Preferred physical characteristics of lidocaine thin film for women with vestibulodynia.

Introduction: Vestibulodynia (VBD) is the most common cause of sexual pain in the United States, affecting up to 15% of reproductive-aged women during their lifetime with limited treatment options. The purpose of this study was to describe ideal physical characteristics of a vulvar film designed for insertional sexual pain in sexually active women with VBD. Methods: Twenty women were recruited to participant in one of six, semi-structured 60-minute focus group discussions regarding treatment options for VBD. Heterosexual women, aged 18-51 years old with a diagnosis of vulvodynia, vestibulodynia or insertional dyspareunia fit the inclusion criteria. Those who reported no episodes of vaginal intercourse in the prior 18 months were excluded. A new vulvar film technology loaded with 50 mg of 5% lidocaine was introduced to the group. Participants took part in focus groups on a rolling basis depending on availability. Focus group discussions were audio-recorded and transcribed verbatim. Two study investigators coded the transcripts using inductive coding and merged their respective projects to resolve disagreements. We analyzed data related to each code to develop code clusters and higher-level primary topics regarding device preferences. Data related to each of these primary topics was analyzed to assess the range of participant attitudes and preferences and to identify patterns within each primary topic. Results: One hundred and sixteen women were recruited, and twenty women were enrolled. The mean age for the participants was 33.3 years. Most women were educated with at least some college (93%), White (78.6%), married (75%), and had income greater than $100,000 (50%). Analysis of the focus group discussions identified five common topics addressed by participants: desired loaded medication, film size, film shape, film flexibility, and ease and accuracy of use. Concerns across topics included comfort, sexual spontaneity, and efficacy. Interest in loading the device with other acceptable medications or combination with lidocaine was independently noted in 2/6 (33%) of the focus groups. Discussion: Mucoadhesive vulvar thin films may be an acceptable drug delivery system for insertional sexual pain for women with VBD.

Credentialing and Patient Safety in Robotic Gynecologic Surgery: Changes over the Last Eight Years.

Background and Objectives: Robotic gynecologic surgery has outpaced data showing risks and benefits related to cost, quality outcomes, and patient safety. We aimed to assess how credentialing standards and perceptions of safe use of robotic gynecologic surgery have changed over time. Methods: An anonymous, online survey was distributed in 2013 and in 2021 to attending surgeons and trainees in accredited obstetrics and gynecology residency programs. Results: There were 367 respondents; 265 in 2013 and 102 in 2021. There was a significant increase in robotic platform use from 2013 to 2021. Percentage of respondents who ever having performed a robotic case increased from 48% to 79% and those who performed > 50 cases increased from 25% to 59%. In 2021, a greater percentage of attending physicians reported having formalized protocol for obtaining robotic credentials (93% vs 70%, p = 0.03) and maintaining credentialing (90% vs 27%, p < 0.01). At both time points, most attendings reported requiring proctoring for 1 - 5 cases before independent use. Opinions on the number of cases needed for surgical independence changed from 2013 to 2021. There was an increase in respondents who believed > 20 cases were required (from 58% to 93% of trainees and 29% to 70% of attendings). In 2021, trainees were less likely to report their attendings lacked the skills to safely perform robotic surgery (25% to 6%, p < 0.01). Discussion: Greater experience with robotic platforms and expansion of credentialing processes over time correlated with improved confidence in surgeon skills. Further work is needed to evaluate if current credentialing procedures are sufficient.

Teratogenic medication use associated with favourable odds of contraception counselling in a cohort of women with systemic lupus erythematosus at a large tertiary academic medical centre.

