Injectable Antioxidant and Oxygen-Releasing Lignin Composites to Promote Wound Healing.

The application of engineered biomaterials for wound healing has been pursued since the beginning of tissue engineering. Here, we attempt to apply functionalized lignin to confer antioxidation to the extracellular microenvironments of wounds and to deliver oxygen from the dissociation of calcium peroxide for enhanced vascularization and healing responses without eliciting inflammatory responses. Elemental analysis showed 17 times higher quantity of calcium in the oxygen-releasing nanoparticles. Lignin composites including the oxygen-generating nanoparticles released around 700 ppm oxygen per day at least for 7 days. By modulating the concentration of the methacrylated gelatin, we were able to maintain the injectability of lignin composite precursors and the stiffness of lignin composites suitable for wound healing after photo-cross-linking. In situ formation of lignin composites with the oxygen-releasing nanoparticles enhanced the rate of tissue granulation, the formation of blood vessels, and the infiltration of α-smooth muscle actin+ fibroblasts into the wounds over 7 days. At 28 days after surgery, the lignin composite with oxygen-generating nanoparticles remodeled the collagen architecture, resembling the basket-weave pattern of unwounded collagen with minimal scar formation. Thus, our study shows the potential of functionalized lignin for wound-healing applications requiring balanced antioxidation and controlled release of oxygen for enhanced tissue granulation, vascularization, and maturation of collagen.

IL-10 promotes endothelial progenitor cell infiltration and wound healing via STAT3.

Endothelial progenitor cells (EPCs) contribute to de novo angiogenesis, tissue regeneration, and remodeling. Interleukin 10 (IL-10), an anti-inflammatory cytokine that primarily signals via STAT3, has been shown to drive EPC recruitment to injured tissues. Our previous work demonstrated that overexpression of IL-10 in dermal wounds promotes regenerative tissue repair via STAT3-dependent regulation of fibroblast-specific hyaluronan synthesis. However, IL-10's role and specific mode of action on EPC recruitment, particularly in dermal wound healing and neovascularization in both normal and diabetic wounds, remain to be defined. Therefore, inducible skin-specific STAT3 knockdown mice were studied to determine IL-10's impact on EPCs, dermal wound neovascularization and healing, and whether it is STAT3-dependent. We show that IL-10 overexpression significantly elevated EPC counts in the granulating wound bed, which was associated with robust capillary lumen density and enhanced re-epithelialization of both control and diabetic (db/db) wounds at day 7. We noted increased VEGF and high C-X-C motif chemokine 12 (CXCL12) levels in wounds and a favorable CXCL12 gradient at day 3 that may support EPC mobilization and infiltration from bone marrow to wounds, an effect that was abrogated in STAT3 knockdown wounds. These findings were supported in vitro. IL-10 promoted VEGF and CXCL12 synthesis in primary murine dermal fibroblasts, with blunted VEGF expression upon blocking CXCL12 in the media by antibody binding. IL-10-conditioned fibroblast media also significantly promoted endothelial sprouting and network formation. In conclusion, these studies demonstrate that overexpression of IL-10 in dermal wounds recruits EPCs and leads to increased vascular structures and faster re-epithelialization.

Spectrum of Typical and Atypical Pulmonary CT Imaging Findings of COVID-19 Infection: A Retrospective Study.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. It was declared a public health emergency by WHO in January 2020. The definitive diagnostic test for COVID-19 is a real time polymerase chain reaction test (RT-PCR) which is highly specific, but sensitivity is variable. COVID-19 typically presents clinically with respiratory and systemic symptoms. The majority of the infected patients are asymptomatic during the course of the disease, which we have not included in our study. Imaging findings on high-resolution computed tomography (HRCT) chest are important to diagnose the disease in early stage, for treatment planning and to predict the patient prognosis. The purpose of our study was to characterize typical and atypical pulmonary and extra-pulmonary HRCT findings in patients with COVID-19 infection and to help in the management of patients.  In this retrospective study, we have included 70 patients who had undergone HRCT examination of the chest in the Radiodiagnosis Department, Maharishi Markandeshwar Medical College, Kumarhatti, Solan, Himachal Pradesh, India. The HRCT findings of the chest of these patients in the study will be evaluated and data will be statistically analyzed.

