cMPL-Based Purification and Depletion of Human Hematopoietic Stem Cells: Implications for Pre-Transplant Conditioning

The transplantation of gene-modified autologous hematopoietic stem and progenitor cells (HSPCs) offers a promising therapeutic approach for hematological and immunological disorders. However, this strategy is often limited by the toxicities associated with traditional conditioning regimens. Antibody-based conditioning strategies targeting cKIT and CD45 antigens have shown potential in mitigating these toxicities, but their long-term safety and efficacy in clinical settings require further validation. In this study, we investigate the thrombopoietin (TPO) receptor, cMPL, as a novel target for conditioning protocols. We demonstrate that high surface expression of cMPL is a hallmark feature of long-term repopulating hematopoietic stem cells (LT-HSCs) within the adult human CD34+ HSPC subset. Targeting the cMPL receptor facilitates the separation of human LT-HSCs from mature progenitors, a delineation not achievable with cKIT. Leveraging this finding, we developed a cMPL-targeting immunotoxin, demonstrating its ability to selectively deplete host cMPLhigh LT-HSCs with a favorable safety profile and rapid clearance within 24 hours post-infusion in rhesus macaques. These findings present significant potential to advance our understanding of human hematopoiesis and enhance the therapeutic outcomes of ex vivo autologous HSPC gene therapies.

Busulfan Combined with Immunosuppression Allows Efficient Engraftment of Gene-Modified Cells in a Rhesus Macaque Model

Busulfan conditioning is utilized for hematopoietic stem cell (HSC) depletion in the context of HSC gene-therapy conditioning but may result in insufficient immunosuppression. In this study, we evaluated whether additional immunosuppression is required for efficient engraftment of gene-modified cells using a rhesus HSC lentiviral gene-therapy model. We transduced half of rhesus CD34+ cells with an enhanced green fluorescent protein (GFP)-encoding vector (immunogenic) and the other half with a γ-globin-encoding vector (no predicted immunogenicity). After autologous transplantation of both transduced cell populations following myeloablative busulfan conditioning (5.5 mg/kg/day for 4 days), we observed immunological rejection of GFP-transduced cells up to 3 months post-transplant and stable engraftment of γ-globin-transduced cells in two animals, demonstrating that ablative busulfan conditioning is sufficient for engraftment of gene-modified cells producing non-immunogenic proteins but insufficient to permit engraftment of immunogenic proteins. We then added immunosuppression with abatacept and sirolimus to busulfan conditioning and observed engraftment of both GFP- and γ-globin-transduced cells in two animals, demonstrating that additional immunosuppression allows for engraftment of gene-modified cells expressing immunogenic proteins. In conclusion, myeloablative busulfan conditioning should permit engraftment of gene-modified cells producing non-immunogenic proteins, while additional immunosuppression is required to prevent immunological rejection of a neoantigen.

Das Krosserezidiv – eine Nachkontrolle nach 34 Jahren

Ziel: Erfassung der Langzeit-Rezidivrate der Krossektomie der Vena saphena magna. Methode: anamnestische, inspektorische und farbduplexsonographische Nachkontrolle von 125 Fällen im Mittel 34 Jahre nach der Krossektomie. Ergebnis: Die klinisch-inspektorische Untersuchung ergab 47% Krosserezidive, doch farbduplexsonographisch war die Rezidivrate mit 60% wesentlich höher. 42,4% waren echte Rezidive genau aus der alten Ligaturstelle, und zwar waren sie in 17,6% strang- oder knäuelförmig und in 24,8% handelte es sich um eine einläufige Varize. Die übrigen 17,6% waren Pseudorezidive aus der Umgebung der alten Magnaligatur. Schlußfolgerung: Diese Langzeitverlaufskontrollstudie bestätigt die in der Literatur beschriebenen Daten über Krosserezidive. Mit Farbduplexsonographie werden Krosserezidive häufiger erfaßt als bei der klinischen Untersuchung. Eine Krossektomierezidivrate nach einer Verlaufszeit von 34 Jahren wurde unseres Wissens bisher noch nicht publiziert. Die Resultate können als Basis dienen für die anlaufende Forschung über die Ursachen und die Verhinderung der Rezidive nach korrekter Krossektomie.

