Progesterone receptor in the vascular endothelium triggers physiological uterine permeability preimplantation.

Vascular permeability is frequently associated with inflammation and is triggered by a cohort of secreted permeability factors such as vascular endothelial growth factor (VEGF). Here, we show that the physiological vascular permeability that precedes implantation is directly controlled by progesterone receptor (PR) and is independent of VEGF. Global or endothelial-specific deletion of PR blocks physiological vascular permeability in the uterus, whereas misexpression of PR in the endothelium of other organs results in ectopic vascular leakage. Integration of an endothelial genome-wide transcriptional profile with chromatin immunoprecipitation sequencing revealed that PR induces an NR4A1 (Nur77/TR3)-dependent transcriptional program that broadly regulates vascular permeability in response to progesterone. Silencing of NR4A1 blocks PR-mediated permeability responses, indicating a direct link between PR and NR4A1. This program triggers concurrent suppression of several junctional proteins and leads to an effective, timely, and venous-specific regulation of vascular barrier function that is critical for embryo implantation.

Synthesis of Crystallographically Characterizable Bis(cyclopentadienyl) Sc(II) Complexes: (C5H2tBu3)2Sc and {[C5H3(SiMe3)2]2ScI}1.

The synthesis of previously unknown bis(cyclopentadienyl) complexes of the first transition metal, i.e., Sc(II) scandocene complexes, has been investigated using C5H2(tBu)3 (Cpttt), C5Me5 (Cp*), and C5H3(SiMe3)2 (Cp″) ligands. Cpttt2ScI, 1, formed from ScI3 and KCpttt, can be reduced with potassium graphite (KC8) in hexanes to generate dark-red crystals of the first crystallographically characterizable bis(cyclopentadienyl) scandium(II) complex, Cpttt2Sc, 2. Complex 2 has a 170.6° (ring centroid)-Sc-(ring centroid) angle and exhibits an eight-line EPR spectrum characteristic of Sc(II) with Aiso = 82.6 MHz (29.6 G). It sublimes at 200 °C at 10-4 Torr and has a melting point of 268-271 °C. Reductions of Cp*2ScI and Cp″2ScI under analogous conditions in hexanes did not provide new Sc(II) complexes, and reduction of Cp*2ScI in benzene formed the Sc(III) phenyl complex, Cp*2Sc(C6H5), 3, by C-H bond activation. However, in Et2O and toluene, reduction of Cp*2ScI at -78 °C gives a dark-red solution, 4, which displays an eight-line EPR pattern like that of 1, but it did not provide thermally stable crystals. Reduction of Cp″2ScI, in THF or Et2O at -35 °C in the presence of 2.2.2-cryptand, yields the green Sc(II) metallocene iodide complex, [K(crypt)][Cp″2ScI], 5, which was identified by X-ray crystallography and EPR spectroscopy and is thermally unstable. The analogous reaction of Cp*2ScI with KC8 and 18-crown-6 in Et2O gave the ligand redistribution product, [Cp*2Sc(18-crown-6-κ2O,O')][Cp*2ScI2], 6, as the only crystalline product. Density functional theory calculations on the electronic structure of these compounds are reported in addition to a steric analysis using the Guzei method.

Desensitization using pegaspargase in the era of commercially available Erwinia: A single-institution report on efficacy, cost, and resource utilization.

