Unrelated bone marrow transplantation for leukocyte adhesion deficiency

The severe form of leukocyte adhesion deficiency type I (LAD-I) usually leads to death early in life. Allogeneic haematopoietic transplantation is the only cure. Unrelated transplantation has been reported only once. We describe three children with LAD-I transplanted with T cell non-depleted bone marrow from unrelated HLA-matched donors. All patients engrafted, one of them at second transplant. One patient developed grade I and one grade II acute GVHD. Two patients are alive, one of them with a decrease in CD11/CD18 expression. Early referral for HLA-matched unrelated BMT is a reasonable option for patients with LAD-I lacking an HLA-matched related donor.

Black tea represents a major source of dietary phenolics among regular tea drinkers

The phenolic composition and antioxidant activities [TEAC, ORAC, FRAP] of consumer brews (1 tea bag in 230 ml for 1 min) of seven different brands of black tea from the British market were investigated. The main phenolic compounds identified were epigallocatechin gallate, four theaflavins, as well as epicatechin gallate, theogallin (tentative assignment), quercetin-3-rutinoside and 4-caffeoyl quinic acid. Thearubigins represented an estimated 75-82% of the total phenolics. Further, polyphenol fractions were in decreasing order theaflavins, flavan-3-ols, flavonols, gallic acids and hydroxycinnamates. On average, a cup of a consumer brew of black tea is providing polyphenols at the level of 262mg GAE/serving, of which 65 mg were assigned to individual polyphenols. The antioxidant activity of black tea preparations is higher than that of most reported dietary agents on a daily basis. Correlations were observed between the antioxidant activities and the sum of all quantified polyphenols by HPLC analysis as well as with the total phenolics. Treatment of the black tea brew with simulated gastric juice resulted in a significant increase of the identified theaflavins implying a partial cleavage of thearubigins in the environment of the gastric lumen. Therefore, black tea can be considered to be a rich source of polyphenols and/or antioxidants.

[Functional capacity and cartilage oligomeric protein (COMP) in serum of patients with maturity-onset polyarthritis]

OBJECTIVE

To compare late onset with adult onset rheumatoid arthritis.

METHODS

Fifty-eight patients with late onset rheumatoid arthritis (LORA) were compared to 117 patients with adult onset rheumatoid arthritis (AORA) with respect to clinical and functional parameters. Furthermore, in 104 patients serum cartilage oligomeric matrix protein (COMP) was measured. Results were compared by means of ANOVA and possible influences of age, gender and clinical parameters were evaluated by Spearman rank correlation.

RESULTS

Except a different distribution in gender (40% males in the LORA group) and a higher ESR, no differences could be found with respect to clinical parameters. However, a significantly higher HAQ score and significantly higher serum-COMP levels could be shown in the LORA group. HAQ scores correlated not only with disease activity parameters (C-reactive protein, disease activity score) but also with the age. Serum-COMP levels did show a correlation with the age as well, but not with disease activity.

CONCLUSION

It is concluded that the higher serum-COMP levels in late onset rheumatoid arthritis could be due to concomitant osteoarthritic processes in larger joints, which are not symptomatic. The age dependence of the HAQ score is only weak, but may be the reason why patients with LORA show a worse functional capacity compared to patients with adult onset rheumatoid arthritis.

Tumor-targeted gene delivery: an attractive strategy to use highly active effector molecules in cancer treatment

We have developed surface-shielded ligand-polycation based gene delivery systems which are able to target gene expression to distant tumors after systemic application. Tumor-specific targeting is achieved by (1) incorporation of cell-binding ligands; and (2) shielding of the complexes from non-specific interactions with blood components and non-target cells. Shielding of polycation/DNA complexes can be achieved by coating with either polyethylene glycol or by incorporating the ligand transferrin at high densities. Following systemic application, surface-shielded DNA complexes coding for a highly active, yet highly toxic cytokine, tumor necrosis factor-alpha (TNFalpha), localized gene expression to distant tumors, resulting in hemorrhagic tumor necrosis and inhibition of tumor growth. TNFalpha activity was confined to the tumor without systemic TNF-related toxicity. These results indicate that targeted gene delivery may be an attractive strategy to use highly potent molecules in cancer treatment.

