Genetic reversal of the globin switch concurrently modulates both fetal and sickle hemoglobin and reduces red cell sickling

We previously reported initial clinical results of post-transcriptional gene silencing of BCL11A expression (NCT03282656) reversing the fetal to adult hemoglobin switch. A goal of this approach is to increase fetal hemoglobin (HbF) expression while coordinately reducing sickle hemoglobin (HbS) expression. The resulting combinatorial effect should prove effective in inhibiting HbS polymerization at lower physiologic oxygen values thereby mitigating disease complications. Here we report results of exploratory single-cell analysis of patients in which BCL11A is targeted molecularly and compare results with cells of patients treated with hydroxyurea (HU), the current standard of care. We use single-cell assays to assess HbF, HbS, oxygen saturation, and hemoglobin polymer content in RBCs for nine gene therapy trial subjects (BCLshmiR, median HbF% = 27.9) and compare them to 10 HU-treated subjects demonstrating high and comparable levels of HbF (HU High Responders, median HbF% = 27.0). All BCL11A patients achieved the primary endpoint for NCT03282656, which was defined by an absolute neutrophil count greater than or equal to 0.5 × 109 cells/L for three consecutive days, achieved within 7 weeks following infusion. Flow cytometric assessment of single-RBC HbF and HbS shows fewer RBCs with high HbS% that would be most susceptible to sickling in BCLshmiR vs. HU High Responders: median 42% of RBCs with HbS%>70% in BCLshmiR vs. 61% in HU High Responders (p = 0.004). BCLshmiR subjects also demonstrate more RBCs resistant to HbS polymerization at lower physiologic oxygen tension: median 32% vs. 25% in HU High Responders (p = 0.006). Gene therapy-induced BCL11A down-regulation reverses the fetal-to-adult hemoglobin switch and induces RBCs with higher HbF%, lower HbS%, and greater resistance to deoxygenation-induced polymerization in clinical trial subjects compared with a cohort of highly responsive hydroxyurea-treated subjects.

251 PREVALENCE AND CHARACTERISTICS OF SWALLOWING/COMMUNICATION IMPAIRMENTS IN FRAIL OLDER ADULTS ATTENDING THE EMERGENCY DEPARTMENT: A RETROSPECTIVE COHORT STUDY

Background

The presentation of frail older adults to the Emergency Department (ED) may be complicated by swallowing and/or communication impairment. Adults with communication impairment may experience difficulty accessing healthcare. Dysphagia is associated with frailty irrespective of age and/or number of chronic diseases [1]. This study aims to determine the prevalence and characteristics of swallowing and/or communication impairments among frail older adults attending the ED.

Methods

A retrospective cohort study of consecutive ED attendees aged ≥ 75 years assessed by an interdisciplinary Gerontological ED team between October 2021 – February 2022 was conducted. A swallow/communication screening tool determined requirement for Speech and Language Therapy (SLT) referral. Data related to demographics and SLT interventions was extracted. Data analysis was completed using STATA Version 12. Ethical approval was obtained.

Results

Among 518 patients, 118 (23%) (mean age 82.4 (+/-6.4) years, 54% male) required SLT assessment. These patients had high rates of frailty (Median CFS= 6 (IQR 5-7), suspected delirium (4AT ≥ 4 in 45%), suspected malnutrition (MNA score 0-11 in 75%), and probable sarcopenia (SARC-F= ≥ 4 in 75%). Therapy Outcome Measurement Scales and the Functional Oral Intake Scale were used in this first episode of SLT care. Oropharyngeal dysphagia was identified for 43% (27% mild, 10% moderate, 3% moderate-severe, 3% severe), with 6% presenting with signs/symptoms of oesophageal dysphagia. Changes in baseline communication was identified for 57%; cognitive communication difficulties (38%), dysarthria (11%), dysphonia (8%). SLT intervention and management approaches were initiated in the ED.

Conclusion

Findings indicate a high prevalence of swallowing/communication impairment in frail older adults attending the ED. Future research should explore SLT outcomes at point of discharge to refine these swallowing/communication presentations.

Reference

1. Bahat G et al. Association between dysphagia and frailty in community-dwelling older adults. The Journal of Nutrition, Health & Ageing. 2019:23, 571–577.

Restored Macrophage Function Ameliorates Disease Pathophysiology in a Mouse Model for IL10 Receptor-deficient Very Early Onset Inflammatory Bowel Disease

BACKGROUND AND AIMS

Mutations in IL10 or the IL10 receptor lead to very early onset [VEO] inflammatory bowel disease [IBD], a life-threatening disease which is often unresponsive to conventional medication. Recent studies have demonstrated that defective IL-10 receptor signalling in innate immune cells is a key driver of severe intestinal inflammation in VEO-IBD. Specifically, IL10 unresponsiveness of macrophages, which govern the tight balance between pro- and anti-inflammatory responses in the intestinal system, plays a central role in the events leading to excessive inflammatory responses and the development of IBD.

