Development of a Resonant Microwave Sensor for Sediment Density Characterization

In this study, a sensor based on the development of a planar antenna immersed in sediments dedicated to water content monitoring in this type of material is proposed and experimentally validated. It is produced by a conventional Printed Circuit Board (PCB) manufacturing process on a double-sided metalized FR4 substrate. The sensitivity of the sensor is ensured by the variation of the real part of the complex dielectric permittivity of sediments with water content at around 1 GHz. As shown, in this frequency range, electrode polarization and Maxwell–Wagner polarization effects become negligible, leading to only a bulk water polarization sensitivity. The sensor operates in the reflection mode by monitoring the variation of the resonant frequency as a function of the sediment density through the S₁₁ reflection measurements. An experimental sensitivity of 820 MHz.g−1.cm3 was achieved. Despite the simplification of data interpretation at the considered frequency, the influence of ionic species such as NaCl in sediments on the real part of the relative complex dielectric permittivity is highlighted. This demonstrates the importance of considering a second parameter such as the S₁₁ level at low frequency or the electrical conductivity to extract the density from the frequency measurements.

Sunlight exposure is just one of the factors which influence vitamin D status

Studies on the determinants of vitamin D status have tended to concentrate on input - exposure to ultraviolet B radiation and the limited sources in food. Yet, vitamin D status, determined by circulating concentrations of 25-hydroxyvitamin D (25(OH)D), can vary quite markedly in groups of people with apparently similar inputs of vitamin D. There are small effects of polymorphisms in the genes for key proteins involved in vitamin D production and metabolism, including 7-dehydrocholesterol reductase, which converts 7-dehydrocholesterol, the precursor of vitamin D, to cholesterol, CYP2R1, the main 25-hydroxylase of vitamin D, GC, coding for the vitamin D binding protein which transports 25(OH)D and other metabolites in blood and CYP24A1, which 24-hydroxylates both 25(OH)D and the hormone, 1,25-dihydroxyvitamin D. 25(OH)D has a highly variable half-life in blood. There is evidence that the half-life of 25(OH)D is affected by calcium intake and some therapeutic agents. Fat tissue seems to serve as a sink for the parent vitamin D, which is released mainly when there are reductions in adiposity. Some evidence is presented to support the proposal that skeletal muscle provides a substantial site of sequestration of 25(OH)D, protecting this metabolite from degradation by the liver, which may help to explain why exercise, not just outdoors, is usually associated with better vitamin D status.

1,25-Dihydroxycholecalciferol (calcitriol) modifies uptake and release of 25-hydroxycholecalciferol in skeletal muscle cells in culture

The major circulating metabolite of vitamin D₃, 25-hydroxycholecalciferol [25(OH)D], has a remarkably long half-life in blood for a (seco)steroid. Data from our studies and others are consistent with the hypothesis that there is a role for skeletal muscle in the maintenance of vitamin D status. Muscle cells internalise vitamin D-binding protein (DBP) from the circulation by means of a megalin/cubilin plasma membrane transport mechanism. The internalised DBP molecules then bind to actin and thus provide an intracellular array of high affinity binding sites for its specific ligand, 25(OH)D. There is evidence that the residence time for DBP in muscle cells is short and that it undergoes proteolytic degradation, releasing bound 25(OH)D. The processes of internalisation of DBP and its intracellular residence time, bound to actin, appear to be regulated. To explore whether 1,25-dihydroxycholecalciferol (calcitriol) has any effect on this process, cell cultures of myotubes and primary skeletal muscle fibers were incubated in a medium containing 10^-10M calcitriol but with no added DBP. After 3h pre-incubation with calcitriol, the net uptake of 25(OH)D by these calcitriol-treated cells over a further 4h was significantly greater than that in vehicle-treated control cells. This was accompanied by a significant increase in intracellular DBP protein. However, after 16h of pre-incubation with calcitriol, the muscle cells showed a significantly depressed ability to accumulate 25(OH)D compared to control cells over a further 4 or 16hours. These effects of pre-incubation with calcitriol were abolished in fibers from VDR-knockout mice. The effect was also abolished by the addition of 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS), which inhibits chloride channel opening. Incubation of C2 myotubes with calcitriol also significantly reduced retention of previously accumulated 25(OH)D after 4 or 8h. It is concluded from these in vitro studies that calcitriol can modify the DBP-dependent uptake and release of 25(OH)D by skeletal muscle cells in a manner that suggests some inducible change in the function of these cells.

The effect of parathyroid hormone on the uptake and retention of 25-hydroxyvitamin D in skeletal muscle cells

Data from our studies, and those of others, support the proposal that there is a role for skeletal muscle in the maintenance of vitamin D status. We demonstrated that skeletal muscle is able to internalise extracellular vitamin D binding protein, which then binds to actin in the cytoplasm, to provide high affinity binding sites which accumulate 25-hydroxyvitamin D₃ (25(OH)D₃) [1]. This study investigated the concentration- and time-dependent effects of parathyroid hormone (PTH) on the capacity of muscle cells to take up and release ³H-25(OH)D₃. Uptake and retention studies for ³H-25(OH)D₃ were carried out with C2C12 cells differentiated into myotubes and with primary mouse muscle fibers as described [1]. The presence of PTH receptors on mouse muscle fibers was demonstrated by immunohistochemistry and PTH receptors were detected in differentiated myotubes, but not myoblasts, and on muscle fibers by Western blot. Addition of low concentrations of vitamin D binding protein to the incubation media did not alter uptake of 25(OH)D₃. Pre-incubation of C2 myotubes or primary mouse muscle fibers with PTH (0.1 to 100 pM) for 3h resulted in a concentration-dependent decrease in 25(OH)D₃ uptake after 4 or 16h. These effects were significant at 0.1 or 1pM PTH (p<0.001) and plateaued at 10pM, with 25(OH)D₃ uptake reduced by over 60% (p<0.001) in both cell types. In C2 myotubes, retention of 25(OH)D₃ was decreased after addition of PTH (0.1 to 100pM) in a concentration-dependent manner by up to 80% (p<0.001) compared to non-PTH treated-C2 myotubes. These data show that muscle uptake and retention of 25(OH)D₃ are modulated by PTH, a physiological regulator of mineral homeostasis, but the cell culture model may not be a comprehensive reflection of vitamin D homeostatic mechanisms in whole animals.

