Diagnosing and Grading of Sinusoidal Obstructive Syndrome after Hematopoietic Stem Cell Transplant of Children, Adolescent and Young Adults treated in a Pediatric Institution with Pediatric Protocols

INTRODUCTION

Sinusoidal obstructive syndrome (SOS), or veno-occlusive disease (VOD), of the liver has been recognized as a complex, life-threatening complication in the post-hematopoietic stem cell transplant (HSCT) setting. The diagnostic criteria for SOS have evolved over the last several decades with a greater understanding of the underlying pathophysiology, with two recent diagnostic criteria introduced in 2018 (EBMT criteria) and 2020 (Cairo criteria).

OBJECTIVE

We sought out to evaluate the performance characteristics in diagnosing and grading SOS in pediatric patients of the four different diagnostic criteria (Baltimore, Modified Seattle, EBMT, and Cairo) and severity grading systems (defined by the EBMT and Cairo criteria).

STUDY

Design: Retrospective chart review of children, adolescent and young adults (CAYA) who underwent conditioned autologous and allogeneic HSCT between 2017 and 2021 at a single pediatric institution.

RESULTS

A total of 250 consecutive patients underwent at least one HSCT at UCSF Benioff Children's Hospital San Francisco for a total of 307 HSCT. The day 100 cumulative incidence of SOS was 12.1%, 21.1%, 28.4%, and 28.4% per the Baltimore, Modified Seattle, EBMT, and Cairo criteria, respectively (p<0.001). We found that patients diagnosed with grade ≥4 SOS per the Cairo criteria were more likely to be admitted to the PICU (92% vs. 58%, p=0.035) and intubated (85% vs. 32%, p=0.002) than those diagnosed with grade ≥4 per EBMT criteria. Age <3 years-old (HR 1.76, 95% [1.04-2.98], p=0.036), an abnormal BMI (HR 1.69, 95% [1.06-2.68], p=0.027), and high-risk patients per our institutional guidelines (HR 1.68, 95% [1.02-2.76], p=0.041) were significantly associated with SOS per the Cairo criteria.

CONCLUSIONS

We demonstrate that age <3 years, abnormal BMI, and other high-risk criteria associate strongly with subsequent SOS development. Patients with moderate to severe SOS based on Cairo severity grading criteria may correlate better with clinical course based on ICU admissions and intubations when compared to the EBMT severity grading system.

A pilot trial of prophylactic defibrotide to prevent serious thrombotic microangiopathy in high-risk pediatric patients

BACKGROUND

Transplant-associated thrombotic microangiopathy (TA-TMA) is an endothelial injury complication of hematopoietic stem cell transplant (HSCT) leading to end-organ damage and high morbidity and mortality. Defibrotide is an anti-inflammatory and antithrombotic agent that may protect the endothelium during conditioning.

PROCEDURE

We hypothesized that prophylactic use of defibrotide during HSCT conditioning and acute recovery could prevent TA-TMA. A pilot single-arm phase II trial (NCT#03384693) evaluated the safety and feasibility of administering prophylactic defibrotide to high-risk pediatric patients during HSCT and assessed if prophylactic defibrotide prevented TA-TMA compared to historic controls. Patients received defibrotide 6.25 mg/kg IV q6h the day prior to the start of conditioning through day +21. Patients were prospectively monitored for TA-TMA from admission through week 24 post transplant. Potential biomarkers of endothelial injury (suppression of tumorigenicity 2 [ST2], angiopoietin-2 [ANG-2], plasminogen activator inhibitor-1 [PAI-1], and free hemoglobin) were analyzed.

RESULTS

Twenty-five patients were enrolled, 14 undergoing tandem autologous HSCT for neuroblastoma and 11 undergoing allogeneic HSCT. Defibrotide was discontinued early due to possibly related clinically significant bleeding in 12% (3/25) of patients; no other severe adverse events occurred due to the study intervention. The other 22 patients missed a median of 0.7% of doses (0%-5.2%). One patient developed nonsevere TA-TMA 12 days post HSCT. This observed TA-TMA incidence of 4% was below the historic rate of 18%-40% in a similar population of allogeneic and autologous patients.

