected dramatically the peptide's activity and resulted in various analogs that displayed potent antibacterial activity but reduced hemolytic activity. Among these, maximal antibacterial activity was displayed by a 15-mer version that was more potent by 2 orders of magnitude compared with native dermaseptin S4. These results emphasize the notion that peptide-based antibiotics represent a highly modular synthetic antimicrobial system and provide indications of how the peptide's physico-chemical properties affect potency and selectivity.

Fluorescence-based selection of gene-corrected hematopoietic stem and progenitor cells from acid sphingomyelinase-deficient mice: implications for Niemann-Pick disease gene therapy and the development of improved stem cell gene transfer procedures.

The general utility of a novel, fluorescence-based procedure for assessing gene transfer and expression has been demonstrated using hematopoietic stem and progenitor cells. Lineage-depleted hematopoietic cells were isolated from the bone marrow or fetal livers of acid sphingomyelinase-deficient mice, and retrovirally transduced with amphotropic or ecotropic vectors encoding a normal acid sphingomyelinase (ASM) cDNA. Anti-c-Kit antibodies were then used to label stem- and progenitor-enriched cell populations, and the Bodipy fluorescence was analyzed in each group after incubation with a Bodipy-conjugated sphingomyelin. Only cells expressing the functional ASM (ie, transduced) could degrade the sphingomyelin, thereby reducing their Bodipy fluorescence as compared with nontransduced cells. The usefulness of this procedure for the in vitro assessment of gene transfer into hematopoietic stem cells was evaluated, as well as its ability to provide an enrichment of transduced stem cells in vivo. To show the value of this method for in vitro analysis, the effects of retroviral transduction using ecotropic versus amphotropic vectors, various growth factor combinations, and adult bone marrow versus fetal liver stem cells were assessed. The results of these studies confirmed the fact that ecotropic vectors were much more efficient at transducing murine stem cells than amphotropic vectors, and that among the three most commonly used growth factors (stem cell factor [SCF] and interleukins 3 and 6 [IL-3 and IL-6]), SCF had the most significant effect on the transduction of stem cells, whereas IL-6 had the most significant effect on progenitor cells. In addition, it was determined that fetal liver stem cells were only approximately twofold more "transducible" than stem cells from adult bone marrow. Transplantation of Bodipy-selected bone marrow cells into lethally irradiated mice showed that the number of spleen colony-forming units that were positive for the retroviral vector (as determined by polymerase chain reaction) was 76%, as compared with 32% in animals that were transplanted with cells that were nonselected. The methods described within this manuscript are particularly useful for evaluating hematopoietic stem cell gene transfer in vivo because the marker gene used in the procedure (ASM) encodes a naturally occurring mammalian enzyme that has no known adverse effects, and the fluorescent compound used for selection (Bodipy sphingomyelin) is removed from the cells before transplantation.

Bone marrow transplantation in acid sphingomyelinase-deficient mice: engraftment and cell migration into the brain as a function of radiation, age, and phenotype.

Types A and B Niemann-Pick disease (NPD) result from the deficient activity of the lysosomal hydrolase, acid sphingomyelinase (ASM). A long-term goal of our research is to evaluate the effects of bone marrow transplantation (BMT) and hematopoietic stem cell gene therapy (HSCGT) on the NPD phenotype. As an initial step toward this goal, we have undertaken a study aimed at optimizing hematopoietic cell engraftment in acid sphingomyelinase "knock-out" (ASMKO) mice. Several parameters were analyzed, including the effects of radiation and donor cell number on survival and engraftment of newborn and adult animals, the number of donor cells detected in the brain posttransplantation, and the levels of ASM activity achieved in the brain. A total of 202 ASMKO and normal animals were transplanted and studied, and the overall conclusions were: (1) newborn ASMKO animals were more susceptible to radiation-induced mortality than normal animals, (2) at low radiation doses, increasing the donor cell number improved engraftment, while this was less evident at the higher radiation doses, (3) engraftment was easier to achieve in normal as compared with ASMKO animals, (4) among newborn transplants, the number of donor cells detected in the brain was directly correlated with engraftment in the blood, (5) more donor cells were detected in the brains of newborn ASMKO animals as opposed to newborn normal animals, and (6) no donor cells were found in the brains of animals transplanted as adults, including those that were highly engrafted in the blood. These results provide important information regarding the design of future BMT and HSCGT studies in ASMKO mice and other mouse models and demonstrate the potential of altering the NPD phenotype by these therapeutic strategies.

Photosensitized inactivation of Plasmodium falciparum- and Babesia divergens-infected erythrocytes in whole blood by lipophilic pheophorbide derivatives.

BACKGROUND AND OBJECTIVES: Blood transfusions can transmit parasitic infections, such as those caused by Plasmodium (malaria), Trypanosoma cruzi (Chagas' disease), and Babesia (babesiosis). A higher degree of blood transfusion safety would be reached if methods were available for inactivating such parasites. MATERIALS AND METHODS: We evaluated the effectiveness of photosensitization using lipophilic pheophorbide and red light illumination to eradicate red blood cells infected with Plasmodium falciparum, and with Babesia divergens, in whole blood. Fluorescence microscopy and conventional fluorometry showed the specific accumulation of pheophorbide derivatives in the RBC infected with either parasite, compared with uninfected RBC. The effectiveness of different derivatives in eradicating infected RBC was first estimated in parasite cultures. RESULTS: The best photosensitizer was the N-(4-butanol) pheophorbide derivative (Ph4-OH) at 0.2 microM concentration and 5-min illumination. In whole blood, the eradication of RBC infected with B. divergens and P. falciparum was obtained with 2 microM Ph4-OH and 10 and 20 min illumination, respectively. Under these conditions of photosensitization, low levels of RBC hemolysis were noted even after 2 weeks of storage at 4 degrees C and a subsequent 48-hour incubation at 37 degrees C. No reduction of negative charges on treated RBC was noted and no increase in methemoglobin content. CONCLUSIONS: In plasma, Ph4-OH is mainly transported by high-density lipoproteins (HDL). This high affinity for HDL may explain the selective accumulation of lipophilic pheophorbide derivatives in the intracellular parasites. Photosensitization with pheophorbide derivatives may be a promising approach to inactivation of transfusion-transmissible parasites and viruses in blood bank units.