Dimethylsulphoxide-induced toxicity

Thawed cryopreserved synovial mesenchymal stem cells show comparable effects to cultured cells in the inhibition of osteoarthritis progression in rats

Intra-articular injections of mesenchymal stem cells (MSCs) can inhibit the progression of osteoarthritis (OA). Previous reports have used cultured MSCs, but the ability to use thawed cryopreserved MSC stocks would be highly advantageous. Our purpose was to elucidate whether thawed cryopreserved MSCs show comparable inhibitory effects on OA progression in rats to those obtained with cultured MSCs. Cultured rat synovial MSCs or thawed MSCs were compared for in vitro viability and properties. The inhibitory effect of thawed MSCs on OA progression was evaluated by injecting cryopreservation fluid and thawed MSCs in meniscectomized rats. Cartilage degeneration was assessed using gross finding and histological scores. Cultured MSCs were then injected into one knee and thawed MSCs into the contralateral knee of the same individual to compare their effects. Cultured MSCs and MSCs thawed after cryopreservation had comparable in vitro colony formation and chondrogenic potentials. In the rat OA model, the gross finding and histological scores were significantly lower in the thawed MSC group than in the cryopreservation fluid group at 8 weeks. Finally, cartilage degeneration did not differ significantly after injection of cultured and thawed MSCs. In conclusion, thawed MSCs showed comparable inhibitory effects on OA progression to cultured MSCs.

Exposure to DMSO during infancy alters neurochemistry, social interactions, and brain morphology in long-evans rats

INTRODUCTION

Dimethyl sulfoxide (DMSO) is a widely used solvent to dissolve hydrophobic substances for clinical uses and experimental in vivo purposes. While usually regarded safe, our prior studies suggest changes to behavior following DMSO exposure. We therefore evaluated the effects of a five-day, short-term exposure to DMSO on postnatal infant rats (P6-10).

METHODS

DMSO was intraperitoneally injected for five days at 0.2, 2.0, and 4.0 ml/kg body mass. One cohort of animals was sacrificed 24 hr after DMSO exposure to analyze the neurometabolic changes in four brain regions (cortex, hippocampus, basal ganglia, and cerebellum) by hydrophilic interaction liquid chromatography. A second cohort of animals was used to analyze chronic alterations to behavior and pathological changes to glia and neuronal cells later in life (P21-P40).

RESULTS

164 metabolites, including key regulatory molecules (retinoic acid, orotic acid, adrenic acid, and hypotaurine), were found significantly altered by DMSO exposure in at least one of the brain regions at P11 (p < .05). Behavioral tests showed significant hypoactive behavior and decreased social habits to the 2.0 and 4.0 ml DMSO/kg groups (p < .01). Significant increases in number of microglia and astrocytes at P40 were observed in the 4.0 ml DMSO/kg group (at p < .015.) CONCLUSIONS: Despite short-term exposure at low, putatively nontoxic concentrations, DMSO led to changes in behavior and social preferences, chronic alterations in glial cells, and changes in essential regulatory brain metabolites. The chronic neurological effects of DMSO exposure reported here raise concerns about its neurotoxicity and consequent safety in human medical applications and clinical trials.

Advanced Nanomaterials-Assisted Cell Cryopreservation: A Mini Review

Cell cryopreservation is of vital significance both for transporting and storing cells before experimental/clinical use. Cryoprotectants (CPAs) are necessary additives in the preserving medium in cryopreservation, preventing cells from freeze-thaw injuries. Traditional organic solvents have been widely used in cell cryopreservation for decades. Given the obvious damage to cells due to their undesirable cytotoxicity and the burdensome post-thaw washing cycles before use, traditional CPAs are more and more likely to be replaced by modern ones with lower toxicity, less processing, and higher efficiency. As materials science thrives, nanomaterials are emerging to serve as potent vehicles for delivering nontoxic CPAs or inherent CPAs comparable to or even superior to conventional ones. This review will introduce some advanced nanomaterials (e.g., organic/inorganic nanoCPAs, nanodelivery systems) utilized for cell cryopreservation, providing broader insights into this developing field.

Cryopreservation in 95% serum with 5% DMSO maintains colony formation and chondrogenic abilities in human synovial mesenchymal stem cells

Background

Synovial mesenchymal stem cells (MSCs) are an attractive cell source for cartilage and meniscus regeneration. The optimum cryopreservation medium has not been determined, but dimethylsulfoxide (DMSO) should be excluded, if possible, because of its toxicity. The purposes of our study were to examine the possible benefits of higher concentrations of serum and the effectiveness of 100% serum (without DMSO) for the cryopreservation of synovial MSCs.

Methods

Human synovium was harvested from the knees of four donors with osteoarthritis during total knee arthroplasty. Synovial MSCs (8 × 10⁵ cells) were suspended in 400 μL medium and used as a Time 0 control. The same number of synovial MSCs was also suspended in 400 μL α-MEM medium containing 10% fetal bovine serum (FBS) (5% DMSO, and 1% antibiotic), 95% FBS (and 5% DMSO), or 100% FBS (no DMSO) and cryopreserved at − 80 °C for 7 days. After thawing, the cell suspensions (1.5 μL; 3 × 10³ cells) were cultured in 60 cm² dishes for 14 days for colony formation assays. Additional 62.5 μL samples of cell suspensions (1.25 × 10⁵ cells) were added to tubes and cultured for 21 days for chondrogenesis assays.