Externe Retraktions-Technik (ERT) verbessert den Endoskopieraum bei der endoskopischen subfaszialen Diszision der Perforansvenen

Ziel: Beschreibung einer chirurgischen Technik zur subfaszialen Raumentwick-lung bei der Endoskopie der Perforanten. Überprüfung der Technik an einer konsekutiven Patientenkohorte. Methode: Wesentliche Bestandteile der Technik sind präoperative Entstauung, intraoperative Blutleere sowie die zeltförmige Aufspannung des Haut-Faszien-Lappens mittels externer Retraktions-Technik (ERT). Dies geschieht mit einer eigens dafür konstruierten atraumatischen Hautfaß-zange (ERT-Zange). Eine Kohorte von 62 Patienten wurde insgesamt 67 Mal endoskopiert. Die beschriebene Technik für die subfasziale Raumentwicklung wurde in dieser Kohorte bezüglich technischer Machbarkeit, Erreichbarkeit der insuffizienten Perforanten sowie Nebenwirkungen und Komplikationen überprüft. Ergebnis: Eine gute Raumentwicklung konnte bei 64 von 67 Endoskopien erreicht werden. Wegen mangelhafter Entstauung und insuffizienter Blutsperre konnte das Ziel dreimal nicht erreicht werden. In 4 Fällen konnte eine distale Cockett-Perforans nicht dargestellt werden. Die häufigste Nebenwirkung sind sichtbare postoperative Einstichstellen der Hautfaßzange. Sie ist allerdings bedeutungslos. Schlußfolgerung: Die Optimierung des Arbeitsraumes bei der subfaszialen Perforantenendoskopie mit der atraumatischen Hautfaßzange ist eine zuverlässige, schnelle, billige und sichere Methode.

The Relationship Between Dormant Cancer Cells and Their Microenvironment

The majority of cancer deaths are due to metastases that can occur years or decades after primary tumor diagnosis and treatment. Disseminated tumor cells (DTCs) surviving in a dormant state in target organs appear to explain the timing of this phenomenon. Knowledge on this process is important as it might provide a window of opportunity to prevent recurrences by eradicating dormant DTCs and/or by maintaining DTCs in a dormant state. Importantly, this research might offer markers of dormancy for early monitoring of metastatic relapse. However, our understanding of the mechanisms underlying the regulation of entry into and exit from dormancy is still limited and crippling any therapeutic opportunity. While cancer cell-intrinsic signaling pathways have been linked to dormancy regulation, it is likely that these pathways and the switch controlling reactivation from dormancy are regulated by microenvironmental cues. Here we review and discuss recent findings on how the microenvironment regulates cancer dormancy and raise new questions that may help advance the field.

Electrokinetic coupling in unsaturated porous media

We consider a charged porous material that is saturated by two fluid phases that are immiscible and continuous on the scale of a representative elementary volume. The wetting phase for the grains is water and the nonwetting phase is assumed to be an electrically insulating viscous fluid. We use a volume-averaging approach to derive the linear constitutive equations for the electrical current density as well as the seepage velocities of the wetting and nonwetting phases on the scale of a representative elementary volume. These macroscopic constitutive equations are obtained by volume-averaging Ampère's law together with the Nernst-Planck equation and the Stokes equations. The material properties entering the macroscopic constitutive equations are explicitly described as functions of the saturation of the water phase, the electrical formation factor, and parameters that describe the capillary pressure function, the relative permeability functions, and the variation of electrical conductivity with saturation. New equations are derived for the streaming potential and electro-osmosis coupling coefficients. A primary drainage and imbibition experiment is simulated numerically to demonstrate that the relative streaming potential coupling coefficient depends not only on the water saturation, but also on the material properties of the sample, as well as the saturation history. We also compare the predicted streaming potential coupling coefficients with experimental data from four dolomite core samples. Measurements on these samples include electrical conductivity, capillary pressure, the streaming potential coupling coefficient at various levels of saturation, and the permeability at saturation of the rock samples. We found very good agreement between these experimental data and the model predictions.

