Fibrocytes in health and disease

Fibrocytes, a group of bone marrow-derived mesenchymal progenitor cells, were first described in 1994 as fibroblast-like, peripheral blood cells that migrate to regions of tissue injury. These cells are unique in their expression of extracellular matrix proteins concomitantly with markers of hematopoietic and monocyte lineage. The involvement of fibrocytes and the specific role they play in the process of wound repair has been a focus of study since their initial description. Fibrocytes contribute to the healing repertoire via several mechanisms; they produce a combination of cytokines, chemokines, and growth factors to create a milieu favorable for repair to occur; they serve as antigen presenting cells (APCs); they contribute to wound closure; and, they promote angiogenesis. Furthermore, regulatory pathways involving serum amyloid P, leukocyte-specific protein 1, and adenosine A2A receptors have emphasized the significant role that fibrocytes have in wound healing and fibrosis. The therapeutic targeting of fibrocytes holds promise for the augmentation of wound repair and the treatment of different fibrosing disorders

Optimization of percutaneous biopsy for diagnosis and pretreatment risk assessment of neuroblastoma

BackgroundImage- guided percutaneous core needle biopsy (PCNB) is increasingly utilized to diagnose solid tumors. The objective of this study is to determine whether PCNB is adequate for modern biologic characterization of neuroblastoma.ProcedureA multi- institutional retrospective study was performed by the Pediatric Surgical Oncology Research Collaborative on children with neuroblastoma at 12 institutions over a 3- year period. Data collected included demographics, clinical details, biopsy technique, complications, and adequacy of biopsies for cytogenetic markers utilized by the Children’s Oncology Group for risk stratification.ResultsA total of 243 children were identified with a diagnosis of neuroblastoma: 79 (32.5%) tumor excision at diagnosis, 94 (38.7%) open incisional biopsy (IB), and 70 (28.8%) PCNB. Compared to IB, there was no significant difference in ability to accurately obtain a primary diagnosis by PCNB (95.7% vs 98.9%, P = .314) or determine MYCN copy number (92.4% vs 97.8%, P = .111). The yield for loss of heterozygosity and tumor ploidy was lower with PCNB versus IB (56.1% vs 90.9%, P < .05; and 58.0% vs. 88.5%, P < .05). Complications did not differ between groups (2.9 % vs 3.3%, P = 1.000), though the PCNB group had fewer blood transfusions and lower opioid usage. Efficacy of PCNB was improved for loss of heterozygosity when a pediatric pathologist evaluated the fresh specimen for adequacy.ConclusionsPCNB is a less invasive alternative to open biopsy for primary diagnosis and MYCN oncogene status in patients with neuroblastoma. Our data suggest that PCNB could be optimized for complete genetic analysis by standardized protocols and real- time pathology assessment of specimen quality.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154667/1/pbc28153_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154667/2/pbc28153.pd

Optimization of percutaneous biopsy for diagnosis and pretreatment risk assessment of neuroblastoma

Background: Image-guided percutaneous core needle biopsy (PCNB) is increasingly utilized to diagnose solid tumors. The objective of this study is to determine whether PCNB is adequate for modern biologic characterization of neuroblastoma. Procedure: A multi-institutional retrospective study was performed by the Pediatric Surgical Oncology Research Collaborative on children with neuroblastoma at 12 institutions over a 3-year period. Data collected included demographics, clinical details, biopsy technique, complications, and adequacy of biopsies for cytogenetic markers utilized by the Children\u27s Oncology Group for risk stratification. Results: A total of 243 children were identified with a diagnosis of neuroblastoma: 79 (32.5%) tumor excision at diagnosis, 94 (38.7%) open incisional biopsy (IB), and 70 (28.8%) PCNB. Compared to IB, there was no significant difference in ability to accurately obtain a primary diagnosis by PCNB (95.7% vs 98.9%, P =.314) or determine MYCN copy number (92.4% vs 97.8%, P =.111). The yield for loss of heterozygosity and tumor ploidy was lower with PCNB versus IB (56.1% vs 90.9%, P \u3c.05; and 58.0% vs. 88.5%, P \u3c.05). Complications did not differ between groups (2.9 % vs 3.3%, P = 1.000), though the PCNB group had fewer blood transfusions and lower opioid usage. Efficacy of PCNB was improved for loss of heterozygosity when a pediatric pathologist evaluated the fresh specimen for adequacy. Conclusions: PCNB is a less invasive alternative to open biopsy for primary diagnosis and MYCN oncogene status in patients with neuroblastoma. Our data suggest that PCNB could be optimized for complete genetic analysis by standardized protocols and real-time pathology assessment of specimen quality

