Outpatient parenteral antimicrobial therapy (OPAT) in the Republic of Ireland: results of a national survey.

Outpatient parenteral antimicrobial therapy (OPAT) services are not well developed in the Republic of Ireland. A national programme is being instituted to standardise care. This survey aims to assess the current use of outpatient intravenous antibiotics and to quantify the needs that physicians identify in the development of a national programme. General medical consultant physicians and clinical microbiology consultants were contacted through the Royal College of Physicians of Ireland (RCPI) from April to June 2012. Data were analysed using SPSS version 20. A total of 512 physicians were contacted, of which 55 (10.7 %) responded. The majority, 38/55 (69 %), practice general internal medicine in combination with a medical specialty, 2 (4 %) general internal medicine alone, 8 (15 %) clinical microbiology and 7 (13 %) a medical specialty alone. Of those practising a medical specialty, 12 (27 %) practice infectious diseases. Seventy-four percent reported having discharged patients with intravenous antibiotics; however, 47 % did not have a designated service available. Of those with no service, 100 % identified a need for these resources. Of those responsible for an OPAT service, 56 % had not audited their service. The most common indications were skin and soft tissue infections, osteomyelitis and respiratory tract infection. Flucloxacillin was the most commonly reported antibiotic. Eleven percent responded that they never monitor laboratory studies for patients discharged with intravenous antibiotics. While OPAT services in Ireland are not well developed, patients are being discharged with intravenous antibiotics. This survey underscores the need to develop the national programme to standardise care and ensure patients receive safe and efficient therapy.

The myofibroblast, cadherin, alpha smooth muscle actin and the collagen effect.

In granulation tissue the myofibroblast, a specialized fibroblast characterized by cytoplasmic stress fibres with alpha smooth muscle actin (SMA), develops from mechano-tension between cells. In vitro the myofibroblast phenotype can be induced in the absence of obvious tension by plating human dermal fibroblasts at low density (LD). Upon reaching confluence the LD-plated cells express alpha SMA within stress fibres. In contrast, few cells express alpha SMA when those same fibroblasts are plated at high density (HD). Cadherins, trans-membrane proteins, and link cells tie the cytoskeletal stress fibres of neighbouring cells together. By immunohistology myofibroblasts (LD-plated fibroblasts) are shown to express cadherin-11 on their surface and between cells, while HD-plated fibroblasts expressed less cadherin-11 on their surface. Western blot analysis revealed elevated concentrations of cadherin-11 and alpha SMA in confluent LD-plated cell lysates. Reduced amounts of both proteins were found in confluent HD-plated cell lysates. Plating fibroblasts on collagen inhibits alpha SMA synthesis. When confluent LD-plated myofibroblasts were covered with a collagen lattice for 24 h, both the expression of cadherin-11 and alpha SMA were reduced by 50%. There is the possibility that direct linkage of the cytoskeleton stress fibres by cell surface cadherins maintains tension between neighbouring cells, which induces alpha SMA expression in stress fibres. Cell contact with collagen reduces cadherin expression, which may eliminate the generation of mechano-tension between fibroblasts. The other possibility is that the myofibroblast phenotype may be induced by factors other than mechano-tension.

Effects of interleukin-8 on granulation tissue maturation.

The inflammatory alpha-chemokine, interleukin-8 (IL-8), affects the function and recruitment of various inflammatory cells, fibroblasts, and keratinocytes. Gap junctions are anatomical channels that facilitate the direct passage of small molecules between cells. The hypothesis is that IL-8 enhances gap junctional intercellular communication (GJIC) between fibroblasts in granulation tissue, which increases the rate of granulation tissue maturation. In vitro, human dermal fibroblasts were incubated with IL-8 prior to scrape loading, a technique that quantifies GJIC. Polyvinyl alcohol (PVA) sponges were implanted within subcutaneous pockets in rats and received local injections of either IL-8 or saline and were harvested on day 11. In vitro, IL-8 treated fibroblasts demonstrated an increase in GJIC by scrape loading compared to saline treated controls. In vivo, IL-8 treated PVA sponges demonstrated a decrease in cell density and an increase in vascularization compared to saline controls by H&E staining. Polarized light viewed Sirius red-stained specimens demonstrated greater collagen birefringence intensity, indicating thicker, more-mature collagen fibers. IL-8 increases GJIC in cultured fibroblasts and induces a more rapid maturation of granulation tissue.

Fetal rat amniotic fluid: transforming growth factor beta and fibroblast collagen lattice contraction.

BACKGROUND: In several mammalian animal models, early-gestational-age fetal wounds heal without scar, but wounds of late gestational age heal with scar. This change in wound healing phenotype can be a result of both intrinsic (i.e., cellular characteristics) and extrinsic (i.e., environmental) factors. Our question was: Does amniotic fluid (AF) influence the change from scarless to scar-forming repair in the rat? METHODS: Rat AF was investigated for its modulation of fibroblast-populated collagen lattice (FPCL) contraction and morphological changes of adult fibroblasts. AF was also assayed for transforming growth factor beta (TGF-beta) levels. Adult rat dermal fibroblasts in monolayer and incorporated into FPCLs were incubated with AF additions from gestational age 14, 16, 18, and 21 days at 10% (v/v). RESULTS: Day 14 AF significantly stimulated FPCL contraction, but AF of 16, 18, and 21 days inhibited FPCL contraction. Fluorescence histology identified microtubules and microfilaments in AF treated adult rat dermal fibroblasts. The staining pattern of microtubules in Day 14 AF-treated fibroblasts showed denser structures at the cell center. Cells incubated with Day 16 or 18 AF showed fine peripheral microtubules. A mink lung epithelial cell bioassay was used to analyze concentrations of TGF-beta in AF. TGF-beta levels were greatly elevated in Day 14 AF, but were relatively low in Day 16, 18 and 21 AF. The inhibitor of FPCL contraction from AF of Days 16, 18, and 21 was not identified. CONCLUSION: It is proposed that the robust expression of TGF-beta or cytoskeletal changes induced by Day 14 AF contributes to enhanced FPCL contraction.