CONCLUSIONS

Our study provides evidence that defibrotide prophylaxis is feasible in pediatric patients undergoing HSCT at high risk for TA-TMA and preliminary data indicating that defibrotide may reduce the risk of TA-TMA.

Diagnostic work-up for severe aplastic anemia in children: Consensus of the North American Pediatric Aplastic Anemia Consortium

The North American Pediatric Aplastic Anemia Consortium (NAPAAC) is a group of pediatric hematologist-oncologists, hematopathologists, and bone marrow transplant physicians from 46 institutions in North America with interest and expertise in aplastic anemia, inherited bone marrow failure syndromes, and myelodysplastic syndromes. The NAPAAC Bone Marrow Failure Diagnosis and Care Guidelines Working Group was established with the charge of harmonizing the approach to the diagnostic workup of aplastic anemia in an effort to standardize best practices in the field. This document outlines the rationale for initial evaluations in pediatric patients presenting with signs and symptoms concerning for severe aplastic anemia.

Plasma-derived factor X concentrate compassionate use for hereditary factor X deficiency: Long-term safety and efficacy in a retrospective data-collection study

BACKGROUND

Coagadex is a high-purity plasma-derived factor X concentrate (pdFX) developed to treat hereditary factor X deficiency (FXD).

OBJECTIVE

Evaluate the efficacy and safety of pdFX administered to patients with hereditary FXD.

METHODS

This was an open-label, multicenter, retrospective analysis of patients receiving pdFX for compassionate use. Efficacy end points included treatments administered, the number and treatment of bleeds, and investigator assessments. Adverse drug reactions (ADRs) were monitored.

RESULTS

Fifteen patients were included: seven received routine prophylaxis, seven received on-demand treatment, and one alternated. Most were aged ≥12 years (n = 13) and had severe hereditary FXD (n = 12). The median follow-up time was 19.2 months (range, 3.5-48.8). The number of infusions per patient per month was higher for the routine prophylaxis group (median [range], 5.4 [1.4-10.1]) than for the on-demand group (0.8 [0.1-2.3]), as was the dose per infusion (27.9 [21.9-53.6] IU/kg vs 20.0 [13.6-27.7] IU/kg). Patients experienced 88 bleeds (34 minor, 7 major, 47 unclassified). The monthly bleed rate per patient was 0.04 in the routine prophylaxis group (based on 17 bleeds in four patients) and 0.8 in the on-demand group (based on 71 bleeds in eight patients). pdFX was used to treat 79 bleeds and was rated effective in all instances. In an overall assessment, investigators rated pdFX as excellent for 14 patients (93.3%) and good for 1 patient (6.3%). No ADRs or safety concerns were reported.

CONCLUSIONS

This analysis supports the use of pdFX as a safe, effective treatment for hereditary FXD. Routine prophylaxis with pdFX may reduce bleed frequency.

[Forcasting the prevalence of myopia among students aged 6-18 years in China from 2021 to 2030]

Objective: To predict the prevalence of myopia among Chinese students aged 6-18 years under different intervention scenarios from 2021 to 2030. Methods: The multi-state Markov model was developed based on the transition process of study stages and myopia statuses. The development of myopia was simplified into two statuses: non-myopia and myopia. Students aged 6-18 years were also divided according to their study stages including senior kindergarten, primary school (from Grade 1 to 6), junior school (from Grade 1 to 3) and high school (from Grade 1 to 3). The parameters were extracted from the National Myopia Investigation in 2018 and published articles of cohort studies. The transition probability was applied to simulate the intervention scenarios, and sensitivity analysis was carried out. Results: The cumulative incidence of myopia among Chinese school-aged children and adolescents would increase consistently. It would be 91.3% (min to max: 83.7% to 96.7%) upon graduation from high school. Without any intervention, the myopia prevalence would increase to 61.8% (min to max: 55.4% to 69.5%) by 2030 among Chinese school-aged children and adolescents. And the myopia prevalence among students in primary schools, junior schools and high schools would be 45.6% (min to max: 40.2% to 54.3%), 81.3% (min to max: 72.6% to 91.0%) and 90.5% (min to max: 82.4% to 96.7%), respectively, all higher than the national target. If the interventions could achieve 70% of the desired effect, the myopia prevalence would be lower than the national target at each stage. Conclusions: Without effective interventions, the prevalence of myopia among students aged 6-18 years may keep increasing in the next ten years. If the interventions achieve the desired effect, the national target for myopia prevention and control could be reached. It is urgent to identify more effective interventions and call on the whole society to participate in the myopia prevention action to achieve the national goal by 2030. (Chin J Ophthalmol, 2021, 57: 261-267).