Apnea of prematurity: from cause to treatment

Apnea of prematurity (AOP) is a common problem affecting premature infants, likely secondary to a “physiologic” immaturity of respiratory control that may be exacerbated by neonatal disease. These include altered ventilatory responses to hypoxia, hypercapnia, and altered sleep states, while the roles of gastroesophageal reflux and anemia remain controversial. Standard clinical management of the obstructive subtype of AOP includes prone positioning and continuous positive or nasal intermittent positive pressure ventilation to prevent pharyngeal collapse and alveolar atelectasis, while methylxanthine therapy is a mainstay of treatment of central apnea by stimulating the central nervous system and respiratory muscle function. Other therapies, including kangaroo care, red blood cell transfusions, and CO2 inhalation, require further study. The physiology and pathophysiology behind AOP are discussed, including the laryngeal chemoreflex and sensitivity to inhibitory neurotransmitters, as are the mechanisms by which different therapies may work and the potential long-term neurodevelopmental consequences of AOP and its treatment

High and Low Molecular Weight Hyaluronic Acid Differentially Regulate Human Fibrocyte Differentiation

Following tissue injury, monocytes can enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but little is known about what regulates this differentiation. Extracellular matrix contains high molecular weight hyaluronic acid (HMWHA; ∼2×10(6) Da). During injury, HMWHA breaks down to low molecular weight hyaluronic acid (LMWHA; ∼0.8-8×10(5) Da).In this report, we show that HMWHA potentiates the differentiation of human monocytes into fibrocytes, while LMWHA inhibits fibrocyte differentiation. Digestion of HMWHA with hyaluronidase produces small hyaluronic acid fragments, and these fragments inhibit fibrocyte differentiation. Monocytes internalize HMWHA and LMWHA equally well, suggesting that the opposing effects on fibrocyte differentiation are not due to differential internalization of HMWHA or LMWHA. Adding HMWHA to PBMC does not appear to affect the levels of the hyaluronic acid receptor CD44, whereas adding LMWHA decreases CD44 levels. The addition of anti-CD44 antibodies potentiates fibrocyte differentiation, suggesting that CD44 mediates at least some of the effect of hyaluronic acid on fibrocyte differentiation. The fibrocyte differentiation-inhibiting factor serum amyloid P (SAP) inhibits HMWHA-induced fibrocyte differentiation and potentiates LMWHA-induced inhibition. Conversely, LMWHA inhibits the ability of HMWHA, interleukin-4 (IL-4), or interleukin-13 (IL-13) to promote fibrocyte differentiation.We hypothesize that hyaluronic acid signals at least in part through CD44 to regulate fibrocyte differentiation, with a dominance hierarchy of SAP>LMWHA≥HMWHA>IL-4 or IL-13

Identification of Markers that Distinguish Monocyte-Derived Fibrocytes from Monocytes, Macrophages, and Fibroblasts

The processes that drive fibrotic diseases are complex and include an influx of peripheral blood monocytes that can differentiate into fibroblast-like cells called fibrocytes. Monocytes can also differentiate into other cell types, such as tissue macrophages. The ability to discriminate between monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions could be beneficial in identifying therapies that target either stromal fibroblasts or fibrocytes. and in sections from human lung. We found that markers such as CD34, CD68, and collagen do not effectively discriminate between the four cell types. In addition, IL-4, IL-12, IL-13, IFN-γ, and SAP differentially regulate the expression of CD32, CD163, CD172a, and CD206 on both macrophages and fibrocytes. Finally, CD49c (α3 integrin) expression identifies a subset of fibrocytes, and this subset increases with time in culture.These results suggest that discrimination of monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions is possible, and this may allow for an assessment of fibrocytes in fibrotic diseases

