Comparison between indicine and taurine cattle DNA methylation reveals epigenetic variation associated to differences in morphological adaptive traits

Indicine and taurine subspecies present distinct morphological traits as a consequence of environmental adaptation and artificial selection. Although the two subspecies have been characterized and compared at genome-wide level and at specific loci, their epigenetic diversity has not yet been explored. In this work, Reduced Representation Bisulphite Sequencing (RRBS) profiling of the taurine Angus (A) and indicine Nellore (N) cattle breeds was applied to identify methylation differences between the two subspecies. Genotyping by sequencing (GBS) of the same animals was performed to detect single nucleotide polymorphisms (SNPs) at cytosines in CpG dinucleotides and remove them from the differential methylation analysis. A total of 660,845 methylated cytosines were identified within the CpG context (CpGs) across the 10 animals sequenced (5 N and 5 A). A total of 25,765 of these were differentially methylated (DMCs). Most DMCs clustered in CpG stretches nearby genes involved in cellular and anatomical structure morphogenesis. Also, sequences flanking DMC were enriched in SNPs compared to all other CpGs, either methylated or unmethylated in the two subspecies. Our data suggest a contribution of epigenetics to the regulation and divergence of anatomical morphogenesis in the two subspecies relevant for cattle evolution and sub-species differentiation and adaptation.

Identification of genomic regions associated with total and progressive sperm motility in Italian Holstein bulls

Sperm motility is directly related to the ability of sperm to move through the female reproductive tract to reach the ovum. Sperm motility is a complex trait that is influenced by environmental and genetic factors and is associated with male fertility, oocyte penetration rate, and reproductive success of cattle. In this study we carried out a GWAS in Italian Holstein bulls to identify candidate regions and genes associated with variations in progressive and total motility (PM and TM, respectively). After quality control, the final data set consisted of 5,960 records from 949 bulls having semen collected in 10 artificial insemination stations and genotyped at 412,737 SNPs (call rate >95%; minor allele frequency >5%). (Co)variance components were estimated using single trait mixed models, and associations between SNPs and phenotypes were assessed using a genomic BLUP approach. Ten windows that explained the greatest percentage of genetic variance were located on Bos taurus autosomes 1, 2, 4, 6, 7, 23, and 26 for TM and Bos taurus autosomes 1, 2, 4, 6, 8, 16, 23, and 26 for PM. A total of 150 genes for TM and 72 genes for PM were identified within these genomic regions. Gene Ontology enrichment analyses identified significant Gene Ontology terms involved with energy homeostasis, membrane functions, sperm-egg interactions, protection against oxidative stress, olfactory receptors, and immune system. There was significant enrichment of quantitative trait loci for fertility, calving ease, immune response, feed intake, and carcass weight within the candidate windows. These results contribute to understanding the architecture of the genetic control of sperm motility and may aid in the development of strategies to identify subfertile bulls and improve reproductive success.

Genomic breed composition of pure registered Brazilian Gir

INTRODUCTION

Gir is a Bos indicus breed originally from India, first imported to Brazil in 1850. High-performance Dairy Gir has been systematically selected in Brazil from its arrival. Since the major phenotypic difference between Gir in India and Brazil is a higher milk production in the former, it is speculated that Brazilian Gir was strategically crossed with Holstein or another Bos taurus to improve milk yield. This study evaluated the purity of Brazilian Gir breed stocks from BASA Farms in Brazil, trying to identify possible admixture events with other cattle breeds based on DNA analysis.

MATERIALS AND METHODS

The population included 1061 pure registered individuals genotyped using two commercial platforms with 37 k and 25 k SNPs. Admixture analysis was performed individually to estimate levels of genomic composition derived from six different reference populations, three indicine and three taurine breeds.

RESULTS

A Gir ancestry of 99% or higher was found for 94.2% of the population, while the remaining showed levels of non-Gir ancestry up to 6.8%. Only five individuals were identified with possible taurine ancestry, all of them exhibiting levels lower than 2%. The remaining non-Gir ancestry identified was derived from indicine breeds. The levels of admixture observed in the population were from low to non-detectable. No consistent patterns of admixture were observed indicating sustained introgression of taurine lines as means of genetic improvement.