METHODS AND RESULTS

We here evaluated haematopoietic stem cell gene therapy in a VEO-IBD mouse model and demonstrated that the therapeutic response closely correlates with gene correction of the IL10 signalling pathway in intestinal macrophages. This finding prompted us to evaluate the therapeutic efficacy of macrophage transplantation in the Il10rb-/- VEO-IBD mouse model. A 6-week regimen employing a combination of depletion of endogenous hyperinflammatory macrophages followed by intraperitoneal administration of wild-type [WT] macrophages significantly reduced colitis symptoms.

CONCLUSIONS

In summary, we show that the correction of the IL10 receptor defect in macrophages, either by genetic therapy or transfer of WT macrophages to the peritoneum, can ameliorate disease-related symptoms and potentially represent novel treatment approaches for VEO-IBD patients.

Aged marrow macrophages expand platelet-biased hematopoietic stem cells via Interleukin1B

The bone marrow microenvironment (BMME) contributes to the regulation of hematopoietic stem cell (HSC) function, though its role in age-associated lineage skewing is poorly understood. Here we show that dysfunction of aged marrow macrophages (Mφs) directs HSC platelet-bias. Mφs from the marrow of aged mice and humans exhibited an activated phenotype, with increased expression of inflammatory signals. Aged marrow Mφs also displayed decreased phagocytic function. Senescent neutrophils, typically cleared by marrow Mφs, were markedly increased in aged mice, consistent with functional defects in Mφ phagocytosis and efferocytosis. In aged mice, Interleukin 1B (IL1B) was elevated in the bone marrow and caspase 1 activity, which can process pro-IL1B, was increased in marrow Mφs and neutrophils. Mechanistically, IL1B signaling was necessary and sufficient to induce a platelet bias in HSCs. In young mice, depletion of phagocytic cell populations or loss of the efferocytic receptor Axl expanded platelet-biased HSCs. Our data support a model wherein increased inflammatory signals and decreased phagocytic function of aged marrow Mφs induce the acquisition of platelet bias in aged HSCs. This work highlights the instructive role of Mφs and IL1B in the age-associated lineage-skewing of HSCs, and reveals the therapeutic potential of their manipulation as antigeronic targets.

Type I IFNs drive hematopoietic stem and progenitor cell collapse via impaired proliferation and increased RIPK1-dependent cell death during shock-like ehrlichial infection

Type I interferons (IFNα/β) regulate diverse aspects of host defense, but their impact on hematopoietic stem and progenitor cells (HSC/HSPCs) during infection remains unclear. Hematologic impairment can occur in severe infections, thus we sought to investigate the impact of type I IFNs on hematopoiesis in a tick-borne infection with a virulent ehrlichial pathogen that causes shock-like disease. During infection, IFNα/β induced severe bone marrow (BM) loss, blunted infection-induced emergency myelopoiesis, and reduced phenotypic HSPCs and HSCs. In the absence of type I IFN signaling, BM and splenic hematopoiesis were increased, and HSCs derived from Ifnar1-deficient mice were functionally superior in competitive BM transplants. Type I IFNs impaired hematopoiesis during infection by both limiting HSC/HSPC proliferation and increasing HSPC death. Using mixed BM chimeras we determined that type I IFNs restricted proliferation indirectly, whereas HSPC death occurred via direct IFNαR -mediated signaling. IFNαR-dependent signals resulted in reduced caspase 8 expression and activity, and reduced cleavage of RIPK1 and RIPK3, relative to Ifnar1-deficient mice. RIPK1 antagonism with Necrostatin-1s rescued HSPC and HSC numbers during infection. Early antibiotic treatment is required for mouse survival, however antibiotic-treated survivors had severely reduced HSPCs and HSCs. Combination therapy with antibiotics and Necrostatin-1s improved HSPC and HSC numbers in surviving mice, compared to antibiotic treatment alone. We reveal two mechanisms whereby type I IFNs drive hematopoietic collapse during severe infection: direct sensitization of HSPCs to undergo cell death and enhanced HSC quiescence. Our studies reveal a strategy to ameliorate the type I IFN-dependent loss of HSCs and HSPCs during infection, which may be relevant to other infections wherein type I IFNs cause hematopoietic dysfunction.

The Ehrlichiae are important emerging, tick-borne pathogens that cause immune suppression and cytopenias, though the underlying mechanisms are unclear. In a model of shock-like illness caused by Ixodes ovatus ehrlichia, type I interferons (IFNs) induce hematopoietic dysfunction by reducing hematopoietic stem cell (HSC) proliferation and driving cell death of hematopoietic progenitors (HSPCs). Using mixed bone marrow chimeras, we demonstrate that HSPC loss occurs via intrinsic type I IFN signaling, whereas HSC proliferation is regulated via an extrinsic mechanism. In contrast to sterile inflammation, infection-induced type I IFNs induced RIPK1-dependent loss of hematopoietic progenitors. HSPCs were rescued during infection by inhibiting RIPK1 with Necrostatin-1s. While antibiotic treatment protected against otherwise lethal infection, mice recovering from infection exhibited significantly reduced HSCs and HSPCs. Co-treatment with both antibiotics and Necrostatin-1s significantly increased HSPC frequencies and the number of HSCs compared to antibiotics alone. Blood production is essential for life and necessary for host defense, thus our work reveals a therapeutic strategy to rescue and improve hematopoiesis in patients recovering from serious infectious disease.