BACKGROUND: Pegaspargase is a therapeutic enzyme that is utilized in treatment regimens targeting pediatric acute lymphoblastic leukemia. However, many patients experience hypersensitivity reactions, requiring discontinuation of the therapy. Historically, this necessitated switching to an alternative form of the drug, most commonly asparaginase Erwinia chrysanthemi; however, in recent years this was difficult due to drug shortages and eventually commercial discontinuation. We report here our experience performing pegaspargase desensitizations in patients with prior hypersensitivity reactions. PROCEDURE: Patients with a clinical hypersensitivity reaction to pegaspargase were identified. When due for their next dose, patients were admitted to the pediatric intensive care unit, bone marrow transplant unit, or oncology unit, and underwent desensitization utilizing a rigorous premedication and multistep dilution-based protocol. Serum asparaginase activity levels were drawn after desensitization to assess for therapeutic levels of enzyme activity. RESULTS: We identified 11 patients who underwent a total of 33 desensitizations to pegaspargase and calaspargase pegol-mknl. No patients experienced clinically significant hypersensitivity reactions necessitating stopping the infusion, nor administration of rescue medications. All serum asparaginase activity levels collected demonstrated enzyme activity levels above predefined therapeutic thresholds. Cost analysis revealed substantial savings when patients received asparaginase desensitization over the now commercially available asparaginase E. chrysanthemi (recombinant) rywn. CONCLUSIONS: Performing desensitization to pegaspargase in the pediatric acute lymphoblastic leukemia population is feasible, safe, and effective. It is financially advantageous over available alternative approaches, and requires fewer injections and presentations to care.

Synthesis and Crystallographic Characterization of a Reduced Bimetallic Yttrium ansa-Metallocene Hydride Complex, [K(crypt)][(µ-CpAn)Y(µ-H)]2 (CpAn = Me2Si[C5H3(SiMe3)-3]2), with a 3.4 Å Yttrium-Yttrium Distance.

The reduction of a bimetallic yttrium ansa-metallocene hydride was examined to explore the possible formation of Y-Y bonds with 4d1 Y(II) ions. The precursor [CpAnY(µ-H)(THF)]2 (CpAn = Me2Si[C5H3(SiMe3)-3]2) was synthesized by hydrogenolysis of the allyl complex CpAnY(η3-C3H5)(THF), which was prepared from (C3H5)MgCl and [CpAnY(µ-Cl)]2. Treatment of [CpAnY(µ-H)(THF)]2 with excess KC8 in the presence of one equivalent of 2.2.2-cryptand (crypt) generates an intensely colored red-brown product crystallographically identified as [K(crypt)][(µ-CpAn)Y(µ-H)]2. The two rings of each CpAn ligand in the reduced anion [(µ-CpAn)Y(µ-H)]21- are attached to two yttrium centers in a "flyover" configuration. The 3.3992(6) and 3.4022(7) Å Y···Y distances between the equivalent metal centers within two crystallographically independent complexes are the shortest Y···Y distances observed to date. Ultraviolet-visible (UV-visible)/near infrared (IR) and electron paramagnetic resonance (EPR) spectroscopy support the presence of Y(II), and theoretical analysis describes the singly occupied molecular orbital (SOMO) as an Y-Y bonding orbital composed of metal 4d orbitals mixed with metallocene ligand orbitals. A dysprosium analogue, [K(18-crown-6)(THF)2][(µ-CpAn)Dy(µ-H)]2, was also synthesized, crystallographically characterized, and studied by variable temperature magnetic susceptibility. The magnetic data are best modeled with the presence of one 4f9 Dy(III) center and one 4f9(5dz2)1 Dy(II) center with no coupling between them. CASSCF calculations are consistent with magnetic measurements supporting the absence of coupling between the Dy centers.

Primary Invasive Cutaneous Fusariosis in Patients with STAT3 Hyper-IgE Syndrome.

Dominant negative (DN) mutations in signal transducer and activator of transcription 3 (STAT3) are known to cause hyper-IgE syndrome, a rare primary immunodeficiency. STAT3 DN patients are prone to develop fungal infections, including chronic mucocutaneous candidiasis due to impaired IL-17-mediated immunity, and pulmonary aspergillosis. Despite having preserved phagocyte functions, STAT3 DN patients present connective tissue abnormalities and a defect in the immunological skin barrier. Fusarium species are ubiquitous molds, whose potential to infect humans depends on the host's innate and cellular immune status. Our aim was to describe four STAT3 DN patients with fusariosis confined to the skin. Medical records were reviewed and summarized. Four patients, aged 4, 11, 30, and 33 years, presented with chronic skin lesions which started in the extremities. Two patients had remote lesions, and none had systemic involvement. Skin biopsies showed mycelial threads with deep inflammatory-occasionally granulomatous-infiltrates, reaching the dermis; cultures grew Fusarium solani. Response to treatment was heterogeneous, often requiring multimodal therapies, including topical antifungal preparations. In this work, we describe primary invasive cutaneous fusariosis as a syndromic entity in four STAT3 DN patients.