Results

Colony numbers were significantly higher in the Time 0 and 95% FBS groups than in the 10% FBS group (n = 24). Colony numbers were much lower in the 100% FBS group than in the other three groups. The cell numbers per dish reflected the colony numbers. Cartilage pellet weights were significantly heavier in the 95% FBS group than in the 10% FBS group, whereas no difference was observed between the Time 0 and the 95% FBS groups (n = 24). No cartilage pellets formed at all in the 100% FBS group.

Conclusion

Synovial MSCs cryopreserved in 95% FBS with 5% DMSO maintained their colony formation and chondrogenic abilities to the same levels as observed in the cells before cryopreservation. Synovial MSCs cryopreserved in 100% FBS lost their colony formation and chondrogenic abilities.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2700-3) contains supplementary material, which is available to authorized users.

Hematopoietic SCT with cryopreserved grafts: adverse reactions after transplantation and cryoprotectant removal before infusion

Transplantation of hematopoietic stem cells (HSCs) has been successfully developed as a part of treatment protocols for a large number of clinical indications, and cryopreservation of both autologous and allogeneic sources of HSC grafts is increasingly being used to facilitate logistical challenges in coordinating the collection, processing, preparation, quality control testing and release of the final HSC product with delivery to the patient. Direct infusion of cryopreserved cell products into patients has been associated with the development of adverse reactions, ranging from relatively mild symptoms to much more serious, life-threatening complications, including allergic/gastrointestinal/cardiovascular/neurological complications, renal/hepatic dysfunctions, and so on. In many cases, the cryoprotective agent (CPA) used-which is typically dimethyl sulfoxide (DMSO)-is believed to be the main causal agent of these adverse reactions and thus many studies recommend depletion of DMSO before cell infusion. In this paper, we will briefly review the history of HSC cryopreservation, the side effects reported after transplantation, along with advances in strategies for reducing the adverse reactions, including methods and devices for removal of DMSO. Strategies to minimize adverse effects include medication before and after transplantation, optimizing the infusion procedure, reducing the DMSO concentration or using alternative CPAs for cryopreservation and removing DMSO before infusion. For DMSO removal, besides the traditional and widely applied method of centrifugation, new approaches have been explored in the past decade, such as filtration by spinning membrane, stepwise dilution-centrifugation using rotating syringe, diffusion-based DMSO extraction in microfluidic channels, dialysis and dilution-filtration through hollow-fiber dialyzers and some instruments (CytoMate, Sepax S-100, Cobe 2991, microfluidic channels, dilution-filtration system, etc.) as well. However, challenges still remain: development of the optimal (fast, safe, simple, automated, controllable, effective and low cost) methods and devices for CPA removal with minimum cell loss and damage remains an unfilled need.

Effect of different administration paradigms on cholinesterase inhibition following repeated chlorpyrifos exposure in late preweanling rats

Chlorpyrifos (CPS) is widely used in agricultural settings and residue analysis has suggested that children in agricultural communities are at risk of exposure. This has resulted in a large amount of literature investigating the potential for CPS-induced developmental neurotoxic effects. Two developmental routes of administration of CPS are orally in corn oil at a rate of 0.5 ml/kg and subcutaneously in dimethyl sulfoxide (DMSO) at a rate of 1.0 ml/kg. For comparison between these methods, rat pups were exposed daily from days 10 to 16 to CPS (5 mg/kg) either orally dissolved in corn oil or subcutaneously dissolved in DMSO, both at rates of either 0.5 or 1.0 ml/kg. A representative vehicle/route group was present for each treatment. Both the low and high volume CPS in DMSO subcutaneous groups were lower than that of the low and high volume CPS in oil oral groups. At 4 h following the final administration, serum carboxylesterase was inhibited > 90% with all treatments. For cholinesterase activity in the cerebellum, medulla-pons, forebrain, and hindbrain, and serum, inhibition in the CPS-oil groups was similar and inhibition in the CPS-DMSO groups was similar. However, significantly greater inhibition was present in the high volume CPS-DMSO group as compared to the CPS-oil groups. Inhibition in the low volume CPS-DMSO group was generally between that in the CPS-oil groups and the high volume CPS-DMSO group. These data suggest that using DMSO as a vehicle for CPS may alter the level of brain ChE inhibition.

Busulfan loading into poly(alkyl cyanoacrylate) nanoparticles: Physico-chemistry and molecular modeling

The busulfan is an alkylating agent widely used for the treatment of haematological malignancies and nonmalignant disorders. For a long time, it has been available only in an oral form. This treatment leads to a wide variability in bioavailability and side effects such as the veino-occlusive disease. Thus, an intravenous formulation of busulfan-loaded nanoparticles may be considered as a major progress. This study deals with busulfan entrapment by nanoprecipitation into five different types of poly(alkyl cyanoacrylate) polymers. The polymers leading to the highest busulfan loading efficiencies were poly(isobutyl cyanoacrylate) (PIBCA) and poly(ethyl cyanoacrylate). Molecular modeling along with energy minimization process was employed to identify the nature of the interactions occurring between busulfan and PIBCA. Further, optimization studies enabled to obtain PIBCA nanoparticles displaying busulfan loading ratios equal to 5.9% (w/w) together with nanoparticle yields of 71% (w/w). Since busulfan is a highly reactive molecule, we performed (1)H-NMR spectroscopy experiments showing that chemical integrity of the drug was preserved after loading into nanoparticles. The in vitro release studies under sink conditions, in water, or in rat plasma showed a fast release in the first 10 min followed by a slower one over 6 h. This phenomenon could be explained by the semi-polar characteristics of busulfan.