Hyaluronan, a double-edged sword in kidney diseases.

Over the years, hyaluronic acid (HA) has emerged as an important molecule in nephrological and urological studies involving extracellular matrix (ECM) organization, inflammation, tissue regeneration, and viral sensing. During this time, many have noted the perplexing double-edged nature of the molecule, at times promoting pro-fibrotic events and at other times promoting anti-fibrotic events. Different molecular weights of HA can be attributed to these disparities, though most studies have yet to focus on this subtlety. With regard to the kidney, HA is induced in the initial response phase of injury and is subsequently decreased during disease progression of AKI, CKD, and diabetic nephropathy. These and other kidney diseases force patients, particularly pediatric patients, to face dialysis, surgical procedures, and ultimately, transplant. To summarize the current literature for researchers and pediatric nephrologists, this review aims to expound HA and elucidate its paradoxical effects in multiple kidney diseases using studies that emphasize HA molecular weight when available.

Interleukin-10 Producing T Lymphocytes Attenuate Dermal Scarring.

OBJECTIVE: Demonstrate the impact of IL-10 producing T lymphocytes on mediating dermal scarring. SUMMARY BACKGROUND DATA: We demonstrated that CD4+ cells are essential to improving postinjury wound healing and preventing fibrosis. CD4+ subsets secrete differential cytokine and growth factor profiles, though their role in fibrosis is not known. IL-10, a key anti-inflammatory cytokine shown to promote regenerative wound healing, is secreted by some CD4+ subsets. We, therefore, hypothesize that IL-10 producing CD4+ T lymphocyte subsets selectively attenuate dermal wound fibrosis. METHODS: IL-10-/- and wild-type murine splenocytes were enriched for CD4+ lymphocytes and adoptively transferred into severe combined immunodeficient (SCID) mice that received full-thickness wounds which were analyzed at days 7 and 28 for inflammation and collagen content. We then sorted CD4+CD44int/lowFoxP3-CD62L+ T cells (Tnaive) or CD4+CD44HiFoxP3- type 1 regulatory (Tr1) T cell subsets from 10BiT murine splenocytes, activated them, and transferred them into wounds. In vitro, dermal fibroblasts were cocultured with Tnaive or Tr1 and the effect on extracellular matrix (ECM) regulation was analyzed. RESULTS: The anti-inflammatory and antifibrotic effects of CD4+ cells on SCID wounds were lost with cells from IL-10-/- mice. Adoptive transfer of Tr1 into SCID mice resulted in accelerated wound closure at d7 with reduced fibrosis at d28, with Tr1 favoring hyaluronan production by fibroblasts, an ECM molecule implicated in IL-10-induced regenerative healing. CONCLUSIONS: IL-10 producing T-lymphocytes, specifically Tr1, regulate inflammatory cell cytokine expression to promote HA-rich ECM deposition and attenuate fibrosis. Promoting IL-10 producing lymphocytes in wounds may be a therapeutic target to promote regenerative wound healing.

Immunologic Roles of Hyaluronan in Dermal Wound Healing.

Hyaluronic acid (HA), a glycosaminoglycan ubiquitous in the skin, has come into the limelight in recent years for its role in facilitating dermal wound healing. Specifically, HA's length of linearly repeating disaccharides-in other words, its molecular weight (MW)-determines its effects. High molecular weight (HMW)-HA serves an immunosuppressive and anti-inflammatory role, whereas low molecular weight (LMW)-HA contributes to immunostimulation and thus inflammation. During the inflammatory stage of tissue repair, direct and indirect interactions between HA and the innate and adaptive immune systems are of particular interest for their long-lasting impact on wound repair. This review seeks to synthesize the literature on wound healing with a focus on HA's involvement in the immune subsystems.

Novel antimicrobial ointment for infected wound healing in an in vitro and in vivo porcine model.