OBJECTIVE: SLE primarily affects women of childbearing age, who have an increased risk of pregnancy complications, especially in the setting of active disease. Contraception counselling is particularly important given the teratogenicity of some medications used for SLE treatment. Our study describes the frequency of contraception counselling provided by multiple subspecialties to women with SLE and investigates associations between teratogenic medication use and receiving contraception counselling. METHODS: This was a cross-sectional retrospective study of women (aged 15-46 years) diagnosed with SLE who were seen in various outpatient clinics at a large tertiary academic medical centre over a 2-year period. Demographic data were retrieved via the university-affiliated central data repository, and additional data, including documentation of contraception counselling, were obtained via manual chart abstraction. Univariable associations between variables and contraception counselling were assessed to produce unadjusted ORs and 95% CIs. Multivariable models were generated to evaluate independent associations between variables and contraception counselling. RESULTS: Data from 478 women (52% African American, 25% Caucasian) with SLE were included. Rheumatology was the subspecialty to document contraception counselling most frequently (57%). Nearly 80% of women received counselling from at least one subspecialty, 44% from at least two. Factors associated with having lower odds of receiving contraception counselling were older age and Caucasian race. Women on teratogenic medications (methotrexate, mycophenolate mofetil/mycophenolic acid, cyclophosphamide) had higher odds of receiving contraception counselling from at least one subspecialty (OR 2.01; 95% CI 1.23 to 3.26), from two or more subspecialties (OR 2.18; 95% CI 1.50 to 3.17), and from rheumatology (OR 1.86; 95% CI 1.27 to 2.73). CONCLUSIONS: In this study, women with SLE on teratogenic medications had higher odds of receiving contraception counselling from rheumatology and from at least two subspecialties. Multidisciplinary approaches to enhance contraception counselling should be encouraged.

Patient Characteristics Associated with Access to Minimally Invasive Gynecologic Surgery: Changes during the COVID-19 Pandemic.

STUDY OBJECTIVE: To evaluate patient characteristics that affect access to minimally invasive gynecologic surgery (MIGS) subspecialty care and identify changes during the coronavirus disease 2019 pandemic. DESIGN: Retrospective cohort study of patients referred to MIGS from 2014 to 2016 (historic cohort) compared with those referred to MIGS in 2020 (pandemic cohort). Primary outcome was the interval between referral and first appointment. SETTING: Single-institution academic MIGS division. PATIENTS: Historic cohort (n = 1082) and pandemic cohort (n = 770). INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: Demographics and socioeconomic variables (race, ethnicity, language, insurance, employment, and socioeconomic factors by census tract) and distance from hospital were compared between historic and pandemic cohorts with respect to referral interval using the chi-square, Fisher exact tests, and logistic regression. After adjusting for referral indication, being unemployed and living in an area with less population density, less education, and higher percentage of poverty were associated with a referral interval >30 days in the historic cohort. In the pandemic cohort, only unemployment persisted as a covariate associated with prolonged referral interval and new associated variables were primary language other than English (odds ratio, 3.20; 95% confidence interval [CI], 1.60-6.40) and "other" race (odds ratio, 2.22; 95% CI, 1.34-3.68). The odds of waiting >30 days increased by 6% with the addition of 1 demographic risk factor (95% CI, 1.01-1.10) and by 17% for 3 risk factors (95% CI, 1.03-1.34) in the historic cohort whereas no significant intersectionality was identified in the pandemic cohort. Average referral intervals were significantly shorter during the pandemic (31 vs 50 days, p <.01). Telemedicine appointments had a significantly shorter referral interval than in-person appointments (27 vs 47 days, p <.01). Of patients using telemedicine, a greater proportion were non-Hispanic, English speaking, employed, privately insured, and lived further from the hospital (p <.05). CONCLUSION: Time from referral to first appointment at a tertiary-care MIGS practice during the coronavirus disease 2019 pandemic was shorter than that before the pandemic, likely owing to the adoption of telemedicine. Differences in socioeconomic and demographic factors suggest that telemedicine improved access to care and decreased access disparities for many populations, but not for non-English-speaking patients.

Contraceptive use and counseling in patients with systemic lupus erythematosus.

OBJECTIVES: (1) Describe contraception use in women with systemic lupus erythematosus (SLE); (2) characterize the types of contraception used by this population; (3) determine factors affecting the documentation of contraception use; (4) identify if contraception counseling was received in this population at risk for adverse pregnancy outcomes. STUDY DESIGN: This cross-sectional study analyzed data from clinic visits from 2016 - 2018 among 453 women of reproductive age who have SLE. Documentation of contraception use, contraception method, contraception counseling, and other medication use were abstracted from the medical record and analyzed with percentage based statistics, chi-squared test, t-test, and logistic regression. RESULTS: Of the 453 women included in the analysis, 71% had a method of contraception documented within 2 years of the study period. Only 37% were using highly effective contraception. 78% had documentation of contraception counseling. Half (50%) were using teratogenic medications; patients on teratogenic medications had higher odds of having a contraceptive method documented (OR 1.56, 95% CI 1.04 - 2.36) however 24% did not have any contraception documented. 28% of patients were using contraception for which they had a possible or absolute contraindication. CONCLUSIONS: Given a substantial proportion of women with SLE did not have any contraception or contraceptive counseling documented, these findings suggest the need to improve universal reproductive health counseling in patients with SLE. IMPLICATIONS: There is room to improve reproductive health care in patients with SLE through provider training to help optimize pregnancy outcomes in this high-risk population.