CONCLUSION

According to these results, genetic improvement achieved by Brazilian Gir breeders is the result of within-breed selection methods applied intensively over the past five decades, rather than the result from sustained introgression.

Bos taurus haplotypes segregating in Nellore (Bos indicus) cattle

Brazil is the largest exporter of beef in the world, and most of that beef derives from Nellore cattle. Although considered a zebu breed (Bos indicus), the history of Nellore cattle in Brazil is marked by the importation of bulls from India, the use of a Creole taurine (Bos taurus) maternal lineage to quickly expand the herds and backcrossing to Nellore bulls to recover zebu ancestry. As a consequence, the current Brazilian Nellore population carries an average taurine ancestry of approximately 1%. Although that percentage seems small, some taurine variants deviate substantially from that average, with the better-known cases being the PLAG1-Q haplotype involved with body size variation and the Guarani (P_G ) polled variant producing hornless animals. Here, we report taurine haplotypes in 9074 Nellore animals genotyped for 539 657 imputed SNP markers. Apart from PLAG1-Q and P_G , our analysis further revealed common taurine haplotypes (>3%) spanning genes related to immunity, growth, reproduction and hair and skin phenotypes. Using data from 22 economically important traits, we showed that many of the major QTL previously reported in the breed are at least partially driven by taurine haplotypes. As B. taurus and B. indicus haplotypes are highly divergent, presenting widely different sets of functional variants, our results provide promising targets for future scrutiny in Nellore cattle.

Pain distraction during awake low anterior resection and Cuddle Delivery initiative for inpatient: frugal procedural options to support surgery in the COVID-19 era

OBJECTIVE

Since minimally invasive surgery and general anesthesia are both aerosol-generating procedures, their use became controversial during the outbreak of coronavirus disease 2019 (COVID-19). Moreover, social distancing resulted in serious psychological consequences for inpatients. This case report investigates pain distraction during awake laparotomy, as well as new possibilities for emotional postoperative support to inpatients.

PATIENTS AND METHODS

A 72-year-old man affected by middle rectal adenocarcinoma underwent lower anterior resection plus total mesorectal excision under combined spinal-epidural anesthesia. A 3D mobile theatre (3DMT) was intraoperatively used for pain distraction. A postoperative "Cuddle delivery" service was instituted: video-messages from relatives and close friends were delivered daily to the patient through the 3DMT. Emotional correlations were investigated through a clinical interview by the psychologist of our Hospital.

RESULTS

Intraoperative, as well as postoperative pain, resulted well-controlled: visual analogue scale (VAS) ≤3. Conversion to general anesthesia and postoperative intensive support/monitoring were unnecessary. The "Cuddle delivery" initiative positively fed our patient's mood and attitude, strengthening his bond to life.

CONCLUSIONS

During pandemic, awake laparotomy under loco-regional anesthesia may be a crucial option in delivering acute care surgery to selected patients when intensive care beds are unavailable. Our procedure introduces potential ways to optimize this approach.

Evidence of distinct gene functional patterns in GC-poor and GC-rich isochores in Bos taurus

Vertebrate genomes are mosaics of megabase-size DNA segments with a fairly homogeneous base composition, called isochores. They are divided into five families characterized by different guanine-cytosine (GC) levels and linked to several functional and structural properties. The increased availability of fully sequenced genomes allows the investigation of isochores in several species, assessing their level of conservation across vertebrate genomes. In this work, we characterized the isochores in Bos taurus using the ARS-UCD1.2 genome version. The comparison of our results with the well-studied human isochores and those of other mammals revealed a large conservation in isochore families, in number, average GC levels and gene density. Exceptions to the established increase in gene density with the increase in isochores (GC%) were observed for the following gene biotypes: tRNA, small nuclear RNA, small nucleolar RNA and pseudogenes that have their maximum number in H2 and H1 isochores. Subsequently, we assessed the ontology of all gene biotypes looking for functional classes that are statistically over- or under-represented in each isochore. Receptor activity and sensory perception pathways were significantly over-represented in L1 and L2 (GC-poor) isochores. This was also validated for the horse genome. Our analysis of housekeeping genes confirmed a preferential localization in GC-rich isochores, as reported in other species. Finally, we assessed the SNP distribution of a bovine high-density SNP chip across the isochores, finding a higher density in the GC-rich families, reflecting a potential bias in the chip, widely used for genetic selection and biodiversity studies.

