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Pancreatic ductal adenocarcinoma (PDAC) remains one of the most challenging cancer to treat. Due to the asymptomatic nature of the disease and ineffective drug treatment modalities, the survival rate of PDAC patients remains one of the lowest. The recurrent genetic alterations in PDAC are yet to be targeted; therefore, identifying effective therapeutic combinations is desperately needed. Here, we performed anin vivoCRISPR screening in a clinically relevant patient-derived xenograft (PDX) model system to identify synergistic drug combinations for PDAC treatment. Our approach revealed protein arginine methyltransferase gene 5 (PRMT5) as a promising druggable candidate whose inhibition creates synergistic vulnerability of PDAC cells to gemcitabine. Genetic and pharmacological inhibition results indicate that of PRMT5 depletion results in synergistic cytotoxicity with Gem due to depleted replication protein A (RPA) levels and an impaired non-homology end joining (NHEJ) DNA repair. Thus, the novel combination creates conditional lethality through the accumulation of excessive DNA damage and cell death, bothin vitroandin vivo. The findings demonstrate that unbiased genetic screenings combined with a clinically relevant model system is an effective approach in identifying synthetic lethal drug combinations for cancer treatment.STATEMENT of SIGNIFICANCEIdentify synergistic drug combinations for PDAC is a significant unmet need. Through CRISPR screening, we discovered and validated that PRMT5 depletion creates synergistic vulnerability of PDAC cells to gemcitabine. Mechanistically, the combination impairs DNA repair, synergistic accumulation of DNA damage and cell deathin vitroandin vivo.

Objective To determine prevalence and key drivers of burnout in Occupational and Environmental Medicine physicians in the United States. Methods A nationwide survey of Occupational Medicine physicians was conducted using the Qualtrics® platform. Burnout, measured by the Maslach Burnout Inventory®, Social Support, and Job Satisfaction were assessed. Results The response rate was 46%, the overall burnout prevalence 38%, and most respondents were men (69%). The mean age and mean years in practice were 56 years and 20 years respectively. Physicians working in government/military (48%) and private medical center group settings (46%) were significantly more likely to report burnout, with consultants (15%) reporting the lowest rate. Conclusions Although the overall burnout prevalence is lower in Occupational Medicine physicians compared with most specialties, the rate varies significantly by practice setting (15% to 48%) affirming the impact of organizational factors.

Blood vascular endothelial cells (BECs) control the immune response by regulating immune cell recruitment, metabolite exchange and blood flow in lymphoid tissues. However, the diversity of BEC and their origins during immune angiogenesis remain poorly understood. Here we profile transcriptomes of BEC from mouse peripheral lymph nodes and map key phenotypes to the vasculature. Our analysis identifies multiple novel subsets including a venous population whose gene signature predicts an unexpectedly selective role in myeloid cell (vs lymphocyte) recruitment to the medulla, confirmed by 2 photon videomicroscopy. We define five phenotypes of capillary lining BEC including a capillary resident regenerative population (CRP) that displays stem cell and migratory gene signatures and contributes to homeostatic BEC turnover and to vascular neogenesis after immunization. Trajectory analyses reveal retention of developmental programs along a progression of cellular phenotypes from CRP to mature venous and arterial BEC subsets. Overall, our single cell atlas provides a molecular blueprint of the lymph node blood vasculature and defines subset specialization for immune cell recruitment and vascular homeostasis.