Common and well-documented HLA alleles over all of Europe and within European sub-regions: A catalogue from the European Federation for Immunogenetics

BACKGROUND

A catalogue of common and well-documented (CWD) human leukocyte antigen (HLA), previously established by the American Society for Histocompatibility and Immunogenetics (ASHI), is widely used as indicator for typing ambiguities to be resolved in tissue transplantation or for checking the universality of any HLA allele in the world. However, European population samples, which are characterized by a substantial level of genetic variation, are underrepresented in the ASHI catalogue. Therefore, the Population Genetics Working Group of the European Federation for Immunogenetics (EFI) has facilitated data collection for an European CWD catalogue.

MATERIALS AND METHODS

To this end, 2nd-field HLA-A, -B, -C,- DRB1,- DQA1,- DQB1 and -DPB1 data of 77 to 121 European population samples (21 571-3 966 984 individuals) from 3 large databases, HLA-net/Gene[VA], allelefrequencies.net and DKMS, were analysed.

RESULTS

The total number of CWD alleles is similar in the EFI (N = 1048) and ASHI (N = 1031) catalogues, but the former counts less common (N = 236 vs 377) and more well-documented (N = 812 vs 654) alleles than the latter, possibly reflecting differences in sample numbers and sizes. Interestingly, approximately half of the CWD alleles reported by EFI were not reported by ASHI and vice-versa, underlining the distinct features of the two catalogues. Also, although 78 common alleles are widely distributed across Europe, some alleles are only common within specific sub-regions, showing regional variability.

CONCLUSION

Although the definition of CWD alleles itself is affected by different parameters, calling for current updates of the list, the EFI CWD catalogue provides new insights into European population genetics and will be a very useful tool for tissue-typing laboratories in and beyond Europe.

Hematopoietic stem cell loss and hematopoietic failure in severe aplastic anemia is driven by macrophages and aberrant podoplanin expression

Severe aplastic anemia (SAA) results from profound hematopoietic stem cell loss. T cells and interferon gamma (IFNγ) have long been associated with SAA, yet the underlying mechanisms driving hematopoietic stem cell loss remain unknown. Using a mouse model of SAA, we demonstrate that IFNγ-dependent hematopoietic stem cell loss required macrophages. IFNγ was necessary for bone marrow macrophage persistence, despite loss of other myeloid cells and hematopoietic stem cells. Depleting macrophages or abrogating IFNγ signaling specifically in macrophages did not impair T-cell activation or IFNγ production in the bone marrow but rescued hematopoietic stem cells and reduced mortality. Thus, macrophages are not required for induction of IFNγ in SAA and rather act as sensors of IFNγ. Macrophage depletion rescued thrombocytopenia, increased bone marrow megakaryocytes, preserved platelet-primed stem cells, and increased the platelet-repopulating capacity of transplanted hematopoietic stem cells. In addition to the hematopoietic effects, SAA induced loss of non-hematopoietic stromal populations, including podoplanin-positive stromal cells. However, a subset of podoplanin-positive macrophages was increased during disease, and blockade of podoplanin in mice was sufficient to rescue disease. Our data further our understanding of disease pathogenesis, demonstrating a novel role for macrophages as sensors of IFNγ, thus illustrating an important role for the microenvironment in the pathogenesis of SAA.

An Immature Myeloid/Myeloid-Suppressor Cell Response Associated with Necrotizing Inflammation Mediates Lethal Pulmonary Tularemia

Inhalation of Francisella tularensis (Ft) causes acute and fatal pneumonia. The lung cytokine milieu favors exponential Ft replication, but the mechanisms underlying acute pathogenesis and death remain unknown. Evaluation of the sequential and systemic host immune response in pulmonary tularemia reveals that in contrast to overwhelming bacterial burden or cytokine production, an overt innate cellular response to Ft drives tissue pathology and host mortality. Lethal infection with Ft elicits medullary and extra-medullary myelopoiesis supporting recruitment of large numbers of immature myeloid cells and MDSC to the lungs. These cells fail to mature and die, leading to subsequent necrotic lung damage, loss of pulmonary function, and host death that is partially dependent upon immature Ly6G+ cells. Acceleration of this process may account for the rapid lethality seen with Ft SchuS4. In contrast, during sub-lethal infection with Ft LVS the pulmonary cellular response is characterized by a predominance of mature neutrophils and monocytes required for protection, suggesting a required threshold for lethal bacterial infection. Further, eliciting a mature phagocyte response provides transient, but dramatic, innate protection against Ft SchuS4. This study reveals that the nature of the myeloid cell response may be the primary determinant of host mortality versus survival following Francisella infection.

Macrophages: Key regulators of steady-state and demand-adapted hematopoiesis

Hematopoietic stem cell (HSC) function is required for balanced blood production throughout life; it is thus essential to understand the mechanisms regulating this highly dynamic process. Bone marrow-resident macrophages (Mϕs) have recently emerged as an important component of the HSC niche, where they contribute to regulating HSC and progenitor cell (HSPC) mobilization and function. Here we review the role of macrophages (Mϕs) on immune cell production, HSPC pool size, and mobilization at steady state and under inflammatory conditions. Inflammation induces marked changes in hematopoiesis to restrict or promote generation of specific cell lineages, and this often has a negative impact on HSC function. Cytokines and growth factors induced during inflammation influence hematopoiesis by acting directly on HSPCs and/or by modulating niche cell function. We focus particular attention on the opposing effects of two key inflammatory proteins, interferon-γ and granulocyte-colony stimulating factor, in regulating bone marrow-resident macrophages (Mϕs) and HSPCs. Macrophages (Mϕs) are essential for tissue homeostasis, and here we highlight their emerging role as a central regulator of both steady-state and demand-adapted hematopoiesis.