Novel composite core-shell nanoparticles as busulfan carriers

This study presents a method for the design of novel composite core-shell nanoparticles able to encapsulate busulfan, a crystalline drug. They were obtained by co-precipitation of mixtures of poly(isobutylcyanoacrylate) (PIBCA) and of a diblock copolymer, poly(epsilon-caprolactone)-poly(ethylene glycol) (PCL-PEG), in different mass ratios. The nanoparticle size, morphology and surface charge were assessed. The chemical composition of the top layers was determined by X-ray photo-electron spectroscopy (XPS). (3)H-labelled busulfan was used in order to determine the drug loading efficiency and the in vitro drug release by liquid scintillation counting. Physico-chemical techniques such as Zeta potential determination and XPS analysis provided evidence about a preferential surface distribution of the PCL-PEG polymer. Therefore, composite nanoparticles have a "core-shell"-type structure, where the "core" is essentially formed by the PIBCA polymer and the "shell" by the PCL-PEG copolymer. The use of PIBCA to form the core of the nanoparticles leads to a 2-4 fold drug loading increase, in comparison to the single PCL-PEG nanoparticles. In addition, the complement activation results showed a significant difference between the composite nanoparticles and the single PIBCA nanoparticles, thus demonstrating that PEG at the surface of the nanoparticles reduced the complement consumption. The PIBCA:PCL-PEG composite nanoparticles prepared using the new co-precipitation method here described represent an original approach for busulfan administration.

Recurrent seizure and sustained encephalopathy associated with dimethylsulfoxide-preserved stem cell infusion

We report the case of a patient who received two infusions of dimethylsulfoxide (DMSO) cryopreserved autologous peripheral blood progenitor cells (PBPCs) after myeloablative chemotherapy for a relapsing lymphoma. A 49-year-old man presented an episode of tonic-clonic seizure over a few minutes after the start of each infusion and developed a profound and sustained but reversible encephalopathy with coma after the second infusion. The patient's neurological condition correlated well with the electrophysiological findings (electroencephalogram and multimodality evoked potentials) and, to a lesser extent, with the radiological abnormalities (magnetic resonance imaging). Severe but reversible neurological complications may occur with the infusion of PBPCs cryopreserved with DMSO.

Renal pathology at autopsy in patients who died after hematopoietic stem cell transplantation

Acute and chronic renal dysfunction are common after hematopoietic stem cell transplantation (HSCT). Although the pathology of chronic HSCT nephropathy is well described, the histologic changes that accompany acute renal dysfunction after HSCT are less well known because renal biopsies are rarely undertaken in the peritransplantation period. Archival renal tissue from consecutive HSCT recipients who died and underwent autopsy at a single center during an 8-year period was studied. Abnormalities of renal pathology were described, and associations of histologic abnormalities with clinical events were systemically studied. Abnormalities of renal histology were common among the 26 patients in this study. The 3 most common histologic abnormalities were glomerular sclerosis (19/26; 73%), tubular epithelial atypia (19/26; 73%), and tubular calcification (18/26; 69%). Tubulitis (16/24; 67%) and interstitial fibrosis (16/26; 62%) were also frequently observed. Clinical veno-occlusive disease was not associated with histologic evidence of thrombotic microangiopathy in the kidney at autopsy. Also, clinical graft-versus-host disease was not associated with renal tubulitis. Unexpectedly, the proportion of patients with tubular atrophy (54%) or interstitial fibrosis (62%) was high, considering the young age of the patients at transplantation and their normal pretransplantation creatinine clearance. Well-recognized histologic abnormalities are common in the kidneys of patients who die after HSCT. Although we did not demonstrate associations of these histologic changes with clinical variables before death, larger studies with prospectively collected renal tissue are warranted.

Renal function following hematological stem cell transplantation in childhood

Renal function greatly influences mortality rates in the early phase following hematological stem cell transplantation (HSCT) in childhood, as well as the quality of life in long-term survivors. Nevertheless, the number of studies in pediatric populations is limited and some important aspects of kidney function after HSCT have only been elucidated in adults. The incidence of acute renal failure (ARF) immediately after HSCT in pediatric patients is between 25% and 50%, with 5%-10% of children requiring renal replacement therapy. Doubling of serum creatinine is associated with a twofold increase in mortality. However, the need for dialysis leads to a further increase in mortality rates to 80%-90%. Specific renal syndromes appear at different times following HSCT, revealing a similar pattern in children and adult patients. In both children and adults, impaired renal function associated with liver impairment (hepatorenal syndrome) is the most important cause for ARF. Therapeutic approaches have not been able to reduce the frequency or to improve outcome so far. In adults surviving long term, bone marrow transplant (BMT) nephropathy is the most frequent renal complication, although a considerable variation in incidence (up to 70%) has been published, partly due to various definitions and manifestations. Little is known about the long-term outcome of renal function in patients treated with HSCT in childhood. However, chronic renal failure has been reported in 0%-28%, but no end-stage renal failure has been published so far. Tubular function following HSCT is rarely investigated, although its impact on long-term survivors of BMT in childhood might be of some importance, especially for growth and bone metabolism.