Room-Temperature Stable Ln(II) Complexes Supported by 2,6-Diadamantyl Aryloxide Ligands.

The sterically bulky aryloxide ligand OAr* (OAr* = -OC6H2-Ad2-2,6tBu-4; Ad = 1-adamantyl) has been used to generate Ln(II) complexes across the lanthanide series that are more thermally stable than complexes of any other ligand system reported to date for 4fnd1 Ln(II) ions. The Ln(III) precursors Ln(OAr*)3 (1-Ln) were synthesized by reacting 1.2 equiv of Ln(NR2)3 (R = SiMe3) with 3 equiv of HOAr* for Ln = La, Ce, Nd, Gd, Dy, Yb, and Lu. 1-Ce, 1-Nd, 1-Gd, 1-Dy, and 1-Lu were identified by single-crystal X-ray diffraction studies. Reductions of 1-Ln with potassium graphite (KC8) in tetrahydrofuran in the presence of 2.2.2-cryptand (crypt) yielded the Ln(II) complexes [K(crypt)][Ln(OAr*)3] (2-Ln). The 2-Ln complexes for Ln = Nd, Gd, Dy, and Lu were characterized by X-ray crystallography and found to have Ln-O bond distances 0.038-0.087 Å longer than those of their 1-Ln analogues; this is consistent with 4fn5d1 electron configurations. The structure of 2-Yb has Yb-O distances 0.167 Å longer than those predicted for 1-Yb, which is consistent with a 4f14 electron configuration. Although 2-La and 2-Ce proved to be challenging to isolate, with 18-crown-6 (18-c-6) as the potassium chelator, La(II) and Ce(II) complexes with OAr* could be isolated and crystallographically characterized: [K(18-c-6)][Ln(OAr*)3] (3-Ln). The Ln(II) complexes decompose at room temperature more slowly than other previously reported 4fn5d1 Ln(II) complexes. For example, only 30% decomposition of 2-Dy was observed after 30 h at room temperature compared to complete decomposition of [Dy(OAr')3]- and [DyCp'3]- under similar conditions (OAr' = OC6H2-2,6-tBu2-4-Me; Cp' = C5H4SiMe3).

Threshold Collision-Induced Dissociation of Hydrated Thorium(IV) Trihydroxide Cation: Experimental and Theoretical Investigation of the Binding Energies for Th(OH)3+(H2O)n Complexes (n = 1-4).

Threshold collision-induced dissociation of Th(OH)3+(H2O)n (n = 1-4) with xenon was performed using a guided ion beam tandem mass spectrometer. The primary dissociation pathway for all complexes is a loss of a single water molecule followed by the sequential loss of additional water molecules at higher collision energies. The data were analyzed using a statistical model after accounting for lifetime effects and reactant internal and kinetic energy distributions to obtain 0 K bond dissociation energies (BDEs). These were also converted using rigid rotor/harmonic oscillator approximations to yield thermodynamic values at room temperature. The 0 K BDEs of H2O ligands to Th(OH)3+ (IV) are experimentally determined for the first time as 106 ± 6, 89 ± 6, 76 ± 4, and 51 ± 4 kJ/mol for the first, second, third, and fourth water ligand added. These values agree reasonably well with values calculated at the B3LYP, B3PW91, and PBE0 levels of theory with aug-cc-pVQZ basis sets, whereas B3LYP-GD3BJ, MP2, and CCSD(T) single point energies with (without) counterpoise corrections systematically overestimate the bond energies by about 15 (20), 19 (25), and (18) kJ/mol, respectively.