[Treatment of macular hematoma complicating AMD by vitrectomy, subretinal r-TPA injection, intravitreal injection of bevacizumab combined with gas tamponade: Report of 4 cases]

INTRODUCTION

The occurrence of a subretinal hematoma in age-related macular degeneration (AMD) is a serious complication that can impact the visual prognosis with a poor functional recovery. The management of this complication remains controversial. Several therapeutic methods have been described. We report the results of four patients treated with a protocol combining: vitrectomy, subretinal injection of r-TPA 0.025mg/0.3ml, intravitreal injection of 0.05ml of bevacizumab and retinal tamponade with 20% SF6 gas.

PATIENTS AND METHODS

Our series consists of four patients with a submacular hematoma complicating AMD, included in succession between October 2013 and October 2014 and treated with the same treatment protocol and by the same surgeon. All patients underwent surgery within eight days after the onset of the macular hematoma. Patients with a consultation period longer than eight days did not undergo this treatment. Face down postoperative positioning was then carried out for seven days by the patients.

RESULTS

We observed a shift in the macular hematoma in the four patients, which allowed the identification of secondary neovascularization responsible for the bleeding. The visual acuity improved in three patients from hand motion (HM) preoperatively to 2/10 at one month postoperatively. One patient maintained visual acuity 1/20 during the entire follow-up despite almost complete resorption of the subretinal hematoma. These visual acuities were stable at 6 months postoperatively.

DISCUSSION

Macular subretinal hematoma can cause severe visual loss by several mechanisms. The blood accumulates between the neurosensory retina and the retinal pigment epithelium, which causes a toxic effect on the surrounding tissues, thus resulting in a loss of photoreceptors and cellular destruction in the pigment epithelium and choriocapillaris, evolving into a fibroglial scar.

CONCLUSION

The therapeutic evaluation of this protocol in our series of four patients gives a favorable result. We observed an improvement in visual acuity in 3/4 of cases. This surgical technique appears to be effective in the treatment of this complication of AMD. However, a study on a larger scale is needed to confirm these results.

Silver(i) coordination polymers with 3,3′,5,5′-tetrasubstituted 4,4′-bipyridine ligands: towards new porous chiral materials

The first homochiral metal–organic framework (MOF) based on an atropisomeric 4,4′-bipyridine ligand is described.

First report of pediatric hematopoietic stem cell transplantation activities in the eastern mediterranean region from 1984 to 2011: on behalf of the pediatric cancer working committee of the eastern mediterranean blood and marrow transplantation group

To describe the hematopoietic stem cell transplantation (HSCT) activities for children in the Eastern Mediterranean (EM) region, data on transplants performed for children less than 18 years of age between 1984 and 2011 in eight EM countries (Egypt, Iran, Jordan, Lebanon, Oman, Pakistan, Saudi Arabia and Tunisia) were collected. A total of 5187 transplants were performed, of which 4513 (87%) were allogeneic and 674 (13%) were autologous. Overall, the indications for transplantation were malignant diseases in 1736 (38.5%) and non-malignant in 2777 (61.5%) patients. A myeloablative conditioning regimen was used in 88% of the allografts. Bone marrow (BM) was the most frequent source of stem cells (56.2%), although an increasing use of PBSC was observed in the last decade. The stem cell source of autologous HSCT has shifted over time from BM to PBSC, and 80.9% of autologous HSCTs were from PBSCs. The donors for allogeneic transplants were matched-related in 94.5% of the cases, and unrelated transplants, mainly cord blood (99%) in 239 (5.5%) cases. This is the first report to describe the pediatric HSCT activities in EM countries. Non-malignant disorders are the main indication for allogeneic transplantation. Frequency of alternate donor transplantation is low.

Evidence for a specific uptake and retention mechanism for 25-hydroxyvitamin D (25OHD) in skeletal muscle cells

Little is known about the mechanism for the prolonged residence time of 25-hydroxyvitamin D (25OHD) in blood. Several lines of evidence led us to propose that skeletal muscle could function as the site of an extravascular pool of 25OHD. In vitro studies investigated the capacity of differentiated C2 murine muscle cells to take up and release 25OHD, in comparison with other cell types and the involvement of the membrane protein megalin in these mechanisms. When C2 cells are differentiated into myotubes, the time-dependent uptake of labeled 25OHD is 2-3 times higher than in undifferentiated myoblasts or nonmuscle osteoblastic MG63 cells (P < .001). During in vitro release experiments (after 25OHD uptake), myotubes released only 32% ± 6% stored 25OHD after 4 hours, whereas this figure was 60% ± 2% for osteoblasts (P < .01). Using immunofluorescence, C2 myotubes and primary rat muscle fibers were, for the first time, shown to express megalin and cubilin, endocytotic receptors for the vitamin D binding protein (DBP), which binds nearly all 25OHD in the blood. DBP has a high affinity for actin in skeletal muscle. A time-dependent uptake of Alexafluor-488-labeled DBP into mature muscle cells was observed by confocal microscopy. Incubation of C2 myotubes (for 24 hours) with receptor-associated protein, a megalin inhibitor, led to a 40% decrease in 25OHD uptake (P < .01). These data support the proposal that 25OHD, after uptake into mature muscle cells, is held there by DBP, which has been internalized via membrane megalin and is retained by binding to actin.

A preliminary investigation of Beta-hCG expression in patients with osteosarcoma

There are eight reported cases in the literature of osteosarcomas secreting β-hCG. Our primary aim was to investigate the rate of β-hCG expression in osteosarcoma and attempt to understand the characteristics of osteosarcomas that secrete β-hCG. We reviewed 37 histopathology slides (14 biopsies and 23 surgical specimens) from 32 patients with osteosarcoma. The slides were retrospectively stained for β-hCG expression. Patient and tumour characteristics, including age, gender, tumour location, subtype, proportion of necrosis, presence of metastases and recurrence were recorded. A total of five of the 32 tumours were found to be positive for β-hCG expression (one strongly and four weakly). This incidence of this expression was found in tumours with poor histological response to neoadjuvant chemotherapy.