Postpartum psychological distress after emergency team response during childbirth.

Purpose: To evaluate the feasibility and acceptability of a protocol determining the relationship between emergency team response (ETR) during childbirth and acute stress disorder (ASD) and post-traumatic stress disorder (PTSD) symptoms. Methods: In a prospective, observational, cohort design, women experiencing ETR during childbirth were approached and recruited on postpartum day-1 and followed for six weeks. Demographics, obstetric and birth characteristics, ASD scores and PTSD scores (by Impact of Events Scale, IES and PCL-civilian) were recorded. Recruitment and retention rates were recorded, and scores were compared to women who did not experience ETR. Results: Three hundred sixty-nine were approached and 249 were enrolled (67.5% recruitment rate). One hundred twenty-five completed all procedures (50.2% retention). Twenty experienced ETR (3.5% event rate), 12 enrolled (60.0% recruitment rate) and 8 completed the study (66.7% retention). The ETR group had higher PCL and IES scores (PCL: ETR median 12, non-ETR median 2, p = .08; IES: ETR median 22.5, non-ETR median 20, p = .08). ASD scores were similar between groups. Conclusions: Methodology investigating the link between ETR and postpartum psychological distress is feasible and acceptable. A relationship between ETR and PTSD symptoms appears to exist, with ETR being associated with higher PTSD scores compared to non-ETR childbirths. Methods that incorporate awareness of the unique concerns of vulnerable populations are needed.

Investigating the causes and consequences of symbiont shuffling in a multi-partner reef coral symbiosis under environmental change.

Dynamic symbioses may critically mediate impacts of climate change on diverse organisms, with repercussions for ecosystem persistence in some cases. On coral reefs, increases in heat-tolerant symbionts after thermal bleaching can reduce coral susceptibility to future stress. However, the relevance of this adaptive response is equivocal owing to conflicting reports of symbiont stability and change. We help reconcile this conflict by showing that change in symbiont community composition (symbiont shuffling) in Orbicella faveolata depends on the disturbance severity and recovery environment. The proportion of heat-tolerant symbionts dramatically increased following severe experimental bleaching, especially in a warmer recovery environment, but tended to decrease if bleaching was less severe. These patterns can be explained by variation in symbiont performance in the changing microenvironments created by differentially bleached host tissues. Furthermore, higher proportions of heat-tolerant symbionts linearly increased bleaching resistance but reduced photochemical efficiency, suggesting that any change in community structure oppositely impacts performance and stress tolerance. Therefore, even minor symbiont shuffling can adaptively benefit corals, although fitness effects of resulting trade-offs are difficult to predict. This work helps elucidate causes and consequences of dynamism in symbiosis, which is critical to predicting responses of multi-partner symbioses such as O. faveolata to environmental change.

Thrombospondin-1 restrains neutrophil granule serine protease function and regulates the innate immune response during Klebsiella pneumoniae infection.

Neutrophil elastase (NE) and cathepsin G (CG) contribute to intracellular microbial killing but, if left unchecked and released extracellularly, promote tissue damage. Conversely, mechanisms that constrain neutrophil serine protease activity protect against tissue damage but may have the untoward effect of disabling the microbial killing arsenal. The host elaborates thrombospondin-1 (TSP-1), a matricellular protein released during inflammation, but its role during neutrophil activation following microbial pathogen challenge remains uncertain. Mice deficient in TSP-1 (thbs1(-/-)) showed enhanced lung bacterial clearance, reduced splenic dissemination, and increased survival compared with wild-type (WT) controls during intrapulmonary Klebsiella pneumoniae infection. More effective pathogen containment was associated with reduced burden of inflammation in thbs1(-/-) mouse lungs compared with WT controls. Lung NE activity was increased in thbs1(-/-) mice following K. pneumoniae challenge, and thbs1(-/-) neutrophils showed enhanced intracellular microbial killing that was abrogated with recombinant TSP-1 administration or WT serum. Thbs1(-/-) neutrophils exhibited enhanced NE and CG enzymatic activity, and a peptide corresponding to amino-acid residues 793-801 within the type-III repeat domain of TSP-1 bridled neutrophil proteolytic function and microbial killing in vitro. Thus, TSP-1 restrains proteolytic action during neutrophilic inflammation elicited by K. pneumoniae, providing a mechanism that may regulate the microbial killing arsenal.