Colonic venous malformation and portal hypertension: association, management, and review of the literature

We present a case of an adolescent with lower gastrointestinal bleeding caused by a colorectal venous malformation (VM) with concomitant portal hypertension. After an episode of massive gastrointestinal bleeding, we performed an extended right hemicolectomy and resection of the VM and selective portosystemic shunt. Here, we present the case and review the literature regarding portal hypertension and gastrointestinal vascular malformations. Additionally, we discuss the physiologic and hemodynamic effects of gastrointestinal vascular malformations on the portal system

Management and outcomes of peripancreatic fluid collections and pseudocysts following non-operative management of pancreatic injuries in children

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Background: Peripancreatic fluid collection and pseudocyst development is a common sequela following non-operative management (NOM) of pancreatic injuries in children. Our purpose was to review management strategies and assess outcomes. Methods: A multicenter, retrospective review was conducted of children treated with NOM following blunt pancreatic injury at 22 pediatric trauma centers between the years 2010 and 2015. Organized fluid collections were called “acute peripancreatic fluid collection” (APFC) if identified \u3c 4 weeks and “pseudocyst” if \u3e 4 weeks following injury. Data analysis included descriptive statistics Wilcoxon rank-sum, Kruskal–Wallis and t tests. Results: One hundred patients with blunt pancreatic injury were identified. Median age was 8.5 years (range 1–16). Forty-two percent of patients (42/100) developed organized fluid collections: APFC 64% (27/42) and pseudocysts 36% (15/42). Median time to identification was 12 days (range 7–42). Most collections (64%, 27/42) were observed and 36% (15/42) underwent drainage: 67% (10/15) percutaneous drain, 7% (1/15) needle aspiration, and 27% (4/15) endoscopic transpapillary stent. A definitive procedure (cystogastrostomy/pancreatectomy) was required in 26% (11/42). Patients with larger collections (≥ 7.1 cm) had longer time to resolution. Comparison of outcomes in patients with observation vs drainage revealed no significant differences in TPN use (79% vs 75%, p = 1.00), hospital length of stay (15 vs 25 median days, p = 0.11), time to tolerate regular diet (12 vs 11 median days, p = 0.47), or need for definitive procedure (failure rate 30% vs 20%, p = 0.75). Conclusions: Following NOM of blunt pancreatic injuries in children, organized fluid collections commonly develop. If discovered early, most can be observed successfully, and drainage does not appear to improve clinical outcomes. Larger size predicts prolonged recovery. Level of evidence: III Study type: Case series

The utility of ERCP in pediatric pancreatic trauma

© 2017 Elsevier Inc. Background/purpose: Endoscopic retrograde cholangiopancreatography (ERCP) is an adjunct for pediatric pancreatic injury management, but its use and utility in pediatric patients are unclear. We set out to evaluate the use of ERCP and its effects on outcomes. Methods: A retrospective review was performed for children who had pancreatic injuries at 22 pediatric trauma centers between 2010 and 2015. ERCP details and outcomes were collected. Analysis was performed using descriptive statistics and Wilcoxon rank-sum tests. Results: ERCP was used at 14/22 centers for 26 patients. Indications were duct evaluation, duct leak control, pseudocyst, fistula, and stricture. ERCP altered management or improved outcomes in 13/26 (50%), most commonly in patients with ERCP for duct evaluation, stricture, and fistula. In patients managed nonoperatively, those with early endoscopic intervention (within one week of injury) with stent or sphincterotomy (n = 9) had similar time to regular diet [median (IQR)]: [10 (7–211) vs 7 (4–12) days; p = 0.55], similar hospital days: [12 (8–20) vs 11 (6–19) days, p = 0.63], and similar time on parenteral nutrition: [17 (10–40) vs 10 (6–18) days; p = 0.19] compared to patients who were only observed. Conclusions: In children with blunt pancreatic injury, ERCP can be useful to diagnose duct injury and for management of late complications such as stricture and fistula. However, early endoscopic intervention for pancreatic duct disruption may not improve outcome or expedite recovery. Further study is needed. Study type: Retrospective Study; Treatment Study. Level of evidence: III