Electrocardiogram is very useful for predicting acute heart failure following myeloablative chemotherapy with hematopoietic stem cell transplantation rescue

A prospective study was conducted in 71 evaluable patients who received myeloablative hematopoietic stem cell transplantation (HSCT) at our facility from 1995 to 2002, to find a sensitive marker for post-transplant heart failure, including echocardiographic systolic and diastolic markers and QTc interval. QTc was found to be an independent and significant risk factor for acute heart failure (AHF) on multivariate logistic regression analysis (OR 1.5, P=0.01, 95% confidence interval (CI) 1.1-2.0), while no significant differences between patients with AHF and those without AHF were found in age, sex, treatment history, type of conditioning regimen, and echocardiographic systolic and diastolic markers. On further analysis, post-transplant risk of AHF appeared to be increased as QTc was prolonged. The post-transplant risk of AHF in the group with longest QTc on multivariate logistic regression analysis was found to be 9.8 times that in the group with shortest QTc (P=0.04, 95% CI 1.0-100). These results suggest that echocardiographic markers are less valuable predictors of post-transplant AHF, but that prolongation of the QTc, an ECG marker, before HSCT is strongly associated with onset of AHF after HSCT.

A phase II trial of liposomal busulphan as an intravenous myeloablative agent prior to stem cell transplantation: 500 mg/m(2) as a optimal total dose for conditioning

We conducted a phase I/II trial, to evaluate the efficacy and safety of an intravenous liposomal formulation of busulphan (LBu) as a myeloablative agent for stem cell transplantation (SCT). The liposomal busulphan was administered as a 3 h infusion twice daily over 4 consecutive days. Six adults received 1.6-2 mg/kg/dose and 18 children received 1.8-3 mg/kg/dose. Pharmacokinetic parameters were studied after the first and the last dose of busulphan. No significant difference in clearance, AUC, elimination half-lives or distribution volume between the first and the last dose was found in either groups. A significantly (P < 0.005) higher clearance was observed in children after the first and the last dose (3.61 and 3.79 ml/min/kg, respectively) compared to adults (2.40 and 2.33 ml/min/kg, respectively). The elimination half-lives after the first and the last dose were significantly (P < 0.005) shorter in children (2.59 and 2.72 h, respectively) compared to adults (3.35 and 3.61 h, respectively). Clearance correlated significantly with age. However, no significant correlation with age was observed when clearance was adjusted to the body surface area. Two cases of VOD following a total dose of 24 mg/kg were observed. Six patients experienced mucositis. No other organ toxicity was observed. We conclude that intravenous liposomal busulphan pharmacokinetics is age dependent. A dosage schedule based on body surface area should be used especially in young children to reduce the age-dependent difference in kinetics. An intravenous liposomal dose of busulphan of 500 mg/m(2) is suggested to reach a similar systemic exposure and myeloablative effect in both children and adults. Moreover, the novel liposomal form of busulphan showed a favorable toxicity profile and seems safe as a part of the high-dose therapy prior to SCT.

Positive selection of CD34+ cells by immunoadsorption: factors affecting the final yield and hematopoietic recovery in patients with hematological malignancies and solid tumors

There is a progressive increase in the use of selected hematopoietic progenitor cells after myeloablative therapy in patients affected by malignancies. Our goal was to determine which blood parameters, in the starting cell population, influence the concentration of CD34+ progenitors and the removal of unwanted cells in the final product. Also, we evaluated the hematopoietic recovery and toxicity associated with peripheral blood stem cell infusion. We retrospectively reviewed 53 procedures of positive selection of CD34+ cells, performed with the Ceprate SC immunoadsorption system, in 47 paticnts affected by various hematologic malignancies and solid tumors. An increased percentage of CD34+ cells in the starting fraction was associated both with the final purity and enrichment of CD34+ cells and with a decreased percentage of CD3+ and CD19+ cells in the final product. A low platelet count before selection had a borderlinc influence on the recovery of CD34+ cells. Forty patients received a median of 5 x 10(6) CD34+ cells per kg; the absolute neutrophil count (ANC) reached 0.5 x 10(9)/l in a median of 10 days whereas a PLT count above 20 x 10(9)/l was observed in 14 days. The reinfusion of selected CD34+ cells, containing a very low amount of dymethylsulfoxide. was well tolerated and no adverse reactions were observed. Autologous transplantation with selected CD34+ cells is a safe and well-tolerated procedure in patients affected by hematologic malignancies and solid tumors. Positive selection of CD34+ cells seems to be related to the quality of the apheresis products, particularly to the initial CD34+ cell and PLT content.

Malignancy and renal disease

A variety of renal diseases and electrolyte disorders may be associated with various malignancies or with treatment of malignancy with chemotherapeutic drugs or radiation. This article reviews renal disease in cancer patients, which constitutes a major source of morbidity and mortality.