Macrophage-Lineage Cells Negatively Regulate the Hematopoietic Stem Cell Pool in Response to Interferon Gamma at Steady State and During Infection

Bone marrow (BM) resident macrophages (Mϕs) regulate hematopoietic stem cell (HSC) mobilization; however, their impact on HSC function has not been investigated. We demonstrate that depletion of BM resident Mϕs increases HSC proliferation as well as the pool of quiescent HSCs. At the same time, during bacterial infection where BM resident Mϕs are selectively increased we observe a decrease in HSC numbers. Moreover, strategies that deplete or reduce Mϕs during infection prevent HSC loss and rescue HSC function. We previously found that the transient loss of HSCs during infection is interferon-gamma (IFNγ)-dependent. We now demonstrate that IFNγ signaling specifically in Mϕs is critical for both the diminished HSC pool and maintenance of BM resident Mϕs during infection. In addition to the IFNγ-dependent loss of BM HSC and progenitor cells (HSPCs) during infection, IFNγ reduced circulating HSPC numbers. Importantly, under infection conditions AMD3100 or G-CSF-induced stem cell mobilization was impaired. Taken together, our data show that IFNγ acts on Mϕs, which are a negative regulator of the HSC pool, to drive the loss in BM and peripheral HSCs during infection. Our findings demonstrate that modulating BM resident Mϕ numbers can impact HSC function in vivo, which may be therapeutically useful for hematologic conditions and refinement of HSC transplantation protocols.

Helicobacter pylori infection does not promote hepatocellular cancer in a transgenic mouse model of hepatitis C virus pathogenesis

Helicobacter pylori (H. pylori) and hepatitis C virus (HCV) infect millions of people and can induce cancer. We investigated if H. pylori infection promoted HCV-associated liver cancer. Helicobacter-free C3B6F1 wild-type (WT) and C3B6F1-Tg(Alb1-HCVN)35Sml (HT) male and female mice were orally inoculated with H. pylori SS1 or sterile media. Mice were euthanized at ~12 mo postinoculation and samples were collected for analyses. There were no significant differences in hepatocellular tumor promotion between WT and HT mice; however, HT female mice developed significantly larger livers with more hepatic steatosis than WT female mice. H. pylori did not colonize the liver nor promote hepatocellular tumors in WT or HT mice. In the stomach, H. pylori induced more corpus lesions in WT and HT female mice than in WT and HT male mice, respectively. The increased corpus pathology in WT and HT female mice was associated with decreased gastric H. pylori colonization, increased gastric and hepatic interferon gamma expression, and increased serum Th1 immune responses against H. pylori. HT male mice appeared to be protected from H. pylori-induced corpus lesions. Furthermore, during gastric H. pylori infection, HT male mice were protected from gastric antral lesions and hepatic steatosis relative to WT male mice and these effects were associated with increased serum TNF-α. Our findings indicate that H. pylori is a gastric pathogen that does not promote hepatocellular cancer and suggest that the HCV transgene is associated with amelioration of specific liver and gastric lesions observed during concurrent H. pylori infection in mice.

MyD88 signaling in CD4 T cells promotes IFN-γ production and hematopoietic progenitor cell expansion in response to intracellular bacterial infection

Hematopoietic stem and progenitor cell (HSPC) phenotype and function can change in response to infectious challenge. These changes can be mediated by cytokines, IFNs, and pathogen-associated molecules, via TLR, and are thought to promote tailored immune responses for particular pathogens. In this study, we investigated the signals that activate HSPCs during ehrlichiosis, a disease characterized by profound hematopoietic dysfunction in both humans and mice. In a mouse model of ehrlichiosis, we observed that infection-induced proliferation of bone marrow HSPCs was dependent on IFN-γ signaling and was partially dependent on MyD88. However, MyD88 was not required in HSPCs for their expansion during infection, because similar frequencies of MyD88-deficient and wild-type HSPCs proliferated in mixed bone marrow chimeric mice. MyD88-deficient mice exhibited low serum and bone marrow concentration of IFN-γ compared with wild-type mice. We next identified CD4 T cells as the primary cells producing IFN-γ in the bone marrow and demonstrated a nonredundant role for CD4-derived IFN-γ in increased HSPCs. Using mixed bone marrow chimeric mice, we identified a requirement for MyD88 in CD4 T cells for increased T-bet expression, optimal IFN-γ production, and CD4 T cell proliferation. Our data demonstrate an essential role for CD4 T cells in mediating HSPC activation in response to bacterial infection and illustrate a novel role for MyD88 signaling in CD4 T cells in this process. These findings further support the idea that IFN-γ production is essential for HSPC activation and hematopoietic responses to infection.