Non-intrusive characterization of the redox potential of landfill leachate plumes from self-potential data

Contaminant plumes (e.g., associated with leakages from municipal landfills) provide a source of natural electrical potentials (or "self-potentials") recordable at the Earth's surface. One contribution to these self-potentials is associated with pore water flow (i.e., the "streaming potential"), and the other is related to redox conditions. A contaminant plume can be regarded as a "geobattery": the source current potentially results from the degradation of the organic matter by micro-organisms, which produces electrons. These electrons are then carried by nanowires that connect bacteria and thorough metallic particles that precipitate in areas of strong redox potential gradient. In the case of the Entressen landfill (South of France), reported here, the hydraulic head differences measured in piezometers outside the contaminant plume is strongly linked to the surface self-potential signals, with a correlation coefficient of -0.94. We used a Bayesian method that combines hydraulic head and self-potential data collected outside the contaminated area to estimate the streaming potential component of the collected self-potential data. Once the streaming potential contribution was removed from the measured self-potentials, the correlation coefficient between the residual self-potentials and the measured redox potentials in the aquifer was 0.92. The slope of this regression curve was close to 0.5, which was fairly consistent with both finite element modelling and the proposed geobattery model.

Chemico-electromechanical coupling in microporous media

We determine the macroscopic transport properties of isotropic microporous media by volume-averaging the local Nernst-Planck and Navier-Stokes equations in nonisothermal conditions. In such media, the excess of charge that counterbalances the charge deficiency of the surface of the minerals is partitioned between the Gouy-Chapman layer and the Stern layer. The Stern layer of sorbed counterions is attached to the solid phase, while the Gouy-Chapman diffuse layer is assumed to have a thickness comparable to the size of the pores. Rather than using Poisson-Boltzmann distributions to describe the ionic concentrations in the pore space of the medium, we rely on Donnan distributions obtained by equating the chemical potentials of the water molecules and ions between a reservoir of ions and the pore space of the medium. The macroscopic Maxwell equations and the macroscopic linear constitutive transport equations are derived in the vicinity of equilibrium, assuming that the porous material is deformable. In the vicinity of thermodynamic equilibrium, the cross-coupling phenomena of the macroscopic constitutive equations of transport follow Onsager reciprocity. In addition, all the material properties entering the constitutive equations depend only on two textural properties, the permeability and the electrical formation factor.

Late recurrent saphenofemoral junction reflux after ligation and stripping of the greater saphenous vein

OBJECTIVE

This study was done to determine the long-term incidence of refluxing epifascial-to-deep vein reconnections in the area of the former saphenofemoral junction after ligation of the true junction, along with all proximal tributaries, and resection of the greater saphenous vein.

PATIENTS AND METHODS

A total of 125 limbs in 77 patients, representing 66% of 117 survivors among 602 patients who underwent operation between 1960 and 1967, were evaluated clinically and with duplex sonography for possible superficial-to-deep vein reconnections and clinical recurrence of thigh varicosities at a mean follow-up of 34 years.

RESULTS

Clinical examination suggested saphenofemoral recurrence in 59 limbs (47%). In 11 instances these were actually varices associated with isolated superficial system reflux or reflux originating from a distally located perforating vein. Color-coded duplex ultrasonography demonstrated saphenofemoral reflux in 75 limbs (60%), versus the 48 identified on clinical examination (P <.001), and documented that the junction ligation had not been performed incorrectly by absence of the terminal valve or any patent proximal saphenous remnant. The reflux originated at the site of the ligated saphenofemoral junction in 53 limbs (71%) and from a nearby circumjunctional deep vein in the other 22 (29%). Of the real junctional recurrences, 22 appeared as a tangled cluster, and 31 involved a single-lumen varix. Only 27 recurrences were sufficiently symptomatic to warrant consideration of additional treatment; 25 of these were clinically evident, single-lumen, true junctional recurrences.

CONCLUSIONS

This 34-year clinical follow-up study shows a 60% incidence of junctional and circumjunctional reconnections after ligation of the true saphenofemoral junction and its related tributaries. Color-coded duplex sonography is a necessary concomitant to clinical examination, detecting more recurrences and defining the pathologic anatomy to direct clinically indicated additional treatments.

Experimental reproduction of winter dysentery in lactating cows using BCV -- comparison with BCV infection in milk-fed calves

Infection models were developed for adult cows and for young calves using the same strain of bovine coronavirus (BCV), which for the first time allows experimental reproduction of winter dysentery (WD) in seronegative lactating cows. The cattle were infected through direct contact with an experimentally inoculated calf. All experimental cattle shed faecal BCV with development of diarrhoea, being profusely watery with small amounts of blood in the most severely affected animals, including both cows and calves. The cows, in contrast to the calves, showed depressed general condition and appetite leading to a marked decrease in milk yield. Further age-associated differences were a shorter incubation period in the two youngest calves, but with milder fever and milder decrease in white blood cell counts. These findings shed light on the apparent epidemiological differences between WD and calf BCV diarrhoea suggesting that, (1) the same strains of BCV cause natural outbreaks of calf diarrhoea and WD, (2) seronegative cows are more severely affected by the infection than seronegative conventionally reared calves, and (3) unaffected general condition in diarrhoeic calves may lead to underestimation of the occurrence of calf diarrhoea in WD outbreaks.