Pharmacokinetics of liposomal busulphan in man

High doses of busulphan are used in conditioning regimens before stem cell transplantation. Great inter-patient variations in pharmacokinetics and a correlation between toxicity and high systemic exposure of busulphan have been shown in several studies. Some authors have suggested therapeutic drug monitoring and intravenous busulphan aiming to reduce the conditioning-related toxicity. Liposomal busulphan (LBu) might be an alternative to intravenous administration of high-dose busulphan in conditioning. In the present study, we investigated the pharmacokinetics of LBu in man. Seventeen consecutive patients were enrolled in the study. LBu as a single low dose (2 to 8 mg) was given to 12 patients (six adults and six children). Five patients received two high doses of LBu which replaced the first and the last doses of the conditioning regimen. The high dose of LBu was raised from 0.4 to 0.9 mg/kg. A significant linear correlation (r2 = 0.928) was found between the dose of LBu and the area under the plasma concentration-time curve (AUC) (P < 0.001). AUC corrected for 1 mg/kg was 5491 +/- 912 ng.h/ml and 5955 +/- 627 ng.h/ml (low dose of LBu in children and adults, respectively) and 6167 +/- 1385 ng.h/ml and 6933 +/- 656 ng.h/ml (ie the first and the last high doses of LBu, respectively). No significant correlation was found between clearance and age or apparent volume of distribution and age (r2 = 0.146 and r2 = 0.046, respectively). No toxicity related to the liposomal formulation of busulphan was observed. We conclude that LBu is suitable for conditioning before stem cell transplantation.

Reversible leukoencephalopathy associated with re-infusion of DMSO preserved stem cells

We report a case of posterior reversible leuko- encephalopathy (PRL) following the infusion of dimethylsulfoxide (DMSO) cryopreserved autologous stem cells in the setting of myeloablative chemotherapy in a patient with recurrent Ewing's sarcoma. Magnetic resonance (MR) imaging revealed white matter changes which resolved over the next 2 months. Bone Marrow Transplantation (2000) 26, 797-800.

Neurological events associated with the infusion of cryopreserved bone marrow and/or peripheral blood progenitor cells

Reports of neurological toxicity of cryopreserved stem cell infusion are infrequent. Three of 179 consecutive patients experienced significant neurological events in this context. Transient global amnesia developed following infusion in one patient and in the other two, cerebral infarction occurred. Profound hypotension, bradyarrhythmias or hypoxia were not associated with any of these episodes. These events may have been related to infused DMSO, which in the non-transplant setting has been associated with neurological toxicity and local infusion of which has resulted in acute vasospasm in animal models. These cases suggest that infusion of cryopreserved stem cells may result in cerebrovascular ischaemia. Bone Marrow Transplantation (2000) 25, 1285-1287.

Cardiac and pulmonary toxicity in patients undergoing high-dose chemotherapy for lymphoma and breast cancer: prognostic factors

We sought to define risk factors predisposing breast cancer and lymphoma patients to cardiac and pulmonary toxicity when undergoing high-dose chemotherapy (HDC) and autologous stem cell rescue (ASCR). Additionally, we evaluated in depth the predictive value of the ejection fraction measured prior to HDC in determining cardiac toxicity. In this retrospective analysis, 24 variables were examined in 138 patients undergoing HDC and ASCR from 1990 until 1995. Logistic regression models were used to model the probability of experiencing cardiac and pulmonary toxicity as a function of the 24 prognostic covariates. Cardiac toxicity occurred in 12% of patients and pulmonary toxicity in 24% of patients. Bivariate analyses showed that patients with lymphoma (as opposed to breast cancer) and those with a higher cardiac risk factor score were more likely to experience cardiac toxicity. Multivariate logistic regression models predicted lymphoma and older age to be risk factors for cardiac toxicity. History of an abnormal ejection fraction and higher doses of anthracyclines prior to HDC may also contribute to cardiac toxicity. Pulmonary toxicity occurred more commonly in lymphoma than breast cancer patients, likely due to the busulfan used in the HDC regimen. No other risk factors for pulmonary toxicity were identified. We conclude that older patients with lymphoma should be carefully evaluated prior to being accepted for HDC programs. Older patients with breast cancer may tolerate this procedure well. There is a trend towards cardiac toxicity in patients with a past history of low ejection fraction, although seemingly poor cardiac risk patients may fare well with HDC if carefully selected with the aid of a thorough cardiac evaluation.

Effects of long-term storage at -90 degrees C of bone marrow and PBPC on cell recovery, viability, and clonogenic potential