The use of β-hCG expression as a diagnostic, prognostic or follow-up marker is questionable and needs further investigation with a larger sample size.

Predictors of bone loss in childhood hematologic malignancies: a prospective study

SUMMARY

Twenty-nine children with malignancies and age, gender-matched controls were prospectively studied over 14 months. Patients had higher parathyroid hormone (PTH) levels and fat mass, lower bone mass, and bone mass increments at follow-up than controls. Lean mass, age at diagnosis, systemic and intrathecal therapy were predictors of bone mass changes on adjusted analyses.

INTRODUCTION

Children with hematologic malignances have low bone mass. We prospectively investigated anthropometric, clinical, and hormonal predictors of changes in bone mass in children receiving cancer therapy.

METHODS

Twenty-nine children, mean age of 9 ± 2.9 years and 32 age and gender-matched controls, were studied. Seven had completed their course 40 ± 22 weeks prior, while 22 were still receiving therapy for 80 ± 28 weeks. Age at diagnosis, calcium intake, exercise activity, systemic corticosteroids in dexamethasone (Dex) dose, and methotrexate (MTX), and intrathecal MTX therapy received within follow-up period were assessed. Routine chemistries, PTH, 25-hydroxy vitamin D (25-OHD), bone remodeling markers, bone mass, and body composition were measured at baseline and 14 months.

RESULTS

Patients had lower exercise activity, sun exposure, and bone markers levels than controls. They had higher PTH levels and fat mass, lower bone mass at the spine, hip, and total body, and lower increments at these sites on follow-up. Predictors of bone mass changes on univariate analyses were: age at diagnosis (R = -0.50 to -0.44, p < 0.05), Dex-MTX doses (R = -0.58 to -0.41, p < 0.05), intrathecal therapy (p < 0.03),% changes in lean mass (R = 0.37 to 0.54, p < 0.04), 25-OHD levels (R = 0.39, p < 0.03), and PTH levels (R = -0.47 to -0.41, p < 0.05). Lean mass, age at diagnosis, systemic and intrathecal therapy were predictors of bone mass changes on adjusted analyses.

CONCLUSION

This study provides insight into the pathophysiology of bone loss in children receiving cancer therapy and possible interventions to optimize their skeletal health.

Abstract P1-11-17: Neglected and Non-Neglected Locally Advanced Breast Cancer: Effects of Neoadjuvant Chemotherapy and Survival

Background: Locally advanced breast cancer is a frequent clinical entity that compromises a biologically heterogeneous group that can also be divided chronologically by the duration between onset of symptoms and presentation for medical care.

Methods: Retrospective review of all patients with locally advanced breast cancer (LABC) treated in a general oncology practice between 1997 and 2007. Patients with LABC at presentation and have available follow-up were included. Patients were staged or restaged according to AJCC 7th edition. Patients were divided between two groups: those who presented within 3 months of onset of symptoms and signs of disease (non-neglected) and those who presented after more than 3 months (neglected). DFS was calculated from time of diagnosis till time of distant recurrence or last follow-up. Overall survival was calculated from time of diagnosis till time of last follow-up or death. Study was approved by IRB of the American University of Beirut. Data was entered and analyzed using SPSS. Survival was calculated and estimated according to Kaplan Meier method.

Results: Total number of patients with LABC was 109 pts. Median age at diagnosis was 48 yrs (Range: 21-78 y). Hormone receptors were positive in 71% of cases. Number of neglected cases at presentation were 61 patients and non-neglected 48. Pre-operative therapy, adjuvant chemotherapy, hormonal therapy and radiation therapy were conformal with standard current guidelines. Neoadjuvant chemotherapy was given in 24% (27/109) of all cases. Adjuvant trastuzumab was used starting June 2005. Patients were followed closely every three months and compliance with therapy was excellent.

Overall Survival (OS) of all patients was 68% at 5 years and 34% at 10 years. Median Survival was 100 months for non-neglected and 62 months for neglected disease (P: 0.06)

Survival data

Conclusions: Locally advanced disease confers a bad prognosis and poor outcome in patients with breast cancer. Patients who present within 3 months of onset of symptoms have a better survival than those who present with neglected disease. Neglected disease, even though not necessarily biologically aggressive, continues to have an adverse effect on survival. Survival continues to decline between 5 and 10 years. Additional patient demographics and tumor characteristics as well as shorter delays at presentation will be presented.

Zinc and biotin deficiencies after pancreaticoduodenectomy

We report zinc and biotin deficiencies after pancreaticoduodenectomy in a 16 year old female presenting clinically with marked alopecia, total body hair loss, dry skin with scales, and maculopathy with significant vision loss. These micronutrient deficiencies likely occurred due to resection of the duodenum and proximal jejunum, sites of primary absorption of several micronutrients and their protein carriers, including zinc and biotin. Early diagnosis is essential to prevent irreversible sequelae. Adequate supplementation of zinc and biotin as well as dietary advice is needed for clinical improvement.

Imaging gold nanoparticles in living cell environments using heterodyne digital holographic microscopy

This paper describes an imaging microscopic technique based on heterodyne digital holography where subwavelength-sized gold colloids can be imaged in cell environments. Surface cellular receptors of 3T3 mouse fibroblasts are labeled with 40 nm gold nanoparticles, and the biological specimen is imaged in a total internal reflection configuration with holographic microscopy. Due to a higher scattering efficiency of the gold nanoparticles versus that of cellular structures, accurate localization of a gold marker is obtained within a 3D mapping of the entire sample's scattered field, with a lateral precision of 5 nm and 100 nm in the x,y and in the z directions respectively, demonstrating the ability of holographic microscopy to locate nanoparticles in living cell environments.