Association of obesity with survival in patients with endometrial cancer.

BACKGROUND: Obesity confers an overall increased risk for development of endometrial cancer. However there are conflicting reports regarding the effect of obesity on patients' overall and disease specific survival. The purpose of this study was to evaluate the effect of obesity on survival in women with endometrial cancer. METHODS: After IRB approval, records of women with diagnosis and treatment of endometrial cancer from 1999 to 2016 were abstracted for histopathological, treatment and demographic data. Death was confirmed by query of the Social Security Death Index. Kaplan Meier survival curves and Cox regression modeling was performed with Stata version 14.0. RESULTS: Of 1732 evaluable patients, there were significant differences in age at diagnosis, histology (endometrioid versus non-endometrioid), stage, race, grade, hypertension, hyperlipidemia, diabetes, and treatment between normal weight, overweight, obese, and morbidly obese patients (p < 0.01). There was a linear association of younger age at diagnosis with increasing obesity (p < 0.01) R2 = 0.04. Younger age, endometrioid histology, lower stage, and statin use were independently associated with decreased hazard of death (p < 0.01). However, in stratified analysis of non-endometrioid histologies, patients with Stage 3 and 4 disease over the age of 65 showed a survival benefit for women associated with obesity (p = 0.02). CONCLUSIONS: Obesity is associated with younger age at diagnosis and earlier stage disease. Obesity is associated with improved disease specific survival for stage 3 and 4 non-endometrioid endometrial cancers.

Two Sides of the Same Coin: Pediatric-Onset and Adult-Onset Common Variable Immune Deficiency.

PURPOSE: Common variable immunodeficiency (CVID) is a complex, heterogeneous immunodeficiency characterized by hypogammaglobulinemia, recurrent infections, and poor antibody response to vaccination. While antibiotics and immunoglobulin prophylaxis have significantly reduced infectious complications, non-infectious complications of autoimmunity, inflammatory lung disease, enteropathy, and malignancy remain of great concern. Previous studies have suggested that CVID patients diagnosed in childhood are more severely affected by these complications than adults diagnosed later in life. We sought to discern whether the rates of various infectious and non-infectious conditions differed between pediatric-diagnosed (ages 17 or younger) versus adult-diagnosed CVID (ages 18 or older). METHODS: Using the United States Immunodeficiency Network (USIDNET) database, we performed a retrospective analysis of 457 children and adults with CVID, stratified by age at diagnosis. Chi-squared testing was used to compare pediatric versus adult groups. RESULTS: After correcting for multiple comparisons, we identified few statistically significant differences (p ≤ 0.0004) between pediatric and adult groups. Pediatric-onset CVID patients had more frequent diagnoses of otitis media, developmental delay, and failure to thrive compared with adult-onset CVID patients. Adult CVID patients were more frequently diagnosed with bronchitis, arthritis, depression, and fatigue. Diagnoses of autoimmunity, lymphoma, and other malignancies were higher in adults but not to a significant degree. Serum immunoglobulins (IgG, IgA, and IgM) and lymphocyte subsets did not differ significantly between the two groups. When complications of infections and co-morbid conditions were viewed categorically, there were few differences between pediatric-onset and adult-onset CVID patients. CONCLUSIONS: These results suggest that pediatric CVID is not a distinct phenotype. Major features were comparable across the groups. This study underscores the need for continued longitudinal study of pediatric and early-onset CVID patients to further characterize accrual of features over time.

GATA2 deficiency: a protean disorder of hematopoiesis, lymphatics, and immunity.

