Clinical Experience With Minocycline and Rifampin-Impregnated Central Venous Catheters in Bone Marrow Transplantation Recipients: Efficacy and Low Risk of Developing Staphylococcal Resistance

In this retrospective evaluation of the 4-year clinical use of minocycline and rifampin-impregnated catheters in bone marrow transplantation (BMT) patients, we report low risk of development of staphylococcal resistance to the antibiotics coating the catheters and efficacy in preventing primary staphylococcal bloodstream infections.

Treatment of severe post-traumatic bone defects with autologous stem cells loaded on allogeneic scaffolds

Mesenchymal stem cells may differentiate into angiogenic and osteoprogenitor cells. The effectiveness of autologous pluripotent mesenchymal cells for treating bone defects has not been investigated in humans. We present a case series to evaluate the rationale of using nucleated cells from autologous bone marrow aspirates in the treatment of severe bone defects that failed to respond to traditional treatments. Ten adult patients (mean age, 49.6-years-old) with severe bone defects were included in this study. Lower limb bone defects were >or=5 cm3 in size, and upper limb defects .or=2 cm3. Before surgery, patients were tested for antibodies to common pathogens. Treatment consisted of bone allogeneic scaffold enriched with bone marrow nucleated cells harvested from the iliac crest and concentrated using an FDA-approved device. Postsurgery clinical and radiographic follow-up was performed at 1, 3, 6, and 12 months. To assess viability, morphology, and immunophenotype, bone marrow nucleated cells were cultured in vitro, tested for sterility, and assayed for the possible replication of adventitious (contaminating) viruses. In 9 of 10 patients, both clinical and radiographic healing of the bone defect along with bone graft integration were observed (mean time, 5.6 months); one patient failed to respond. No post-operative complications were observed. Bone marrow nucleated cells were enriched 4.49-fold by a single concentration step, and these enriched cells were free of microbial contamination. The immunophenotype of adherent cells was compatible with that of mesenchymal stem cells. We detected the replication of Epstein-Barr virus in 2/10 bone marrow cell cultures tested. Hepatitis B virus, cytomegalovirus, parvovirus B19, and endogenous retrovirus HERV-K replication were not detected. Overall, 470 to 1,150 million nucleated cells were grafted into each patient. This case series, with a mean follow-up of almost 2 years, demonstrates that an allogeneic bone scaffold enriched with concentrated autologous bone marrow cells obtained from the iliac crest provides orthopedic surgeons a novel option for treating important bone defects that are unresponsive to traditional therapies.

The subchondral bone in articular cartilage repair: current problems in the surgical management

As the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention is being directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only. It is becoming apparent that without support from an intact subchondral bed, any treatment of the surface chondral lesion is likely to fail. This article reviews issues affecting the entire osteochondral unit, such as subchondral changes after marrow-stimulation techniques and meniscectomy or large osteochondral defects created by prosthetic resurfacing techniques. Also discussed are surgical techniques designed to address these issues, including the use of osteochondral allografts, autologous bone grafting, next generation cell-based implants, as well as strategies after failed subchondral repair and problems specific to the ankle joint. Lastly, since this area remains in constant evolution, the requirements for prospective studies needed to evaluate these emerging technologies will be reviewed.

[A novel therapeutic approach to bone replacement: vitalisation of industrial processed allogenic bone graft with autologous bone marrow]

AIM

Osseous defects of the human skeleton are a common problem in reconstructive orthopaedic and trauma surgery. In spite of a long-standing history of research on different organic and inorganic bone replacement materials, a clinically applicable alternative to autogenous bone transplants has not been found.

METHODS

The current paper describes a novel bone replacement material, which is vitalised through injection of autologous bone marrow. Industrially processed bone allografts were used for bone replacement; the cancellous bone graft was gained from femoral heads from living human donors and processed by a French tissue bank (Banque de Tissus France, TBF). Sterile packed allogenic bone grafts can be stored at room temperature, are easy to handle and can be adapted to almost every bone defect due to their stability and versatility.