Microbial contamination of wounds is a significant problem that delays healing, particularly when bacterial biofilms are present. A novel combination of pectinic acid (PG) + caprylic acid (CAP) was previously found in vitro to be highly effective in eradicating various pathogens in biofilms with minimal cytotoxicity. In this study, a novel wound ointment was formulated with PG + CAP and first assessed in vitro using a well-established biofilm eradication model. In vitro, the PG + CAP ointment was shown to be efficacious in reducing the microbial biofilms. This ointment was then tested in vivo in two pilot porcine wound healing models, with and without Staphylococcus aureus microbial challenge. Ointments were applied to each wound daily, and healing by wound closure area measurement was assessed weekly over 4 weeks. After 4 weeks, pigs were sacrificed and wounds were scored for reepithelialization, inflammation, granulation tissue, and collagen deposition. We compared PG + CAP to hydroxyethylcellulose + glycerol ointment base (control) and MediHoney (comparator). In the porcine microbial challenge model, the novel antimicrobial PG + CAP wound ointment rapidly eradicated bacterial organisms embedded in wounds, was safe and well-tolerated, and was associated with enhanced healing compared to ointment base and MediHoney. Specifically, the cumulative histopathology, reepithelialization of epidermis, and mature granulation tissue in the wound bed was significantly better with PG + CAP than with control and MediHoney treatments. This ointment warrants further study as a non-antibiotic ointment for use in treating a wide array of infected wounds.

Hyaluronidases in Human Diseases.

With the burgeoning interest in hyaluronic acid (HA) in recent years, hyaluronidases (HYALs) have come to light for their role in regulating catabolism of HA and its molecular weight (MW) distribution in various tissues. Of the six hyaluronidase-like gene sequences in the human genome, HYALs 1 and 2 are of particular significance because they are the primary hyaluronidases active in human somatic tissue. Perhaps more importantly, for the sake of this review, they cleave anti-inflammatory and anti-fibrotic high-molecular-weight HA into pro-inflammatory and pro-fibrotic oligosaccharides. With this, HYALs regulate HA degradation and thus the development and progression of various diseases. Given the dearth of literature focusing specifically on HYALs in the past decade, this review seeks to expound their role in human diseases of the skin, heart, kidneys, and more. The review will delve into the molecular mechanisms and pathways of HYALs and discuss current and potential future therapeutic benefits of HYALs as a clinical treatment.

The Role of an IL-10/Hyaluronan Axis in Dermal Wound Healing.

Scar formation is the typical endpoint of postnatal dermal wound healing, which affects more than 100 million individuals annually. Not only do scars cause a functional burden by reducing the biomechanical strength of skin at the site of injury, but they also significantly increase healthcare costs and impose psychosocial challenges. Though the mechanisms that dictate how dermal wounds heal are still not completely understood, they are regulated by extracellular matrix (ECM) remodeling, neovascularization, and inflammatory responses. The cytokine interleukin (IL)-10 has emerged as a key mediator of the pro- to anti-inflammatory transition that counters collagen deposition in scarring. In parallel, the high molecular weight (HMW) glycosaminoglycan hyaluronan (HA) is present in the ECM and acts in concert with IL-10 to block pro-inflammatory signals and attenuate fibrotic responses. Notably, high concentrations of both IL-10 and HMW HA are produced in early gestational fetal skin, which heals scarlessly. Since fibroblasts are responsible for collagen deposition, it is critical to determine how the concerted actions of IL-10 and HA drive their function to potentially control fibrogenesis. Beyond their independent actions, an auto-regulatory IL-10/HA axis may exist to modulate the magnitude of CD4+ effector T lymphocyte activation and enhance T regulatory cell function in order to reduce scarring. This review underscores the pathophysiological impact of the IL-10/HA axis as a multifaceted molecular mechanism to direct primary cell responders and regulators toward either regenerative dermal tissue repair or scarring.

Wound Healing and Wound Care in Neonates: Current Therapies and Novel Options.