Haploinsufficiency of the hematopoietic transcription factor GATA2 underlies monocytopenia and mycobacterial infections; dendritic cell, monocyte, B, and natural killer (NK) lymphoid deficiency; familial myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML); and Emberger syndrome (primary lymphedema with MDS). A comprehensive examination of the clinical features of GATA2 deficiency is currently lacking. We reviewed the medical records of 57 patients with GATA2 deficiency evaluated at the National Institutes of Health from January 1, 1992, to March 1, 2013, and categorized mutations as missense, null, or regulatory to identify genotype-phenotype associations. We identified a broad spectrum of disease: hematologic (MDS 84%, AML 14%, chronic myelomonocytic leukemia 8%), infectious (severe viral 70%, disseminated mycobacterial 53%, and invasive fungal infections 16%), pulmonary (diffusion 79% and ventilatory defects 63%, pulmonary alveolar proteinosis 18%, pulmonary arterial hypertension 9%), dermatologic (warts 53%, panniculitis 30%), neoplastic (human papillomavirus+ tumors 35%, Epstein-Barr virus+ tumors 4%), vascular/lymphatic (venous thrombosis 25%, lymphedema 11%), sensorineural hearing loss 76%, miscarriage 33%, and hypothyroidism 14%. Viral infections and lymphedema were more common in individuals with null mutations (P = .038 and P = .006, respectively). Monocytopenia, B, NK, and CD4 lymphocytopenia correlated with the presence of disease (P < .001). GATA2 deficiency unites susceptibility to MDS/AML, immunodeficiency, pulmonary disease, and vascular/lymphatic dysfunction. Early genetic diagnosis is critical to direct clinical management, preventive care, and family screening.

GATA2 haploinsufficiency caused by mutations in a conserved intronic element leads to MonoMAC syndrome.

Previous reports of GATA2 mutations have focused on the coding region of the gene or full gene deletions. We recently identified 2 patients with novel insertion/deletion mutations predicted to result in mRNA nonsense-mediated decay, suggesting haploinsufficiency as the mechanism of GATA2 deficient disease. We therefore screened patients without identified exonic lesions for mutations within conserved noncoding and intronic regions. We discovered 1 patient with an intronic deletion mutation, 4 patients with point mutations within a conserved intronic element, and 3 patients with reduced or absent transcription from 1 allele. All mutations affected GATA2 transcription. Full-length cDNA analysis provided evidence for decreased expression of the mutant alleles. The intronic deletion and point mutations considerably reduced the enhancer activity of the intron 5 enhancer. Analysis of 512 immune system genes revealed similar expression profiles in all clinically affected patients and reduced GATA2 transcript levels. These mutations strongly support the haploinsufficient nature of GATA2 deficiency and identify transcriptional mechanisms and targets that lead to MonoMAC syndrome.

A qualitative analysis of patients' experiences with an emergency department diagnosis of gastrointestinal cancer.

OBJECTIVES: Optimally, cancer is diagnosed through periodic screening or detection of early symptoms in primary care settings. However, an estimated 23%-52% of gastrointestinal (GI) cancers are diagnosed in the emergency department (ED). Cancer diagnosed in the ED has been associated with worse clinical and patient-reported outcomes even after adjustment for cancer stage. We sought to explore patients' accounts of patient and health care system factors related to their diagnosis in the ED and their lived experience of receiving a diagnosis in this setting. METHODS: Patients with an ED visit during or within 30 days of their GI cancer diagnosis at an urban academic hospital serving a largely disadvantaged population were recruited. Interviews were coded in NVivo 12 and analyzed using a thematic analysis approach. RESULTS: Patient-reported factors associated with their experiences included denial and avoidance of symptoms, mistrust of the health system, and lack of cancer screening knowledge. Health care system factors included misdiagnosis and delayed access to specialty care or tests. Experiences receiving a cancer diagnosis in the ED were overwhelmingly negative. CONCLUSIONS: This study highlights the unmet needs in identifying and diagnosing patients who ultimately present to the ED for evaluation and eventual diagnosis of cancer. Our results shed light on several modifiable factors, including the need for increased public awareness of the asymptomatic nature of cancer and the importance of cancer screening. Additionally, health care systems modifications beyond the ED are needed to improve access to timely care when symptoms arise.