Wernicke's encephalopathy during total parenteral nutrition in a child with acute lymphoblastic leukemia and acute pancreatitis

We herein describe a 16-year-old child with acute lymphoblastic leukemia and acute pancreatitis who developed Wernicke's encephalopathy secondary to prolonged total parenteral nutrition (TPN) that lacked vitamin B1 supplementation. The patient showed a direct and complete response to thiamine therapy. Diagnostic challenges are discussed and recommendations for prophylactic vitamin B1 supplementation in children with leukemia who are placed on TPN are made.

Hematopoietic stem cell transplantation in Lebanon: first comprehensive report

Hematopoietic SCT (HSCT) has become a curative therapeutic strategy for several malignant and nonmalignant diseases. We report the comprehensive results of the first 10 years of experience in HSCT from the two major BMT units in Lebanon: Makassed University Hospital and the American University of Beirut Medical Center. The median and the 5-year overall survival (OS) were 97 months and 58%, respectively, for the 84 patients who received allogeneic HSCT, and 60 months and 50%, respectively, for the 228 patients who received autologous BMT. The results for myeloablative allogeneic transplantation were as follows: AML (n=28, 5-year OS 58%, 5-year disease-free survival (DFS) 48%), CML (n=9, 5-year OS 66%, 5-year DFS 52%), ALL (n=13, 2-year OS 10%, 2-year DFS 10%), thalassemia (n=10, 5-year transfusion-free survival 67%). The results for autologous HSCT were as follows: diffuse large B-cell lymphoma (DLBCL) in relapse (n=37, 5-year OS 68%, 5-year progression-free survival (PFS) 65%), Hodgkin's lymphoma (n=55, 5-year OS 55%, 5-year PFS 36%), and first-line multiple myeloma (n=71, 5-year OS 53%, 5-year PFS 24%). For allogeneic transplanted patients, the cumulative TRM was 23% and the incidence of acute GVHD was 23%. For autografted patients, TRM was 2.6%. These results indicate that despite the relatively low socioeconomic status of the Lebanese population, both allogeneic and autologous HSCT are feasible with outcomes similar to developed countries.

L-asparaginase-induced posterior reversible encephalopathy syndrome during acute lymphoblastic leukemia treatment in children

L-asparaginase is a critical component in the treatment of acute lymphoblastic leukemia in children. It is known to cause coagulation abnormalities, thrombosis and hemorrhage in the central nervous system in addition to vasculitis and hypersensitivity reactions. The purpose of this article is to present the first case-series of posterior reversible encephalopathy syndrome (PRES) associated with L-asparaginase treatment. We report 3 cases of children with acute lymphoblastic leukemia who developed seizures and altered sensorium after L-asparaginase therapy. MRI showed increased T(2) signal intensity predominant in the posterior regions of the brain suggestive of PRES. Two of our patients developed septic shock and deteriorated whereas one patient improved and recovered completely.

3D Reconstruction of dental specimens from 2D histological images and μCT-Scans

Direct comparison of experimental and theoretical results in biomechanical studies requires a careful reconstruction of specimen surfaces to achieve a satisfactory congruence for validation. In this paper a semi-automatic approach is described to reconstruct triangular boundary representations from images originating from, either histological sections or microCT-, CT- or MRI-data, respectively. In a user-guided first step, planar 2D contours were extracted for every material of interest, using image segmentation techniques. In a second step, standard 2D triangulation algorithms were used to derive high quality mesh representations of the underlying surfaces. This was accomplished by converting the 2D meshes into 3D meshes by a novel lifting procedure. The meshes can be imported as is into finite element programme packages such as Marc/Mentat or COSMOS/M. Accuracy and feasibility of the algorithm is demonstrated by reconstructing several specimens as examples and comparing simulated results with available measurements performed on the original objects.

Impact of chronic transfusion on incidence of pain and acute chest syndrome during the Stroke Prevention Trial (STOP) in sickle-cell anemia

OBJECTIVE

The Stroke Prevention Trial (STOP) demonstrated that chronic transfusion is highly effective in reducing the risk of stroke in children with sickle-cell disease and an abnormal transcranial Doppler ultrasonography examination result. Our objective was to determine whether chronic transfusion therapy reduces the incidence of pain and acute chest syndrome.

METHODS

During STOP, 130 children with sickle-cell anemia or sickle beta(0)-thalassemia and abnormal transcranial Doppler ultrasonography examination result were randomly assigned to chronic transfusion (n = 63) or observation (n = 67). In addition to monitoring for stroke, nonneurologic sickle-cell complications were identified and recorded.

RESULTS

Mean age at STOP study entry was 8.3 +/- 3.3 years, and mean follow-up was 19.6 +/- 6.5 months. Hospitalization rates (based on intent-to-treat analysis) for acute chest syndrome were 4.8 and 15.3 per 100 patient-years (P =.0027) and for pain were 16.2 and 27.6 per 100 patient-years (P =.13) in the chronic transfusion and observed groups, respectively. If analyzed according to treatment actually received, the difference in pain rate becomes significant (9.7 vs 27.1 events per 100 patient-years, P =.014), and transfusion remains protective from acute chest syndrome (2.2 vs 15.7 events per 100 patient-years, P =.0001).

CONCLUSIONS

Compliance with aggressive chronic transfusion reduces the frequency of acute chest syndrome and pain episodes.

Purified poloxamer 188 for treatment of acute vaso-occlusive crisis of sickle cell disease: A randomized controlled trial

CONTEXT

Sickle cell disease (SCD) can cause severe painful episodes that are often thought to be caused by vaso-occlusion. The current therapy for these uncomplicated painful episodes includes hydration, oxygen, and analgesics. Purified poloxamer 188 may increase tissue oxygenation and thereby reduce inflammation, pain, and the overall duration of such painful episodes in patients with SCD.

OBJECTIVE

To compare the duration of painful episodes in patients with SCD treated with purified poloxamer 188 to that of similar episodes experienced by patients who receive a placebo.

DESIGN AND SETTING

Randomized, double-blind, placebo-controlled, intention-to-treat trial conducted between March 1998 and October 1999 in 40 medical centers in the United States.

PARTICIPANTS

Two hundred fifty-five patients with SCD (aged 9-53 years) who had a painful episode sufficiently severe to require hospitalization and narcotic analgesics.