Exosome poly-ubiquitin inhibits platelet activation, downregulates CD36 and inhibits pro-atherothombotic cellular functions.

INTRODUCTION: Activated platelets shed microparticles from plasma membranes, but also release smaller exosomes from internal compartments. While microparticles participate in athero-thrombosis, little is known of exosomes in this process. MATERIALS & METHODS: Ex vivo biochemical experiments with human platelets and exosomes, and FeCl3 -induced murine carotid artery thrombosis. RESULTS: Both microparticles and exosomes were abundant in human plasma. Platelet-derived exosomes suppressed ex vivo platelet aggregation and reduced adhesion to collagen-coated microfluidic channels at high shear. Injected exosomes inhibited occlusive thrombosis in FeCl3 -damaged murine carotid arteries. Control platelets infused into irradiated, thrombocytopenic mice reconstituted thrombosis in damaged carotid arteries, but failed to do so after prior ex vivo incubation with exosomes.CD36 promotes platelet activation, and exosomes dramatically reduced platelet CD36.CD36 is also expressed by macrophages, where it binds and internalizes oxidized LDL and microparticles, supplying lipid to promote foam cell formation. Platelet exosomes inhibited oxidized-LDL binding and cholesterol loading into macrophages. Exosomes were not competitive CD36 ligands, but instead sharply reduced total macrophage CD36 content. Exosomal proteins, in contrast to microparticle or cellular proteins, were highly adducted by ubiquitin. Exosomes enhanced ubiquitination of cellular proteins, including CD36, and blockade of proteosome proteolysis with MG-132 rescued CD36 expression. Recombinant unanchored K48 poly-ubiquitin behaved similarly to exosomes, inhibiting platelet function, macrophage CD36 expression and macrophage particle uptake. CONCLUSIONS: Platelet-derived exosomes inhibit athero-thrombotic processes by reducing CD36-dependent lipid loading of macrophages and by suppressing platelet thrombosis. Exosomes increase protein ubiquitination and enhance proteasome degradation of CD36.

Thrombospondin-1 triggers macrophage IL-10 production and promotes resolution of experimental lung injury.

Mononuclear phagocyte recognition of apoptotic cells triggering suppressive cytokine signaling is a key event in inflammation resolution from injury. Mice deficient in thrombospondin (TSP)-1 (thbs1⁻/⁻), an extracellular matrix glycoprotein that bridges cell-cell interactions, are prone to lipopolysaccharide-induced lung injury and show defective macrophage interleukin (IL)-10 production during the resolution phase of inflammation. Reconstitution of IL-10 rescues thbs1⁻/⁻ mice from persistent neutrophilic lung inflammation and injury and thbs1⁻/⁻ alveolar macrophages show defective IL-10 production following intratracheal instillation of apoptotic neutrophils despite intact efferocytosis. Following co-culture with apoptotic neutrophils, thbs1⁻/⁻ macrophages show a selective defect in IL-10 production, whereas prostaglandin E2 and transforming growth factor beta 1 responses remain intact. Full macrophage IL-10 responses require the engagement of TSP-1 structural repeat 2 domain and the macrophage scavenger receptor CD36 LIMP-II Emp sequence homology (CLESH) domain in vitro. Although TSP-1 is not essential for macrophage engulfment of apoptotic neutrophils in vivo, TSP-1 aids in the curtailment of inflammatory responses during the resolution phase of injury in the lungs by providing a means by which apoptotic cells are recognized and trigger optimal IL-10 production by macrophages.

P2RY1 and P2RY12 polymorphisms and on-aspirin platelet reactivity in patients with coronary artery disease.