Association of missense variants in GDF9 with litter size in Entlebucher Mountain dogs

In the past two decades, average litter size (ALS) in Entlebucher Mountain dogs decreased by approximately 0.8 puppies. We conducted a GWAS for ALS using the single-step methodology to take advantage of 1632 pedigree records, 892 phenotypes and 372 genotypes (173 662 markers) for which only 12% of the dogs had both phenotypes and genotypes available. Our analysis revealed associations towards the growth differentiation factor 9 gene (GDF9), which is known to regulate oocyte maturation. The trait heritability was estimated at 43.1%, from which approximately 15% was accountable by the GDF9 locus alone. Therefore, markers flanking GDF9 explained approximately 6.5% of the variance in ALS. Analysis of WGSs revealed two missense substitutions in GDF9, one of which (g.11:21147009G>A) affected a highly conserved nucleotide in vertebrates. The derived allele A was validated in 111 dogs and shown to be associated with decreased ALS (-0.75 ± 0.22 puppies per litter). The variant was further predicted to cause a proline to serine substitution. The affected residue was immediately followed by a six-residue deletion that is fixed in the canine species but absent in non-canids. We further confirmed that the deletion is prevalent in the Canidae family by sequencing three species of wild canids. Since canids uniquely ovulate oocytes at the prophase stage of the first meiotic division, requiring maturation in the oviduct, we conjecture that the amino acid substitution and the six-residue deletion of GDF9 may serve as a model for insights into the dynamics of oocyte maturation in canids.

Genomic clues of the evolutionary history of Bos indicus cattle

Together with their sister subspecies Bos taurus, zebu cattle (Bos indicus) have contributed to important socioeconomic changes that have shaped modern civilizations. Zebu cattle were domesticated in the Indus Valley 8000 years before present (YBP). From the domestication site, they expanded to Africa, East Asia, southwestern Asia and Europe between 4000 and 1300 YBP, intercrossing with B. taurus to form clinal variations of zebu ancestry across the landmass of Afro-Eurasia. In the past 150 years, zebu cattle reached the Americas and Oceania, where they have contributed to the prosperity of emerging economies. The zebu genome is characterized by two mitochondrial haplogroups (I1 and I2), one Y chromosome haplogroup (Y3) and three major autosomal ancestral groups (Indian-Pakistani, African and Chinese). Phenotypically, zebu animals are recognized by their hump, large ears and excess skin. They are rustic, resilient to parasites and capable of bearing the hot and humid climates of the tropics. Many resources are available to study the zebu genome, including commercial arrays of SNP, reference assemblies and publicly available genotypes and whole-genome sequences. Nevertheless, many of these resources were initially developed to support research and subsidize industrial applications in B. taurus, and therefore they can produce bias in data analysis. The combination of genomics with precision agriculture holds great promise for the identification of genetic variants affecting economically important traits such as tick resistance and heat tolerance, which were naturally selected for millennia and played a major role in the evolution of B. indicus cattle.

Reference range of liver corrected T1 values in a population at low risk for fatty liver disease-a UK Biobank sub-study, with an appendix of interesting cases

Purpose

Corrected T1 (cT1) value is a novel MRI-based quantitative metric for assessing a composite of liver inflammation and fibrosis. It has been shown to distinguish between non-alcoholic fatty liver disease (NAFL) and non-alcoholic steatohepatitis. However, these studies were conducted in patients at high risk for liver disease. This study establishes the normal reference range of cT1 values for a large UK population, and assesses interactions of age and gender.