Identification of patients with low-risk pulmonary embolism suitable for outpatient treatment using the pulmonary embolism severity index (PESI)

BACKGROUND

There is increasing evidence that outpatient treatment of patients with low-risk stable pulmonary embolism (PE) is safe, effective and potentially reduces costs. It is not clear how many patients presenting to an Irish Emergency Department (ED) are potentially suitable for outpatient management.

AIMS

To identify how many patients presenting to our ED over a 1-year period who were diagnosed with acute PE are potentially suitable for outpatient treatment.

METHODS

A retrospective observational study was conducted over a 1-year period. Clinical notes for patients who had a positive computed tomographic pulmonary angiogram (CTPA) within 24 h of presentation to the ED were examined to risk stratify the patients according to the pulmonary embolism severity index (PESI).

RESULTS

Forty-seven patients who presented to our ED were diagnosed with a PE. Clinical notes were missing for 3 cases, and 44 cases were analysed further. The mean age was 64.3 (±16.8 SD) years and 24 (54.5 %, 95 % CI 40-68.3 %) were males. Six patients (13.6 %, 95 % CI 6.4-26.7 %) had a background of cancer. Fifteen cases (34.1 %, 95 % CI 21.9-48.7 %) were deemed to be low risk as they were categorised as PESI risk class I or II. Our study found that 61/420 (14.5 %, 95 % CI 11.5-18.2) of CTPAs done were positive for PE.

CONCLUSION

This study suggests that a significant percentage of patients diagnosed with acute PE are low risk as per PESI and therefore potentially suitable for outpatient management.

Prevalence of murine Helicobacter spp. Infection is reduced by restocking research colonies with Helicobacter-free mice

Most academic research colonies of mice are endemically infected with enterohepatic Helicobacter spp. (EHS). We evaluated EHS prevalence in surveillance mice before and after a 10-y period of requiring that imported mice be free of EHS by embryo transfer rederivation or purchase from approved vendors. In 2009, composite fecal samples from CD1 surveillance mice representing colony health in 57 rooms located in 6 facilities were evaluated for EHS infection by using PCR assays. Fecal samples were screened with primers designed to detect all known EHS, and positive samples were further assayed by using primers specific for H. hepaticus, H. bilis, H. rodentium, and H. typhlonicus. Most EHS were detected in surveillance mice within the first month of dirty bedding exposure, with prevalence ranging from 0% to 64% as monoinfections or, more commonly, infections with multiple EHS. Compared with 1999 prevalence data, EHS remained endemic in colonies importing the lowest number of EHS-free mice. EHS were absent or the prevalence was greatly reduced in colonies receiving the highest percentage of EHS-free mice. This study demonstrates that the management decision to require exclusive importation of EHS-free mice reduced EHS prevalence on an institutional scale without intensive labor and expense associated with other techniques or interference with research objectives.

Infection-induced dysregulation of the hematopoietic stem cell niche (111.36)

Hematopoietic stem cells (HSCs) are critical in replenishing all cells of the blood. At homeostasis, HSCs reside in close proximity to bone-lining osteoblasts within the endosteal niche. Osteoblasts produce CXCL12, a chemokine that supports HSC retention in the bone marrow (BM). BM-resident macrophages have recently been shown to retain HSCs in the endosteum through regulation of osteoblast function. How BM-resident macrophages contribute to HSC function during infection has not been addressed. Ehrlichiosis, a tick-born disease, results in anemia and thrombocytopenia, stemming, in part, from alterations in hematopoiesis. Using Ehrlichia muris infection of C57BL/6 mice we observed an IFNγ-dependent increase in F480+Ly6G+CD169+ BM-resident macrophages. These macrophages exhibited increased expression of MHCII and CD80 during infection indicating an activated phenotype. Infection also resulted in reduced expression of osteoblast-specific genes within cells of the endosteum, including osteocalcin and Cxcl12. By histology, we observed a diminished osteoblast lining. Furthermore, HSCs were mobilized into the bloodstream, indicating a dysregulation of the endosteal HSC niche. Our current hypothesis is that during ehrlichial infection, expansion and activation of resident macrophages results in altered osteoblast function and subsequent HSC mobilization from the BM. Future experiments will address mechanisms of macrophage-mediated alterations to the HSC niche during infection.

Must we review printed lab reports without checking them? A prospective analysis of emergency department practice

This study investigated if results of haematology and biochemistry laboratory tests, carried out at the point of care in our Emergency Department, are checked by the clinician who ordered the test, mitigating the requirement to check printed reports later. Five hundred and nineteen (519) laboratory reports were examined for significant abnormal results and documentation in clinical notes. Thirty percent (30%, n = 158) of these met the inclusion criteria for 'significantly abnormal' laboratory results. Of the 158 significantly abnormal results, 34.8% (n = 55) were not documented in the ED clinical case notes. No patient was discharged inappropriately. Our study suggests it is safe to stop routinely rechecking printed biochemistry and haematology laboratory reports in our department.