Weight Stigma by Association Among Parents of Children With Obesity: A Randomized Trial.

OBJECTIVE: To experimentally test weight stigma and weight stigma by association in a parent-child relationship using a large, community-based sample. METHODS: We conducted a randomized experiment on Amazon Mechanical Turk using an online survey. Participants were randomly assigned to view a picture of a parent-child dyad, for which the parent and child's gender (male vs. female) and weight status (with obesity vs. without obesity) were manipulated. Participants read identical parenting descriptions that adhered to the American Academy of Pediatrics' parenting recommendations, then rated the parent's perceived effectiveness, helpfulness, and level of caring using a parenting questionnaire based on Barnhart et al (2013). RESULTS: Participants (N = 1862; Mage = 36.8 [11.2] years) rated parents of children with obesity as less effective compared to parents of children without obesity (P = .010) and parents with obesity as less effective compared to parents without obesity (P = .033). Participants also rated parents with obesity as less helpful compared to parents without obesity (P = .021). No differences emerged in perceived caring. Parenting evaluations did not differ across daughters versus sons or mothers versus fathers. CONCLUSIONS: Parents of children with obesity may experience weight stigma by association, which could have direct consequences for the parents, the children, and the parent-child relationship.

Targeted Therapies for the Neurofibromatoses.

Over the past several years, management of the tumors associated with the neurofibromatoses has been recognized to often require approaches that are distinct from their spontaneous counterparts. Focus has shifted to therapy aimed at minimizing symptoms given the risks of persistent, multiple tumors and new tumor growth. In this review, we will highlight the translation of preclinical data to therapeutic trials for patients with neurofibromatosis, particularly neurofibromatosis type 1 and neurofibromatosis type 2. Successful inhibition of MEK for patients with neurofibromatosis type 1 and progressive optic pathway gliomas or plexiform neurofibromas has been a significant advancement in patient care. Similar success for the malignant NF1 tumors, such as high-grade gliomas and malignant peripheral nerve sheath tumors, has not yet been achieved; nor has significant progress been made for patients with either neurofibromatosis type 2 or schwannomatosis, although efforts are ongoing.

Trends in Opioid Prescriptions after Laparoscopic Sterilization.

BACKGROUND AND OBJECTIVES: Examine trends in opioid prescriptions after laparoscopic sterilization over time, and identify any individual patient, provider, or procedural factors influencing prescribing. METHODS: A retrospective observational cohort analysis of laparoscopic sterilizations between January 1, 2016 and December 31, 2019 at Montefiore Medical Center. A review of the medical records was performed and information on patient demographics, comorbid conditions, and surgical characteristics were collected. The number of opioid pills prescribed postoperatively and any pain related patient calls, visits, or refills was recorded. RESULTS: Between January 1, 2016 and December 31, 2019, 615 laparoscopic sterilizations were performed. The median number of opioid pills prescribed was 10, ranging from 0 to 40. There was a significant decrease in the number of opioid pills prescribed (p < .0001) and refill incidence (p < .001) over time. Patients with a documented diagnosis of pelvic pain received significantly more opioid pills (p = .02), as did patients who underwent tubal occlusion versus salpingectomy (p = .01). There was no association between the number of opioid pills prescribed and other patient or procedural characteristics. Finally, the number of pills prescribed was not associated with urgent patient contact (p = .34). CONCLUSIONS: The overall number of opioid pills prescribed after laparoscopic sterilization decreased at our institution over time, which paralleled a decrease in refills and urgent postoperative patient contact. Further, few clinical characteristics influenced postoperative prescribing and there was no association between number of pills prescribed and urgent patient contact. These findings suggest excess prescribing and highlight the need to identify and adopt an evidenced-based approach to postsurgical opioid prescriptions.

MRI findings in juvenile Huntington's disease.