RESULTS

From July 2003 to February 2006 125 patients,70 men and 55 women, underwent bone grafting with composite transplants composed of autogenous marrow cells and industrial processed bone allografts. The average age at surgery was 62 (14-84) years; the follow-up period was 11 months. The indication to use the allograft included the whole spectrum of bony defects conventionally treated with autologous cancellous bone grafts such as primary and revision surgery in THA (n = 64) and the treatment of pseudarthrosis particularly of the lower limb (n = 30).

CONCLUSION

In comparison to current bone replacement materials applied in clinical use, this approach promises to replicate the biomechanical and biological properties of autogenous cancellous bone. This is an important advantage over conventional approaches to ensure successful healing and regeneration of bone defects. Hence application of vitalised bone allograft represents an important alternative to conventional autogenous cancellous bone which avoids certain complications associated with harvesting and transplantation of autogenous bone. This applies in particular in situations in which harvesting of autogenous cancellous bone is not or no longer possible.

Transendocardial autologous bone marrow in chronic myocardial infarction using a helical needle catheter: 1-year follow-up in an open-label, nonrandomized, single-center pilot study (the TABMMI study)

BACKGROUND

Cell therapy has shown benefit in preclinical and clinical studies, although debate continues on the mechanism of action and the most appropriate methods for performing such therapies. We assessed the hypothesis that helical needle transendocardial (TE) delivery of autologous bone marrow (ABM) mononuclear cells around regions of hypo- or akinesia in patients after chronic myocardial infarction (MI) would be safe and possibly improve ejection fraction (EF).

METHODS AND RESULTS

Ten stable post-MI patients with an EF <40% were enrolled. Autologous bone marrow cells were aspirated from the iliac crest and delivered percutaneously with a TE helical needle catheter. A total of 86 x 10(6) cells were injected into 7.1 +/- 3.1 sites around the infarct to target the peri-infarct zones. Two-dimensional echocardiographic left ventricle EF measurements, 24-hour Holter, and exercise tolerance testing were performed at baseline, day of procedure, 1 and 12 weeks, and 6 and 12 months. There were no adverse events associated with the catheter-based cell transplantation procedure. At 6 and 12 months, all patients showed an improvement in left ventricle EF over baseline (35.2 +/- 4.6 to 40.8 +/- 4.5, P = .003 at 6 months; 35.2 +/- 4.6 to 42.3 +/- 5.1, P = .0001 at 12 months).

CONCLUSIONS

Autologous bone marrow cells delivered with the helical needle TE catheter was safe in this small uncontrolled study in patients with chronic MI. Increased EF and other positive data trends support continued development of this therapeutic strategy in larger controlled trials.

Cell transplantation with a catheter-based approach: an efficient method for the treatment of heart failure with multiple lesions

Cell transplantation is emerging as a potential therapeutic approach for the treatment of heart failure. At present, popular methods of cell delivery may not be efficient in perfusing cells through the whole myocardium. We have developed a novel catheter-based method for global transplantation of cells. Heart failure was induced in rabbit by intravenous administration of doxorubicin. Autologous bone marrow mononuclear cells were transplanted into failing hearts via the root of the aorta. Bilateral sinus aortae and coronary arteries were visualized by angiography during the cell transplantation procedure; there was no intraprocedural death. Four weeks after cell transplantation, there was an improvement in the mean left ventricular ejection fraction from baseline 72.13% to 81.54% (P = 0.034). Transplanted cells were observed throughout the cardiac layers of left and right ventricles. In conclusion, cell transplantation through the root of the aorta is a useful approach to globally supply cells into the heart.

Study of in vivo differentiation of rat bone marrow stromal cells into schwann cell-like cells

In order to raise an abundant and accessible reservoir for Schwann cells (SCs), which are used as seed cells for constructing tissue-engineered nerve grafts, we investigated the feasibilty of in vivo differentiation of bone marrow stromal cells (MSCs) into SC-like cells. In this study, MSCs were harvested from adult rats' bone marrow, culture-expanded, and characterized. Subcultured MSCs were then labeled with Hoechst 33342, followed by transplantation into the nerve regeneration chamber, which was made of a silicone tube bridging the sciatic nerve defect of the rats. Four weeks after surgery, some of the differentiated MSCs turned into SC-like cells immunopositive to S-100 protein, accompanied by myelination of the regenerated nerve fibers. Walking-track analyses provided evidence that transplantation of MSCs contributed to reconstruction of the sciatic nerve and reinnervation of target tissues. The experimental results suggest that MSCs are capable of differentiating into SC-like cells in vivo, making them a promising candidate for cell transplantation in peripheral nerve repair.