Blood vascular endothelial cells (BECs) control the immune response by regulating blood flow and immune cell recruitment in lymphoid tissues. However, the diversity of BEC and their origins during immune angiogenesis remain unclear. Here we profile transcriptomes of BEC from peripheral lymph nodes and map phenotypes to the vasculature. We identify multiple subsets, including a medullary venous population whose gene signature predicts a selective role in myeloid cell (vs lymphocyte) recruitment to the medulla, confirmed by videomicroscopy. We define five capillary subsets, including a capillary resident precursor (CRP) that displays stem cell and migratory gene signatures, and contributes to homeostatic BEC turnover and to neogenesis of high endothelium after immunization. Cell alignments show retention of developmental programs along trajectories from CRP to mature venous and arterial populations. Our single cell atlas provides a molecular roadmap of the lymph node blood vasculature and defines subset specialization for leukocyte recruitment and vascular homeostasis., The origin and diversity of blood vascular endothelial cells (BEC) in lymphoid tissues is unclear. Here, the authors profile murine BECs from peripheral lymph nodes by single cell analysis and identify subsets of cells specialised for immune cell recruitment and vascular homeostasis.

Although the homing of lymphocytes to GALT has been extensively studied, little is known about how high endothelial venules (HEVs) within Peyer’s patches (PPs) are patterned to display dominantly mucosal addressin cell adhesion molecule 1 (MAdCAM-1). In this study, we report that Nkx2-3–deficient mice show gradual loss of MAdCAM-1 in PPs postnatally and increased levels of mRNA for peripheral lymph node addressin (PNAd) backbone proteins as well as enhanced expression of MECA79 sulfated glycoepitope at the luminal aspect of HEVs, thus replacing MAdCAM-1 with PNAd. Induction of PNAd in mutant PPs requires lymphotoxin β receptor activity, and its upregulation needs the presence of mature T and B cells. Furthermore, treatment with MECA-79 anti-PNAd mAb in vivo effectively blocks lymphocyte homing to mutant PPs. Despite the replacement of MAdCAM-1 by PNAd in HEV endothelia, lymphocytes could efficiently home to PPs in mutant mice. We conclude that although Nkx2-3 activity controls the addressin balance of HEVs in GALT, the general HEV functionality is preserved independently from Nkx2-3, indicating a substantial plasticity in the specification of GALT HEV endothelium.

Chemokine (CC motif) receptor-like 2 (CCRL2) binds leukocyte chemoattractant chemerin and can regulate local levels of the attractant, but does not itself support cell migration. In this study, we show that CCRL2 and VCAM-1 are upregulated on cultured human and mouse vascular endothelial cells (EC) and cell lines by proinflammatory stimuli. CCRL2 induction is dependent on NF-κB and JAK/STAT signaling pathways, and activated endothelial cells specifically bind chemerin. In vivo, CCRL2 is constitutively expressed at high levels by lung endothelial cells and at lower levels by liver endothelium; and liver but not lung EC respond to systemic LPS injection by further upregulation of the receptor. Plasma levels of total chemerin are elevated in CCRL2−/− mice and are significantly enhanced after systemic LPS treatment in CCRL2−/− mice compared with wild-type mice. Following acute LPS-induced pulmonary inflammation in vivo, chemokine-like receptor 1 (CMKLR1)+ NK cell recruitment to the airways is significantly impaired in CCRL2−/− mice compared with wild-type mice. In vitro, chemerin binding to CCRL2 on endothelial cells triggers robust adhesion of CMKLR1+ lymphoid cells through an α4β1 integrin/VCAM-1–dependent mechanism. In conclusion, CCRL2 is expressed by EC in a tissue- and activation-dependent fashion, regulates circulating chemerin levels and its bioactivity, and enhances chemerin- and CMKLR1-dependent lymphocyte/EC adhesion in vitro and recruitment to inflamed airways in vivo. Its expression and/or induction on EC by proinflammatory stimuli provide a novel and specific mechanism for the local enrichment of chemerin at inflammatory sites, regulating the recruitment of CMKLR1+ cells.