INTRODUCTION: Association of P2RY1 and P2RY12 polymorphisms with on-aspirin platelet reactivity was investigated. MATERIALS AND METHODS: Platelet reactivity was assessed by the light transmission aggregometry and TxB(2) assay in 423 patients with coronary artery disease (CAD) on aspirin. High residual platelet reactivity (RPR) was defined by ≥20% and ≥70% maximal aggregation stimulated with 0.5 mg/mL arachidonic acid (AA) and 10 µm ADP, respectively. Moderate RPR was considered aggregation ≥20% with AA, ≥70% with ADP, or ≥1 ng/mL stimulated TxB(2) . Fourteen P2RY1 and 35 P2RY12 single nucleotide polymorphisms (SNPs) were genotyped. RESULTS: High RPR was detected in 24% of the patients. Moderate RPR was observed in 31% with AA, 57% with 5 µm ADP, and 82% with 10 µm ADP. Stimulated TxB(2) was ≥1 ng/mL in 23% of patients. P2RY12 SNP rs9859538 was associated with high RPR (OR = 2.16, 95% CI = 1.24-3.75, P-value = 0.004). Four P2RY12 SNPs, rs1491974, rs10513398, rs3732765, and rs10935841, showed association with moderate RPR (OR = 1.79-2.94, P-value = 0.04-0.028), while five, rs7615865, rs1388623, rs1388622, rs7634096, and rs7637803, were associated with low RPR (OR = 0.50-0.55, P-value = 0.008-0.026), following ADP stimulation. TxB(2) level <1 ng/mL was linked to five P2RY1 SNPs, rs1439010, rs1371097, rs701265, rs12497578, and rs2312265 (OR = 0.36-0.54, P-value = 0.003-0.039). CONCLUSIONS: Polymorphisms in P2RY1 and P2RY12 are associated with on-aspirin platelet reactivity in patients with CAD.

Effects of mindfulness training on body awareness to sexual stimuli: implications for female sexual dysfunction.

OBJECTIVES: Treatments of female sexual dysfunction have been largely unsuccessful because they do not address the psychological factors that underlie female sexuality. Negative self-evaluative processes interfere with the ability to attend and register physiological changes (interoceptive awareness). This study explores the effect of mindfulness meditation training on interoceptive awareness and the three categories of known barriers to healthy sexual functioning: attention, self-judgment, and clinical symptoms. METHODS: Forty-four college students (30 women) participated in either a 12-week course containing a "meditation laboratory" or an active control course with similar content or laboratory format. Interoceptive awareness was measured by reaction time in rating physiological response to sexual stimuli. Psychological barriers were assessed with self-reported measures of mindfulness and psychological well-being. RESULTS: Women who participated in the meditation training became significantly faster at registering their physiological responses (interoceptive awareness) to sexual stimuli compared with active controls (F(1,28) = 5.45, p = .03, η(p)(2) = 0.15). Female meditators also improved their scores on attention (t = 4.42, df = 11, p = .001), self-judgment, (t = 3.1, df = 11, p = .01), and symptoms of anxiety (t = -3.17, df = 11, p = .009) and depression (t = -2.13, df = 11, p < .05). Improvements in interoceptive awareness were correlated with improvements in the psychological barriers to healthy sexual functioning (r = -0.44 for attention, r = -0.42 for self-judgment, and r = 0.49 for anxiety; all p < .05). CONCLUSIONS: Mindfulness-based improvements in interoceptive awareness highlight the potential of mindfulness training as a treatment of female sexual dysfunction.

Atp2b2, encoding plasma membrane Ca2+-ATPase type 2, (PMCA2) exhibits tissue-specific first exon usage in hair cells, neurons, and mammary glands of mice.

Atp2b2 encodes the plasma membrane Ca(2+)-ATPase type 2 (PMCA2) expressed in various tissues, including stereocilia of cochlear and vestibular hair cells, cerebellar Purkinje cells, and lactating mammary epithelia. Mutations of the gene lead to deafness, ataxia, and reduced Ca(2+) levels in milk. Heterozygous mutants also have abnormal hearing, suggesting that precise regulation of Atp2b2 is required for normal function. In this study, we describe Atp2b2 5'-untranslated region genomic structure and transcript usage in mice. Using 5'-rapid amplification of cDNA ends, we observed four transcripts: types alpha, beta, mu and delta, each splicing into a common ATG-containing exon. Types alpha and beta correspond to previously published mammalian cDNA sequences. Types mu and delta constitute novel 5'-untranslated region sequences, and were observed at high levels only in lactating mammary gland. Using real-time reverse transcriptase polymerase chain reaction, we quantified relative transcript usage across several tissues. We show that alpha and beta are abundant throughout the CNS, as well as the cochlea. When we microdissected the cochlea into hair cell and spiral ganglion containing fractions, we found that cochlear hair cell expression is mediated through the type alpha transcript. In situ hybridization studies in cerebellum using exon-specific probes revealed that alpha dominates in Purkinje neurons, while beta is enriched in cerebellar granule neurons. We compared 5'-untranslated region sequence across multiple species, and found high conservation around the first exons for alpha and beta in mammals, but not other species. The regions around the mu and delta first exons are highly conserved between rat and mouse, but less so with other species. Our results show that expression of Atp2b2 is highly regulated, using four different transcriptional start regions, two of which are differentially expressed in neuronal tissue. This suggests that unique regulatory mechanisms are used to control Atp2b2 expression in different types of cells.