Prélèvement osseux tibial pour comblement osseux maxillaire en implantologie

We present an easy and quick technique of tibial bone grafting that can be used in maxillary bone losses, specially in implantology. The surgical technique is performed under general anaesthesia. A 1.5 cm skin incision is made on the anteromedial side of the tibia. Then the bone marrow can be approached through a cortical window drilled with a motorized trephine. At this stage, a disposable bone aspirator is used to collect the cancellous bone. At the end of the procedure, the periosteum, the subcutaneous tissues and the skin are sutured in three layers. The quantity of harvested cancellous bone varies from 18 to 30 cc. The procedure duration is about twenty minutes. The complication rate is low and the patients are able to walk a few hours after the procedure. They leave the hospital on the day after. Tibial bone harvesting is an alternative technique that can be chosen in cases with large bone defects. This tibial graft can be recommended because of its low morbidity, the quality of the bone and the short time duration of the procedure. Some details must be pointed out. A medial tibial surgical approach is for us better than a lateral approach because of its lower morbidity and because the bone is more superficial. The use of a motorized trephine is important to lift precisely the cortical bone window and because it is less traumatic than the hand trephine. The disposable bone aspirator is an excellent option to pick-up bone marrow with a minimum loss of bone material and in a shorter time.

In vivo tracking of bone marrow stromal cells transplanted into mice cerebral infarct by fluorescence optical imaging

Recent experimental studies have indicated that bone marrow stromal cells (BMSC) improve neurological deficits when transplanted into the animal models of various neurological disorders, although precise mechanism still remains unclear. In this study, we developed a new in vivo fluorescence optical imaging protocol to sequentially track the transplanted into the brain of the living animals subjected to cerebral infarct. Mice BMSC were harvested from transgenic mice expressing green fluorescent protein (BMSC-GFP). They were stereotactically transplanted into the ipsilateral striatum of mice subjected to permanent middle cerebral artery occlusion after 7 days of ischemia (n=12). During 12 weeks after transplantation, the skull was exposed and the green fluorescence emitted from the brain surface was sequentially observed, using in vivo fluorescence optical microscopy. As the results, regional green fluorescence was detected in the ipsilateral parietal region 4-12 weeks after transplantation in all animals and became more apparent over the time. The images obtained through the skull were very similar to those acquired by thinning or removing the skull. Immunohistochemistry evaluation revealed that the transplanted cells migrated towards the ischemic boundary zone and expressed the neuronal or astrocytic marker, supporting the findings on fluorescence optical images. Sequential visualization of the BMSC transplanted into the brain of living animals would be valuable for monitoring the migration, growth and differentiation of the transplanted cells to explore the fate and safety of stem cell transplantation for various neurological disorders.

Catheter-based transendocardial delivery of autologous bone-marrow-derived mononuclear cells in patients listed for heart transplantation