INTERVENTION

Patients were randomly assigned to receive an intravenous infusion of purified poloxamer 188, 100 mg/kg for 1 hour followed by 30 mg/kg per hour for 47 hours (n = 127), or a matching volume of saline placebo (n = 128).

MAIN OUTCOME MEASURE

Duration of the painful episode, from randomization to crisis resolution.

RESULTS

Mean (SD) duration of the painful episodes was 141 (42) hours in the placebo group compared with 133 (41) hours in those treated with purified poloxamer 188, a 9-hour reduction (P =.04). Subset analyses indicated an even more pronounced purified poloxamer 188 effect in children aged 15 years or younger (21 hours; P =.01) and in patients who were receiving hydroxyurea (16 hours; P =.02). Finally, the proportion of patients achieving crisis resolution was increased by purified poloxamer 188 (65/126 [52%] vs 45/123 [37%]; P =.02). Similar results were observed in children aged 15 years or younger (22/37 [60%] vs 10/36 [28%]; P =.009) and in patients who were also receiving hydroxyurea (12/26 [46%] vs 4/28 [14%]; P =.02).

CONCLUSIONS

A decrease in the duration of painful episodes and an increase in the proportion of patients who achieved resolution of the symptoms were observed when the purified poloxamer 188-treated patients were compared with the patients receiving placebo. However, the difference between these groups was significant but relatively small. In subgroup analysis, a more significant effect on both parameters was observed in children and in patients who were receiving concomitant hydroxyurea. It is important to confirm both of these observations in further prospective trials.

Neuronal synthesized insulin roles on neural differentiation within fetal rat neuron cell cultures

We previously, described the production and secretion of insulin by fetal neurons in culture and demonstrated that neuronal synthesized insulin [I(n)] promoted neurofilament distribution and axonal growth. In this study we investigated the role of I(n) in promoting neural differentiation. Stem cells from 16 day gestational age rat brains were cultured in an insulin-free defined medium (IFDM) and treated with: 5, 20 or 100 ng/ml of exogenous insulin, 100 ng/ml insulin-like growth factor I (IGF-I) or an anti-insulin antibody. The neurons were studied at 1 and 3 days of incubation. The total number of cells showed no significant difference (P>0.05) in any of the media used, except the IFDM at day 3 of incubation treated with the anti-insulin antibody (P<0.05) and IGF-I to 20 ng/ml of insulin (P<0.05). No significant difference (P>0.05) was found in the number of differentiated neurons incubated in the IFMD, in which the neurons produce and secrete I(n), between days 1 and 3 of incubation, but neural differentiation decreased significantly (P<0.05) when treated with the anti-insulin antibody. Exogenous insulin significantly increased (P<0.05) the number of differentiated neurons compared to the IFDM. A significant reduction (P<0.05) of differentiated neurons was observed at day 3 of incubation with IGF-I compared to all the different media. Thus, I(n) has a role in promoting neural differentiation and growth, but exogenous insulin promoted neural differentiation and growth beyond I(n).

PMMA-based composite materials with reactive ceramic fillers: IV. Radiopacifying particles embedded in PMMA beads for acrylic bone cements

New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS) and embedded in poly(methylmethacrylate-co-ethylacrylate) beads with about 7 mol% of ethyl acrylate repeating units. The encapsulation was performed through a conventional suspension polymerization process. The influence of (i) the concentration of the dispersion stabilizer and (ii) the alumina content upon the shape, size, and size distribution of the acrylic beads was studied. Cements were prepared from each batch by hand-mixing alumina-filled acrylic beads with a liquid monomer mixture containing methyl methacrylate, n-butyl methacrylate, and N,N-dimethyl-p-toluidine. Benzoyl peroxide was previously added to the solid part. The powder-to-liquid ratio was equal to 2 for each formulation. Compressive strength of cured cement decreases with alumina content, whereas compressive modulus remains roughly constant. These results are in contradiction to those obtained for cements based on a mixture of gamma-MPS-treated alumina and unfilled acrylic beads. Nevertheless, they are interpreted in terms of alumina arrangement in the cement. In the first case, alumina particles contribute to the reinforcement of the dispersed acrylic phase, with poor benefits for the whole materials. In the second case, they allow the reinforcement of the continuous acrylic phase and, therefore, the cement's one.

PMMA-based composite materials with reactive ceramic fillers: part III: radiopacifying particle-reinforced bone cements

New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS), able to act both as radiopacifying and reinforcing agents. The present study deals with the handling characteristics and the compressive behavior of such cements. The influence of the particles morphology, their surface-modification by gamma-MPS bonding agent, their concentration in the cement, the powder-to-liquid ratio and the benzoyl peroxide concentration are reported. The role of grafted gamma-MPS molecules as coupling agent was confirmed. For several formulations, compressive strength and modulus reached 150 MPa and 3400 MPa respectively. Limitations in the use of such formulations are also comprehensively discussed.

Use of amphotericin B colloidal dispersion in children

PURPOSE

To describe the experience with a new lipid-based amphotericin product (amphotericin B colloidal dispersion or ABCD) in children with fever and neutropenia who are at high risk for fungal infection.

PATIENTS AND METHODS

Forty-nine children with febrile neutropenia were treated in a prospective, randomized trial comparing ABCD with amphotericin B. An additional 70 children with presumed or proven fungal infection were treated with 5 different open-label studies of ABCD. Patients were registered into these studies for reasons of: 1) failure to respond to amphotericin B; 2) development of nephrotoxicity or preexisting renal impairment; or 3) willingness to participate in a dose-escalation study. Extensive data detailing response and toxicity were collected from each patient.

RESULTS

In the randomized trial, there was significantly less renal toxicity in the children receiving ABCD than in those receiving amphotericin B (12.0% vs. 52.4% [P = 0.003]). Other adverse symptoms were not significantly different. In the additional open-label studies, although 80% of patients receiving ABCD reported some adverse symptom, the majority of these were infusion related, and nephrotoxicity was reported in only 12% of these patients.