GENERAL PURPOSE: To provide wound care information that considers the specific physiology of neonates. TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Differentiate the use of hydrocolloids, hydrogels, foam dressings, and barrier creams in the neonatal population.2. Identify issues related to the use of solvents, alginates, collagen dressings, and negative-pressure wound therapy in neonates. ABSTRACT: OBJECTIVETo discuss what is known about the wound milieu in premature and full-term neonates, including the unique challenges pediatric clinicians face, the therapies that have proven effective, and the therapies contraindicated for use in neonatal wound healing to guide treatment that accounts for the specific physiological characteristics of this often overlooked population. DATA SOURCES: Data were collected on neonatal wound healing from a wide variety of sources, including PubMed, Google Scholar, journals, and textbooks. STUDY SELECTION: Selection criteria included publications focused on the differences and nuances of wound healing in neonates in comparison with all other age groups. DATA EXTRACTION: Data were extracted based on articles covering wound healing therapies with proven effectiveness in neonates. Terms for neonatal wound care were compiled, and then a comprehensive literature search was performed by the authors. DATA SYNTHESIS: Although many therapies are safe for treatment of older children and adolescents, most have not been explicitly tested for neonatal use. This article reviews therapies with proven effectiveness and/or specific concerns in the neonatal population. CONCLUSION: This review sheds light on the advantages and disadvantages of current standards of care regarding wound healing for neonates to direct researchers and clinicians toward developing treatments specifically for this delicate population.

To discuss what is known about the wound milieu in premature and full-term neonates, including the unique challenges pediatric clinicians face, the therapies that have proven effective, and the therapies contraindicated for use in neonatal wound healing to guide treatment that accounts for the specific physiological characteristics of this often overlooked population. Data were collected on neonatal wound healing from a wide variety of sources, including PubMed, Google Scholar, journals, and textbooks. Selection criteria included publications focused on the differences and nuances of wound healing in neonates in comparison with all other age groups. Data were extracted based on articles covering wound healing therapies with proven effectiveness in neonates. Terms for neonatal wound care were compiled, and then a comprehensive literature search was performed by the authors. Although many therapies are safe for treatment of older children and adolescents, most have not been explicitly tested for neonatal use. This article reviews therapies with proven effectiveness and/or specific concerns in the neonatal population. This review sheds light on the advantages and disadvantages of current standards of care regarding wound healing for neonates to direct researchers and clinicians toward developing treatments specifically for this delicate population.

Thirty-year Perspective of the Long-term Survival, CD4 Percentage and Social Achievements of Perinatally HIV-infected Children as a Function of Their Birth Era.

BACKGROUND: Pediatric HIV has evolved from a pre-antiretroviral (ART) era (pre-1989 or pre-ART) to an ART era (1989 to 1996) and to a highly active antiretroviral therapy (HAART) era (post-1996). As we have passed the third decade following these individuals, we thought it useful to review clinical, laboratory and social outcomes. METHODS: A retrospective, cross-sectional study of 399 children infected perinatally. They were divided into pre-ART, ART and HAART groups. A Kaplan-Meier plot was constructed. One hundred seventy-nine have been lost to follow-up at an average of 7.6 (0.3-27.6) years. RESULTS: Approximately 40%, 80% and 90% of individuals in the pre-ART, ART and HAART groups have long-term survival. One hundred twenty-one died at an average of 5.1 (0-26.1) years. Pre-ART, ART and HAART groups had mean most recent CD4% values (±SEM) of 16.74 (1.09), 22.97 (0.96) and 33.07 (2.09), respectively (P < 0.001). Pre-ART RNA is limited in that era and present if they survived to another era. In this group, the median RNA values in those who died (311,300, n = 16) was greater than in survivors (19,402, n = 45). Forty-three percent of the individuals in the ART group and 77% of individuals in the HAART group had most recent HIV RNA <400 copies/mL. Eighteen individuals >18 years of age have only a grade school or no education. Fifty-five have graduated high school or received an equivalency diploma. Twenty-three more have completed college. Nadir and recent CD4% of those who did and did not complete high school was equivalent to college graduates. Sixteen survivors (1/2 male) have had 18 uninfected children. CONCLUSIONS: This first long-term follow-up study demonstrates remarkable survival and social skills of our patients.

Colitis as the Sole Initial Presentation of Chronic Granulomatous Disease: Histopathologic Clues to Diagnosis.

Chronic granulomatous disease is a rare, inherited immunodeficiency disorder that reduces the superoxide generation ability of phagocytes, leading to recurrent infections and granulomatous inflammation. We report the case of a previously healthy 3-year-old boy who presented with classic features of Crohn disease. Suspicion from histopathologiclogic assessment allowed early diagnosis and treatment for chronic granulomatous disease before the onset of infections.