Growing evidence suggests that transplantation of autologous bone-marrow mononuclear cells (ABMMNCs) can improve the perfusion and contractile function of ischemic myocardium. This procedure could potentially benefit transplant candidates awaiting a donor heart. To study the safety and feasibility of ABMMNC injection, we performed a prospective, nonrandomized, open-label study in 5 heart transplant candidates with severe ischemic heart failure. Each patient underwent baseline single-photon emission computed tomography, a ramp treadmill protocol, 2-dimensional echocardiography, 24-hour Holter monitoring, and signal-averaged electrocardiography, which were repeated at 2 and 6 months. Transendocardial delivery of ABMMNCs was done with the aid of electromechanical mapping to identify viable myocardium. Each patient received 15 ABMMNC injections of 0.2 cc each. There were no deaths, significant arrhythmias, or other major complications. The ABMMNC injection reduced the amount of ischemic myocardium (not statistically significant). More important, exercise test results improved significantly. Myocardial volume oxygen consumption increased from 10.6 +/- 3 mL/kg/min (baseline) to 16.3 +/- 7 mL/kg/min (2 months) and 23 +/- 7 mL/kg/min (6 months) (P = 0.0091). In 4 of the 5 cases, this was such an improvement that the patients were no longer eligible for cardiac transplantation. In addition, metabolic equivalents improved from 3.03 +/- 0.66 (baseline) to 4.65 +/- 1.99 (2 months) and 6.5 +/- 2.0 (6 months) (P = 0.0092). In conclusion, ABMMNC injections were performed safely and resulted in improved exercise capacity. This technique may hold promise as an alternative to medical management in patients with severe ischemic heart failure who are ineligible for conventional revascularization.

CD34 selection using three immunoselection devices: comparison of T-cell depleted allografts

BACKGROUND

T-cell depletion of allografts markedly reduces the incidence of GvHD following BMT. The approach taken at our Center has utilized the physical separation method of counterflow centrifugal elutriation (CCE), augmented by recovery of stem cells from lymphocyte-rich fractions by immunoaffinity selection of CD34(+) stem cells. We wanted to compare the performance characteristics of three commercially available selection devices, as well as the clinical outcomes of patients who received allografts engineered by the different devices.

METHODS

BM allografts were prepared for patients undergoing BMT for hematologic malignancies. BM cells were separated into lymphocyte-rich and lymphocyte-depleted fractions using CCE, followed by recovery of CD34(+) cells from the lymphocyte-rich fraction using one of three immunoselection devices [CellPro CEPRATE, Nexell Isolex 300i (software version 2.5) and AmCell CliniMACS]. Allografts consisted of the lymphocyte-depleted fraction plus the CD34-selected fraction.

RESULTS

Yields of CD34(+) cells were comparable for the three devices. However, there were significant differences in purity (CEPRATE < Isolex 300i < CliniMACS) and time from start of fractionation to infusion (CEPRATE < CliniMACS < Isolex 300i). More technical problems were encountered with the Isolex 300i device. Allograft compositions were comparable. Transplant outcomes (engraftment and incidence of GvHD) also were comparable.

DISCUSSION

Qualitatively and quantitatively, allografts prepared with the CEPRATE, Isolex 300i (v 2.5) and CliniMACS devices should be considered comparable for use in this setting and probably also for direct T-cell depletion of BM.

A flow cytometric technique using thiazole orange to detect platelet engraftment following pediatric stem-cell transplants

BACKGROUND

Thiazole orange (TO) is a nucleic-acid-specific dye that enters cells without pretreatment. When it binds to either RNA or DNA, there is an increase in fluorescence emission. This property has been utilized to measure the amount of newly released platelets using flow cytometry. These newly released platelets differ from more mature platelets because they still contain residual amounts of RNA, and have become known as reticulated platelets.

METHODS

Peripheral blood samples were collected at least 48 h following platelet infusion. For validation, manual reticulocyte counts obtained in the laboratory were compared with results obtained using TO and flow cytometry. Following validation, experiments using platelet-rich plasma were performed to evaluate the presence of reticulated platelets in the sample.

RESULTS

Validation experiments comparing the manual and flow cytometric reticulocyte counts gave a strong relationship between the two values (r(2) = 0.92). Reticulated platelet studies performed on platelet-rich plasma samples yielded the following results. Patients who did not engraft within 4 days were significantly different from patients who did engraft within 4 days, idiopathic thrombocytoperic purpura (ITP) patients, and donor platelet segments (all P < 0.0008). Patients who engrafted within 4 days, ITP patients, and donor platelet segments were all statistically similar (all P > 0.08).

DISCUSSION

The statistical difference between patients who did engraft within 4 days and those who did not suggests that this method could have an important clinical impact in determining those patients who are still in need of platelet support. However, great care must be taken when performing and analyzing the results.

