Efficacy of autologous peripheral blood stem cell (PBSC) harvest and engraftment after ablative chemotherapy in pediatric patients

Thirty-five pediatric patients, 1-16 years of age (median 6.3 years), with neoplastic solid tumors (n=32) or acute leukemia (n=3) underwent peripheral blood stem cell (PBSC) harvest and transplantation at Children's Memorial Hospital between September 1992 and April 1997. A median of four phereses were performed on each patient. Blood samples from 34 of the 35 patients were harvested through existing double-lumen central catheters, using either a Fenwal CS-3000 or COBE Spectra pheresis machine. The pheresis procedures were well tolerated overall. A median of 3.7 x 10(6)/kg CD34+ cells were infused (range, 0.2-15.5 x 10(6)/kg), and all patients engrafted. The median time to an absolute neutrophil count >500/microL was 13 days (range, 9-44 days) and to a platelet count >20,000/microL was 21 days (range, 9-210 days). Two patients died from transplant-related complications. Patients were discharged from the hospital after a median of 22 days (range, 15-64 days). Twenty of the 35 patients are alive, 17 of whom remain disease-free with a median follow-up of 1144 days. According to this study, PBSCs can be successfully harvested and re-infused for marrow reconstitution after myeloablative therapy in children for a variety of pediatric malignancies with low morbidity and mortality.

Mechanisms of ferric citrate uptake by human hepatoma cells

The mechanisms of uptake of non-transferrin-bound iron by human hepatoma cells (HuH7) were investigated using 59Fe-citrate and [14C]citrate. The amount of iron associated with the cells increased linearly with time, whereas citrate uptake reached a plateau after 45 min, resulting in a cellular accumulation of iron over citrate. The cells displayed high-affinity membrane binding sites for citrate with maximum binding of 118 +/- 17 pmol citrate/mg protein and a dissociation constant of 21 +/- 2 microM (n = 3). Iron uptake was saturable with a maximum uptake rate of 1.95 +/- 0.43 pmol . mg protein-1 . min-1 and an apparent Michaelis constant of 1.1 +/- 0.1 microM. Nonradioactive ferric citrate and citrate inhibited 59Fe uptake to a similar degree. This suggests that the uptake of citrate-bound iron is dependent on either binding to specific citrate binding sites or the concentration of unbound iron. The uptake of iron was inhibited by ferricyanide (>100 microM) and ferrous iron chelators but stimulated by ferrocyanide and ascorbate, suggesting that the iron is reduced from Fe3+ to Fe2+ and transported into the cell by an iron carrier-mediated step.

Creating a framework for clinical nursing practice to advance in the West Midlands region

The West Midlands Regional Health Authority identified a lack of opportunities for nurses to develop advanced clinical practice through a recognized programme at Postgraduate diploma/Masters degree level. Education for clinical practice must be equally grounded in theory and practice. Advanced clinical practice requires more than just skills acquisition, it has a much wider remit incorporating elements of clinical expertise and higher level decision making, research awareness, teaching and role modelling, informing policy making and leading in the provision of patient care within individual Trusts. This initiative has encouraged universities, trusts and provider units to work together to identify and prepare students and staff for their changes in role, and to review existing boundaries for practice which will enable new approaches to team work and the provision of holistic patient care.

Outpatient total body irradiation prior to bone marrow transplantation in pediatric patients: a feasibility analysis

Outpatient total body irradiation (TBI) prior to bone marrow transplantation has been accomplished in a total of 68 pediatric patients. The TBI regimen was fractionated with a total dose of 12 Gy in eight fractions twice daily. Antiemetic therapy consisted of oral ondansetron three times daily throughout the TBI course. Eight patients experienced mild nausea without vomiting, and four patients experienced mild nausea and vomiting. One patient required intravenous hydration after severe nausea and vomiting. Another patient experienced intractable diarrhea and dehydration which required inpatient management. Outpatient TBI prior to bone marrow transplantation is feasible in pediatric patients.