CONCLUSIONS

ABCD was well-tolerated at doses up to 5 times greater then those usually tolerated with amphotericin B. Renal toxicity was markedly less than expected, and there were no other unexpected severe toxicities. Further randomized studies are needed to further define the role of this and other liposomal products in children.

Brain endogenous insulin effects on neurite growth within fetal rat neuron cell cultures

We have previously described insulin to be synthesized "de novo" within the fetal rat brain and that brain endogenous insulin [I(n)] promoted neurofilament distribution within fetal neurons. In this study, we investigated the role of I(n) in neuron axonal growth. Rat fetal brain stem cells from 16-day gestational age were cultured in an IFDM and treated with an insulin antibody. In addition, the cell cultures were also treated in defined medium with the addition of: 5 ng, 20 ng or 100 ng/ml of insulin or 100 ng/ml insulin-like growth factor 1 (IGF-1). The neuron cell cultures were studied at 1 and 3 days of incubation. The presence of preproinsulin mRNA and insulin immunoreaction confirmed the "de novo" synthesis of insulin by the fetal neuron cell cultures. Axonal growth was similar by day 1 of the study in all the media, but in insulin medium containing 100 ng/ml of insulin the axonal length was significantly longer. By day 3 of incubation I(n) promoted axonal growth. Treating the neurons with an insulin antibody confirmed these findings, with a significant decrease in axonal length (p<0.05). The treatment with different concentrations of exogenous insulin did not promote axonal growth beyond I(n) by day 3 of incubation. IGF-1 did not promote axonal growth by day 3 of incubation. In summary, I(n) may promote axonal growth during brain development.

Impact of oligohydramnios on maternal and perinatal outcomes of spontaneous premature rupture of the membranes at 18-28 weeks

OBJECTIVE

We compare the maternal and perinatal outcomes between 69 patients with oligohydramnios and 49 patients with adequate fluid at the time of initial evaluation for PROM.

METHODS

One hundred and eighteen patients with spontaneous premature rupture of the membranes (PROM) at 18-28 weeks are included in the study. Inclusion criteria are singleton gestation, normal fetal anatomical survey and normal amniotic fluid prior to PROM, and absence of labor or abruption at the time of PROM. Oligohydramnios is defined as an amniotic fluid index (AFI) <5 cm of measurable pockets of amniotic fluid which are free of umbilical cord. Expectant management was carried during the 3-year period. The overall perinatal survival is 66%. Pulmonary hypoplasia is present in 18%, and skeletal deformities in 3% of all neonates.

RESULTS

There is no significant difference between the two groups in the mean gestational ages at PROM (172+/-17 d vs. 171+/-14 d), latency periods (9+/-14 d vs. 8+/-13 d), incidences of chorioamnionitis (48 vs. 39%), endometritis (19 vs. 14%), neonatal sepsis (11 vs. 13%), or skeletal deformities (6 vs. 0%). Patients with oligohydraminos have significantly higher incidences of fetal heart rate decelerations (59 vs. 38%) and C-section (38 vs. 16%) (P < 0.05) than patients with adequate amniotic fluid.

CONCLUSIONS

After adjusting for confounding variables, neonates with oligohydramnios are twice as likely to develop pulmonary hypoplasia (20 vs. 10%) and more likely to experience neonatal death (30 vs. 20%) when compared to those with adequate fluid, even though the difference is not statistically significant.

Effects of brain endogenous insulin on neurofilament and MAPK in fetal rat neuron cell cultures

We demonstrated the 'de novo' synthesis of insulin within the fetal nervous system in vivo and in vitro. We undertook this study to show a role for brain endogenous insulin within the fetal brain. We used neuron cell cultures (NCC) from 19 days gestational age fetal rat brains incubated in an insulin free/serum free defined medium. The neurons showed the presence of preproinsulin I and II mRNA using polymerase chain reaction and insulin immunoreaction employing peroxidase anti-peroxidase and radioimmunoassay techniques. Using an anti-pan neurofilament antibody (that recognizes non-phosphorylated neurofilaments) neurofilament immunoreaction (NFI) was observed within the neuron body, dendrites and axon. Either insulin antibody or isoproterenol treatment induced the neurites to retract and most of the neurons become round, with NFI confined to the neuron body. The antibody treatments induced the neurons to become hypertrophic and vacuolated. With PD98059 treatment NFI was only observed within the neuron body. The addition of insulin reversed the effects of isoproterenol and PD98059, but not those of the insulin antibody. Treatment with wortmannin had no effect. Western blot analysis showed that the basal level of mitogen activated protein kinase (MAPK) phosphorylation was inhibited by the treatment of the NCC with isoproterenol or trypsin, but was significantly increased by treatment with exogenous insulin, demonstrating that brain endogenous insulin phosphorylated MAPK (p<0.05). Thus, brain endogenous insulin promotes neurite outgrowth, probably via MAPK and by stimulating neurofilament distribution via this mechanism participates in neuron differentiation.

Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography

BACKGROUND

Blood transfusions prevent recurrent stroke in children with sickle cell anemia, but the value of transfusions in preventing a first stroke is unknown. We used transcranial Doppler ultrasonography to identify children with sickle cell anemia who were at high risk for stroke and then randomly assigned them to receive standard care or transfusions to prevent a first stroke.

METHODS

To enter the study, children with sickle cell anemia and no history of stroke had to have undergone two transcranial Doppler studies that showed that the time-averaged mean blood-flow velocity in the internal carotid or middle cerebral artery was 200 cm per second or higher. The patients were randomly assigned to receive standard care or transfusions to reduce the hemoglobin S concentration to less than 30 percent of the total hemoglobin concentration. The incidence of stroke (cerebral infarction or intracranial hemorrhage) was compared between the two groups.

RESULTS

A total of 130 children (mean [+/-SD] age, 8.3+/-3.3 years) were enrolled; 63 were randomly assigned to receive transfusions and 67 to receive standard care. At base line, the transfusion group had a slightly lower mean hemoglobin concentration (7.2 vs. 7.6 g per deciliter, P=0.001) and hematocrit (20.4 vs. 21.7 percent, P=0.002). Ten patients dropped out of the transfusion group, and two patients crossed over from the standard-care group to the transfusion group. There were 10 cerebral infarctions and 1 intracerebral hematoma in the standard-care group, as compared with 1 infarction in the transfusion group -- a 92 percent difference in the risk of stroke (P<0.001). This result led to the early termination of the trial.