Autologous BM and PB HPC are usually stored from weeks to months until reinfusion after myeloablative chemotherapy. HPC have been stored for up to 16 months at -90 degrees C, using a mixture of 5% DMSO, 6% hydroxyethyl starch (HES), and 4% HSA as a cryoprotectant. Long-term storage (LTS) has usually entailed rate-controlled freezing using 10% DMSO and preservation in liquid nitrogen. The effects of LTS at -90 degrees C on the in vitro cell recovery, viability, and colony-forming unit-granulocyte macrophage (CFU-GM) clonogenic potential of autologous HPC that were not transplanted was studied. Sixteen BM and sixteen PB HPC had been cryopreserved for a median of 53 months (range 27-71) and 35 months (range 26-78), respectively. Samples of frozen HPC were thawed after 48 h, and the nucleated cell count, viability by trypan blue exclusion, and culture for CFU-GM were obtained. Following LTS, the cells were thawed and examined using the same assays. No difference in the median percentage recovery of nucleated cells was found in either the BM or PB HPC between the samples stored for 48 h and after LTS (5.73 x 10(9) versus 5.61 x 10(9) and 6.20 x 10(9) versus 5.78 x 10(9), respectively). In addition, no difference in median percentage viability was found in either the BM or PB HPC sampled at 48 h and at the end of LTS (75% versus 74% and 75% versus 76%, respectively). Finally, the median number of CFU-GM cultured from BM HPC at 48 h was 2.41 x 10(5) (range 0.33-11.01 x 10(5)) and at the end of LTS was 1.93 x 10(5) (range 0.32-10.55), representing a median recovery of 93% (range 19%-308%). Similarly, the median number of CFU-GM cultured from PB HPC was 1.66 x 10(5) (range 0-50.57) and at the end of LTS was 0.93 x 10(5) (range 0-44.9), representing a median recovery of 80% (range 36%-165%). This difference in percentage recovery was not significant (p = 0.514). There was poor correlation between the number of nucleated cells harvested and the percentage recovery of nucleated cells, cell viability, or CFU-GM for either the BM or PB HPC. Similarly, there was poor correlation between the number of CFU-GM in the harvest and their percentage recovery following LTS for both BM and PB HPC. Finally, there was poor correlation between the storage time of the BM or PB HPC and the percentage recovery of nucleated cells, cell viability, and CFU-GM. These data suggest that LTS of HPC at -90 degrees C is not associated with decreased recovery of nucleated cells or in vitro viability and is associated with only a modest decrease in clonogenic potential. This indicates that storage of HPC at -90 degrees C for periods in excess of 3 years is possible.

Acute renal failure following bone marrow transplantation

Acute renal failure (ARF) is one of the most frequent and potentially life threatening complications following bone marrow transplantation (BMT). Several renal syndromes that occur are either unique or occur with a disproportionate frequency post-BMT. Clinically ARF can be classified according to the time of onset post-BMT. Immediate ARF syndromes include tumor lysis syndrome and marrow-infusion associated toxicity, which usually occur within 5 days post-BMT. Hepatorenal-like syndrome secondary to venoocclusive disease occur within one month and is the most common cause of early ARF syndrome. The late renal syndromes, more than 4 weeks post-BMT, include BMT-associated nephropathy, which may be acute or chronic, and cyclosporin nephrotoxicity. Other non-specific causes of ARF such as sepsis, hypotension, volume depletion, nephrotoxic agents and obstructive uropathy can also occur at any time period. Frequently ARF is multifactorial in these patients with complicated clinical course. Therapeutic approach depend on the underlying etiology. Supportive treatment such as optimization of volume status and dialysis when indicated are important steps as specific therapy is rarely available. Therefore, efforts should be targeted to the prevention of ARF. This includes prophylaxis for tumor lysis syndrome and marrow infusion toxicity by hydration and alkaline diuresis, avoiding nephrotoxic agents, early recognition and treatment of infection and correction of volume depletion.

Transplantation of CD34+ hematopoietic progenitor cells

We have developed an avidin-biotin immunoadsorption technique in conjunction with a monoclonal anti-CD34 antibody that is capable of selecting CD34+ progenitor cells from marrow and mobilized peripheral blood. Clinical studies with these CD34+ selected cells have shown that the cells are capable of rapid and durable engraftment. In addition, there is significantly less infusional toxicity to the patient because the volume in which the CD34+ selected cells are contained is much less than that of a typical marrow or apheresis buffy coat. Selection of CD34+ progenitor cells also offers other potential advantages, including T-cell depletion of allografts and tumor cell depletion of autografts. CD34+ selection can also be used to facilitate other manipulations of marrow and peripheral blood, including gene transfection, ex vivo stem cell expansion, tumor purging, and progenitor cell banking. Future graft engineering studies are expected to clarify these relationships and enable refinement of the graft to the point at which GVHD can be minimized, graft survival maximized, and relapse-free survival prolonged.

A semiautomated technique for volume reduction of stem cell suspensions for autotransplantation

Infusion of thawed cryopreserved autologous stem cells (SC) is associated with a variety of complications due to the presence of dimethyl sulfoxide (DMSO) and free hemoglobin and to volume overload. Commonly, the DMSO is not removed before infusion for fear that prolonged in vitro exposure of the cells to DMSO leads to loss of clonogenic activity. We describe a simple technique for the substantial reduction in volume and DMSO content of bone marrow (BM) and peripheral blood stem cell (PBSC) suspensions. Sixty-five patients were transplanted with thawed, volume-reduced SC cryopreserved according to Stiff et al. Semiautomated volume reduction was performed on a COBE 2991 cell processor. The median volumes of cryopreserved SC were 1152 ml and 933 ml for the pools of PBSC products and the mixed pools of BM and PBSC, respectively, whereas the volume of SC infused was 153 ml (78% reduction). There were no differences in cell recoveries between PBSC and BM (98%). Only 2 patients demonstrated minimal side effects during infusion. A cohort of 16 metastatic breast cancer patients underwent PBSC harvests following chemotherapy/G-CSF priming and subsequent autotransplantation. Median time to an absolute neutrophil count > 500/microliters was 8 days (range 6-14 days), and median time to a platelet count > 20,000/microliters was 11 days (range 6-18 days). Volume reduction of SC products without the risk of graft failure was performed simply and resulted in few complications during infusion.