Methods

MR data were acquired on a 1.5 T system as part of the UK Biobank Imaging Enhancement study. Measures for Proton Density Fat Fraction and cT1 were calculated from the MRI data using a multiparametric MRI software application. Data that did not meet quality criteria were excluded from further analysis. Inter and intra-reader variability was estimated in a set of data. A cohort at low risk for NAFL was identified by excluding individuals with BMI ≥ 25 kg/m² and PDFF ≥ 5%. Of the 2816 participants with data of suitable quality, 1037 (37%) were classified as at low risk.

Results

The cT1 values in the low-risk population ranged from 573 to 852 ms with a median of 666 ms and interquartile range from 643 to 694 ms. Iron correction of T1 was necessary in 36.5% of this reference population. Age and gender had minimal effect on cT1 values.

Conclusion

The majority of cT1 values are tightly clustered in a population at low risk for NAFL, suggesting it has the potential to serve as a new quantitative imaging biomarker for studies of liver health and disease.

MUGBAS: a species free gene-based programme suite for post-GWAS analysis

Genome Wide Association Studies between molecular markers and phenotypes are now routinely run in model and non-model species. However, tools to estimate the probability of association of functional units (e.g. genes) containing multiple markers are not developed for species other than humans. Here we introduce MUGBAS (MUlti species Gene-Based Association Suite), software that estimates the P-value of a gene using information on annotation, single marker GWA results and genotype. The software is species and annotation independent, fast, highly parallelized and ready for high-density marker studies.

AVAILABILITY AND IMPLEMENTATION

https://bitbucket.org/capemaster/mugbas

Imputation accuracy is robust to cattle reference genome updates

Genotype imputation is routinely applied in a large number of cattle breeds. Imputation has become a need due to the large number of SNP arrays with variable density (currently, from 2900 to 777,962 SNPs). Although many authors have studied the effect of different statistical methods on imputation accuracy, the impact of a (likely) change in the reference genome assembly on imputation from lower to higher density has not been determined so far. In this work, 1021 Italian Simmental SNP genotypes were remapped on the three most recent reference genome assemblies. Four imputation methods were used to assess the impact of an update in the reference genome. As expected, the four methods behaved differently, with large differences in terms of accuracy. Updating SNP coordinates on the three tested cattle reference genome assemblies determined only a slight variation on imputation results within method.

Is there a role of percutaneous drainage in non-parasitic splenic cysts? Case report

Pathogenesis, classification and treatment of non-parasitic splenic cysts (NPSCs) are controversial. The utility of percutaneous aspiration of the cyst is not well understood. We report a case of a 32 year-old woman with a symptomatic giant epidermoid cyst of the spleen treated with laparoscopic splenectomy. A percutaneous transcatheter drainage was performed under ultrasound guidance before surgical procedure in order to classify the type of cyst and to choose the best treatment.

Noise correlations and SNR in phased-array MRS

The acquisition of magnetic resonance spectroscopy (MRS) signals by multiple receiver coils can improve the signal-to-noise ratio (SNR) or alternatively can reduce the scan time maintaining a reliable SNR. However, using phased array coils in MRS studies requires efficient data processing and data combination techniques in order to exploit the sensitivity improvement of the phased array coil acquisition method. This paper describes a novel method for the combination of MRS signals acquired by phased array coils, even in presence of correlated noise between the acquisition channels. In fact, although it has been shown that electric and magnetic coupling mechanisms produce correlated noise in the coils, previous algorithms developed for MRS data combination have ignored this effect. The proposed approach takes advantage of a noise decorrelation stage to maximize the SNR of the combined spectra. In particular Principal Component Analysis (PCA) was exploited to project the acquired spectra in a subspace where the noise vectors are orthogonal. In this subspace the SNR weighting method will provide the optimal overall SNR. Performance evaluation of the proposed method is carried out on simulated (1)H-MRS signals and experimental results are obtained on phantom (1)H-MR spectra using a commercially available 8-element phased array coil. Noise correlations between elements were generally low due to the optimal coil design, leading to a fair SNR gain (about 0.5%) in the center of the field of view (FOV). A greater SNR improvement was found in the peripheral FOV regions.