Growth patterns in pubertal HIV-infected adolescents and their correlation with cytokines, IGF-1, IGFBP-1, and IGFBP-3.

OBJECTIVE: This study aims to describe the final adult height (FAH) and pubertal growth patterns in human immunodeficiency virus (HIV)-infected adolescents and to compare these to an age-matched population of seroreverting HIV-exposed, uninfected (HEU) adolescents. It further aims to evaluate the interplay of proinflammatory cytokines with insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP-3), and IGFBP-1 during the pubertal growth spurt. METHODS: HIV-infected (n=34) and HEU (n=12) adolescents who had achieved FAH were evaluated. Auxologic data, viral load, CD4+ T-lymphocyte (CD4) count, and the use of highly active antiretroviral therapy were obtained via a retrospective chart review. Serum interleukin (IL)-1α, IL-6, tumor necrosis factor (TNF)-α, IGFBP-1, IGFBP-3, and IGF-1 were assessed. RESULTS: The mean FAH standard deviation score for the HIV-infected group was -0.78 (±1.1) compared to 0.05 (±0.78) for the HEU (p=0.034). There was a positive correlation between CD4 count and FAH (p=0.019). The mean age and magnitude of peak growth velocity (GV) was within normal limits. IL-1α, IL-6, TNF-α, IGFBP-3, and IGF-1 were not significantly correlated with HIV RNA or height. IGFBP-1 was detectable in 100% of poorly controlled HIV-infected patients and 25% of the HEU cohort (p=0.0003). CONCLUSIONS: The FAH of HIV-infected patients was significantly shorter than that of HEU patients, and it positively correlated with CD4 count. Our cohort demonstrated normal timing and magnitude of peak GV during puberty.

Acute poststreptococcal glomerulonephritis: a manifestation of immune reconstitution inflammatory syndrome.

Immune reconstitution inflammatory syndrome (IRIS) is a well-described complication of initiation of highly active antiretroviral therapy in HIV-infected patients. As the immune system recovers, an inappropriate inflammatory response often occurs that causes significant disease. It is most commonly seen in patients naïve to therapy with CD4+ T-lymphocyte counts <100 cells/cmm and usually presents as a flare of mycobacterial, cytomegalovirus, or herpes zoster infections. Less commonly, this syndrome occurs in response to noninfectious triggers and results in autoimmune or malignant disease. Here we present the first case of acute poststreptococcal glomerulonephritis associated with varicella zoster virus and IRIS in an adolescent with perinatally acquired HIV and hepatitis C virus infections. Our patient was not naïve to therapy but was starting a new regimen of therapy because of virologic failure and had a relatively high CD4+ T-lymphocyte count. This case report indicates that IRIS remains a concern after initiation of a new highly active antiretroviral therapy regimen in HIV-infected patients with high viral loads, even in the presence of CD4+ T-lymphocyte counts >100 cells/cmm. It may present as infectious, malignant, or autoimmune conditions including poststreptococcal glomerulonephritis.

Hyper interleukin-10 in an HIV-positive child with t-cell lymphoma and candidal sepsis.

We describe a case in which a human immunodeficiency virus (HIV)-positive child presented in severe metabolic acidosis secondary to his candidal sepsis and T-cell lymphoma, a rare finding in pediatric AIDS. Significantly elevated levels of Interleukin-10 (IL-10) were found in the patient's serum, which may have played a role in acute demise.

Natural history of HIV infected pediatric long-term or slow progressor population after the first decade of life.

BACKGROUND: Perinatally infected long-term nonprogressors/slow progressors represent a select group of individuals. There is very limited information on this group of children beyond the first decade of life. A group of HIV-infected long-term nonprogressor/slow progressor children was studied. METHODS: We enrolled 20 HIV-infected adolescents who were receiving no or minimal therapy (defined as single or dual nucleoside therapy) before the age of 10 years and who had maintained CD4 counts above 25% for the first decade of life. We analyzed immunologic and virologic characteristics. Thymic receptor excision circles (TREC) were measured on stored frozen peripheral blood mononuclear cells. CD4 count, viral load and other pertinent information including race and age were obtained from individual medical records. RESULTS: Nine of the 20 patients recruited were noted to have developed falling CD4 counts at or around puberty, whereas the other 11 remained stable. There was no difference in TREC values or HIV RNA values before or after puberty between the 2 groups of patients. Those who remained stable, in terms of maintaining CD4 T cells as a group had falling viral loads with age. Those whose CD4 values declined after puberty had viral loads that did not decrease with age. CONCLUSION: A select group of patients who never received HAART during their first decade of life will continue to maintain good CD4 associated with declining HIV RNA values. Thymic output is not predictive of those that don't maintain CD4 T cells.