CONCLUSIONS

Transfusion greatly reduces the risk of a first stroke in children with sickle cell anemia who have abnormal results on transcranial Doppler ultrasonography.

Stroke prevention trial in sickle cell anemia

Stroke occurs in 7-8% of children with Sickle Cell Disease (Hb SS) and is a major cause of morbidity. Rates of recurrence have been reduced from 46-90% to less than 10% through chronic blood transfusions. Prevention of first stroke, however, would be preferable because even one stroke can cause irreversible brain injury. Transcranial Doppler (TCD) ultrasound can detect arterial blood flow rates associated with subsequent stroke risk. By combining TCD screening and a potentially effective treatment, first stroke may be prevented. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) is the first stroke prevention trial in Hb SS and the first randomized, controlled use of transfusion in Hb SS. This multi-center trial is designed to test whether reducing sickle hemoglobin to 30% or less with periodic blood transfusions will reduce first-time stroke by at least 70% compared to standard care. Primary endpoints will be clinically evident symptoms of cerebral infarction with consistent findings on Magnetic Resonance Imaging and Angiography (MRI/MRA) or symptomatic intracranial hemorrhage. Secondary endpoints will be asymptomatic brain lesions detected by MRI in brain areas not involved in primary endpoints. The design calls for a 6-month start-up interval, 18 months of TCD screening and randomization, and observation for stroke from entry through month 54. Key features of the trial are standardized TCD and MRI/MRA protocols interpreted blindly, and blinded adjudication of endpoints. The sample size (60 per treatment group) is based on prospective data relating TCD velocity to risk of stroke. A time-averaged mean velocity of > or = 200 cm/sec is associated with a 46% risk of cerebral infarction over 39 months. The sample size is sufficient to detect 70% reduction in the primary endpoint at 90% power. This trial will determine if transfusion is effective in the primary prevention of stroke. Secondary aims may further the understanding of the effects of transfusion on the brain and guide future research into cerebrovascular disease in Hb SS.

Successful treatment of relapsed infant acute lymphoblastic leukemia with intensive antimetabolite-based chemotherapy

PURPOSE

The treatment of infant acute lymphoblastic leukemia (ALL) continues to be a significant challenge for pediatric oncologists due to the high incidence of early relapses. Salvage regimens used to date have met limited success. We describe two cases of relapsed infant ALL who have achieved long-term survival with an intensive antimetabolite-based salvage regimen.

PATIENTS AND METHODS

Two consecutive infants with relapsed ALL presented at our institution and were treated with an antimetabolite-based regimen. Both cases exhibited clinical and biological phenotypes previously associated with infantile ALL.

RESULTS

Both patients have achieved prolonged and sustained remissions 48 and 30 months EFS respectively following therapy with intensive antimetabolite-based salvage regimen.

CONCLUSIONS

An intensive multiagent antimetabolite based salvage regimen resulted in prolonged EFS in two cases of relapsed infant ALL. Dose intensification was achieved by administering repeated cycles of the same treatment schema using high dose chemotherapy throughout therapy. These infants were spared prophylactic cranial irradiation without a negative impact on outcome. The use of L-asparaginase, timed after high-dose Cytarabine (ARA-C) throughout therapy, might have contributed to their cure.

Effects of CD34+ selection and T cell immunodepletion on cord blood hematopoietic progenitors: relevance to stem cell transplantation

Cord blood (CB) has been used recently for stem cell transplantation. We have investigated two different approaches to deplete CB samples of T cells capable of mounting graft-vs.-host disease (GVHD). The methods used were selection of CD34+ cells using avidin-biotin columns (CellPro) and T cell immunodepletion with T10B9 monoclonal antibody (mAb) plus complement. Using the avidin-biotin columns, 10.3% of the original CD34+ cells were recovered. Although this technique yielded a population containing 60 +/- 5.5% CD34+ cells, about 1 log of CFU-GM progenitors were lost. In contrast, after the T10B9 mAb and complement immunodepletion, 75 +/- 19% and 62 +/- 7% of the CD34+ cells and CFU-GM were recovered, respectively. T cell depletion was 3.6 logs using the CellPro columns and 2.2 logs after immunodepletion. To investigate whether cell losses following T cell depletion could be overcome by ex vivo expansion, cells were cultured in the presence of recombinant human interleukin-3 (rhIL-3) and recombinant human c-kit ligand (stem cell factor [rhSCF]) for 7 days. There were 14- and six-fold expansions in the number of progenitors recovered after CellPro and immunodepletion, respectively. To asses the engraftment potential of expanded cells, we used a murine transplantation model in which the presence of human cells was identified by the anti-CD45 mAb. Cells expanded in vitro engrafted in irradiated BNXid mice as efficiently as nonexpanded cells, suggesting that expansion did not affect their transplantability. This study shows that both techniques resulted in significant T cell depletion of CB. Furthermore, in vitro expansion could overcome cell losses sustained during the separation techniques without impairing the engraftment potential of the expanded cells.

Incidence of calcifications in the breast after surgical reduction and liposuction

Liposuction of the breast in combination with vertical mammaplasty was applied to 250 breasts among 386 reductions of large breasts performed in 2 years (1989 to 1991). To evaluate the possible damage to the breast caused by this combined procedure, especially in terms of the occurrence of the postoperative development of calcifications, a comparative study of preoperative and postoperative mammograms was undertaken in 60 randomly selected cases (120 breasts), 34 with and 26 without liposuction. Altogether, 13 calcifications (11 percent) were discovered during the 6- to 30-month follow-up, representing the lowest rate reported in the literature. Deep intraparenchymal calcifications were more frequent after liposuction; most (5 of 7) were macrocalcifications. None could be confused with malignant calcifications because they were more scattered, more regular, and less numerous. Attempts to evaluate the fat content of breasts via preoperative mammography failed to prove this examination a useful way to predict the viability of breast liposuction.