Cardiac tamponade during laparoscopic Nissen fundoplication

Laparoscopic Nissen fundoplication is becoming a popular technique in the surgical management of reflux disease. The advantages of laparoscopic surgery include shorter hospital stays, greater patient acceptance and decreased overall morbidity. Laparoscopic surgery eliminates the necessity for an upper abdominal incision and the consequent post-operative impairment of pulmonary mechanics. Laparoscopic Nissen fundoplication has been associated with a low incidence of severe peri-operative complications although of a different nature to those following the open procedure. We are reporting a rare case of acute cardiovascular collapse secondary to cardiac tamponade during laparoscopic Nissen fundoplication.

c-fos expression in isolated rat spinal cord

Expression of c-fos-immunoreactivity (c-fos-ir) has been demonstrated in the dorsal horn of lumbar segments of an isolated spinal cord preparation from 3 week old rats. The method of preparation generated a low level of c-fos-ir activity which was not significantly altered by low intensity (1.5 times threshold) dorsal root stimulation, but was significantly increased by high intensity (20 times threshold) stimulation. Replacement of the calcium in the bathing medium by 2 mM manganese suppressed all detectable c-fos-ir, whereas inclusion of 0.5 microM capsaicin caused intense c-fos-ir expression in the absence of stimulation. The number of dorsal horn cells exhibiting c-fos-ir increased between 0.5 and 1 h after stimulation, reaching a maximum at 2 h, with no further increase at longer intervals. Few positive cells were found when the incubation temperature was reduced from 27 to 20 degrees C. The strongest increase in c-fos-ir was found in the dorsal horn ipsilateral to the stimulated dorsal root and a smaller, but significant, increase was also seen in the contralateral dorsal horn. Cords obtained from animals treated at 1 day old with capsaicin to destroy afferent C fibres showed a reduction in the number of c-fos-ir positive cells induced by high intensity dorsal root stimulation. This preparation will aid detailed investigation of the pharmacology of nociceptive pathways.

Inhibition of uptake of transferrin-bound iron by human hepatoma cells by nontransferrin-bound iron

The liver acquires iron from transferrin by transferrin receptor-mediated (TR) and transferrin receptor-independent pathways (NTR) and from nontransferrin-bound iron (NTB-Fe). Iron uptake by the NTR processes involves an iron-carrier mediated step. Experiments, using human hepatoma cells (HuH7) transfected with TR antisense (sense for control) RNA expression vectors to suppress TR expression, were performed to examine the effect of unlabeled NTB-Fe as iron citrate on the uptake of 59Fe-125I-transferrin. This was to determine if the uptake of transferrin-bound iron (Tf-Fe) and NTB-Fe uptake is mediated by a common iron-carrier. Iron citrate inhibited the uptake of 59Fe-transferrin (2.5 micromol/L Fe) in a concentration-dependent manner with a maximum effect when the citrate-iron:Tf-Fe molar ratio was 10:1. Transferrin uptake was not affected. At a lower Tf-Fe concentration of (0.125 micromol/L) when uptake of iron is TR-mediated, a 10-fold molar excess of iron citrate had no effect on Tf-Fe uptake by HuH7 TR antisense and sense cells. However, at a higher Tf-Fe concentration (2.5 micromol/L), when uptake occurs mainly by the NTR-mediated process, there was a 40% reduction in the membrane-bound and intracellular uptake of iron. Iron citrate did not affect the maximum rate (Vmax) of Tf-Fe uptake but the Michaelis-Menten constant (Km) for Tf-Fe uptake by the NTR-mediated process was increased, indicating there was competitive inhibition of Tf-Fe uptake by iron citrate. These results suggest that the uptake of NTB-Fe and Tf-Fe by the NTR- mediated process occurs by the same cellular pathway, using a common iron-carrier.