An appendiceal leiomyoma in a child with acquired immunodeficiency syndrome.

Children with acquired immunodeficiency syndrome (AIDS) are at an increased risk for lymphoproliferative and neoplastic disorders. Included among these are smooth muscle neoplasms such as leiomyomas and leiomyosarcomas. There have been at least 15 reported cases of smooth muscle tumors in the approximately 8,000 children with AIDS, however the incidence in immunocompetent children is only two per ten million. The lesions in children with human immunodeficiency virus infection are usually found in the lung, liver, and gastrointestinal tract. Here, we present an unusual case of a 12-year-old African American girl with vertically acquired AIDS who presented to the pediatric emergency department with severe diffuse abdominal pain. She was ultimately found to have an appendiceal leiomyoma on abdominal exploration, the first reported case. Our report suggests that smooth muscle tumors of the appendix be included in the differential diagnosis of abdominal masses in children with AIDS.

Correlation between HIV-Specific CD8 cell production of interferon- gamma and plasma levels of HIV RNA in perinatally infected pediatric populations.

BACKGROUND: CD8 cell responses to human immunodeficiency virus (HIV) have been correlated with virus control in adults, and this study outcome has been controversial. Attempts to establish the same correlation in small numbers of children have also been made, with similar controversy resulting. METHODS: A total of 110 perinatally infected children were studied. Nine of the children (mean age, 1.9 years vs. 11.8 years for the remaining 101 children) received treatment with antiretrovirals within the first 3 months of life. CD4 cell and HIV RNA levels were measured. Production of interferon- gamma after exposure to recombinant vaccinia vectors was measured by enzyme-linked immunospot (ELISPOT) assay. RESULTS: Responses to Pol and Gag antigens exceeded those to Nef and Env antigens, with responses significantly approximated by a quadratic function for which peak responses occurred at plasma HIV RNA levels of 103-104 HIV RNA copies/mL. Children who are treated early in life with highly active antiretroviral therapy have fewer total responses of ELISPOT-forming cells to HIV antigens than do children who are treated later in life.

Fever and rash in a 3-year-old girl: Rocky Mountain spotted fever.

Initial symptoms of Rocky Mountain spotted fever (RMSF), a tick-borne illness caused by Rickettsia rickettsii, are nonspecific and include headache, gastrointestinal disturbances, malaise, and myalgias, followed by fever and rash. The classic triad of fever, rash, and history of tick exposure is uncommon at presentation. Clinical manifestations of RMSF range from virtually asymptomatic to severe. Because of the potentially fatal outcome of RMSF, presumptive clinical diagnosis and empiric antimicrobial therapy can be critical. We present the case of a 3-year-old girl from New York State who presented with fever and rash.

Immunoreconstitution in children receiving highly active antiretroviral therapy depends on the CD4 cell percentage at baseline.

The effect of highly active antiretroviral therapy (HAART) in 85 children infected with human immunodeficiency virus type 1 (HIV-1) was compared retrospectively among Centers for Disease Control and Prevention (CDC) immunologic groups 1-3. The duration of HAART did not vary significantly among the immunologic groups (median, 39.07 months). The CD4 cell percentage increased in 39.1%, 58.3%, and 90% of patients in CDC groups 1-3, respectively (P <.001). HAART resulted in the suppression of HIV-1 below detectable levels in 34.8%, 25%, and 32% of patients in the 3 CDC groups, respectively, and in a frequent switch from syncytium-inducing to nonsyncytium-inducing virus. Thymic excision circles increased in a subset of patients with increases in CD4 cell percentage independently of HIV RNA level. The results support the option of delaying HAART in early asymptomatic HIV-1 disease in children and the use of other markers of disease progression, in addition to virus load.