Retarded recovery of functional T cell frequencies in T cell-depleted bone marrow transplant recipients

We have studied the effect of removing donor T cells by treatment with the monoclonal antibody Leu-1 and complement before marrow transplantation on the regeneration of functionally competent T lymphocytes in the blood at selected times after transplant. Using sensitive limiting-dilution methods that allow us to enumerate helper, cytotoxic, and proliferating T lymphocyte precursors, we report that regeneration of a functional T cell compartment is more severely impaired for the first 180 days after transplantation in those patients given T cell-depleted bone marrow than in recipients of untreated marrow. After this first 6 months, however, patients given T cell- depleted bone marrow had blood T cell frequencies comparable to those observed in patients given untreated marrow. Diminished frequencies of reactive T cells in recipients of depleted marrow could leave them more susceptible to infection or to the recurrence of neoplastic cells.     

Restriction fragment length polymorphisms as markers of engraftment in allogeneic marrow transplantation

We have used DNA hybridization techniques employing restriction fragment length polymorphisms (RFLPs) to quantitate the level of donor cell engraftment in bone marrow transplantation recipients. The genetic origin of the bone marrow cells and various peripheral blood populations was analyzed in 14 patients. We found at least one informative polymorphism for each donor-recipient pair. Additional markers of engraftment included cytogenetic analysis, HLA typing, and red cell typing. By DNA analysis, four patients had complete engraftment, five had partial engraftment, and five had no evidence of donor cell engraftment. In three cases, DNA analysis permitted detection of minor populations (5% to 10%) of donor or host cells. Eight of fourteen patients were evaluable for chimerism posttransplant by cytogenetic analysis. In five cases, cytogenetic results were completely concordant with DNA analyses. In two cases of apparent autologous recovery, as assessed using RFLPs, a small number of cells of donor karyotype was seen. In one other case, a small number of cells of host karyotype was not detected by RFLP studies. HLA typing in three partially engrafted patients was purely either of donor or host type. Red cell typing was discordant with DNA and/or cytogenetic results in four of eight cases. We conclude that DNA analysis at a limited number of informative genetic loci is useful for quantitating the degree of engraftment in multiple populations of nondividing cells following allogeneic bone marrow transplantation.     

Granulopoietic effects of human bone marrow fibroblastic cells and abnormalities in the "granulopoietic microenvironment"

The in vitro granulopoietic effects of adherent bone marrow fibroblastic cells (FC) were studied in normal humans and in patients with acute myelogenous leukemia (AML) and myeloproliferative disorders (MPD). To determine their influence on granulopoiesis, we established FC in liquid-phase cultures, overlaid the adherent FC with normal bone marrow cells in agar, and subsequently measured the growth of CFU-C. When using target marrows containing few spontaneous colonies, increased numbers of CFU-C were found above the FC obtained from normals. No growth greater than controls was observed in those areas lacking FC. If target marrows contained large numbers of spontaneous CFU-C, actual inhibition of colony formation was produced by FC co- incubation. In contrast to normals, FC obtained from untreated AML and MPD patients typically failed to enhance granulopoiesis. Regardless of source, FC were not synergistic with the effects of placenta- conditioned media (typically being inhibitory) for colony number, but were synergistic for colony size. Conditioned media obtained from FC cultures did not enhance colony formation and actually inhibited spontaneous colony formation. Thus, microenvironmental abnormalities in interactions between "stromal cells" and hematopoietic progenitors may be important in the pathogenesis and clinical expression of hematopoietic malignancies in humans.     

Divergent molecular phenotypes of KG1 and KG1a myeloid cell lines

The cell line KG1 derived from a patient with erythroleukemia in myeloblastic relapse has the composite phenotype and functional repertoire of myeloblasts. In marked contrast, its subline KG1a has lost myeloid features, acquired new karyotypic markers, and has three characteristics associated with immature T cells: low-level expression of the T cell receptor beta mRNA (but not alpha) transcribed from a germline gene; high-level expression of T3 delta mRNA and intracellular, but not cell surface, T3 protein; and expression of the CD7/gp40 T cell-associated membrane antigen. Both KG1 and KG1a transcribe unrearranged IgH genes. These data suggest that either the KG1 cell line was derived from a common myeloid-lymphoid progenitor or that the KG1a subline phenotype is aberrant.     

Bone marrow transplantation for paroxysmal nocturnal hemoglobinuria: eradication of the PNH clone and documentation of complete lymphohematopoietic engraftment

Paroxysmal nocturnal hemoglobinuria (PNH) involves the proliferation of an abnormal and possibly premalignant hematopoietic stem cell. Successful treatment of PNH by marrow grafting requires that the PNH clone be eradicated by the pretransplant conditioning regimen. Four patients with PNH-associated marrow aplasia were transplanted with marrow from their HLA-matched, MLR-nonreactive siblings. Three patients were conditioned with cyclophosphamide, procarbazine, and antithymocyte serum (CTX/PCZ/ATS), and one was conditioned with busulfan/CTX/PCZ/ATS. Persistent complete engraftment of myeloid, lymphoid, and erythroid cell lines was demonstrated in all four patients by DNA sequence polymorphism analysis or cytogenetics, and RBC typing. There was no recurrence of the abnormal clone of cells for up to five years after transplantation despite the use of a conditioning regimen in three of them, which is not usually associated with permanent marrow aplasia. Bone marrow transplantation is a curative therapy in patients whose illness is severe enough to warrant the risk.     