Design and gene delivery activity of modified polyethylenimines

The polycation polyethylenimine (PEI) has recently been widely employed for the design of DNA delivery vehicles. Gene delivery using PEI involves condensation of DNA into compact particles, uptake into the cells, release from the endosomal compartment into the cytoplasm, and uptake of the DNA into the nucleus. Particularly for in vivo gene delivery, optimal coordination and timing between DNA complexation for protection of the DNA from nucleases and the disassembly of the complexes is essential. For in vivo application, DNA complexes have to pass a variety of anatomical and physiological barriers, and an environment of biological fluids and extracellular matrix before reaching their targets. Furthermore, targeted gene delivery is seriously hampered by non-specific interactions with non-target cells. Strategies have been developed to protect transfection complexes from non-specific interactions and to increase target specificity and gene expression.

Complement 1 inhibitor is a regulator of the alternative complement pathway

We studied complement 1 inhibitor (C1-INH) as an inhibitor of the alternative complement pathway. C1-INH prevented lysis, induced by the alternative complement pathway, of paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes in human serum. It inhibited the binding of both factors B and C3 to PNH and rabbit erythrocytes and blocked the ability of factor B to restore alternative-pathway function in factor B-depleted serum. C1-INH did not bind to factors B or D but did bind to immobilized C3b and cobra venom factor (CVF), a C3b analogue. C1-INH prevented factor B from binding to CVF-coated beads and dissociated bound factor B from such beads. Factor B and C1-INH showed cross competition in binding to CVF-coated beads. Factor D cleaved factor B into Bb and Ba in the presence of C3b. Cleavage was markedly inhibited when C3b was preincubated with C1-INH. C1-INH inhibited the formation of CVFBb and decreased the C3 cleavage. Removal of C1-INH from serum, in the presence of Mg-EGTA with an anti-C1-INH immunoabsorbant, markedly increased alternative-pathway lysis. C1-INH interacts with C3b to inhibit binding of factor B to C3b. At physiologic concentrations, it is a downregulator of the alternative pathway convertase.

CD4-independent infection of human B cells with HIV type 1: detection of unintegrated viral DNA

Although B lymphocytes are a major constituent of lymphoid organs and acquire a significantly altered phenotype and function in HIV-infected individuals, it remains unclear whether CD4-negative B cells are a susceptible host for viral entry and long-term productive infection. We screened a number of Epstein-Barr virus (EBV)-positive and-negative Burkitt's lymphoma (BL) B cell lines as well as subpopulations of normal B cells that include tonsillar naive and germinal center/memory B cells for the expression of HIV-1 receptors CD4, CXCR4, and CCR5. Cell lines and resting or activated normal B cells lacked CD4 and CCR5 but expressed CXCR4. We demonstrate HIV-1 infection of a CD4-negative, EBV-negative (BL) cell line, CA46, which remained productively infected yet noncytopathic for more than 36 months in culture. HIV-1 (HTLV-III(B)) infection of CA46 cells was mediated through CXCR4 in a CD4-independent manner and correlated with upregulation of the expression of B cell activation markers CD23 and CD95 (Fas receptor). Despite Fas receptor expression, HIV-1-infected CA46 cells remained resistant to Fas-mediated cell death. CA46-derived, CD4-independent viral isolates were proficient in infecting and causing syncytium formation in Molt4 T cells. The HIV-1 genomic organization in persistently infected CA46 clones was found to be predominantly unintegrated linear and circular DNA. Importantly, naive and germinal center/memory B cells could also be infected by HIV-1 in a CD4-independent manner. Although these B cell subpopulations expressed moderate to high levels of CXCR4, they required activation through CD40 and interleukin 4 receptor for infection. These findings point to B cells as an additional HIV-1 target and suggest a structural evolution of the HIV-1 genome responsible for CD4-independent and noncytopathic infections.