A virtual reality simulator for bone marrow harvest for pediatric transplant

Bone marrow transplant is a relatively new procedure to treat recently considered incurable diseases. One important part of the procedure is the process of harvesting the donor bone marrow. We are developing a virtual reality simulator for bone marrow harvest that integrates interactive stereo visualization and force feedback techniques. The main objective is to offer a low cost virtual reality system to boost current adopted training methodologies for bone marrow harvesting.

Transendocardial delivery of autologous bone marrow enhances collateral perfusion and regional function in pigs with chronic experimental myocardial ischemia

OBJECTIVES

We tested the hypothesis that intramyocardial injection of autologous bone marrow (ABM) promotes collateral development in ischemic porcine myocardium. We also defined, in vitro, whether bone marrow (BM) cells secrete vascular endothelial growth factor (VEGF) and macrophage chemoattractant protein-1 (MCP-1).

BACKGROUND

The natural processes leading to collateral development are extremely complex, requiring multiple growth factors interacting in concert and in sequence. Because optimal angiogenesis may, therefore, require multiple angiogenic factors, we thought that injection of BM, which contains cells that secrete numerous angiogenic factors, might provide optimal therapeutic angiogenesis.

METHODS

Bone marrow was cultured four weeks in vitro. Conditioned medium was assayed for VEGF and MCP-1 and was added to cultured pig aortic endothelial cells (PAEC) to assess proliferation. Four weeks after left circumflex ameroid implantation, freshly aspirated ABM (n = 7) or heparinized saline (n = 7) was injected transendocardially into the ischemic zone (0.2 ml/injection at 12 sites). Echocardiography to assess myocardial thickening and microspheres to assess perfusion were performed at rest and during stress.

RESULTS

Vascular endothelial growth factor and MCP-1 concentrations increased in a time-related manner. The conditioned medium enhanced, in a dose-related manner, PAEC proliferation. Collateral flow (ischemic/normal zone X 100) improved in ABM-treated pigs (ABM: 98 +/- 14 vs. 83 +/- 12 at rest, p = 0.001; 89 +/- 18 vs. 78 +/- 12 during adenosine, p = 0.025; controls: 92 +/- 10 vs. 89 +/- 9 at rest, p = 0.49; 78 +/- 11 vs. 77 +/- 5 during adenosine, p = 0.75). Similarly, contractility increased in ABM-treated pigs (ABM: 83 +/- 21 vs. 60 +/- 32 at rest, p = 0.04; 91 +/- 44 vs. 36 +/- 43 during pacing, p = 0.056; controls: 69 +/- 48 vs. 64 +/- 46 at rest, p = 0.74; 65 +/- 56 vs. 37 +/- 56 during pacing, p = 0.23).

CONCLUSIONS

Bone marrow cells secrete angiogenic factors that induce endothelial cell proliferation and, when injected transendocardially, augment collateral perfusion and myocardial function in ischemic myocardium.

Enhancement of angiogenesis by the implantation of self bone marrow cells in a rat ischemic heart model

Background. Bone marrow contains various kinds of primitive cells which differentiate into endothelial cells and could secrete several growth factors. Therefore, we attempted to induce therapeutic angiogenesis using self bone marrow cells in a rat model. Materials and methods. Quantitative angiogenesis was examined using a sponge implantation assay that indicated whether the rat bone marrow cells had induced angiogenesis or not. Employing a rat ischemic heart model, bone marrow cells were injected directly into the ischemic area and the number of vessels was examined immunohistochemically using the anti-CD31 monoclonal antibody. The contributed growth factors revealed the levels present in the ischemic myocardium by an enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction. Results. The sponge implantation assay showed that bone marrow cells induced angiogenesis. Light microscopic analysis of the vessel count positively stained by anti-CD31 in the ischemic area showed that angiogenesis had been induced to a significantly greater degree in the group implanted with bone marrow cells (BMI group) than in the group injected with phosphate-buffered saline (PBS group) 1 week after BMI. Levels of the inflammatory cytokines interleukin-1 (IL-1beta) and cytokine-induced neutrophil chemoattractant (CINC) in the BMI group were significantly elevated compared with those in the PBS group. Conclusions. Self bone marrow cell implantation induced angiogenesis in a rat ischemic heart model as a result of elevation of the levels of IL-1beta and CINC. Thus, bone marrow implantation could be a novel and simple method to induce therapeutic angiogenesis.