Distinct genetic pathways define pre-malignant versus compensatory clonal hematopoiesis in Shwachman-Diamond syndrome

To understand the mechanisms that mediate germline genetic leukemia predisposition, we studied the inherited ribosomopathy Shwachman-Diamond syndrome (SDS), a bone marrow failure disorder with high risk of myeloid malignancies at an early age. To define the mechanistic basis of clonal hematopoiesis in SDS, we investigate somatic mutations acquired by patients with SDS followed longitudinally. Here we report that multiple independent somatic hematopoietic clones arise early in life, most commonly harboring heterozygous mutations in EIF6 or TP53. We show that germline SBDS deficiency establishes a fitness constraint that drives selection of somatic clones via two distinct mechanisms with different clinical consequences. EIF6 inactivation mediates a compensatory pathway with limited leukemic potential by ameliorating the underlying SDS ribosome defect and enhancing clone fitness. TP53 mutations define a maladaptive pathway with enhanced leukemic potential by inactivating tumor suppressor checkpoints without correcting the ribosome defect. Subsequent development of leukemia was associated with acquisition of biallelic TP53 alterations. These results mechanistically link leukemia predisposition to germline genetic constraints on cellular fitness, and provide a rational framework for clinical surveillance strategies.

A study assessing the feasibility of randomization of pediatric and young adult patients between matched unrelated donor bone marrow transplantation and immune-suppressive therapy for newly diagnosed severe aplastic anemia: A joint pilot trial of the North American Pediatric Aplastic Anemia Consortium and the Pediatric Transplantation and Cellular Therapy Consortium

BACKGROUND

Recent data show survival after matched unrelated donor (MUD) bone marrow transplantation (BMT) is similar to matched sibling procedures for young patients with severe aplastic anemia (SAA). Donor delays, risk of transplant-related mortality (TRM), and concern about chronic graft versus host disease raise questions about whether MUD BMT or immune suppression therapy (IST) should be preferred initial therapy for young patients lacking matched sibling donors.

PROCEDURE

We performed a pilot trial to assess the feasibility of randomizing patients under age 26 with newly diagnosed SAA to receive IST versus MUD BMT. Primary aims assessed the acceptability of randomization and timing of BMT. Secondary aims measured toxicities, response, and survival.

RESULTS

Sixty-seven patients with possible SAA were screened at nine centers. Of 57 with confirmed SAA, 23 underwent randomization and received therapy with a median follow-up of 18 months. Of 12 randomized to BMT, 10 started BMT as initial therapy at a median of 36 days after randomization. One BMT recipient experienced secondary graft failure, requiring a second procedure. Six of 11 randomized to IST responded, whereas five with refractory disease underwent successful salvage BMT. One patient achieving complete response relapsed after discontinuation of immune suppression and died of infection after salvage BMT.

CONCLUSIONS

This feasibility study showed that a high percentage of patients underwent randomization and received up-front MUD BMT. Our study lays the groundwork for a larger randomized trial that will define best initial therapy for young patients with SAA who have an available MUD.