Residual dependency estimation of independent components applied to EEG event related potentials associated with emotional processing

Independent component analysis can be employed as an exploratory method in electroencephalographic (EEG) data analysis. However, the assumption of statistical independence among the estimated components is not always fulfilled by ICA-based numerical methods. Furthermore it may happen that one physiological source can be split in two or more components. As a consequence, the estimated components must be further investigated to assess the existence of reciprocal similarities. In this work a method for finding residual dependency subsets of component is proposed. Firstly a hierarchical clustering stage is carried out to classify ICA results. Then the hierarchical tree is investigated at each level by two indices to evaluate the tightness of all clusters. At the same time clustered scalp projections are compared with a template, which is shaped by applying ensemble ICA to a training dataset. Results are shown on EEG data acquired in event-related brain potentials (ERPs) studies for emotional pictures processing. In this kind of experiment ERPs are measured whilst unpleasant and neutral images are shown to a subject. The clustering procedure and the performance indices succeeded in isolating compact groups of components. These components, taken together, reflect the brain's biopotentials related to emotional processing at different cortical areas.

Multichannel techniques for motion artifacts removal from electrocardiographic signals

Electrocardiographic (ECG) signals are affected by several kinds of artifacts, that may hide vital signs of interest. Motion artifacts, due to the motion of the electrodes in relation to patient skin, are particularly frequent in bioelectrical signals acquired by wearable systems. In this paper we propose different approaches in order to get rid of motion confounds. The first approach we follow starts from measuring electrode motion provided by an accelerometer placed on the electrode and use this measurement in an adaptive filtering system to remove the noise present in the ECG. The second approach is based on independent component analysis methods applied to multichannel ECG recordings; we propose to use both instantaneous model and a frequency domain implementation of the convolutive model that accounts for different paths of the source signals to the electrodes.

Large-scale feasibility of gene transduction into human CD34+ cell-derived dendritic cells by adenoviral/polycation complex

With a view to using multiple injections of anti-cancer dendritic cell (DC)-based vaccines, we evaluated the feasibility of the adenoviral transduction of large amounts of human CD34+ cell-derived DCs, and analysed the persistence of the transgene expression and the integrity of DC functional activity after the transduction/cryopreservation procedures. Mature DCs generated from highly enriched human CD34+ cells were transduced by a recombinant adenovirus (rAd-MFG) that carried a modified, membrane-exposed, alkaline phosphatase (AP) sequence as the reporter gene. Cationic lipids such as LipofectAmine or poly-L-lysine were mixed with the viral particles before the transduction of the target cells. The highest transduction efficiency was obtained at a multiplicity of infection (MOI) rate of 500 (AP + DCs: 50 +/- 2%, viability =95%) under both small- and large-scale conditions. The addition of poly-L-lysine or LipofectAmine increased the percentage of transduced cells at an MOI of 500 (CD1a+/AP+ cells = 85 +/- 3% and 80 +/- 2% respectively). Polycations made it possible to reduce the amounts of viral particles, with high efficiency of transduction being achieved at a MOI of 100 with 10 microg/ml poly-L-lysine (CD1a+/AP+: 68 +/- 9%) or 30 microg/ml LipofectAmine (CD1a+/AP+: 60 +/- 7%). Evaluation of the immunophenotype of the transduced DCs showed that the lack of a DC subpopulation was more susceptible to adenoviral transduction. Cryopreservation of transduced DCs did not modify the viability or percentage of AP+ cells that maintain antigen-presenting cell (APC) functions. These findings indicate the efficacy of this method for the transduction of large amounts of CD34+ cell-derived DCs using small quantities of adenoviral vector mixed with polycations. Cryopreservation of transduced DCs did not damage their viability or APC functions, thus making it possible to plan multiple injections of engineered DC-based vaccines.