A comparison of conservative and aggressive transfusion regimens in the perioperative management of sickle cell disease. The Preoperative Transfusion in Sickle Cell Disease Study Group

BACKGROUND

Preoperative transfusions are frequently given to prevent perioperative morbidity in patients with sickle cell anemia. There is no consensus, however, on the best regimen of transfusions for this purpose.

METHODS

We conducted a multicenter study to compare the rates of perioperative complications among patients randomly assigned to receive either an aggressive transfusion regimen designed to decrease the hemoglobin S level to less than 30 percent (group 1) or a conservative regimen designed to increase the hemoglobin level to 10 g per deciliter (group 2).

RESULTS

Patients undergoing a total of 604 operations were randomly assigned to group 1 or group 2. The severity of the disease, compliance with the protocol, and the types of operations were similar in the two groups. The preoperative hemoglobin level was 11 g per deciliter in group 1 and 10.6 g per deciliter in group 2. The preoperative value for hemoglobin S was 31 percent in group 1 and 59 percent in group 2. The most frequent operations were cholecystectomies (232), head and neck surgery (156), and orthopedic surgery (72). With the exception of transfusion-related complications, which occurred in 14 percent of the operations in group 1 and in 7 percent of those in group 2, the frequency of serious complications was similar in the two groups (31 percent in group 1 and 35 percent in group 2). The acute chest syndrome developed in 10 percent of both groups and resulted in two deaths in group 1. A history of pulmonary disease and a higher risk associated with surgery were significant predictors of the acute chest syndrome.

CONCLUSIONS

A conservative transfusion regimen was as effective as an aggressive regimen in preventing perioperative complications in patients with sickle cell anemia, and the conservative approach resulted in only half as many transfusion-associated complications.

Hemolytic jaundice due to G6PD deficiency causing kernicterus in a female newborn

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited deficiency of an enzyme necessary to protect the erythrocyte from oxidative stress and hemolysis. Without this enzyme, affected neonates are at risk for acute onset of hemolytic jaundice and severe sequelae, from hearing loss and mild retardation to kernicterus. In some populations, especially in blacks and those of Mediterranean ancestry, the incidence of G6PD deficiency has been reported to be as high as 10% to 14%. We describe a female newborn who had acute onset of hyperbilirubinemia leading to kernicterus in the first week of life. Investigation proved G6PD deficiency. This case suggests a need to screen for this disease or to follow serial bilirubin levels in populations at risk.

Risk of recurrent stroke in patients with sickle cell disease treated with erythrocyte transfusions

OBJECTIVE

To determine the effect of a transfusion program on risk of stroke recurrence in children with sickle cell disease.

DESIGN

The clinical course and experience with transfusion therapy at eight centers were reviewed for subjects whose initial stroke occurred after January 1988.

RESULTS

Sixty subjects were observed for 191.7 patient-years. Eight had a single recurrent stroke (two intracranial hemorrhages and six infarctions) for a prevalence of 13.3%, or one recurrence for each 24 patient-years of observation. Thirteen subjects had 15 transient neurologic events; two of these had subsequent strokes, but the overall risk was similar for those who did and those did not have transient events. Hemoglobin S levels were greater than the desired maximum of 30% at the time of 7 of 16 transient events and five of six recurrent infarctions. The stroke recurrence rate was similar to those in previous reports of children receiving long-term transfusion therapy but significantly less than that reported for children who did not receive transfusions (p < 0.001).

CONCLUSIONS

We conclude that maintenance of hemoglobin S at a level less than 30% appears to be effective in reducing the rate of recurrent infarction but does not prevent transient neurologic events. Transient neurologic events are common but do not appear to be related to recurrent stroke.

[Analysis of 156 breast reconstructions by transverse rectus abdominis muscle flap (TRAM)]

The myocutaneous rectus abdominis flap described by Hartrampf was used for 156 breast reconstructions between 1982 and 1992. 107 reconstructions were done with one pedicle. 142 were delayed reconstructions. Partial necrosis of the flap occurred in 10% of the cases in bipedicled flaps and 20% in unilateral flaps. No hernia occurred in this series. Cosmetic results are considered satisfactory or very satisfactory in 59% of the cases when evaluated by the medical team and 76.5% when evaluated by the patients. As a conclusion of this study, the TRAM flap is preferred in delayed reconstructions when local and general conditions are suitable, rather than latissimus dorsi flap reconstructions which require an implant.

Study of early hematopoietic precursors in human cord blood

Human cord blood is a source of transplantable stem cells. These stem cells express the antigen CD34, are resistant to treatment with 4-hydroperoxycyclophosphamide (CD34+/4-HCres), and do not give rise to colonies when plated in clonogenic assays. We studied the number of CD34+ cells present in cord blood and developed a two-step assay for early precursors (pre-colony-forming units, pre-CFU) capable of giving rise to committed progenitors. In this assay CD34+/4-HCres cord blood cells were cultured in suspension with different growth factors. After 7 days in suspension the remaining cells were plated in clonogenic assays, for granulocyte-macrophage colony-forming units (CFU-GM), erythroid burst-forming units (BFU-E), and mixed lineage colony-forming units (CFU-MIX), in the presence of pure factors or a combination of recombinant human (rh) interleukin 3 (IL-3) and medium conditioned by the PU34 primate cell line. Pre-CFU for all precursors were identified. These pre-CFU developed into committed progenitors in response to rhIL-3. The combinations of rhIL-3 plus rh interleukin 1 (IL-1) or rhIL-3 plus rh interleukin 6 (IL-6) did not enhance recovery of progenitors. The developing CFU-GM were responsive to rh granulocyte-macrophage colony-stimulating factor (GM-CSF) and rh granulocyte colony-stimulating factor (G-CSF) but much less so to rhIL-3. BFU-E and CFU-MIX developed in suspension but could only be detected when cells were replated in the presence of a combination of rhIL-3 and PU34 but not rhIL-3 alone. This assay may be useful in evaluating the number of early hematopoietic precursors present in cord blood samples and in defining growth factor combinations that could enhance hematopoietic recovery after cord blood stem cell transplants.