Reduced Toxicity Conditioning for Nonmalignant Hematopoietic Cell Transplants

Allogeneic hematopoietic cell transplantation (HCT) for children with nonmalignant disorders is challenged by potential drug-related toxicities and poor engraftment. This retrospective analysis expands on our single pediatric medical center experience with targeted busulfan, fludarabine, and intravenous (IV) alemtuzumab as a low-toxicity regimen to achieve sustained donor engraftment. Sixty-two patients received this regimen for their first HCT for a nonmalignant disorder between 2004 and 2018. Donors were matched sibling in 27%, 8/8 HLA allele-matched unrelated in 50%, and 7/8 HLA allele-mismatched in 23% (some of whom received additional immunoablation with thiotepa or clofarabine). Five patients experienced graft failure for a cumulative incidence of 8.4% (95% CI, 1 to 16%). In engrafted patients, the median donor chimerism in whole blood and CD3, CD14/15, and CD19 subsets at 1-year were 96%, 90%, 99%, and 99%, respectively. Only one patient received donor lymphocyte infusions (DLIs) for poor chimerism. Two patients died following disease progression despite 100% donor chimerism. The 3-year cumulative incidence of treatment-related mortality was 10% (95% CI, 2 to 17%). Overall survival and event-free-survival at 3-years were 87% (95% CI, 78 to 95%) and 80% (95% CI, 70 to 90%), respectively. The 6-month cumulative incidence of grade II to IV acute graft-versus-host disease (GVHD) was 7% (95% CI, 3 to 13%), while the 3-year cumulative incidence of chronic GVHD was 5% (95% CI, 0 to 11%). These results suggest that use of targeted busulfan, fludarabine and IV alemtuzumab offers a well-tolerated option for children with nonmalignant disorders to achieve sustained engraftment with a low incidence of GVHD.

Immunosuppressive therapy for pediatric aplastic anemia: a North American Pediatric Aplastic Anemia Consortium study

Quality of response to immunosuppressive therapy and long-term outcomes for pediatric severe aplastic anemia remain incompletely characterized. Contemporary evidence to inform treatment of relapsed or refractory severe aplastic anemia for pediatric patients is also limited. The clinical features and outcomes for 314 children treated from 2002 to 2014 with immunosuppressive therapy for acquired severe aplastic anemia were analyzed retrospectively from 25 institutions in the North American Pediatric Aplastic Anemia Consortium. The majority of subjects (n=264) received horse anti-thymocyte globulin (hATG) plus cyclosporine (CyA) with a median 61 months follow up. Following hATG/CyA, 71.2% (95%CI: 65.3,76.6) achieved an objective response. In contrast to adult studies, the quality of response achieved in pediatric patients was high, with 59.8% (95%CI: 53.7,65.8) complete response and 68.2% (95%CI: 62.2,73.8) achieving at least a very good partial response with a platelet count ≥50×10⁹L. At five years post-hATG/CyA, overall survival was 93% (95%CI: 89,96), but event-free survival without subsequent treatment was only 64% (95%CI: 57,69) without a plateau. Twelve of 171 evaluable patients (7%) acquired clonal abnormalities after diagnosis after a median 25.2 months (range: 4.3-71 months) post treatment. Myelodysplastic syndrome or leukemia developed in 6 of 314 (1.9%). For relapsed/refractory disease, treatment with a hematopoietic stem cell transplant had a superior event-free survival compared to second immunosuppressive therapy treatment in a multivariate analysis (HR=0.19, 95%CI: 0.08,0.47; P=0.0003). This study highlights the need for improved therapies to achieve sustained high-quality remission for children with severe aplastic anemia.

Low Exposure Busulfan Conditioning to Achieve Sufficient Multilineage Chimerism in Patients with Severe Combined Immunodeficiency

After allogeneic hematopoietic cell transplantation (HCT), the minimal myeloid chimerism required for full T and B cell reconstitution in patients with severe combined immunodeficiency (SCID) is unknown. We retrospectively reviewed our experience with low-exposure busulfan (cumulative area under the curve, 30 mg·hr/L) in 10 SCID patients undergoing either first or repeat HCT from unrelated or haploidentical donors. The median busulfan dose required to achieve this exposure was 5.9 mg/kg (range, 4.8 to 9.1). With a median follow-up of 4.5 years all patients survived, with 1 requiring an additional HCT. Donor myeloid chimerism was generally >90% at 1 month post-HCT, but in most patients it fell during the next 3 months, such that 1-year median myeloid chimerism was 14% (range, 2% to 100%). Six of 10 patients had full T and B cell reconstitution, despite myeloid chimerism as low as 3%. Three patients have not recovered B cell function at over 2 years post-HCT, 2 of them in the setting of treatment with rituximab for post-HCT autoimmunity. Low-exposure busulfan was well tolerated and achieved sufficient myeloid chimerism for full immune reconstitution in over 50% of patients. However, other factors beyond busulfan exposure may also play critical roles in determining long-term myeloid chimerism and full T and B cell reconstitution.