In response to infection, all cattle produced early interferon type 1 in serum and, except for one calf, in nasal secretions. A finding not previously reported is the detection of interferon type 1 responses in bovine milk. All cattle developed high IgM antibody responses and long-lasting IgA antibody responses both systemically and locally. The serum IgM antibody responses came earlier in most of the calves than in the cows. Prolonged IgM antibody responses were detected in serum and milk, while those in nasal secretions were much shorter. BCV-specific IgA was present in nasal secretions from all cattle throughout the 6 months follow-up. The IgA antibody response in serum was detected up to 17 months post-infection and the duration showed an age-related variation indicating a more prominent IgA memory in the adult cattle and in the older calves than in the younger ones. BCV-specific IgG was detected in all cattle during the experimental period of up to 22 months.

In conclusion, WD was reproduced in seronegative lactating cows. The cows showed a more severe general diseases than seronegative calves infected concurrently. Very long-lasting IgA antibody responses were detected both systemically and locally.

Capture ELISA systems for the detection of bovine coronavirus-specific IgA and IgM antibodies in milk and serum

Isotype-capture ELISAs for BCV-specific IgA and IgM were developed and tested on milk and serum samples from Swedish cattle. The capture ELISAs showed higher sensitivity than indirect ELISAs for detection of BCV-specific IgA and IgM. In the capture ELISAs the agreement between detection in milk and serum samples was 94% for IgA and 86% for IgM. The correlation between log(10) titres in milk and serum was r=0.82 (P<0.001) for IgA and 0.84 (P<0.001) for IgM. Milk seemed a better target than serum for diagnosing specific IgA at low levels. There was no variation in the isotype-specific BCV antibody titres between healthy quarters of the same udder, but subclinical mastitis was associated with higher levels of IgA antibodies and weak false IgM positive reactions in undiluted milk. Bovine IgA and IgM antibodies in milk and serum showed high stability towards freezing and thawing and storage at room temperature. The antibody responses to BCV were followed in milk and serum from six dairy cows and in serum from four calves for a period of 1 year after an outbreak of winter dysentery (WD). In this outbreak some animals became reinfected with BCV. The IgA and IgM capture ELISAs differentiated between primarily BCV infected and reinfected animals. In the primarily infected cattle, IgM antibodies were first detected in milk and serum four to nine days after the first WD symptoms observed, and were subsequently detected for at least 2-3 weeks. IgM was also detected in the reinfected cows, but mostly at lower levels and for a shorter period of time than in the primarily infected animals. In milk, however, the IgM response of the reinfected cows was detected for a longer period of time than in serum. Six months after the outbreak, IgA was still detected in both serum and milk of all six cows and also in serum of one calf. The reinfected cows showed higher and more long-lasting peak levels of IgA in milk and serum than the primarily infected cows, indicating boosting of the IgA response.

Evaluation and application of an indirect ELISA for the detection of antibodies to bovine respiratory syncytial virus in milk, bulk milk, and serum

An indirect enzyme-linked immunosorbent assay (ELISA) was developed at the National Veterinary Institute (NVI), Uppsala, to detect antibodies to bovine respiratory syncytial virus (BRSV) in serum and milk. For the evaluation of the NVI ELISA, field sera collected from cattle in England and Sweden were tested in parallel with an ELISA in use at the Central Veterinary Laboratory (CVL), Weybridge. The tests showed 96% agreement. The sensitivity and specificity of the NVI ELISA relative to the CVL ELISA were 94% and 100%, respectively. There was evidence that the difference in sensitivity between the 2 tests was due to the detection of both IgG and IgM class antibodies by the CVL ELISA, whereas the NVI ELISA was designed specifically to detect IgG1. Milk and serum samples from individual cows were tested by the NVI ELISA for presence of antibodies to BRSV. There was a good correlation between the ability to detect antibodies in serum and the ability to detect them in milk, although the antibody titer was generally lower in milk than in serum. Bulk milk samples were collected from farms with severe clinical symptoms of respiratory distress and from farms with no history of respiratory disease. There was a clear distinction between antibody levels in diseased and healthy herds. The NVI ELISA is a rapid and reliable test for detecting antibodies to BRSV in milk, bulk milk, and serum samples.