Inhibition of testosterone 5 alpha-reductase: evidence for tissue-specific regulation of thromboxane A2 receptors

Testosterone has been implicated as a risk factor for cardiovascular diseases and thromboxane A2 (TXA2) may be an important pathophysiologic mediator for them. Testosterone has been shown to increase TXA2 receptor density in several cell types. Testosterone is reduced at the 5 alpha position to its active metabolite, dihydrotestosterone, by 5 alpha-reductase. We determined the effects of epristeride, a 5 alpha-reductase inhibitor, on the density of TXA2 receptors in rat aortic smooth muscle cells and human erythroleukemia cells, a megakaryocyte-like cell, in vitro, and in rat platelets and aortic membranes in vivo. In rat aortic smooth muscle cells, epristeride significantly (P < .01, n = 5) blocked the effect of testosterone to increase TXA2 receptor density (Bmax: 44 +/- 3, 76 +/- 7, 48 +/- 4 and 46 +/- 4 fmol/mg protein, for control cells, cells treated with testosterone (200 nM), cells treated with testosterone and epristeride (10 nM) and cells treated with epristeride, respectively. Epristeride did not block the effect of testosterone in human erythroleukemia cells. Treatment of male rats with epristeride for 2 weeks significantly (P < .01) decreased TXA2 receptor density in aortic membranes (41 +/- 3 for vehicle, n = 10; 27 +/- 3 fmol/mg protein for epristeride, n = 11) but did not significantly change TXA2 receptor density in platelets. Maximum contractile responses of rat aortas to U46619, a TXA2 mimetic, were significantly (P < .001) lower in epristeride-treated rats than in vehicle-treated rats (4.2 +/- 0.1 for vehicle, n = 16, 3.0 +/- 0.2 g tension for epristeride, n = 15). In conclusion, regulation of expression of TXA2 receptors by testosterone in cells of vascular origin, but not in platelets, appears to be via DHT.

Angiogenesis factor in endometrial carcinoma: a new prognostic indicator?

OBJECTIVE

Tumor angiogenesis is believed to be a prognostic indicator associated with tumor growth and metastasis. Studies of angiogenesis in breast, prostate, and lung cancer, as well as melanoma, have shown that neovascularization correlates with the likelihood of metastasis and recurrences. The purpose of this study was to evaluate microvessel density as a prognostic factor in endometrial cancer.

METHODS

Between 1980 and 1991 the tumor registry identified 25 patients with a diagnosis of recurrent endometrial cancer. These patients were matched with 25 patients with nonrecurrent disease for age, stage, grade, and treatment. The histologic slides of the 50 patients were reviewed. The paraffin blocks were obtained, and the area of the deepest myometrial invasion was selected for staining. The microvessels within the invasive cancer were highlighted by means of immunocytochemical staining to detect factor VIII-related antigen. Microvessels were counted by two investigators who were blinded to the patients' clinical status. Survival data were analyzed with Kaplan-Meier survival curves.

RESULTS

Microvessel count was related to likelihood of recurrence, although this trend did not reach statistical significance. Patients with tumors of low capillary density had a mean survival time of 123 months. Patients with tumors of high capillary density had a mean survival time of 75 months (p = 0.02). Among patients with recurrent disease, those with a low capillary count survived a mean of 64 months. Patients with recurrent disease with tumors of high capillary density survived a mean of 45 months (p = 0.002).

CONCLUSION

Angiogenesis factor correlates with survival in endometrial carcinoma.

Fusion of the TEL gene on 12p13 to the AML1 gene on 21q22 in acute lymphoblastic leukemia

Chromosomal rearrangements involving band 12p13 are found in a wide variety of human leukemias but are particularly common in childhood acute lymphoblastic leukemia. The genes involved in these rearrangements, however, have not been identified. We now report the cloning of a t(12;21) translocation breakpoint involving 12p13 and 21q22 in two cases of childhood pre-B acute lymphoblastic leukemia, in which t(12;21) rearrangements were not initially apparent. The consequence of the translocation is fusion of the helix-loop-helix domain of TEL, an ETS-like putative transcription factor, to the DNA-binding and transactivation domains of the transcription factor AML1. These data show that TEL, previously shown to be fused to the platelet-derived growth factor receptor beta in chronic myelomonocytic leukemia, can be implicated in the pathogenesis of leukemia through its fusion to either a receptor tyrosine kinase or a transcription factor. The TEL-AML1 fusion also indicates that translocations affecting the AML1 gene can be associated with lymphoid, as well as myeloid, malignancy.