Autoimmune Cytopenias in Pediatric Hematopoietic Cell Transplant Patients

Background: Autoimmune cytopenias (AICs) are potentially life-threatening complications following hematopoietic cell transplantation (HCT), yet little is understood about the mechanism by which they develop. We hypothesized that discordant B cell and T cell recovery is associated with AICs in transplant patients, and that this might differ based on transplant indication. Methods: In this case control study of children who underwent HCT at our institution, we evaluated the clinical and transplant characteristics of subjects who developed AICs compared to a control group matched by transplant indication and donor type. In cases, we analyzed the state of immune reconstitution, including B cell recovery, T cell recovery, and chimerism, immediately prior to AIC onset. Subjects were stratified by primary indication for transplant as malignancy (n = 7), primary immune deficiency (PID, n = 9) or other non-malignant disease (n = 4). We then described the treatment and outcomes for 20 subjects who developed AICs. Results: In our cohort, cases were older than controls, were more likely to receive a myeloablative conditioning regimen and had a significantly lower prevalence of chronic GVHD. There were distinct differences in the state of immune recovery based on transplant indication. None of the patients (0/7) transplanted for primary malignancy had T cell recovery at AIC onset compared to 71% (5/7) of patients with PID and 33% (1/3) of patients with non-malignant disease. The subset of patients with PID and non-malignant disease who achieved T cell reconstitution (6/6) prior to AIC onset, all demonstrated mixed or split chimerism. Subjects with AIHA or multi-lineage cytopenias had particularly refractory courses with poor treatment response to IVIG, steroids, and rituximab. Conclusions: These results highlight the heterogeneity of AICs in this population and suggest that multiple mechanisms may contribute to the development of post-transplant AICs. Patients with full donor chimerism may have early B cell recovery without proper T cell regulation, while patients with mixed or split donor chimerism may have residual host B or plasma cells making antibodies against donor blood cells. A prospective, multi-center trial is needed to develop personalized treatment approaches that target the immune dysregulation present and improve outcomes in patients with post-transplant AICs.

Comprehensive Review of Preschool Age Anemia in the Pacific Island Jurisdictions

Anemia can be an indicator of poor nutrition and health, and it can have significant consequences. Children are disproportionately affected by anemia. This comprehensive review summarizes the available literature on anemia prevalence in young children in the islands of the Oceania region. The anemia prevalence, the criteria used for diagnosis, the date the data was reported, and the types of samples collected were reviewed. Anemia prevalence estimates were reported for eighteen of the Pacific Island Jurisdictions. From the fifteen data sources that were evaluable, anemia prevalence ranged from 12.3% to over 70%. A major limitation in the data is a lack of representative primary data from many of the jurisdictions in the region. Prevalance estimates reported for those jurisdictions are estimated by regression analysis from the World Health Organization (WHO). Moreover, the primary data available does not use standardized reporting criteria. Nevertheless, this review serves as a new baseline for further investigations on the prevalence of anemia and a baseline for evaluating public health prevention and treatment measures to detect and improve anemia prevalence in the Pacific.

Revesz syndrome masquerading as traumatic retinal detachment

A 13-month-old boy with mild hemophilia A presented for strabismus evaluation and was found to have retinal hemorrhages in the right eye, left exotropia, and left total retinal detachment. These findings were attributed to trauma and hemophilia A. Routine blood work for hemophilia A subsequently showed pancytopenia. A bone marrow aspirate showed marked hypocellularity consistent with severe aplastic anemia, and telomere testing revealed very short telomeres. The patient was found to have a TINF2 mutation consistent with a diagnosis of Revesz syndrome, a variant of dyskeratosis congenita. He underwent successful bone marrow transplantation, and on subsequent evaluation was found to have retinal hemorrhages, vessel sclerosis, and cotton wool spots in the right eye associated with peripheral retinal nonperfusion. He underwent retinal laser treatment to the areas of retinal nonperfusion which resulted in stable visual function.