The Hohn catheter in the management of haemopoietic stem cell transplant recipients

Patients undergoing bone marrow transplantation require a reliable venous access. The authors have tested the feasibility and safety of a new, silicone, open-ended, non-tunnelled central venous catheter (CVC), the Hohn catheter (Bard Access System, USA). From January 1994 to December 1996, 58 Hohn were inserted into 56 bone marrow transplant (BMT) patients (26 women: 30 men; mean age 38 years, range 19-62 years). The CVC was inserted percutaneously at the bedside by puncture of the subclavian or the internal jugular vein. No early complications were observed. Significant late complications were infection (documented only in 14%) and accidental removal (11%). The median life of the CVC was 30 days (range 15-180 days). Major causes of removal were end of use (25 patients) and fever (19 patients; but infection was documented only in eight patients). In spite of the relatively small gauge (5 Fr), the Hohn catheter was adequate for rapid or high density infusion. In our experience, the unique features of the Hohn CVC (versatility, optimal biocompatibility, bedside management, low cost) may contribute to making the BMT procedure safer and less expensive.

Supraclavicular approach to the subclavian/innominate vein for large-bore central venous catheters

Infraclavicular and internal jugular catheterization are commonly used techniques for hemodialysis access, but may at times be impeded in patients whose anatomy makes cannulation difficult. In an effort to enlarge the spectrum of alternative access sites, we evaluated the supraclavicular approach for large-bore catheters. During an 18-month period we prospectively collected data on success rate and major and minor complications of the supraclavicular access for conventional dialysis catheters as well as Dacron-cuffed tunneled devices in 175 adult patients admitted for various extracorporeal therapies and bone marrow transplantation. Two hundred eight large-bore catheters (99 conventional dialysis catheters, 63 semirigid tunneled Dacron-cuffed catheters, and 46 Hickman catheters) were successfully placed in 164 patients (success rate, 93.8%), 58 (33.1%) of whom had been previously catheterized. Complications included pneumothorax (one patient), arterial puncture (seven patients), and puncture of the thoracic duct (two patients) without sequelae. Postinsertional chest radiographs demonstrated impressive coaxial lie of most catheters. Catheter malpositions occurred only sporadically (1%). Difficulty of introducing the catheter via a placed sheath was rarely observed. There was no clinically significant evidence of catheter-induced venous thrombosis or stenosis. We conclude that the supraclavicular route is an easy and safe first approach for large-bore catheters, as well as a useful alternative to traditional puncture sites for precatheterized and anatomically problematic patients.

Reconstruction of mandibular continuity defects in dogs using poly (L-lactide) mesh and autogenic particulate cancellous bone and marrow: preliminary report

PURPOSE

This study evaluated the reconstruction of continuity defects in the canine mandible using a poly [L-lactide] (PLLA) mesh tray and particulate cancellous bone and marrow (PCBM).

MATERIALS AND METHODS

Eight adult dogs were divided into two groups of four dogs each. In group A, each dog had a tray fixed with stainless steel wires on each side of the mandibular stumps with the concave surface of the tray attached to the inferior border of the mandible (U-fixation). In group B, the concave surface was attached to the superior border (inverted U-fixation). Each tray was filled with PCBM from the ilium. After the operation, the dogs were radiographed, and specimens were examined histologically at 3-, 6-, and 12-month intervals.

RESULTS

All of group A showed good clinical healing and the continuity of the mandibular bone was regained within 3 months postoperatively. However, fibrous tissue had invaded through the area above the tray, resulting in a poorly shaped alveolar ridges. In group B, the dogs showed good bony regeneration with well-shaped alveolar ridges. However, two animals in this group had partial exposure of the PLLA mesh tray into the oral cavity.