Refractory and relapsing multiple myeloma treated by blood stem cell transplantation

Between June 1989 and June 1992, 12 patients with advanced multiple myeloma underwent peripheral blood stem cell autotransplantation after high-dose chemotherapy and radiotherapy. The conditioning regimen included melphalan (140 mg/m2), high-dose cyclophosphamide (120 mg/kg), methylprednisolone (2 g daily x 7), and total body irradiation (9-12 Gy). Transplant morbidity included severe mucositis (n = 7) and acute renal failure (n = 2) related to infusion of the stem cells. Engraftment was delayed (n = 4) in this heavily pretreated population, and two patients had complete graft failure. Despite the advanced nature and chemotherapy-refractory state of their disease, 11 of 11 evaluable patients achieved an objective response. Six patients survived to leave the hospital, and four remain alive--one died of acute leukemia induced by prior melphalan exposure. Three of the four are relapse-free at a median of 24.9 months (range, 18-28 months). Some patients with advanced refractory multiple myeloma can achieve objective responses from highdose chemoradiotherapy with peripheral blood stem cell rescue. Harvesting peripheral blood stem cells from high-risk patients early in their disease for later use may decrease the risk of graft failure. Peripheral blood stem cell transplantation after high-dose chemotherapy and total body irradiation can produce durable responses in patients with advanced refractory myeloma.

Reversible encephalopathy after cryopreserved peripheral blood stem cell infusion

We report two patients who experienced severe reversible encephalopathy following infusion of peripheral blood stem cells cryopreserved in 10% dimethylsulfoxide (DMSO). In one patient, reduction of DMSO level with plasmapheresis resulted in marked improvement in encephalopathy. Infusion of large volumes of cryopreserved stem cells may result in a significant toxic reaction. Plasmapheresis may be a treatment option for patients with significant toxicity related to DMSO.

1-O-methyl-rac-glycerol: a new agent for the cryopreservation of mononuclear cells

1-O-methyl-rac-glycerol (1-O-MG), also known as 3-methoxy-1,2-propanediol is a lipophilic derivative of glycerol, and has been studied as a new cryoprotective agent (CPA) for mononuclear blood cells (MNC), a well-established experimental model in cryopreservation. The chemical modification of the glycerol molecule results in improved cryobiological properties, such as membrane permeability, thus allowing easier handling in the freeze/thaw process. The optimum preincubation period for MNC and 1-O-MG before freezing is 5 min at 4 degree C, resulting in 86% recovery of viable cells, whereas optimal recovery of glycerol-frozen MNC is only guaranteed after 30 min of preincubation at room temperature (74% viable recovery). The optimal concentration of 1-O-MG is 10% (v/v). Although this new agent offers no improvement in cryoprotective properties over dimethyl sulfoxide (Me2SO) there may be possible pharmacological advantages when used in humans. It is, however, obviously superior to glycerol with regard to its permeation kinetics. 1-O-MG might therefore also be of interest in the cryoprotection of other hematopoietic cells and biological tissues.

Use of polar solvents in chemoprevention of 1,2-dimethylhydrazine-induced colon cancer

To examine the effect of the polar solvents on 1,2-dimethylhydrazine (DMH)-induced colon cancer, 100 male Sprague-Dawley rats were randomly allocated to a control and three treatment groups. Treated animals received N-methylformamide (NMF), dimethylsulfoxide (DMSO), or methylsulfonylmethane (MSM) added to drinking water 1 week before carcinogen injections commenced and for the duration of the experiment. Primary tumors were detected by serial laparotomy under ether anesthesia performed at 2-month intervals and commencing after carcinogen injections had been completed. The average time to tumor onset was significantly delayed in rats receiving NMF and MSM (P = 0.0141 and 0.0398 respectively, Mantel-Haenszel test). In addition, fewer poorly differentiated tumors were noted in treatment groups. No weight loss or toxicity was observed. These findings demonstrate that the polar solvents significantly reduce the latent period to tumor onset in DMH-induced colon cancer and indicate the need to further investigate such compounds as chemopreventive agents.

Density gradient isolation of peripheral blood mononuclear cells using a blood cell processor

Large numbers of mononuclear cells (MNC) are needed for hematologic reconstitution using peripheral blood stem cells. The possibility of isolating those cells by discontinuous Ficoll-diatrizoate density gradient centrifugation in two blood cell processors (the Haemonetics V50 [V50] and the Cobe 2991 [2991]) were examined. Buffy coats from peripheral blood containing 6.23 X 10(8) MNC were separated in the V50, resulting in a recovery of 75 percent. The purity of the cells, defined as the percentage of lymphocytes and monocytes among all leukocytes, was 95 percent. With larger cell loads (3 to 7 X 10(9) MNC), the yield was higher in the V50 than in the Cobe 2991 (92 versus 75%). After separation in the V50 or the 2991, the cloning efficiencies of hematopoietic progenitor cells (CFU-GM and BFUe) were not different from those of cells isolated on 5 ml Ficoll-diatrizoate gradients in centrifuge tubes. Both leukapheresis and MNC separation can be carried out with the same bowl and tubing set in the V50. With that approach, an average of 6 X 10(9) MNC were processed in 16 experiments. An average recovery of 82 percent with 95 percent purity was achieved. The authors conclude that, in terms of simplicity of operation, cost effectiveness, and maintenance of sterility, the V50 may be better suited than the 2991 for the purification of MNC from peripheral blood.