Studies of enteric pathogens and gamma-globulin levels of neonatal calves in Sweden

Faecal and blood samples were taken from 10-30% of calves, 36 hours to 14 days old, in 47 dairy herds in different regions of Sweden from September 1987 to October 1988 (Olsson et al. 1993). Faecal samples from 279 calves were analysed for the presence of Escherichia coli (K99+), rotavirus and Cryptosporidium sp. Twenty (7.2%) of these samples were from diarrhoeic calves. An ELISA was developed and used for the rotavirus analysis. E. coli K99+ was detected in 11.5%, Cryptosporidium sp. in 6.1% and rotavirus in 5.4% of the faecal samples. The presence of rotavirus alone and the combination rotavirus and E. coli (K99+) was found to be associated with diarrhoea (p < 0.001 and p < 0.01 respectively). Blood samples from 327 calves were analysed for the level of total protein and gamma-globulin. In 43 of these samples (13%) gamma-globulin did not separate from the beta 2-region by electrophoresis. The mean total protein concentration was 53.6 g/l in calves free from diarrhoea. The mean gamma-globulin concentration, adjusted to 7 days age was 5.9 g/l. The 20 diarrhoeic calves had lower levels of both total protein and gamma-globulin, compared with calves without diarrhoea, but the difference was not significant. One litre more of colostrum at the first feed increased the level of total protein of the calves' sera by 1.4 g/l (p = 0.05). Calves born between May and September had a 2.0 g/l higher (p < 0.001) serum concentration of gamma-globulin than calves born between October and April.

Studies of enteric pathogens and gamma-globulin levels of neonatal calves in Sweden

Faecal and blood samples were taken from 10-30% of calves, 36 hours to 14 days old, in 47 dairy herds in different regions of Sweden from September 1987 to October 1988 (Olsson et al. 1993). Faecal samples from 279 calves were analysed for the presence of Escherichia coli (K99+), rotavirus and Cryptosporidium sp. Twenty (7.2%) of these samples were from diarrhoeic calves. An ELISA was developed and used for the rotavirus analysis. E. coli K99+ was detected in 11.5%, Cryptosporidium sp. in 6.1% and rotavirus in 5.4% of the faecal samples. The presence of rotavirus alone and the combination rotavirus and E. coli (K99+) was found to be associated with diarrhoea (p < 0.001 and p < 0.01 respectively). Blood samples from 327 calves were analysed for the level of total protein and gamma-globulin. In 43 of these samples (13%) gamma-globulin did not separate from the beta 2-region by electrophoresis. The mean total protein concentration was 53.6 g/l in calves free from diarrhoea. The mean gamma-globulin concentration, adjusted to 7 days age was 5.9 g/l. The 20 diarrhoeic calves had lower levels of both total protein and gamma-globulin, compared with calves without diarrhoea, but the difference was not significant. One litre more of colostrum at the first feed increased the level of total protein of the calves' sera by 1.4 g/l (p = 0.05). Calves born between May and September had a 2.0 g/l higher (p < 0.001) serum concentration of gamma-globulin than calves born between October and April.

Evaluation of an indirect ELISA for the detection of antibodies to bovine leukaemia virus in milk and serum

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect antibodies to BLV in milk and serum (Juntti et al., 1989). The conjugate consists of a monoclonal anti-bovine IgG1 and IgG2 labelled with horseradish peroxidase (HRP). The indirect ELISA was calibrated with EEC reference serum E 4. Standard serum E 4 was scored positive when diluted 8192 times in negative milk and between 12,800 and 25,600 times in negative serum. The sensitivity and specificity of the indirect ELISA relative to the agar gel immunodiffusion test (AGID) were 100% and 99.8%, respectively. ELISA results for milk and sera from 614 dairy cows agreed to 100%. The absorbance value in bulk milk could be used to roughly predict the rate of BLV infection among lactating cows in a herd. An infection rate of 4 to 5% in a herd could be detected in the ELISA. Results were applied in a nation-wide screening of more than 24,000 bulk-milk samples, and the subsequent introduction of an eradication programme for BLV. The aim is to eliminate the infection from Swedish herds in 5 to 10 years.