The odyssey leading to the discovery of herniation syndromes was prolonged due to a lack of early understanding of the underlying pathophysiology. In 1896, Leonard Hill documented transtentorial pressure gradients as the intervening phenomenon involved in uncal herniation. In 1904, James Collier became the first to describe cerebellar tonsillar herniation as a “false localizing sign” often associated with intracranial tumors. During the infancy of neurological surgery, management of increased intracranial pressure and an improved understanding of brain herniation syndromes were of the utmost importance in achieving a safe technique. Harvey Cushing provided seminal contributions in understanding the pathophysiology of increased intracranial pressure and resulting cardiopulmonary effects. Cushing believed that tonsillar herniation was a cause of acute cardiorespiratory compromise in patients with intracranial tumors. In this vignette, we describe the untold story of Cushing's heroic attempt to treat respiratory arrest operatively during supratentorial tumor surgery with an emergency suboccipital craniectomy to relieve the medullary dysfunction that he believed was caused by compression from tonsillar herniation. This case illustrates a surgeon's determination and courage in fighting for his patient's life in the most desperate of times.

Analytical methods characterizing the immunogenicity of therapeutic proteins are useful for monitoring, characterizing and predicting reactions to biopharmaceuticals. A multiplexed assay capable of isotyping the specific IgG, IgA, IgM and IgE (IgGAME) antibody responses against a biotherapeutic was demonstrated in a hyper-immunized cynomolgus monkey, over a 15-month period. The quantitative range of the antibody measurements was determined to be 15 ng/ml to 50 ng/ml in 10% serum. By the use of any biotinylated or fluorescently tagged therapeutic as a detector, this multiplexed isotyping assay can be broadly applied to human and non-human primate IgG, IgA, IgM and IgE immunogenicity studies.

Lymphocyte recruitment maintains intestinal immune homeostasis but also contributes to inflammation. The orphan chemoattractant receptor GPR15 mediates regulatory T cell homing and immunosuppression in the mouse colon. We show that GPR15 is also expressed by mouse TH17 and TH1 effector cells and is required for colitis in a model that depends on the trafficking of these cells to the colon. In humans GPR15 is expressed by effector cells, including pathogenic TH2 cells in ulcerative colitis, but is expressed poorly or not at all by colon regulatory T (Treg) cells. The TH2 transcriptional activator GATA-3 and the Treg-associated transcriptional repressor FOXP3 robustly bind human, but not mouse, GPR15 enhancer sequences, correlating with receptor expression. Our results highlight species differences in GPR15 regulation and suggest it as a potential therapeutic target for colitis.

Our current understanding of nonaccidental head injury in children is the result of decades of effort and the tireless work of numerous physicians. In 1860 Auguste Ambroise Tardieu, a French forensics expert, recognized important patterns of injury in children and identified nonaccidental trauma as the cause of these injuries. His work was ignored. In the years that followed, physicians continued to report these patterns of injury but were unable to identify the etiology. A fundamental misunderstanding of the usual cause of subdural hematoma (SDH) contributed to the confusion at that time. Early in the 20th century, neurosurgeons such as Wilfred Trotter recognized that SDHs were traumatic in origin. However, even Trotter's efforts to expose faults in the theories that SDHs primarily resulted from inflammatory or infectious processes were not accepted immediately. Eventually, the pattern of injuries in children was again recognized both by neurosurgeons, who began to identify an association between trauma-induced SDHs and retinal hemorrhages, and by radiologists, who began to note SDHs in conjunction with osseous lesions. Not until the 1950s and 1960s, however, did physicians begin to routinely identify nonaccidental trauma as the cause of these injuries. Following the recognition of child abuse, a pattern of injuries in conjunction with shaking was identified and is currently known as shaken baby syndrome. Since its identification, our understanding of this syndrome has been modified as a result of new medical research, legal challenges, and popular media forces.

The odyssey leading to the discovery of herniation syndromes was prolonged due to a lack of early understanding of the underlying pathophysiology. In 1896, Leonard Hill documented transtentorial pressure gradients as the intervening phenomenon involved in uncal herniation. In 1904, James Collier became the first to describe cerebellar tonsillar herniation as a "false localizing sign" often associated with intracranial tumors. During the infancy of neurological surgery, management of increased intracranial pressure and an improved understanding of brain herniation syndromes were of the utmost importance in achieving a safe technique. Harvey Cushing provided seminal contributions in understanding the pathophysiology of increased intracranial pressure and resulting cardiopulmonary effects. Cushing believed that tonsillar herniation was a cause of acute cardiorespiratory compromise in patients with intracranial tumors. In this vignette, we describe the untold story of Cushing's heroic attempt to treat respiratory arrest operatively during supratentorial tumor surgery with an emergency suboccipital craniectomy to relieve the medullary dysfunction that he believed was caused by compression from tonsillar herniation. This case illustrates a surgeon's determination and courage in fighting for his patient's life in the most desperate of times.