Investigation of natural genetic variation in the circadian system of Drosophila melanogaster. II. Biometrical analyses of locomotor activity rhythms recorded in constant darkness

The locomotor activity rhythms of 24 isochromosomal strains of Drosophila melanogaster were recorded in constant conditions, using an experimental design suitable for the serial screening with so many strains using limited equipment. The data obtained were subjected to biometrical genetic analysis. The results show that four characteristics of the rhythms (period, phase, definition, and waveform) display genetically based variation in expression and that each appears to be affected by a range of genes.

Clinical and prognostic significance of chromosomal abnormalities in childhood acute myeloid leukemia de novo

We report on the chromosomal pattern of 120 patients with childhood AML de novo. One hundred and fifteen patients (96%) had adequate samples for analysis; 98 (85%) of these showed clonal karyotypic abnormalities. They were classified into cytogenetic subgroups which were closely correlated with FAB subtypes: t(8;21) and M2 (n = 9); t(15;17) and M3 (n = 12); inv(16) and M4Eo (n = 9); t(9;11) and M5a (n = 10); t(11q23) other than t(9;11) and M4-M5 (n = 11); and t(1;22) and M7 (n = 4). In patients with -7/del(7q) (n = 6), leukemia was preceded by MDS in half of the cases, although they had diverse FAB subtypes. Thirty-seven patients had miscellaneous abnormalities. Despite a high CR rate, patients with t(8;21) had a very poor survival: only one child was event-free at 3 years from diagnosis. One third of patients with t(15;17) died during induction. Those eight who achieved CR fared well: only two relapsed, and six were event-free survivors. Patients with inv(16) had a high remission rate and a long survival: five children were in CR 20 to 136 months. Both groups with t(9;11) and t(11q23) had a high remission rate: however, outcome was superior for the t(9;11) group when compared to either the t(11q23) group (EFS at 3 years +/- SE, 56 +/- 17% vs. 11 +/- 10%, p = 0.07) or to the remaining patients (p = 0.06). Both -7/del(7q) and t(1;22) groups had low CR rates (50%) and poor survival. Cytogenetic analysis identifies clinically distinct subsets of childhood AML and is useful in tailoring treatment for these patients. Favorable cytogenetic groups (t(15;17), inv(16), and t(9;11)) may do well with current therapy protocols, whereas unfavorable groups (t(11q23), t(8;21), -7/del(7q), and t(1;22)) require more effective therapies.

Diversity among seniors. A Toledo, OH, hospital assesses the healthcare needs of elderly African Americans and Hispanics

In 1992, leaders at Mercy Hospital, Toledo, OH, realized the facility's outreach programs were not reaching as many elderly African-American and Hispanic residents from the surrounding neighborhood as they would have liked. Mercy's leaders therefore decided that the hospital could offer cultural-specific programs that better meet the healthcare needs of these populations. To secure residents' perspective, an assessment process was launched. The data gathered from participants in face-to-face interviews revealed that some had problems with access to healthcare. A lack of money and other resources seemed to be the major barriers to care. The key concern of the elderly persons interviewed is securing personalized care or services that help them maintain their independence. A number of participants wanted free transportation (other than to and from the hospital). They need help getting to their physician's office, the pharmacy, the grocery store, and the bank. Public agencies may offer such transportation services. In addition, the Hispanic elderly interviewed would like to see Spanish-speaking personnel in admissions and the emergency department.