Recombinant adenoviral vector-lipofectAMINE complex for gene transduction into human T lymphocytes

We have evaluated, as a vector for gene transfer into human T lymphocytes, a recombinant adenovirus (rAd-MFG-AP) carrying a modified, membrane-exposed, alkaline phosphatase (AP) as reporter gene. CD3+ cells were selected from the buffy coat of healthy donors by the immunomagnetic technique. The positive cell population, comprising 96+/-2% CD3+ cells, was cultured with clinical-grade cytokine(s) for 3-7 days prior to rAd-MFG-AP transduction and the transgene expression was evaluated 48 hr later by indirect immunofluorescence flow cytometry assay with an anti-alkaline phosphatase antibody. The best efficiency of transduction was achieved on incubation of CD3+ cells with IL-2 plus either IL-12 (AP+ cells, 12+/-3%) or IL-7 (AP+ cells, 11+/-3%). To increase further the efficiency of transduction, we have combined LipofectAMINE and rAd-MFG-AP with the aim to enhance the uptake of viral particles into the target cells. The percentage of CD3+ cells transduced by rAd-MFG-AP-LipofectAMINE complex was 24+/-4% (range, 20-35%) after incubation with IL-2 plus IL-7 and 22+/-4% (range, 18-32%) after incubation with II-2 plus IL-12. Forty-eight hours after the incubation with rAd-MFG-AP, the transduced T lymphocytes were subjected to fluorescence-activated cell sorting and fractionated into AP+ and AP- cell subpopulations. The AP+ cell fraction, comprising 96.8% of AP+ cells, was evaluated by FACScan analysis for T lymphocyte surface antigens. The immunophenotyping of the transduced T lymphocytes has shown that there was not a particular subtype of T lymphocytes more susceptible to rAd-MFG-AP transduction. In addition, the transgene expression did not modify T lymphocyte functions, as demonstrated by results obtained by cytotoxicity assay before and after rAd-MFG-AP-LipofectAMINE complex transduction. In conclusion, human T lymphocytes can be efficiently transduced, under clinically applicable conditions, by adenovirus-LipofectAMINE complex after 7 days of culture with IL-2 and IL-12 or IL-7.

Gene transfer into human dendritic antigen-presenting cells by vaccinia virus and adenovirus vectors

In a search for means to deliver exogenous gene(s) into human dendritic cells (DCs) from the perspective of tumor-specific vaccination, we have evaluated two recombinant viruses, both of which carry a reporter gene which is namely a modified vaccinia virus Ankara (MVA) and an adenovirus, as possible expression vectors. The recombinant MVA-P11 LZ vector carries the Escherichia coli lacZ gene coding for the enzyme beta-galactosidase, and the recombinant Ad-MFG-AP vector carries a modified membrane-exposed alkaline phosphatase (AP) gene. DCs were generated ex vivo in the presence of tumor necrosis factor-alpha, granulocyte macrophage colony-stimulating factor, stem cell factor, and flk-2/flt-3 ligand taken from CD34+ hematopoietic progenitors that were mobilized into the peripheral blood of cancer patients treated with high-dose cyclophosphamide and filgrastim. The target cells used for gene delivery were either CD34+ cells that had been subsequently induced to differentiate into mature DCs or DCs transduced after ex vivo generation from CD34+ cells. The results showed that: (a) infection of CD34+ cell derived-DCs (mature DCs) with either viral vector resulted in the efficient synthesis of recombinant protein, and (b) CD34+ cells were permissive for the expression of the recombinant reporter gene after infection with Ad-MFG-AP but not after infection with MVA-P11 LZ. In conclusion, these results suggest that vaccinia and adenovirus vectors are candidate to act as vehicles in genetically engineering human DCs.

Adenovirus vectors for gene transduction into mobilized blood CD34+ cells

Mobilized blood CD34+ cells from cancer patients were ex vivo infected by a recombinant adenovirus vector carrying an alkaline phosphatase gene, whose expression is evaluable by flow cytometry. A mean of 40% CD34+ cells were infected by the vector, with high levels of expression of the transgene. Among attempts to improve infection efficiency by manipulating culture conditions, only reinfection by the same vector achieved a 10% increase of transgene expression. Transduced CD34+ cells were induced to differentiate along the myeloid and the dendritic lineage, and in either case AP+ cells were detectable among the differentiated cell population. We conclude that adenovirus vectors may be useful tools for gene transduction into mobilized blood CD34+ cells, particularly for those applications in which high transgene expression for limited periods of time is required.