Effect of dimethyl sulfoxide on the in vitro and in vivo bactericidal activity of human and mouse neutrophils and mononuclear phagocytes

Dimethyl sulfoxide (DMSO) is reported to have antiinflammatory activity in various systems. Since resistance to bacterial infection can be thought of as a specialized type of inflammation, we were interested in determining the effect of DMSO on phagocyte bactericidal activity. The results indicated that in vitro DMSO treatment of human and mouse neutrophils and mononuclear phagocytes caused a dose-dependent inhibition of the killing of Escherichia coli and Listeria monocytogenes. However, pretreatment of mice with DMSO in vivo caused only a slight decrease in the subsequent in vitro bactericidal activity of neutrophils and macrophages from those mice. In addition, repeated injection of mice with a physiologically relevant dosage of DMSO did not enhance the lethality of either E. coli or L. monocytogenes, nor did it affect the clearance of a sublethal Listeria challenge from the spleen and liver. These results suggest that clinical usage of DMSO should not predispose human subjects to bacterial infection.

A technique for the concentration of nucleated bone marrow cells for in vitro manipulation or cryopreservation using the IBM 2991 blood cell processor

27 bone marrow aspirates were processed on the IBM 2991 Blood Cell Processor to achieve a reduction in volume (greater than 80%) and in red blood cell contamination (greater than 75%), without loss (less than 20%) of nucleated cells. The procedure was used to concentrate nucleated bone marrow cells either prior to cryopreservation for subsequent autologous transplantation, or prior to incubation with a murine monoclonal antibody (OKT3) for allogeneic transplantation. We conclude that the procedures used for the concentration, cryopreservation, thawing and infusion do not adversely affect the viability of cells as assessed by in vitro culture (CFU-GM). Of the marrows processed, 12 have been reinfused and resulted in successful engraftment.

Renal disease in the elderly

With advancing age and in the absence of any disease, there is a significant alteration in kidney structure and a gradual decline in renal function. While RPF, GFR, and tubular reabsorptive capacity decrease with age, abnormal signs or symptoms cannot be detected under ordinary circumstances. The aging kidneys, however, have limited capacity to cope with rapid hemodynamic changes or disturbances in fluid and water balance, and this results in signs and symptoms of renal dysfunction. In the elderly, the incidence of primary renal diseases declines while the incidence of renal diseases secondary to systemic disease increases. AGN, while essentially a disease of the young, does occur in the older age group. RPGN, however, is the most common form of acute primary glomerulonephropathy, followed by membranous glomerulonephritis and glomerulosclerosis. Glomerulonephritis secondary to vasculitis and Wegener's granulomatosis and amyloidosis constitutes the most common secondary glomerulonephropathy. Drug-induced acute or chronic tubulointerstitial nephropathy is seen more frequently in the geriatric age group because of the high incidence of multiple-drug treatment. There is a high incidence of ARF in the elderly which is frequently precipitated by hypovolemia, hypotension, nephrotoxic drugs, surgery, and anesthesia. Clinical manifestations of renal disease in the elderly are often atypical and nonspecific. Abnormal signs and symptoms are frequently attributed to extrarenal diseases or to previously existing disorders. For these reasons, renal disease in the elderly may go undetected. Serum creatinine level may remain within normal range despite a drop in GFR because of a reduction in muscle mass with aging. Therefore, creatinine clearance is a more accurate test for assessment of renal function. A decrease in creatinine clearance should not be ignored or attributed to aging; it is an indication for further renal evaluation.

Prolonged dimethylsulphoxide treatment in 13 patients with systemic amyloidosis

Continuous oral dimethylsulphoxide (DMSO) treatment (7-15 g/day) was given to 3 patients with amyloidosis of familial Mediterranean fever (FMF), 3 patients with idiopathic amyloidosis, and 7 patients with secondary amyloidosis. The nephrotic syndrome and various degrees of renal insufficiency were the major clinical manifestation in all case. Renal function was used as the main parameter for evaluation of therapy. DMSO treatment for 7-16 months produced no effect in the FMF patients and in the patient with idiopathic amyloidosis; they all ran the predictable clinical course of their disease and either died of cardiac failure or have been maintained on chronic haemodialysis. In the 7 patients with secondary amyloidosis an unequivocal improvement of renal function was observed following 3-6 months of DMSO treatment. It was shown by a 30-100% rise of creatinine clearance and a decline in proteinuria. This new equilibrium has been maintained as long as DMSO was administered. No serious side effects of DMSO wee encountered. Mild nausea and an unpleasant breath odour were the patients' main concern. We conclude that a therapeutic trial with oral DMSO is warranted in all patients with secondary amyloidosis. This treatment is unpleasant but bears no exceptional risks. It may significantly prolong life, though its effect on amyloid deposits themselves is doubtful.

Sulindac hepatotoxicity

Two patients who developed painless jaundice while taking sulindac are described. Rechallenge in one case confirmed the association of hepatic damage with sulindac administration. Laboratory data and liver biopsy findings suggested a hepatitis with cholestatic features.