The role of laboratory terrestrial model ecosystems in the testing of potentially harmful substances

: A classification of terrestrial model ecosystems (TMEs) was introduced which is based upon the physical properties of intactness of the physical medium and openness to the atmosphere. This gave rise to four types of system, namely open and closed intact systems and open and closed homogeneous' systems. These systems have different capabilities with respect to fate and effect end-points with various substances. The large closed TMEs are generally very complex, require a high degree of operator skill, expensive and therefore not replicable. Whilst these can provide estimates of losses due to volatility, they are not useful for determining effect end-points because of low replicability; high replicability being necessary because of natural variation in organism response. Open systems, especially those having intact soil-cores, are usually smaller, less complex and therefore more replicable. These have provided useful information on integrative functional effect end-points, but can only produce mass balances with non-volatile substances. Homogenization of the medium has also helped elucidate ecotoxicological effects by increasing replicability, but may introduce artifacts because of the disruption to soil organisms.A major limitation of TME studies would seem to be that few effect end-points can be non-destructively sampled. Further investigations into these may provide information on recovery of terrestrial ecosystems over time after substance application, perhaps using multivariate statistical techniques. Other problems concerning TMEs are related to complexity and scale. In this respect ecosystem functions in which microorganisms play a major role, such as nutrient cycling, provide the greatest similarity when compared to field evaluations of the same substances, especially where the TME is intact. However, effects upon structural aspects of biological communities have in general not been well researched in TMEs. Once these have been added to the more complete set of functional end-points, TMEs will provide a very useful tool in hazard assessments of potentially harmful substances.

Chloroflexus-like organisms from marine and hypersaline environments: Distribution and diversity

We report the presence of a diverse number ofChloroflexus-like organisms in intertidal marine and submerged hypersaline microbial mats using light, infrared fluorescence, and electron microscopy. The intertidal organisms appear morphologically very similar to thermophilicC. aurantiacus while the 2 hypersaline strains are larger and have a more complex ultrastructure composed of chlorosome-bearing internal membranes that appear to arise as invaginations of the cell membrane. By comparing spectroradiometry of microbial mat layers with microscopic observations, we have confirmed that theChloroflexus-like organisms are major constituents of the hypersaline microbial mat communities. In situ studies on mat layers dominated byChloroflexus-like organisms showed that sulfide-dependent photoautotrophic activity sustained by near infrared radiation prevailed. Autoradiographic analyses revealed that autotrophy was sustained in the filaments by 750 nm radiation. Three morphologically distinct strains are now maintained in mixed culture. One of these appears to be growing photoautotrophically.

An investigation of natural genetic variation in the circadian system of Drosophila melanogaster: rhythm characteristics and methods of quantification

Variation in four characteristics of the circadian locomotor activity rhythm was investigated in 24 true-breeding strains of Drosophila melanogaster with a view to establishing methods of phenotypic measurement sufficiently robust to allow subsequent biometric analysis. Between them, these strains formed a representative sample of the genetic variability of a natural population. Period, phase, definition (the degree to which a rhythmic signal was obscured by noise), and rhythm waveform were all found to vary continuously among the strains, although within each strain the rhythm phenotype was remarkably consistent. Each characteristic was found to be sufficiently robust to permit objective measurement using several different methods of quantification, which were then compared.

Experimental expansion of the maxillary sinus

To assess the feasibility of "tissue" expansion as a means of midface advancement for correction of hypoplasia, expanders were placed in the left maxillary sinuses of New Zealand White rabbits. Twenty-one animals were used for the study, all of whom underwent implantation of radiopaque dental amalgam markers adjacent to cranial sutures at 9 days of age. The nonoperative control group (n = 13) underwent no further surgery. At 30 days of age, the experimental group (n = 8) underwent placement of an inflatable 1-mL Silastic tissue expander in the left maxillary sinus. After 1 week, inflation was begun in serial increments of 0.15-mL normal saline to a total volume of approximately 1.05 mL over a 2-week period. Lateral cephalometrograms were obtained at 9, 30, 60, and 90 days of age to measure growth of the craniofacial skeleton. Both groups demonstrated similar growth between 9 and 30 days of age; however, insertion and inflation of the tissue expander resulted in a statistically significant (p < 0.05) increase in posterior facial height, followed, in 30 days, by a significant increase in the length of the anterior cranial base. The remainder of the cranial base and the cranial vault grew without significant differences between the groups. This study demonstrates that changes in facial morphology can be effected in the growing skeleton through tissue expansion and provides further evidence to support the concept of an interrelated facial skeletal-basicranial-neurocranial axis.