Preventing mediastinal shift after pneumonectomy impairs regenerative alveolar tissue growth

To examine the effects of mechanical lung strain on regenerative growth of alveolar septal tissue after pneumonectomy (PNX), we replaced the right lungs of adult dogs with a custom-shaped inflatable silicone prosthesis. The prosthesis was either inflated (Inf) to maintain the mediastinum at the midline or deflated to allow mediastinal shift. The animals were euthanized approximately 15 mo later, and the lungs were fixed at a constant distending pressure. With the Inf prostheses, lung expansion, alveolar septal tissue volumes, surface areas, and diffusing capacity of the tissue-plasma barrier were significantly lower than with the deflated prostheses; the expected post-PNX tissue responses were impaired by 30-60%. Capillary blood volume was significantly higher with Inf prostheses, consistent with microvascular congestion. Measurements in the Inf group remained consistently and significantly higher than those expected for a normal left lung, indicating persistence of partial compensation. In one dog, delayed deflation of the prosthesis 9-10 mo after PNX led to vigorous lung expansion and septal tissue growth, particularly of type II epithelial cells. We conclude that mechanical lung strain is a major signal for regenerative lung growth; however, other signals are also implicated, accounting for a significant fraction of the compensatory response to PNX.

Retinoic acid synthesis for the developing telencephalon

The small lipid retinoic acid is known to promote neuronal differentiation in vitro and to act as a teratogen in the embryonic brain, but very little is known about the natural role of endogenously synthesized retinoic acid in forebrain development. Retinoic acid is synthesized mainly by three retinaldehyde dehydrogenases. We show here where the retinaldehyde dehydrogenases for the developing telencephalon are expressed and how their expression patterns change over developmental time. Retinoic acid diffusing from the retinaldehyde dehydrogenase sites is likely to influence the early telencephalon before the beginning of neurogenesis, as well as differentiation and radial migration of neurons into the cerebral cortex. Because of its diffusible character, retinoic acid represents a unique tool for the coordination of growth processes over an intermediate distance range in the developing telencephalon.

Rescue of recombinant Thogoto virus from cloned cDNA

Thogoto virus (THOV) is a tick-transmitted orthomyxovirus with a genome consisting of six negative-stranded RNA segments. To rescue a recombinant THOV, the viral structural proteins were produced from expression plasmids by means of a vaccinia virus expressing the T7 RNA polymerase. Genomic virus RNAs (vRNAs) were generated from plasmids under the control of the RNA polymerase I promoter. Using this system, we could efficiently recover recombinant THOV following transfection of 12 plasmids into 293T cells. To verify the recombinant nature of the rescued virus, specific genetic tags were introduced into two vRNA segments. The availability of this efficient reverse genetics system will allow us to address hitherto-unanswered questions regarding the biology of THOV by manipulating viral genes in the context of infectious virus.

Standardized measurements and differential spectroscopy in microplates

Microplates (MPs) are excellent devices for the parallel processing of multiple samples for the spectroscopic analysis of chromophores and turbidity, for luminometric measurements, for cell culture applications, or simply for sample storage, library organization, and other high-throughput (HTP) processes. Disadvantages include an ill-defined pathlength, meniscus formation, evaporation, and cross-contamination. Here, we have developed a novel MP and lid system which can serve to minimize these drawbacks. Cup-like lids are inserted into MP wells. Thereby, liquid is pushed aside. The flat bottoms of the cup-like lids guarantee a planar interface and a defined pathlength. In addition, the devised MP system allows for differential spectroscopic analysis of multiple samples comparable to measurements in tandem cuvettes. This was shown by the investigation of the binding of reduced nicotinamide adenine dinucleotide to dihydrolipoamide dehydrogenase. The MP lid system described offers a low-cost solution for standardized spectrophotometric quantitations in any solvent compatible with the MP/lid material. In addition to the system's suitability for routine MP application, it should be advantageous as a simple and noninvasive method, i.e., no labeling and immobilization of analytes is required for detection of the interaction of molecules, for various HTP applications and drug screening purposes.