Mobilized peripheral blood CD34+ cells express more amphotropic retrovirus receptor than bone marrow CD34+ cells

BACKGROUND AND OBJECTIVE

The increased susceptibility to gene transfer by amphotropic retroviral vectors of mobilized peripheral blood (PB) CD34+ cells compared to their bone marrow (BM) counterparts may depend, among other factors, on the level of expression of the amphotropic receptor on the progenitor cell. Using a previously described flow cytometry strategy, we have studied retrovirus binding to mobilized CD+ cells, derived from cancer patients treated with high-dose chemotherapy and growth factor(s), that are efficiently transduced by N2 retrovirus vector.

DESIGN AND METHODS

We measured the binding of the retrovirus to the cells using a rat monoclonal antibody reactive with the gp70 envelope glycoprotein, common to all replication-defective amphotropic retroviruses. Antibody-virus-cell complexes were indirectly labeled and analyzed by flow cytometry. We compared the binding of PA317-N2 vector to CD34+ cells derived from steady-state BM, steady-state PB and mobilized PB from cancer patients treated with high-dose chemotherapy and cytokine.

RESULTS

The fluorescence intensity of mobilized CD34+ cells was approximately one log higher than that of steady-state BM or PB CD34+ cells, indicating that the expression of the amphotropic receptor was increased. Moreover, the virus binding was proportional to the gene transfer rate, as assessed by G418 resistance into mobilized PB-derived CFU-GM. The increase in fluorescence intensity appeared to be restricted to CD34+ cell subset, neither CD2+ nor CD14+ cells bound the virus in an appreciable amount.

INTERPRETATION AND CONCLUSIONS

Virus binding, as assessed by indirect immunofluorescence assay, is increased in mobilized CD34+ cells. The increased binding may contribute to their high susceptibility to retrovirus vector infection.

Elimination of bcl-2-IgH-positive follicular lymphoma cells from blood transplants with high recovery of hematopoietic progenitors by the miltenyi CD34+ cell sorting system

Contamination of autologous blood cell transplants with cells of follicular non-Hodgkin's lymphoma (F-NHL) may contribute to relapse of the malignancy after potentially curative high doses of chemotherapy and radiotherapy. In an attempt to circumvent this limitation, we have evaluated various techniques of selection of CD34+ cells to eliminate malignant cells from blood cell transplants of five patients with F-NHL undergoing high-dose sequential therapy. The contamination of F-NHL cells was evaluated using a nested PCR assay for the detection of bcl-2-IgH rearrangement with a sensitivity of one F-NHL cell in 10(5) normal cells. In two experiments with blood cell transplant fractions of 0.5 x 10(9) nucleated cells, negative selection of CD34+ cells by removal of B cells and other mature cells that naturally adhere to nylon wool fibers decreased the number of CD19+ B cells detectable by flow cytometry but failed to eliminate bcl-2-IgH-positive F-NHL cells detectable by PCR. In contrast, positive selection of CD34+ cells by the Miltenyi MiniMACS high gradient magnetic cell sorting system in five separate experiments resulted in: (1) the elimination of F-NHL cells in four out of five cases as detected both flow cytometry and bclk-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 90.8% +/- 2.3% CD34+ cells; and (3) the recovery of 77.9% +/- 3.2% CD34+ cells. These favorable results were confirmed on a large-scale with a blood cell transplant comprising 5.8 x 10(9) nucleated cells in which positive selection of CD34+ cells by the Miltenyi SuperMACS system resulted in: (1) the elimination of F-NHL cells as detected both by flow cytometry and bcl-2-IgH PCR; (2) a highly purified population of hematopoietic progenitors comprising 94.6% CD34+ cells; and (3) the recovery of 62.7% CD34+ cells. These results, attained with the newly available Super MACS system, compare favorable with previous techniques because they show the feasibility of eliminating F-NHL cells from blood cell transplants without relevant nonspecific loss of hematopoietic progenitors.