[Research advances in diabetic retinopathy telescreening systems]

Diabetic retinopathy has become the main cause of the sight impairment and blindness among the adult population. Early detection of diabetic retinopathy helps to prevent and reduce the damage to eyesight. The development of diabetic retinopathy telescreening systems has been rapid. The operation modes, key technologies, economic benefits and new progression of diabetic retinopathy telescreening systems are reviewed. (Chin J Ophthalmol, 2016, 52: 868-871).

Capacity Building for Rare Bleeding Disorders in the Remote Commonwealth of the Northern Mariana Islands

The US Pacific Commonwealth of the Northern Mariana Islands is home to an underserved hemophilia population. We developed a strategy in 2014 to build sustainable island-wide medical, patient and family, and community support for this rare disease. Collaboration with regional bleeding disorder leadership galvanized a weeklong conference series. More than 200 participants attended discipline-specific seminars; pre-post test evaluations documented educational benefits. This time-concentrated island-wide education intervention promoted the rapid identification of new cases and stimulated sustainable bleeding disorder care development. The education series proved feasible, efficient, and effective in increasing knowledge and reducing patient and professional isolation, serving as a model for improving capacity for orphan diseases (those that affect fewer than 200 000 people in any particular country) in underresourced areas.

Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges

The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV.

Zinc supplementation improves bone density in patients with thalassemia: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Patients with thalassemia major (Thal) frequently have low plasma zinc, which has been associated with low bone mass.

OBJECTIVE

The objective was to determine the effect of zinc supplementation on bone mass in patients with Thal.

DESIGN

Forty-two subjects (21 females aged 10-30 y) with Thal and low bone mass were randomly assigned to receive 25 mg Zn/d or placebo. Bone mineral content (BMC) and areal bone mineral density (aBMD) were assessed by using dual-energy X-ray absorptiometry, and fasting blood was collected for the measurement of plasma zinc at 0, 12, and 18 mo.

RESULTS

Thirty-two subjects, 81% of whom were transfusion dependent, completed the study (mean ± SD: 17.1 ± 5.2 y). Plasma zinc was ≤70 μg/dL in 11 subjects at baseline and increased significantly with zinc supplementation (P = 0.014). Use of intention-to-treat analysis and linear models for longitudinal data, adjusted for baseline and pubertal stage, showed that the zinc group had significantly greater increases in whole-body BMC (adjusted mean ± SE: 63 ± 15 g; P = 0.02), and aBMD (0.023 ± 0.006 g/cm(2); P = 0.04) than did the placebo group after 18 mo. Furthermore, adjusted spine and hip aBMD z scores each decreased by 0.3 SDs (both P = 0.04) in the placebo compared with the zinc group over the 18-mo study.

CONCLUSIONS

In young patients with Thal, zinc supplementation resulted in greater gains in total-body bone mass than did placebo. Zinc was well tolerated and is worthy of investigation in larger trials in Thal patients across a range of ages and disease severity. This trial was registered at clinicaltrials.gov as NCT00459732.

In vitro modeling of the microvascular occlusion and thrombosis that occur in hematologic diseases using microfluidic technology

In hematologic diseases, such as sickle cell disease (SCD) and hemolytic uremic syndrome (HUS), pathological biophysical interactions among blood cells, endothelial cells, and soluble factors lead to microvascular occlusion and thrombosis. Here, we report an in vitro "endothelialized" microfluidic microvasculature model that recapitulates and integrates this ensemble of pathophysiological processes. Under controlled flow conditions, the model enabled quantitative investigation of how biophysical alterations in hematologic disease collectively lead to microvascular occlusion and thrombosis. Using blood samples from patients with SCD, we investigated how the drug hydroxyurea quantitatively affects microvascular obstruction in SCD, an unresolved issue pivotal to understanding its clinical efficacy in such patients. In addition, we demonstrated that our microsystem can function as an in vitro model of HUS and showed that shear stress influences microvascular thrombosis/obstruction and the efficacy of the drug eptifibatide, which decreases platelet aggregation, in the context of HUS. These experiments establish the versatility and clinical relevance of our microvasculature-on-a-chip model as a biophysical assay of hematologic pathophysiology as well as a drug discovery platform.