The effect of neighborhood-based community organizing: results from the Seattle Minority Youth Health Project

OBJECTIVE

To evaluate the effect of a community mobilization and youth development strategy to prevent drug abuse, violence, and risky sexual activity.

DATA SOURCES/STUDY SETTING

Primary surveys of youth, parents, and key neighborhood leaders were carried out at baseline (1994) and at the end of the intervention period (1997). The study took place in four intervention and six control neighborhoods in Seattle.

STUDY DESIGN

The study was designed as a randomized controlled trial with neighborhood as the unit of randomization. The intervention consisted of a paid community organizer in each neighborhood who recruited a group of residents to serve as a community action board. Key variables included perceptions of neighborhood mobilization by youth, parents, and key neighborhood leaders.

DATA COLLECTION/EXTRACTION METHODS

Youth surveys were self-administered during school hours. Parent and neighborhood leader surveys were conducted over the phone by trained interviewers.

PRINCIPAL FINDINGS

Survey results showed that mobilization increased to the same degree in both intervention and control neighborhoods with no evidence of an overall intervention effect. There did appear to be a relative increase in mobilization in the neighborhood with the highest level of intervention activity.

CONCLUSION

This randomized study failed to demonstrate a measurable effect for a community mobilization intervention. It is uncertain whether the negative finding was because of a lack of strength of the interventions or problems detecting intervention effects using individual-level closed-end surveys.

Measuring clinical performance: comparison and validity of telephone survey and administrative data

OBJECTIVE

To compare and validate self-reported telephone survey and administrative data for two Health Plan Employer Data and Information Set (HEDIS) performance measures: mammography and diabetic retinal exams.

DATA SOURCES/STUDY SETTING

A telephone survey was administered to approximately 700 women and 600 persons with diabetes randomly chosen from each of two health maintenance organizations (HMOs).

STUDY DESIGN

Agreement of survey and administrative data was assessed by using kappa coefficients. Validity measures were assessed by comparing survey and administrative data results to a standard: when the two sources agreed, that was accepted as the standard; when they differed, confirmatory information was sought from medical records to establish the standard. When confirmatory information was not available ranges of estimates consistent with the data were constructed by first assuming that all persons for whom no information was available had received the service and alternately that they had not received the service.

PRINCIPAL FINDINGS

The kappas for mammography were .65 at both HMOs; for retinal exam they were .38 and .40. Sensitivity for both data sources was consistently high. However, specificity was lower for survey (range .44 to .66) than administrative data (.99 to 1.00). The positive predictive value was high for mammography using either data source but differed for retinal exam (survey .69 to .78; administrative data .99 to 1.00).

CONCLUSIONS

Administrative and survey data performed consistently in both HMOs. Although administrative data appeared to have greater specificity than survey data the validity and utility of different data sources for performance measurement have only begun to be explored.

Functional maturation of dendritic cells by exposure to CD40L transgenic tumor cells, fibroblasts or keratinocytes

Tumor antigen pulsed dendritic cells (DCs) can induce anti-tumor immunity. We studied strategies for the reliable generation of such a tumor vaccine by functional maturation of DCs via interaction of CD40 with its ligand (CD40L, CD154). Exposure of immature DCs to CD40L transgenic cells, soluble recombinant human CD40L molecules or lipopolysaccharide induced expression of the co-stimulatory molecules, CD80 and CD86, and supported an allogeneic mixed leukocyte reaction. In contrast, the release of IL-12, an important mediator of anti-tumor immunity, and antigen-specific expansion and IFNgamma secretion of lymphocytes, was strongly triggered only by DCs exposed to CD40L transgenic cells.