Combined negative and positive selection of mobilized CD34 blood cells

We tested four negative and two positive selection methods for separation of CD34+ cells from mobilized blood cells, and analysed fold-enrichment, purity and recovery of CD34+ cells after selection procedures. The elimination of mature CD34- cells was achieved by adhesion to nylon-wool fibre (5.9 +/- 1.0 mean fold-enrichment and 65.2 +/- 2.3 mean recovery of CD34+ cells). Standard or modified Ficoll-Hypaque and Percoll density gradients, as well as phagocytosis with magnetic beads, were less effective in eliminating CD34- cells, both purity and fold-enrichment of CD34+ cells being lower than those obtained with separation by nylon-wool. Both positive selection methods tested. Ceprate and MiniMacs System, generated highly purified CD34+ cell populations ranging from 80% to 90%. The recovery of CD34+ cells was optimal with MiniMacs (77.9 +/- 3.6) and low with Ceprate (28.8 +/- 2.8). Based on these results, in two large-scale experiments we combined nylon-wool fibre and MiniMacs System in a two-step separation procedure obtaining a 36.9 +/- 2.6 mean fold-enrichment and a 50.5 +/- 0.3 mean recovery of CD34+ cells. In this way we achieved optimal enrichment and recovery of CD34+ cells, with a substantial saving of cost compared to either selection method alone.

Benefits of blood cell transplant cryopreservation with oxypolygelatine (Gelifundol) plasma substitute

In two groups of 11 patients with poor prognosis malignancies undergoing high-dose sequential chemotherapy, we have evaluated the cryopreservation of blood cell transplants with oxypolygelatine-containing (55% oxypolygelatine, 6% hydroxyethylstarch, 5% dimethyl sulfoxide) vs standard human serum-containing (55% human serum, 6% hydroxyethylstarch, 5% dimethyl sulfoxide) cryoprotectant mixtures. Evidence is presented demonstrating that substitution of human serum proteins with oxypolygelatine has no detrimental effect either in vitro on the post-thawing recovery of hematopoietic progenitors or in vivo on the capacity of marrow reconstituting function in patients treated with myeloablative cancer therapy and autologous blood cell transplant. Oxypolygelatine is commercially available for clinical use as a plasma expander, is 30-fold less expensive than human serum albumin, is certified free of foreign serum proteins and antibodies as well as free of pyrogen, viral, mycoplasmal and bovine spongiform encephalopathy contaminants. Because of these characteristics, oxypolygelatine permits avoidance of: (1) the use of expensive serum albumin; (2) the fastidious preparation of autologous plasma or serum, and (3) the risk of infection associated with the infusion of allogeneic serum. Because of these practical advantages, we recommend the clinical use of oxypolygelatine as a substitute for human serum proteins for the routine cryopreservation of blood cell transplants.

Improvement of supportive nursing care in cancer patients autografted with bone marrow and mobilized peripheral blood haematopoietic progenitors

We report that in cancer patients a dramatic reduction in infection rate, days of isolation, oral mucositis and hospitalization due to high-dose chemotherapy is achievable by autografting with haematopoietic progenitor cells (CPCs) circulating in peripheral blood following cancer therapy with high-dose cyclophosphamide (HD-CTX) and administration of recombinant haematopoietic cytokines. Thirty patients (29 lymphomas, one breast cancer) were treated with total body irradiation and high-dose melphalan followed by either: (i) bone marrow transplant (Group A); (ii) bone marrow plus HD-CTX-mobilized CPC transplant (Group B); or (iii) bone marrow plus HD-CTX- and cytokine-mobilized CPC transplant (Group C). Nursing care load was remarkably higher in Group A patients compared to Group B and C patients, thus demonstrating clinical advantages of transplantation of HD-CTX-f and cytokine-mobilized CPCs.