Representational difference analysis of cDNAs (cDNA-RDA) is a sensitive subtractive hybridization technique capable of isolating rare mRNAs differentially expressed in two cell populations. cDNA-RDA can detect sequences represented at 0.0001% in the starting mRNA. By using reverse transcriptase polymerase chain reaction (PCR), cDNA-RDA also lends itself to studies in which samples are derived from limited numbers of cells. Standard cDNA-RDA protocols depend upon the presence of specific restriction enzyme sites in each cDNA, typically enzymes with four base recognition sequences. These sites are used to reduce the cDNA size range and provide primer sites for subsequent PCR amplification. Consequently, transcripts containing fewer than two of the chosen restriction sites are undetectable by cDNA-RDA. We have developed a restriction enzyme site-independent cDNA-RDA protocol called modified RDA (MRDA). We constructed MRDA test sequences from random hexamer-primed cDNA, thereby increasing the representation of mRNAs which are excluded by cDNA-RDA protocols. MRDA is also more efficient than cDNA-RDA at removing highly expressed housekeeping genes during the subtractive hybridization process, thereby allowing more efficient isolation of preferentially expressed mRNAs. Using MRDA, we isolated cDNAs differentially expressed between limited numbers of human CD4+ naive and memory T lymphocyte subsets and skin- and gut-homing memory T cell subsets.

The Drosophila paired ( prd ) gene, the founding member of the PAX gene family, is required for normal embryonic segmentation and is re-expressed later in development in the head and developing CNS. As for most embryonically active genes, global defects resulting from loss of early prd function obscure an analysis of the role of later expression phases. We used heat inducible targeted ribozymes to functionally ‘knock-out’ prd at late stages. When prd protein levels in the head are reduced in this fashion, the maxillary chemosensory ventral organs fail to develop and dorsal-lateral cirri rows are disrupted. These studies reveal a role for prd in sensory organ development that appears to be conserved in PAX genes throughout the animal kingdom.

Surgery for cranial deformity was associated with significant surgical morbidity during the early part of the 20th century. For this reason, Harvey Cushing was initially not in favor of surgical treatment of craniosynostosis. Later in his career, Cushing began to operate on these children, although it never became a major focus of his practice. Several examples of his patients with cranial deformity are presented, and his limited role in the development of this field is discussed.

Twenty-four asthmatic children ranging in age from 4 to 18 years (average 12.6 years) who had been treated with daily prednisone therapy of 10 to 60 mg/day for an average duration of 26.3 months were studied for possible early detection of bone and other steroid effects. Musculoskeletal symptoms were absent and orthopedic examinations as well as roentgenogram of the hips and shoulders were normal. Fourteen of 24 children had been on 10 mg/day for at least 1 year; and of these 14, 10 were cushingnoid and 7 children showed significant growth suppression, falling below the third percentile level when height measurements were plotted using the National Center for Health Statistics Growth Chart. For detection of early changes of osteonecrosis, bone scintigram using Technetium-99m pyrophosphate was utilized. Twenty-three patients had normal scans. One cushingoid boy with posterior subcapsular cataracts had asymmetry of uptake involving only the right humeral head on two occasions. These findings suggest that an...