The antiangiogenic effect of thrombospondin-2 is mediated by CD36 and modulated by histidine-rich glycoprotein.

Thrombospondins-1 and -2 (TSP-1, TSP-2) are matricellular glycoproteins with potent antiangiogenic activity. We have previously shown that the antiangiogenic activity of TSP-1 is mediated by the interaction of the type I repeats (TSR) with the receptor CD36, although other domains of TSP-1 have also been implicated. We now show that the antiangiogenic activity of TSP-2, which contains three TSRs but, unlike TSP-1, lacks the capacity to activate TGF-beta, is similarly dependent on CD36. Using the corneal pocket assay we found that TSP-2 did not inhibit bFGF-induced angiogenesis in CD36 null mice. We then demonstrated that (125)[I]-TSP-2 bound to murine macrophages and that binding was diminished by 70% by anti-CD36 antibody or by using cells from CD36 null animals. Solid-phase binding studies revealed that (125)[I]-TSP-2 bound to CD36/glutathione-S-transferase (GST) fusion proteins encoding the region spanning amino acids 93-120, but not amino acids 298-439. This 93-120 amino acid region, previously identified as the TSP-1 binding site, is homologous to domains on other TSP binding proteins, such as LIMP-2 and histidine-rich glycoprotein (HRGP). Finally, we showed with an immunoabsorbent binding assay that TSP-2 bound HRGP with high affinity and that HRGP blocked the antiangiogenic activity of TSP-2, acting like a "decoy" receptor. These data suggest that modulation of the TSR/CD36 system may play an important role in the regulation of the angiogenic "switch," and may provide a target for therapeutic interventions.

The second international congress on myeloproliferative and myelodysplastic syndromes.

This meeting was convened by Richard T. Silver, M.D. and co-chaired by Jerry L. Spivak, M.D. It was held from 16 to 18 October 2003 in New York City, New York, USA. Thirty-nine invited speakers from nine different countries participated in the conference. There were more than 350 attendees. There were formal presentations and discussions on biology, clinical aspects, and management of patients with these diverse bone marrow stem cell disorders linked by a variable progression to acute myeloid leukemia. Of considerable interest, a clinical symposium exclusively for patients was held the day preceding the meeting at which John Bennett, Tiziano Barbui, Richard Silver, Jerry Spivak, and Ayalew Tefferi spoke on various topics pertaining to these diseases. This proved to be highly informative to the patients who reported that they enjoyed the program immensely. This was sponsored by the Cancer Research & Treatment Fund, Inc. Representatives of the Myelodysplasia Foundation were also present. This meeting report provides a summary of five different sections prepared by one or more of the session chairs. The keynote address was given by Shahin Rafii (Cornell Medical Center). Most appropriately, this talk focused on the expression and activation of angiogenic factors which play a crucial role in the progression of both myeloproliferative disorders and myelodysplastic syndromes (MDS). Among the known factors, vascular endothelial growth tyrosine kinase receptors (VEGF-R1, R2, and R3) support proliferation, survival, and mobility. Rafii's team has demonstrated that these receptors are expressed on subsets of primary hematopoietic cells as well as leukemic cells. Some leukemic cells express both VEGF-A and VEGF-R2, resulting in the generation of an autocrine loop that supports survival and within the osteoblastic zone translocating these cells to the vascular enriched niche for receipt of molecular instructions required for proliferation and differentiation. A pathologic correlation can be seen in some patients with the identification of abnormal localization of immature precursors (ALIP) in the central portions of the medullary cavity. Misplaced megakaryocytes can release pro-fibrotic factors, including platelet derived growth factors and transforming growth factor-beta. Collectively, these data suggest that chronic disregulation of angiogenic factors alter the microenvironment dislocating marrow stem cells that force both proliferation and differentiation in varying degrees, contributing to these hematological disorders.