Multiple gastric stromal tumors in a child without syndromic association lacks common KIT or PDGFRalpha mutations

A diagnosis of multiple gastric stromal tumors that were nonmetastatic at presentation was made in an 11-year-old girl who presented with hematemesis. Gastrointestinal stromal tumor (GIST) is a rare diagnosis in childhood and reported multiple lesions are generally seen in the context of familial disease, occasionally with syndromic associations. Although there are no reports of genetic mutation in cases of pediatric GIST, very many cases of multiple GISTs investigated on a molecular level have shown germline KIT or platelet-derived growth factor receptor-alpha mutation; these were familial cases. Despite the negative family history in our patient, the multiplicity of lesions in such a young patient raised concern for a genetic predisposition and prompted extensive molecular workup. Repeat evaluation of distinct aliquots of tumor tissue by polymerase chain amplification followed by sequence analysis of selected coding sequences of KIT and platelet-derived growth factor receptor-alpha previously shown to harbor mutations in GIST, yielded no evidence of even a somatic mutation. This clinically unique case is discussed in the context of a literature review.

Culturally sensitive assessment of narrative skills in children

The clinical legacy of William Labov's narrative analysis framework is explored. In recent years, the importance of narration for children's developing literacy and discourse skills has been widely recognized. This article describes a three-step process for assessing children's narrative discourse: elicitation, coding, and scoring. The influences of cultural differences on narration are also presented, with implications and suggestions for culturally sensitive assessment.

Theory of spatiochromatic image encoding and feature extraction

We consider how to interpret, filter, and cross-correlate complex-value color (hue and saturation) images by using a single discrete Fourier transform: the spatiochromatic discrete Fourier transform. The model defines new types of spatiochromatic oriented sinusoidal gratings, termed rainbow gratings, which encode the variation of color over space. We demonstrate how color-opponent detectors observed within the vertebrate visual system can be easily defined by linear filters within this representation. This model also allows us to filter and detect both spatial and chromatic patterns in images by using a single cross-correlation procedure. In doing so, we explore a new form of the Cauchy-Schwartz inequality applied to complex-valued scalar products. Results demonstrate the power of this form of spatiochromatic matched filtering in detecting signals embedded in such a significant amount of noise that they are not visible to the unaided human eye.

Vascular surgical society of great britain and ireland: Re-evaluation of criteria for reoperation in carotid endarterectomy using intraoperative duplex imaging

BACKGROUND: The aim of this study was to compare data obtained during surgery with data collected at 6 weeks after operation to evaluate appropriate criteria for reoperation. METHODS: One hundred and twenty consecutive patients undergoing carotid endarterectomy had duplex scans at operation and 6 weeks later. Neurological evaluation was also documented. RESULTS: Of 96 patients who had a normal intraoperative duplex scan by standard criteria, 91 had normal scans at 6 weeks. One occluded an internal carotid artery (ICA) at 6 weeks with no symptoms. Four had kinks or high-grade contralateral lesions leading to velocity enhancement but no filling defect. All were asymptomatic. Twenty-four patients had abnormal intraoperative scans. Thirteen patients had visible kinking of the ICA or reperfusion hyperaemia; 12 of these patients had normal 6-week scans and one had a mild residual kink but no symptoms. Eleven patients had visible colour-filling defects and significant velocity enhancement. Nine of these were reopened and refashioned. Subsequent duplex imaging was satisfactory in all cases and 6-week scans were normal. One patient had an occluded ICA at operation and developed a dense stroke after operation. Another had residual raised velocities distally which remained at 6 weeks. This patient had no symptoms. CONCLUSION: Intraoperative velocity measurements alone cannot be relied upon as an indication for reoperation. Significant velocity enhancement combined with a visible filling defect appears to represent a satisfactory criterion for reoperation. There were no complications as a result of reoperation. There was no early restenosis in the whole group and there were no neurological sequelae in any patient with a satisfactory scan using the above criteria.

Sparfloxacin versus ciprofloxacin for the treatment of community-acquired, complicated skin and skin-structure infections