Characterisation of the Mechanical Loads and Metabolic Intensity of the CAPO Kids Exercise Intervention for Healthy Primary School Children

Sedentarism is associated with obesity and other chronic diseases at all ages. Increasing physical activity with in-school interventions, focusing on energy expenditure and bone loading reduces risk of a number of costly chronic diseases. The aim of the current study was to characterise the metabolic and musculoskeletal load intensity of the recent successful CAPO Kids exercise intervention. Pre and early pubertal children (10.4 ± 0.5 years old) from the CAPO Kids trial wore an armband sensor to estimate energy expenditure during a 10-minute CAPO Kids session. Eleven participants performed manoeuvres from the session on a force platform to determine vertical ground reaction forces. In total, 28 boys and 20 girls had armband measures and 11 boys and girls undertook GRF testing. The energy expenditure associated with the 10-minute session was 39.7 ± 9.3 kcal, with an average of 4 kcal·min-1. The intensity of physical activity was ‘vigorous’ to ‘very vigorous’ for 34% of the session. Vertical ground reaction forces of the CAPO Kids manoeuvres ranged from 1.3 ± 0.2 BW (cartwheels) to 5.4 ± 2.3 BW (360° jump). CAPO Kids generates adequate load intensity to stimulate positive health adaptations in both metabolic and musculoskeletal systems of pre and early pubertal children.

Key points

• Energy expenditure of a single bout of CAPO Kids yields 39.7±9.3 kcal and includes activities performed at a vigorous and very vigorous intensity.
• Mechanical loads associated with CAPO Kids surpass five times bodyweight and more than 140 bodyweights per second.
• CAPO Kids intervention represents a viable approach to stimulate musculoskeletal and metabolic adaptation in children.

Key words: Pediatrics, energy expenditure, ground reaction forces, physical activity     

Variation in the Utilization of Reconstruction Following Mastectomy in Elderly Women

Background

Regardless of their age, women who choose to undergo postmastectomy reconstruction report improved quality of life as a result. However, actual use of reconstruction decreases with increasing age. Whereas this may reflect patient preference and clinical factors, it may also represent age-based disparity.

Methods

Women aged 65 years or older who underwent mastectomy for DCIS/stage I/II breast cancer (2000–2005) were identified in the SEER-Medicare database. Overall and institutional rates of reconstruction were calculated. Characteristics of hospitals with higher and lower rates of reconstruction were compared. Pseudo-R² statistics utilizing a patient-level logistic regression model estimated the relative contribution of institution and patient characteristics.

Results

A total of 19,234 patients at 716 institutions were examined. Overall, 6 % of elderly patients received reconstruction after mastectomy. Institutional rates ranged from zero to >40 %. Whereas 53 % of institutions performed no reconstruction on elderly patients, 5.6 % performed reconstructions on more than 20 %. Although patient characteristics (%ΔR² = 70 %), and especially age (%ΔR² = 34 %), were the primary determinants of reconstruction, institutional characteristics also explained some of the variation (%ΔR² = 16 %). This suggests that in addition to appropriate factors, including clinical characteristics and patient preferences, the use of reconstruction among older women also is influenced by the institution at which they receive care.

Conclusions

Variation in the likelihood of reconstruction by institution and the association with structural characteristics suggests unequal access to this critical component of breast cancer care. Increased awareness of a potential age disparity is an important first step to improve access for elderly women who are candidates and desire reconstruction.     

A brief review of ventricular assist devices and a recommended protocol for pathology evaluations

Heart failure is a leading cause of death in human populations, and as people live longer, it is becoming an increasingly prominent problem. Because of the insufficient numbers of donor hearts, physicians and engineers are turning to mechanical circulatory support in the form of ventricular assist devices (VADs). Their clinical performance and increasing availability of various types, sizes, and functions are increasing VAD recognition. However, for any implantable medical device, especially one that is life supporting, performance and safety must be evaluated both pre- and postmarket. It has been demonstrated that specific pathology analysis can provide unique and important information to augment the evaluation of performance and safety. To help ensure the safety and efficacy of a device, we propose that regulatory agencies include pathology analysis by experienced, independent pathologists with relevant expertise as an integral component of device submissions. We believe that this analysis should include both gross and microscopic components and, when warranted, supplementary data obtained through radiography, electron microscopy, or both. The pathology data acquired through these analyses should be correlated with clinical data to yield a more thorough data set for submission to the governing regulatory body. Submitting this coordinated analysis of data will demonstrate to regulatory agencies (United States Food and Drug Administration, Therapeutic Goods Administration, Brazilian Health Surveillance Agency, etc.) that the device manufacturer shares their objective: making medical devices as safe and effective as possible.SummaryThis review of ventricular assist devices introduces a recommended protocol for pathology evaluations of devices from organizations or researchers seeking approval by a governing regulatory agency.