1. Two unusual cases of congenital astrocytomas are reported. Clinically, the first case manifested enlarged external genitalia at birth and the occurrence of convulsions at 3 weeks of age. The second case presented with hydrocephalus since birth.2. In the first case, the tumor was noted in the extra-axial suprasellar region roentgenographically and at surgery. The tumors in the pituitary stalk region have been referred to as "infundibulomas" or "neurohypophyseal gliomas." These tumors probably arise from the heterotopic glial tissue which may be present in the subarachnoid space. In the second case, the tumor was located in the hypothalamus, third ventricle, and infiltrated into thalamus and brain stem.3. Brain tumors that are present at birth or appear before the age of 60 days are considered to be congenital tumors. Hydrocephalus is the most common finding. Histologically, most of the congenital gliomas are low grade, well differentiated astrocytomas.4. The literature is reviewed. The roentgenographic ...

Obstruction of the upper gastrointestinal tract in the newborn infant is a surgical emergency requiring immediate operative intervention. The earlier the diagnosis is made in these babies, the better is their chance of survival. Often they have but a single abnormality, and, following correction, will grow to be normal children. It is therefore essential that a diagnosis be made before they are literally worn out by dehydration and hunger. At The Children's Hospital of Philadelphia the vast majority of these infants arrive as diagnostic problems, in spite of repeated roentgen examination. It is almost routine for them to be brought in with either the upper or the lower bowel full of some type of opaque contrast medium; often the entire bowel has been insulted from either end. It is not the purpose of this paper to criticize any particular type of opaque contrast medium, but to condemn unnecessary radiologic procedures which not only delay but often obscure the diagnosis. The Radiation Exposure Problem Rad...

A case of congenital pulmonary lymphangiectasis, associated with spontaneous pneumothorax and air-filled cysts is reported. It is becoming important to include this condition in the differential diagnosis of respiratory distress in the newborn infant, as better techniques for infant survival are developed.

Osgood-Schlatter's disease is a well known entity affecting the adolescent knee. Radiologic examination of the knee has been an integral part of the diagnosis of this condition for decades. However, the soft tissue changes have not been appreciated sufficiently. Emphasis is placed on the use of optimum radiographic technique and xeroradiography in the examination of the soft tissues of the knee.

Seven cases of choanal atresia are presented: four cases with bilateral choanal atresia, and three cases with unilateral choanal atresia. The patients in three of these cases were born with the CHARGE association-an association of choanal atresia with coloboma, heart disease, retarded growth, genital hypoplasia, and ear anomalies. Diagnosis in all cases was confirmed. Computed tomography generally confirms the clinical diagnosis of bilateral choanal atresia. Unilateral choanal atresia, however, presents late, and both the clinical and radiographic manifestations may be subtle. In all our cases of unilateral choanal atresia, computed tomography demonstrated the definitive components accounting for this deformity. Computed tomography, because it so accurately defines the anatomic malformation, is now the imaging modality of choice in this entity.

An unusual case of subcutaneous emphysema of the paramandibular area is presented in which sialography was useful in determining the cause and subsequent treatment.

The postoperative diagnosis of supradiaphragmatic cyst following repair of diaphragmatic hernia should alert the radiologist to the possibility of retention of an unrecognized hernial sac. Cross-table lateral and decubitus views are helpful in recognizing fluid accumulation within the cyst.

A 4-year-old male child with acrocephaly, minimal syndactyly, broad thumbs and great toes, and normal intelligence is classified as having acrocephalosyndactyly type V, or Pfeiffer syndrome. This syndrome is compared with the other acrocephalosyndactyly types and the various broad thumb and great toe syndromes. These entities differ mainly in the type of digital anomaly, the craniofacial characteristics, the presence or absence of growth or mental retardation, and the mode of inheritance. The importance of diagnostic separation of these syndromes is stressed.

The esophagus of a 30-hour-old girl was completely obstructed by an intraluminal mucosal web. This rare esophageal anomaly was associated with a fistula between the trachea and the distal esophagus beyond the site of obstruction. Because of the radiographic findings the correct diagnosis was suspected preoperatively. Surgical treatment by excision of the web and division of the tracheo-esophageal fistula was successful.