Fluoroquinolones have been shown to be effective in the treatment of complicated skin and skin-structure infections, in part because of their broad-spectrum antibacterial activity against causative pathogens that are resistant to older antimicrobial agents. We enrolled 603 adult patients (>58% male, >85% white) in a double-masked, double-dummy, randomized, multicenter trial to compare the efficacy and tolerability of sparfloxacin (400-mg loading dose followed by 200 mg once daily) with those of ciprofloxacin (750 mg twice daily) for 10 days in the treatment of community-acquired, complicated skin and skin-structure infections. The primary efficacy variable was clinical response, based on assessment of signs and symptoms, in the clinically assessable population. Patients in the sparfloxacin and ciprofloxacin groups were comparable with respect to demographic characteristics, underlying diseases, medical history, and laboratory test results. Wound infection was the most common diagnosis, and Staphylococcus aureus was the most frequently isolated pathogen. For the 475 clinically assessable patients, the clinical success rate (percentage of patients cured or improved) was 90.1% (210/233) with sparfloxacin and 87.2% (211/242) with ciprofloxacin. In this analysis (95% confidence interval [CI], -2.8 to 8.6) and the intent-to-treat analyses (95% CI, -4.2 to 6.2), results with sparfloxacin were statistically equivalent to those with ciprofloxacin (95% CI, -1 to 15.3). For bacteriologically assessable patients, eradication rates were 87.0% (141/162) with sparfloxacin and 79.9% (123/154) with ciprofloxacin (95% CI, -1 to 15.3). Eradication rates of S. aureus and coagulase-negative staphylococcal infections were 90.2% (101/112) with sparfloxacin and 77.9% (88/113) with ciprofloxacin. For patients with 2 or more pathogens at baseline (mixed infections), bacteriologic success was 87.6% for sparfloxacin and 77.9% for ciprofloxacin. Pseudomonas aeruginosa infections were eradicated or presumed eradicated in 71.4% (10/14) of sparfloxacin-treated patients and 87.5% (7/8) of ciprofloxacin-treated patients. Overall success rates in the bacteriologically assessable patients for sparfloxacin (84.6% [137/162]) and ciprofloxacin (78.6% [121/154]) were statistically equivalent (95% CI, -2.5 to 14.5). Tolerability was assessed in all patients who received study medication. The overall frequency of treatment-related adverse events was comparable in the 2 treatment groups (26.5% sparfloxacin, 23.3% ciprofloxacin). Drug-related adverse events involving the digestive system occurred in 7.1% of sparfloxacin-treated patients and 19.0% of ciprofloxacin-treated patients; photosensitivity reactions were reported in 11.1% of patients in the sparfloxacin group and 0.7% of patients in the ciprofloxacin group (P < 0.001). The mean change in QTc interval from baseline to the maximum on-treatment value was greater in the sparfloxacin group (9 milliseconds) than in the ciprofloxacin group (3 milliseconds) (P = 0.005; 95% CI, 0.002 to 0.010). The efficacy of sparfloxacin was comparable to that of ciprofloxacin in the treatment of community-acquired, complicated skin and skin-structure infections, including those caused by staphylococci, the most common pathogens. Sparfloxacin's once-daily regimen, high skin-tissue penetration, and improved activity against gram-positive cocci make it a therapeutic alternative to ciprofloxacin for patients who are not at risk for photosensitivity reactions or adverse events associated with prolongation of the QTc interval.

Encouraging narratives in preschoolers: an intervention study

Twenty economically disadvantaged preschoolers (mean age 3;7) were randomly assigned to an intervention or a control group, and their mothers' styles of eliciting narratives from their children were assessed before and after intervention. Mothers of intervention children were encouraged to spend more time in narrative conversation, ask more open-ended and context-eliciting questions, and encourage longer narratives through back-channel responses. Children's narrative and vocabulary skills were assessed before and after the year-long intervention and 14 children participated in a follow-up assessment a year later. Narrative measures included the number and length of narratives as well as how decontextualized and informative they were. Intervention children showed significant vocabulary improvement immediately after intervention terminated, and a year later they showed overall improvements in narrative skill. In particular, intervention children produced more context-setting descriptions about where and especially when the described events took place. Such decontextualized language has been emphasized as important for literacy acquisition.

Randomized, double-blind clinical trial of amphotericin B colloidal dispersion vs. amphotericin B in the empirical treatment of fever and neutropenia

We conducted a prospective, randomized, double-blind study comparing amphotericin B colloidal dispersion (ABCD) with amphotericin B in the empirical treatment of fever and neutropenia. Patients with neutropenia and unresolved fever after > or = 3 days of empirical antibiotic therapy were stratified by age and concomitant use of cyclosporine or tacrolimus. Patients were then randomized to receive therapy with ABCD (4 mg/[kg.d]) or amphotericin B (0.8 mg/[kg.d]) for < or = 14 days. A total of 213 patients were enrolled, of whom 196 were evaluable for efficacy. Fifty percent of ABCD-treated patients and 43.2% of amphotericin B-treated patients had a therapeutic response (P = .31). Renal dysfunction was less likely to develop and occurred later in ABCD recipients than in amphotericin B recipients (P < .001 for both parameters). Infusion-related hypoxia and chills were more common in ABCD recipients than in amphotericin B recipients (P = .013 and P = .018, respectively). ABCD appeared comparable in efficacy with amphotericin B, and renal dysfunction associated with ABCD was significantly less than that associated with amphotericin B. However, infusion-related events were more common with ABCD treatment than with amphotericin B treatment.

Narrative Assessment Profile: discourse analysis for school-age children

The assessment of narrative skills of school-age children is described using a comprehensive discourse analysis approach, the Narrative Assessment Profile. The following dimensions of narration are evaluated: topic maintenance, event sequencing, explicitness, referencing, conjunctive cohesion, and fluency. The purpose of this article is to describe the development of these six dimensions and their symptoms in impaired narrative discourse. Assessment and intervention guidelines are presented.

Narrative skills following traumatic brain injury in children and adults

Personal narratives serve an important function in virtually all societies (Peterson & McCabe, 1991). Through narratives individuals make sense of their experiences and represent themselves to others (Bruner, 1990). The ability to produce narratives has been linked to academic success (Feagans, 1982). Persons who have sustained a traumatic brain injury (TBI) are at risk for impaired narrative ability (Dennis, 1991). However, a paucity of information exists on the discourse abilities of persons with TBI. This is partly due to a lack of reliable tools with which to assess narrative discourse. The present study utilized dependency analysis (Deese, 1984) to document and describe the narrative discourse impairments of children and adults with TBI. Ten children (mean age 12;0) and 10 adults (mean age 35;2) were compared with matched controls. Dependency analysis reliably differentiated the discourse of the individuals with TBI from their controls. Individuals with TBI were significantly more dysfluent than their matched controls. Furthermore, their performance on the narrative task revealed a striking listener burden.