Microenvironmental geometry guides platelet adhesion and spreading: a quantitative analysis at the single cell level

To activate clot formation and maintain hemostasis, platelets adhere and spread onto sites of vascular injury. Although this process is well-characterized biochemically, how the physical and spatial cues in the microenvironment affect platelet adhesion and spreading remain unclear. In this study, we applied deep UV photolithography and protein micro/nanostamping to quantitatively investigate and characterize the spatial guidance of platelet spreading at the single cell level and with nanoscale resolution. Platelets adhered to and spread only onto micropatterned collagen or fibrinogen surfaces and followed the microenvironmental geometry with high fidelity and with single micron precision. Using micropatterned lines of different widths, we determined that platelets are able to conform to micropatterned stripes as thin as 0.6 µm and adopt a maximum aspect ratio of 19 on those protein patterns. Interestingly, platelets were also able to span and spread over non-patterned regions of up to 5 µm, a length consistent with that of maximally extended filopodia. This process appears to be mediated by platelet filopodia that are sensitive to spatial cues. Finally, we observed that microenvironmental geometry directly affects platelet biology, such as the spatial organization and distribution of the platelet actin cytoskeleton. Our data demonstrate that platelet spreading is a finely-tuned and spatially-guided process in which spatial cues directly influence the biological aspects of how clot formation is regulated.

Guidelines for the management of spontaneous intracerebral hemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of acute spontaneous intracerebral hemorrhage.

METHODS

A formal literature search of MEDLINE was performed. Data were synthesized with the use of evidence tables. Writing committee members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statements Oversight Committee and Stroke Council Leadership Committee. It is intended that this guideline be fully updated in 3 years' time.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with intracerebral hemorrhage. The focus was subdivided into diagnosis, hemostasis, blood pressure management, inpatient and nursing management, preventing medical comorbidities, surgical treatment, outcome prediction, rehabilitation, prevention of recurrence, and future considerations.

CONCLUSIONS

Intracerebral hemorrhage is a serious medical condition for which outcome can be impacted by early, aggressive care. The guidelines offer a framework for goal-directed treatment of the patient with intracerebral hemorrhage.

Molecular epidemiology and phylogenetic analysis of a marine fish infectious spleen and kidney necrosis virus-like (ISKNV-like) virus

Infectious spleen and kidney necrosis virus-like (ISKNV-like) virus causes a serious systemic disease with high morbidity and mortality of freshwater and marine fishes. Based on the ISKNV putative major capsid protein (MCP), the vascular endothelial growth factor (VEGF), the mRNA capping enzyme (Capping), and the tumor necrosis factor receptor-associated protein (TNFR) genes, primers were designed and used in PCR to determine the host range of ISKNV-like viruses. From the sampling of >1600 marine fishes representing 6 orders, 25 families, and 86 species collected in the South China Sea, 13 cultured fish species (141 fish) and 39 wild fish species (102 fish) were confirmed hosts of ISKNV-like viruses. The average percentage of infection of ISKNV-like viruses was 14.6%. The results from phylogenetic analysis of these genes revealed that ISKNV-like viruses could be placed into two clusters: cluster I was more related to ISKNV; cluster II included OSGIV (orange-spotted grouper iridovirus) and RBIV (rock bream iridovirus), and was quite different from ISKNV. The results of this study can contribute to the prediction and prevention of ISKNV disease outbreaks.