DNA/polyethylenimine transfection particles: influence of ligands, polymer size, and PEGylation on internalization and gene expression

Receptor-binding ligands have been incorporated into DNA/polyethylenimine (PEI) complexes to enhance cell binding and cellular internalization. This study characterizes receptor-mediated uptake of DNA/PEI complexes on a cellular basis. A novel assay based on flow cytometry was applied, discriminating between total cell-associated and extracellularly bound DNA complexes. Receptor-mediated uptake of ligand-containing DNA/PEI (molecular weight, 800 kd) complexes was found to occur quickly (within 1 hour), whereas unspecific uptake through adsorptive endocytosis is less efficient or requires extended periods to reach the same degree of internalization. Rapid, receptor-mediated internalization requires a small complex size; however, large, aggregated complexes show higher gene expression. Using PEI 25 kd conjugated to large proteins such as transferrin or antibodies, improper condensation with DNA leads to suboptimal uptake and gene expression, whereas partial replacement of ligand-PEI with unconjugated PEI increases both uptake and transfection. In contrast, the 8 kd protein epidermal growth factor conjugated to PEI 25 kd properly condenses DNA and mediates specific uptake into human adenocarcinoma (KB) cells. Modification of the complex surface with appropriate amounts of poly(ethylene glycol) (PEG) does not block ligand-mediated internalization. A higher degree of PEGylation reduces the internalization of transferrin or antibody-containing complexes to a level similar to that of ligand-free complexes. In contrast, epidermal growth factor "mediated uptake is less effected by excessive PEGylation.

Different behavior of branched and linear polyethylenimine for gene delivery in vitro and in vivo

BACKGROUND

Efficient gene transfer is a major challenge for non-viral gene therapy. Understanding how non-viral vectors initiate gene expression could lead to the development of new future vectors with enhanced efficacy.

METHODS

Linear or branched polyethylenimine (PEI)/DNA complexes were generated in varying salt conditions and their transfection efficiencies were compared in vitro and in vivo using reporter genes, luciferase and green fluorescent protein, and rhodamine labeled DNA (pGeneGrip).

RESULTS

The transfection efficiency of linear PEI22/DNA in vitro was generally greater than that of branched PEI/DNA when complexes were generated in salt containing buffer. However, PEI complexes generated under salt-free conditions generally had low transfection activity in vitro. In contrast, PEI22/DNA salt-free complexes were highly active in vivo. Branched PEI/DNA and salt containing PEI22/DNA complexes were generally 10-100-fold less active than the salt-free PEI22/DNA complexes. Salt-free PEI22/DNA complexes were small, but subsequently grew into aggregates when salt was added. In contrast, PEI25/DNA complexes remained small even after salt was added under the same conditions. Furthermore, PEI22/pGeneGrips complexes formed large aggregates associated with the cell membrane, cytoplasm and nucleus, while branched PEI complexes remained as small distinct particles associated with the cell membrane or in the cytoplasm.

CONCLUSIONS

Branched and linear PEI/DNA complexes differ in their ability to transfect cells. The greater efficiency of linear PEI might be due to an inherent kinetic instability under salt conditions. Understanding how to employ this kinetic instability of linear PEI could help in designing future vectors with greater flexibility and transfection efficiency in vivo.

Different strategies for formation of pegylated EGF-conjugated PEI/DNA complexes for targeted gene delivery

With the aim of generating gene delivery systems for tumor targeting, we have synthesized a conjugate consisting of polyethylenimine (PEI) covalently modified with epidermal growth factor (EGF) peptides. Transfection efficiency of the conjugate was evaluated and compared to native PEI in three tumor cell lines: KB epidermoid carcinoma cells, CMT-93 rectum carcinoma cells, and Renca-EGFR renal carcinoma cells. Depending on the tumor cell line, incorporation of EGF resulted in an up to 300-fold increased transfection efficiency. This ligand-mediated enhancement and competition with free EGF strongly suggested uptake of the complexes through the EGF receptor-mediated endocytosis pathway. Shielded particles being crucial for systemic gene delivery, we studied the effect of covalent surface modification of EGF-PEI/DNA complexes with a poly(ethylene glycol) (PEG) derivative. An alternative way for the formation of PEGylated EGF-containing complexes was also evaluated where EGF was projected away from PEI/DNA core complexes through a PEG linker. Both strategies led to shielded particles still able to efficiently transfect tumor cells in a receptor-dependent fashion. These PEGylated EGF-containing complexes were 10- to 100-fold more efficient than PEGylated complexes without EGF.