Rice balls and bear hunts: Japanese and North American family narrative patterns

In past research, the form of Japanese children's personal narratives was found to be distinctly different from that of English-speaking children. Despite follow-up questions that encouraged them to talk about one personal narrative at length, Japanese children spoke succinctly about collections of experiences rather than elaborating on any one experience in particular (Minami & McCabe, 1991). Conversations between mothers and children in the two cultures were examined in order partly to account for the way in which cultural narrative style is transmitted to children. Comparison of mothers from the two cultures yielded the following salient contrasts: (1) In comparison to the North American mothers, the Japanese mothers requested proportionately less description from their children. (2) Both in terms of frequency and proportion, the Japanese mothers gave less evaluation and showed more verbal attention to children than did North American mothers. (3) Japanese mothers pay verbal attention more frequently to boys than to girls. In addition, at five years, Japanese children produce 1.22 utterances per turn on average, while North American children produce 2.00 utterances per turn, a significant difference. Thus, by frequently showing verbal attention to their children's narrative contributions, Japanese mothers not only support their children's talk about the past but also make sure that it begins to take the shape of narration valued in their culture. The production of short narratives in Japan is understood and valued differently from such production in North America.

Remembered voices

The speech children spontaneously quote was examined in two studies. In Study 1, a corpus of personal narratives from 96 children aged 4;0 to 9;0 was analysed; Study 2 investigated reported speech in 25 younger children aged 1;2 to 5;2 interacting with their parents. In both studies, the frequency of reported speech increased with age. Direct quotation was more common than indirect or summarized quotation at all ages. In Study 1, children quoted themselves more frequently than any other speaker, and their mothers more frequently than their fathers. Directives were the most commonly reported speech act from the distant past in both older (Study 1) and younger (Study 2) children. In Study 1, girls used reported speech more frequently than did boys, and their quotations were more direct in form than were those of boys.

Effect of fibrinogen concentrates on blood loss in total knee arthroplasty

Total knee arthroplasty has been associated with marked blood loss that occurs despite the use of a tourniquet and minimal postoperative suction drainage. Autogenous fibrinogen cryoprecipitate was used to coat the operative site with a fibrin clot to determine the effect on postoperative blood loss. A method of determining the inapparent blood loss was used based on the red cell mass of the patient and using the hematocrit at the same point of time in relationship to the surgery for the control and study group. The magnitude of tissue extravasation was surprising, and it was almost double the blood loss expected by traditional methods. The benefit of using fibrinogen concentrates is exclusively confined to the inapparent blood loss and not the postoperative blood loss.

Replication of an RK2 miniplasmid derivative in vitro by a DNA/membrane complex extracted from Escherichia coli: involvement of the dnaA but not dnaK host proteins and association of these and plasmid-encoded proteins with the inner membrane

A DNA/membrane complex extracted from a miniplasmid derivative of the broad host range plasmid RK2 cultured in Escherichia coli capable of synthesizing new plasmid supercoiled DNA in vitro was treated with antibodies that were made against or reacted with the dnaA and dnaK host-encoded proteins, respectively. Anti-dnaA protein antibody inhibited total plasmid DNA synthesis significantly and the synthesis of supercoil plasmid DNA almost completely. In contrast, anti-dnaK protein antibody and nonimmune serum had little or no effect on total plasmid DNA synthesis. Both proteins were found to be present in the inner but not outer membrane fraction of E. coli. A variety of miniplasmid-encoded proteins which had previously been found in the DNA/membrane complex have also been localized to the inner but not outer membrane fraction. These include an essential initiation protein of 32 kDa (and an overlapping protein of 43 kDa coded for by the same gene), as well as a 30-kDa protein that may be linked to incompatibility functions. Various extraction methods were used to distinguish between the associated and the integral nature of the plasmid-encoded proteins. The results demonstrated that the essential replication proteins (32 and 43 kDa) as well as the 30-kDa protein was tightly bound to the inner membrane. Computer analysis of the amino acid sequence of the 32 (and 43)-kDa protein revealed a hydrophobic region that is only half that normally required to span the membrane. Other interactions are discussed with respect to attaching this protein to the membrane.

Maternal speech to verbal and higher functioning versus nonverbal and lower functioning autistic children

The relationship between autistic children's level of functioning and maternal speech to children was examined. Ten higher functioning verbal and 10 lower functioning nonverbal children were videotaped in a 15-minute interaction with their mothers. Results revealed that mothers of the higher functioning verbal children asked more questions, used more language modeling, gave more reinforcement for language, and answered more children-initiated questions than did mothers of the lower functioning nonverbal children. Mothers of the nonverbal children employed more directives, used shorter mean lengths of utterance, and reinforced their children's motoric rather than spoken behavior. Far from being poor models for linguistic behavior, mothers of autistic children appear, therefore, to be quite responsive to their children's relative capabilities.