Juvenile Huntington's disease is a rare neurodegenerative disorder that first affects the basal ganglia. Presented here is a case of juvenile Huntington's disease in an 8-year-old male. Clinical features included epilepsy and developmental delay. Imaging findings showed severe atrophy of the caudate nuclei and putamina which prompted a genetic evaluation. The diagnosis was confirmed via molecular analysis which revealed the amplified CAG triplet characteristic of this disorder. This case report highlights the imaging features common in this rare cause of pediatric epilepsy.

CT and MRI findings in infantile vanishing white matter.

Infantile vanishing white matter disease is an uncommon cause of developmental delay and seizures in children. Presented here is a case of vanishing white matter disease diagnosed at 6 months of age. Imaging findings demonstrated widespread white matter abnormalities throughout the supratentorial and infratentorial brain. The diagnosis of infantile vanishing white matter disease was confirmed via molecular analysis which revealed a rare mutation in the gene responsible for this disorder.

Pulmonary Manifestations of GATA2 Deficiency.

BACKGROUND: GATA2 deficiency is a genetic disorder of hematopoiesis, lymphatics, and immunity caused by autosomal dominant or sporadic mutations in GATA2. The disease has a broad phenotype encompassing immunodeficiency, myelodysplasia, leukemia, and vascular or lymphatic dysfunction as well as prominent pulmonary manifestations. RESEARCH QUESTION: What are the pulmonary manifestations of GATA2 deficiency? STUDY DESIGN AND METHODS: A retrospective review was conducted of clinical medical records, diagnostic imaging, pulmonary pathologic specimens, and tests of pulmonary function. RESULTS: Of 124 patients (95 probands and 29 ascertained), the lung was affected in 56%. In addition to chronic infections, pulmonary alveolar proteinosis (11 probands) and pulmonary arterial hypertension (nine probands) were present. Thoracic CT imaging found small nodules in 54% (54 probands and 12 relatives), reticular infiltrates in 40% (45 probands and four relatives), paraseptal emphysema in 25% (30 probands and one relative), ground-glass opacities in 35% (41 probands and two relatives), consolidation in 21% (23 probands and two relatives), and a typical crazy-paving pattern in 7% (eight probands and no relatives). Nontuberculous mycobacteria were the most frequent organisms associated with chronic infection. Allogeneic hematopoietic stem cell transplantation successfully reversed myelodysplasia and immune deficiency and also improved pulmonary hypertension and pulmonary alveolar proteinosis in most patients. INTERPRETATION: GATA2 deficiency has prominent pulmonary manifestations. These clinical observations confirm the essential role of hematopoietic cells in many aspects of pulmonary function, including infections, alveolar proteinosis, and pulmonary hypertension, many of which precede the formal diagnosis, and many of which respond to stem cell transplantation.

Cortactin colocalizes with filopodial actin and accumulates at IgCAM adhesion sites in Aplysia growth cones.

Both IgCAMs and the actin cytoskeleton play critical roles in neuronal growth cone motility and guidance. However, it is unclear how IgCAM receptors transduce signals from the plasma membrane to induce actin remodeling. Previous studies have shown that local clustering and immobilization of apCAM, the Aplysia homolog of NCAM, induces Src kinase activity and F-actin polymerization in the peripheral domain of cultured Aplysia bag cell growth cones. Therefore, we wanted to test whether the Src kinase substrate and actin regulator cortactin could be a molecular link between Src activity and actin assembly during apCAM-mediated growth cone guidance. Here, we cloned Aplysia cortactin and showed that it is abundant in the nervous system. Immunostaining of growth cones revealed a strong colocalization of cortactin with F-actin in filopodial bundles and at the leading edge of lamellipodia. Perturbation of the cytoskeleton indicated that cortactin distribution largely depends on actin filaments. Furthermore, active Src colocalized with cortactin in regions of actin assembly, including leading edge and filopodia tips. Finally, we observed that cortactin, like F-actin, localizes to apCAM adhesion sites mediating growth cone guidance. Altogether, these data suggest that cortactin is a mediator of IgCAM-triggered actin assembly involved in growth cone motility and guidance.