Publications by authors named "Wasserkrug H"

Prophylactic endoscopy is routine in adults with portal hypertension (PHTN), but there is limited data in pediatrics. We sought to describe our experience with prophylactic endoscopy in pediatric PHTN. This is a retrospective study of 87 children who began surveillance endoscopy prior to gastrointestinal bleeding (primary prophylaxis) and 52 who began after an episode of bleeding (secondary prophylaxis) from 01/01/1994 to 07/01/2019.

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Non-alcoholic fatty liver disease (NAFLD) is an increasing problem in pediatrics with limited treatment options. We prospectively assessed outcomes in patients managed in a hepatology clinic (HC) alone vs. those managed in combination with a multidisciplinary weight management program (MWMP).

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Background: Cryptosporidium enteritis can be devastating in the immunocompromised host. In pediatric liver transplant recipients, infection may be complicated by prolonged carriage of the parasite, rejection, and biliary tree damage and fibrosis. Herein, we report on six patients and their long-term outcomes following cryptosporidiosis.

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Fibroblast proliferation and fibroblast-mediated matrix contraction are critical to wound healing. Different cytokines have been shown to modulate fibroblast functions but little is known about the physiological role of these soluble factors during wound repair. In these experiments we characterized a fibroblast stimulating factor in wound fluid.

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Background: Nitric oxide is synthesized in wounds. Systemic inhibition of wound nitric oxide synthesis decreases wound collagen accumulation and wound mechanical strength. The role of nitric oxide during impaired healing is not known.

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Recently there has been much interest in the use of arginine to stimulate immune responses and to promote wound healing. In the present study, the effect of an oral supplementation with arginine on the metabolism of 45 healthy, nonsmoking, elderly volunteers was investigated. Subjects were divided into two groups that received either arginine aspartate (17 g free arginine) (n = 30) or a placebo (n = 15).

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Background: Experimentally, arginine enhances immune function and promotes wound healing. In this randomized double-blind study we investigated the effect of oral arginine supplementation on wound healing and T-cell function in elderly human beings (more than 65 years of age).

Methods: Thirty elderly, healthy, human volunteers (15 men and 15 women) received daily supplements of 30 gm arginine aspartate (17 gm free arginine).

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In this study we sought to determine the in vivo role of tumor necrosis factor-alpha (TNF-alpha) at the wound-healing site. In vivo abrogation of endogenous TNF-alpha activity in experimental wounds by administration of anti-murine TNF-alpha rabbit serum resulted in a significant 77.5% increase in wound collagen deposition, as assessed by wound sponge granuloma hydroxyproline content.

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Supplemental L-arginine has been shown to enhance thymic and T-cell responses in rodents. We examined the ability of supplemental dietary L-arginine to induce T-cell function in athymic nude mice that lack a normally developed T-cell system. Groups of male nude (nu/nu) mice (Balb/c background) 7 to 8 weeks old were given for 2 weeks 1.

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We examined whether L-arginine is a substrate for nitric oxide (NO) production by peripheral blood mononuclear cells (MNC) in vitro. Minimal extracellular arginine (0.04 mmol/L) is required for maximal lymphocyte proliferation after phytohemagglutinin stimulation.

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Fibroblasts are fundamental to successful wound healing. We hypothesized that the induction and regulation of various fibroblast functions (proliferation, collagen synthesis, and remodeling) are determined by the wound environment. We examined the effect of wound fluid (WF), as a reflection of the wound environment, on the phenotypic expression of normal dermal (NF) and wound-harvested fibroblasts (WHF).

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Arginine has been shown to enhance wound healing and T-cell-mediated immune function in rodents. In this study the effect of oral arginine supplementation on human collagen synthesis and T-cell function was studied in 36 healthy, nonsmoking human volunteers. While volunteers were under local anesthesia, a 5 cm segment of expanded polytetrafluoroethylene tubing (1 mm outer diameter, 90 mu pore size) was inserted subcutaneously into the right deltoid region.

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T-cell depletion leads to impaired wound healing. We studied the effect of combined T-helper and T-suppressor lymphocyte depletion on wound healing and compared it with the effect of all T-cell depletion. Groups of 10 male balb/c mice, 8 weeks old, underwent a 2.

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Wound fluid from 10-day-old healing wounds in rats inhibits lymphocyte immune responses. Since severe injury is frequently complicated by immunosuppression as manifested by sepsis, we hypothesized that the wound may be a source of factors that impair host immune responses. Therefore, we studied the effect of systemic wound fluid administration on the survival of rats subjected to an acute peritonitis model.