CONCLUSION

It is suggested that a combination of the PLLA mesh and PCBM grafts might be a useful technique for functional reconstruction of the jaw bone, specifically using method A (U-fixation) as a technique to reconstruct continuity defects of the mandible, and method B (inverted, U-fixation) as a promising method for alveolar reconstruction to make wearing dentures possible.

Bone marrow purging prior to autologous transplantation

Our data suggest that ex vivo bone marrow purging using monoclonal antibodies (MoAbs) and sheep-anti-mouse immunobeads (SAM beads) prior to autologous bone marrow transplantation (ABMT) allows satisfactory tumor cell reduction without critical stem cell losses. Nevertheless, there is only a reduction but no elimination of tumor cells. The consequences will have to be clinically discussed.

One year's experiences with two different image analysis systems for automated reading of the contrast fluorescence test

We have tested two different personal-computer based color image analysis systems for automated reading of the microlymphocytotoxicity test (LCT) for HLA-A,B,C-typing and screening. Over 17,000 single LCT-reactions were prepared using the simultaneous double fluorescent variant of the LCT (contrast fluorescence test, CFT). All tests were read visually by experienced laboratory staff members. For image analysis, an automated scanning system was used. In a first step, reactions were recorded on a videotape recorder using a color(CCD)-video camera. In a second step, the recorded reactions were analyzed with the two different image analysis systems by specifically developed programs. Good correlation (r = 0.89) of the score values assigned by digital image analysis with the visual tray reading was obtained. Since also the other main performance characteristics of the prototype system (throughput, reliability, compatibility) were acceptable for routine application, we may conclude that digital image analysis is a feasible and very interesting new technique for automated evaluation of the LCT.

Thrombotic complications of silicone rubber catheters during autologous marrow and peripheral stem cell transplantation: prospective comparison of Hickman and Groshong catheters

Thrombosis is common after placement of silicone rubber subclavian vein catheters in patients with malignancy receiving conventional doses of chemotherapy. To determine the incidence of this complication in marrow transplant patients and the effect of different catheter designs on thrombosis rates, patients were randomized to receive either open-ended Hickman catheters or valve-ended Groshong catheters for venous access during the transplantation procedure. A total of 35 catheters were placed, of which 23 were double-lumen (11 Groshong and 12 Hickman) and 12 were single-lumen (six Groshong and six Hickman). Arm venograms were performed on all patients at the time of hematopoietic recovery or occurrence of symptoms of subclavian vein thrombosis. There were 10 cases of total subclavian vein thrombosis (three were symptomatic) and 12 cases of asymptomatic non-occlusive mural thrombi. Only 13 normal veins were found. There was no difference in thrombosis rate between the Hickman and Groshong catheters. Double lumen catheters tended to be more likely to cause total venous occlusion (nine of 23) than single lumen catheters (one of 12) (p = 0.06, Fisher's exact test). We conclude that subclavian vein thrombosis is a common occurrence after placement of silicone rubber catheters for venous access during marrow transplantation. Most cases are asymptomatic. Groshong catheters are just as likely to cause this complication as Hickman catheters.

Synthesis of proteins from [35S]methionine by guinea pig megakaryocytes in vivo and time course of appearance of newly synthesized proteins in platelets

The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS-PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.

Bone marrow processing on the Haemonetics V50 cell separator

We have processed 27 bone marrow (BM) harvests using the Haemonetics V50 cell separator with a paediatric plasmapheresis set and programmed for lymphocyte collection. The mean starting volume of 843 mL was processed in 6-8 cycles to a buffy coat (BC) with a mean volume of 230 mL. The mean starting mononuclear cell (MNC) count was 1.22 x 10 8/kg recipient weight, and recovery was 92%. Clonogenic potential of the BC was assessed using CFU-GM assays and recovery was measured after cryopreservation or purging. On 4 occasions where major ABO incompatibility existed between donor and recipient, both BM and BC were consecutively diluted in compatible blood and processed twice. This achieved a calculated reduction in donor erythrocytes of 98%. The procedure was efficient and yielded a BC fraction suitable for cryopreservation and purging. Adequate stem-cells were retained as verified by CFU-GM assays and documentation of stable engraftment.