Activity of the APC(Cdh1) form of the anaphase-promoting complex persists until S phase and prevents the premature expression of Cdc20p

Cell cycle progression is driven by waves of cyclin expression coupled with regulated protein degradation. An essential step for initiating mitosis is the inactivation of proteolysis mediated by the anaphase-promoting complex/cyclosome (APC/C) bound to its regulator Cdh1p/Hct1p. Yeast APC(Cdh1) was proposed previously to be inactivated at Start by G1 cyclin/cyclin-dependent kinase (CDK). Here, we demonstrate that in a normal cell cycle APC(Cdh1) is inactivated in a graded manner and is not extinguished until S phase. Complete inactivation of APC(Cdh1) requires S phase cyclins. Further, persistent APC(Cdh1) activity throughout G1 helps to ensure the proper timing of Cdc20p expression. This suggests that S phase cyclins have an important role in allowing the accumulation of mitotic cyclins and further suggests a regulatory loop among S phase cyclins, APC(Cdh1), and APC(Cdc20).

Low-molecular-weight heparins

Low-molecular-weight heparins (LMWH) are a new group of parenteral anticoagulants. They represent a major clinical advance in anticoagulation since the identification of unfractionated heparin (UFH) in 1922 and the introduction of the synthetic coumarin derivative, warfarin, in 1948. Their predictable pharmacokinetics, increased bioavailability, and longer plasma half-life allow for once- or twice-daily dosing and eliminate the need for routine laboratory monitoring. This simplified administration stands to alter the clinical practice of anticoagulation. This review high-lights recent clinical trials and focuses on studies comparing LMWH with the other two major anticoagulants: UFH and coumadin.

[Diagnosis of intraperitoneal injuries in patients with pelvic fractures]

It is difficult to diagnose blunt abdominal trauma in unstable patients with pelvic fractures. In the United States the standard diagnostic procedures for these patients were the physical examinations and diagnostic peritoneal lavages. However, abdominal echograms were prevalent in Europe and Japan. We reviewed 60 patients suspected blunt abdominal trauma in 804 pelvic fractures in the past four years. Eighteen DPLs and twenty-five abdominal echograms were done separately. Sensitivity, specificity, and accuracy were 100%, 40%, 66% for DPL and 94.7%, 50%, 84% for abdominal echograms respectively. Besides the better correlation with the results for echogram, it provides easy availability, noninvasiveness, and imaging function. Thus we recommend that the echogram be the first-line screening test DPL acts as a complementary test, especially in the cases of bowel perforation.

Cloning and expression of an antigenic domain of glycoprotein gE of pseudorabies virus in Escherichia coli and its use as antigen in diagnostic assays

Use of a combination of an effective gE gene-deleted pseudorabies virus (PRV) vaccine with a companion diagnostic kit for PRV glycoprotein gE has proven successful in several pseudorabies-eradication programs. To produce a large quantity of functional gE protein for development of a PRV-gE diagnostic kit, an Escherichia coli expression system containing the distal region of the PRV-gE gene of a PRV strain CF was constructed. The expressed protein contained 134 amino acids of gE protein (amino acids 77-210) fused to a 19-amino acids tag containing 6 histidine residues. After induction, a truncated PRV-gE polypeptide of 18-kd was expressed to about 20% of the total E coli proteins. Results of immunoblot analysis indicated that this E coli-produced PRV-gE protein reacted specifically with serum from PRV-hyperimmunized pigs and from field PRV-infected pigs, but not with serum samples from specific-pathogen-free pigs or pigs inoculated with gE-deleted PRV vaccine. These data indicate that, although the recombinant gE protein is produced in E coli, it still retains the antigenicity of the viral gE glycoprotein. Comparison between the recombinant gE protein, using immunoblot analysis with a commercial gE ELISA containing natural PRV-gE protein, revealed comparable test performance. This finding indicated that recombinant gE protein produced by E coli can be used for development of a companion serologic assay for a PRV-gE gene-deleted vaccine.

[Primary tracheal carcinoma--report of 5 patients]

From 1980 through 1985, 5 patients with primary tracheal carcinoma were admitted to Human Cancer Hospital, comprising 0.024% of total admissions during the same period. The incidence of lung cancer and laryngeal cancer was 386 and 43 times as high as that of tracheal carcinoma. All were proved pathologically. 3 patients were given radical operation, followed by radiotherapy; 1 received radiotherapy plus chemotherapy and the other, chemotherapy alone. All three patients treated by operation plus radiotherapy survived for more than 3 years and 2 of them are still alive. Diagnosis, causes and avoidance of misdiagnosis are discussed.