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To further define the role of the thymus in wound healing, we studied the effects of two thymic hormones on fibroplasia in normal euthymic and in nude athymic mice. Groups of 10 mice underwent a 2.5 cm dorsal skin incision with subcutaneous placement of polyvinyl alcohol sponges.

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In order to understand the role of T cells in postinjury fibroplasia, we have studied wound healing in congenitally athymic nude mice that lack a normally developed T cell system. Healing of incisional wounds, as assessed by wound breaking strength, was significantly stronger in nude mice compared with normal thymus-bearing animals. This was accompanied by a marked increase in the amount of reparative collagen synthesized at the wound site, as assessed by the hydroxyproline content of subcutaneously implanted sponges.

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The role of T lymphocytes in wound healing is still not well-defined. Because it had been previously shown that in vivo depletion of T cells leads to impaired wound healing, the effect of depleting T cell subsets on subsequent fibroplasia was studied. T helper/effector cells were depleted by the use of the monoclonal antibody GK1.

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T cell-mediated immunity may play a role in host responses to infection. Arginine is a known thymic and T cell stimulator which enhances host allogenic, mitogenic, and anti-tumor responses. We, therefore, examined the effect of arginine on the survival of rats with severe and lethal peritonitis induced by cecal ligation and double-needle puncture (CLP).

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We have previously shown that 10 day healing wounds in rats contain wound mononuclear cells (WMNC) which inhibit normal lymphocyte mitogenic and allogeneic responses. In the present study we sought to further characterize the WMNC and define their mechanism of action. Polyvinyl alcohol sponges implanted in wounds were harvested and processed 10 days postwounding.

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Previously we have noted that fluid obtained from ten-day-old healing wounds noncytotoxically inhibits the blastogenesis of lymphocytes in response to mitogens or antigens. Since these lymphocytic responses are interleukin 2 (IL-2)-mediated, we looked for a specific IL-2 inhibitor in wound fluid. We have found that wound fluid blocks the response of thymic lymphocytes and of two cloned T-helper cell lines (D10 and HT2) to exogenous human recombinant IL-2.

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To determine the importance of T-lymphocytes in wound healing, we examined the effect of T-lymphocyte depletion on the healing of surgical wounds. Thirty Balb/c mice were injected intraperitoneally with 1 mg of rat anti-mouse (IgG2b) cytotoxic monoclonal antibody (30H12) against the Thy1.2 (all T) determinant.

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To investigate lymphocyte participation in wound healing, the migration of T lymphocyte subsets into healing wounds and subcutaneously implanted polyvinyl alcohol sponges was studied. Frozen sections of 5-, 7-, and 10-day-old incisional wounds and sponges from Lewis rats were stained with mouse anti-rat monoclonal antibodies. Cellular staining to OX1 (all leucocyte), W3/25 (helper/effector T lymphocytes), and OX8 (suppressor/cytotoxic T lymphocytes) was quantitated in two arbitrarily defined areas based on maximal cellular infiltration: the superficial wound, down to and including the papillary dermis, and the deep wound, the reticular dermis.

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Antigen-stimulated lymphocytes secrete lymphokines which have been shown to enhance in vitro fibroblast migration, proliferation, and protein synthesis. In the present experiments, the effect of human recombinant interleukin 2 (RIL-2) on wound healing was assessed in vivo. Groups of male Lewis rats, 225-250 g, underwent intraperitoneal insertion of osmotic pumps and a 7-cm dorsal skin incision with subcutaneous placement of polyvinyl alcohol sponges under anesthesia.

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The purpose of this study was to evaluate the effect of increased arginine levels in intravenous hyperalimentation (IVH) therapy on wound healing and thymic immune function. Groups of SD rats, 275-325 g, underwent placement of internal jugular catheter, 7-cm dorsal skin wounding, insertion of polyvinyl alcohol sponges subcutaneously, and closure of wounds with stainless-steel sutures. Twenty-four hours later, rats were started on IVH at a rate of 0.

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Severe trauma impairs host immunity, which in turn renders the host susceptible to infection often terminating in death. This impairment occurs 7 to 14 days after injury, a time when wound healing is at its maximum. We examined the interactions of wound healing to host immunity by studying the in vitro and in vivo immune effects of wound components (i.

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