The impact of overexpression and deficiency of fatty acid translocase (FAT)/CD36.

Fatty acid translocase (FAT)/CD36 has been associated with diverse normal and pathologic processes. These include scavenger receptor functions (uptake of apoptotic cells and modified lipid), lipid metabolism and fatty acid transport, adhesion, angiogenesis, modulation of inflammation, transforming growth factor-beta activation, atherosclerosis, diabetes and cardiomyopathy. Although CD36 was identified more than 25 years ago, it is only with the advent of recent genetic technology that in vivo evidence has emerged for its physiologic and pathologic relevance. As these in vivo studies are expanded, we will gain further insight into the mechanism(s) by which CD36 transmits a cellular signal, and this will allow the design of specific therapeutics that impact on a particular function of CD36.

CD36 mediates the cardiovascular action of growth hormone-releasing peptides in the heart.

Growth hormone-releasing peptides (GHRPs) are known as potent growth hormone secretagogues whose actions are mediated by the ghrelin receptor, a G protein-coupled receptor cloned from pituitary libraries. Hexarelin, a hexapeptide of the GHRP family, has reported cardiovascular activity. To identify the molecular target mediating this activity, rat cardiac membranes were labeled with a radioactive photoactivatable derivative of hexarelin and purified using lectin affinity chromatography and preparative gel electrophoresis. A binding protein of M(r) 84 000 was identified. The N-terminal sequence determination of the deglycosylated protein was identical to rat CD36, a multifunctional glycoprotein, which was expressed in cardiomyocytes and microvascular endothelial cells. Activation of CD36 in perfused hearts by hexarelin was shown to elicit an increase in coronary perfusion pressure in a dose-dependent manner. This effect was lacking in hearts from CD36-null mice and hearts from spontaneous hypertensive rats genetically deficient in CD36. The coronary vasoconstrictive response correlated with expression of CD36 as assessed by immunoblotting and covalent binding with hexarelin. These data suggest that CD36 may mediate the coronary vasospasm seen in hypercholesterolemia and atherosclerosis.

Hematology grants workshop-2001.

This year the Hematology Grants Workshop, chaired by Dr. Todd, includes a comprehensive listing of available National Institutes of Health, Department of Veterans Affairs, and non-federal grants applicable to fellows and junior faculty as well as to established investigators. In Section II, Dr. Miller discusses the essential principles of successful grant writing with a special emphasis on the young investigator. He highlights the best strategies to take and the common mistakes to avoid. In Section III, Dr. Silverstein outlines the structure of the current NIH Integrated Review Group (IRG) system and the study sections of the most relevance to hematology. He traces the path that a grant takes from review to funding including the way in which grants are reviewed at NIH Study Section Meetings and provides advice in the preparation of revised applications.

Differential roles of CD36 and alphavbeta5 integrin in photoreceptor phagocytosis by the retinal pigment epithelium.

Retinal pigment epithelial (RPE) cells employ alphavbeta5 integrin and CD36 receptors to phagocytose photoreceptor outer segment fragments (OS). We explored special properties of RPE phagocytosis to identify the contribution of CD36 to RPE phagocytosis measuring effects of CD36 antibodies on OS binding and internalization kinetics. Early, CD36 antibodies had no effect on OS binding or internalization. Both control and CD36 antibody treated RPE initiated internalization approximately 2 hours after OS challenge. Later, bivalent CD36 IgG accelerated OS engulfment while monovalent Fab fragments inhibited engulfment. Cross-linking Fab fragments restored the accelerating activity of intact IgG. Strikingly, antibodies were effective even if added to OS already bound by RPE. alphavbeta5 blocking antibody reduced OS binding equally well in the presence of CD36 antibodies but CD36 antibodies accelerated internalization of remaining bound OS. Furthermore, CD36 ligation at either apical or basal RPE surface partially substituted for soluble factors that are required for internalization but not for binding of OS at the RPE apical surface. Our results demonstrate that CD36 ligation is necessary and sufficient to activate the OS internalization mechanism of RPE. They suggest that CD36 acts as a signaling molecule in postbinding steps of RPE phagocytosis independently of the OS binding receptor alphavbeta5 integrin.