Differences in alpha smooth muscle actin expression between fibroblasts derived from Dupuytren's nodules or cords.

Dupuytren's contracture is a fibrotic lesion of the palmar fascia that includes two distinct structures, the nodule and the cord. Histologically the Dupuytren's nodule has a high cell density with numerous myofibroblasts (alpha smooth muscle actin-expressing fibroblasts). The Dupuytren's cord has a rich connective tissue matrix containing a low density of elongated spindle-shaped fibroblasts. The cytoskeletal structures of cultured fibroblasts derived from Dupuytren's nodules and cords of surgically treated patients were studied and compared. Immunohistology showed no obvious morphological differences between Dupuytren's nodule and cord cultured cells, when focal adhesions (vinculin), intermediate filaments (vimentin), microtubules (alpha tubulin), or microfilaments (filamentous actin) were viewed. However, a greater proportion of nodule cultured cells were positive for alpha smooth muscle actin compared to cord-derived cells. The increased expression in nodule cells of alpha smooth muscle actin was confirmed by Western blot analysis. It appears that fibroblasts derived from Dupuytren's nodules or cords retain in vivo cytoskeletal characteristics, when grown in tissue culture.

Increased gelsolin expression and retarded collagen lattice contraction with smooth muscle cells from Crohn's diseased intestine.

Intestinal smooth muscle cells (SMC) produce the fibrotic tissue, strictures, that characterize Crohn's disease. These SMC change their phenotype from a contractile muscle form to an inflammation-responsive form that migrates and synthesizes a collagen matrix. It is postulated that the inflammatory responsive SMC form associates differently with its surrounding collagen matrix compared to the normal SMC form. SMC derived from Crohn's diseased and uninvolved bowel were sustained in cell culture. Cultured SMC incorporated in collagen lattices have the capacity to reduce the size of that lattice, referred to as lattice contraction. At day 2, Crohn's SMC-populated collagen lattices were reduced to 21% of their initial area, while non-Crohn's SMC collagen lattices were reduced to 8%. Crohn's SMC demonstrate retarded lattice contraction compared to non-Crohn's SMC. When grown in monolayer culture, Crohn's-derived SMC cover 30% more area than non-Crohn's SMC. By Western blot analysis Crohn's SMC express more gelsolin, an actin-binding protein found elevated in cells exhibiting increased cell motility. Was the increased expression of gelsolin related to retarded collagen lattice contraction? Intracellular levels of gelsolin were elevated by the electroporation of plasma gelsolin protein into suspended non-Crohn's SMC. When incorporated in collagen lattices, gelsolin loaded cells showed retarded lattice contraction compared to SMC loaded with albumin. Crohn's SMC show increased expression of gelsolin, which may be associated with a diminished capacity to reorganize collagen fiber bundles. It is suggested that increased concentrations of gelsolin in Crohn's SMC is consistent with enhanced cell migration as a consequence of the inflammatory state of Crohn's diseased intestine.

Differences between scar and dermal cultured fibroblasts derived from a patient with recurrent abdominal incision wound herniation.

Fibroblasts were derived from dermis and scar of a 47-year-old white man with a recurrent incisional hernia as a result of fractured ribs. The scar was thin and stretched, suggesting a defect in the maturation of granulation tissue. After surgical repair, biopsy specimens of discarded scar and skin were used to generate fibroblast cell lines. Fibroblasts maintained in medium containing 10% fetal bovine serum and antibiotic were studied between their third and eighth passage. By phase contrast microscopy, no structural differences were obvious, but it was noted that to pass scar fibroblasts, a more aggressive trypsin regimen was required. Immunohistologic and Western blot analysis of patient scar fibroblasts showed (1) more a smooth muscle actin within stress fibers, (2) increased expression of the vitronectin integrin receptor alpha(v) (CD 51), and (3) reduced expression of the collagen integrin receptor alpha2 (CD 49b). The expression of vinculin from focal adhesions or a tubulin from microtubules was the same among cell lines. Contractions of scar and dermal fibroblast-populated collagen lattice were compared. At 24 hours, contractions were 69 percent with newborn fibroblasts (normal); 68 percent for patient dermal fibroblasts; and only 48 percent for patient scar fibroblasts. The retarded contraction of scar fibroblast-populated collagen lattice was significant (p > or = 0.002). Myosin ATPase activity, critical for lattice contraction, and cell migration were equivalent among all cell lines. A plausible mechanism for the retardation of scar lattice contraction is disruption of fibroblasts and collagen interactions, for which the attachment of cells to collagen is altered. It is proposed that either the decrease in the expression of collagen integrin receptor alpha2 (CD 49b), an increase in the expression of the vitronectin receptor alpha(v) (CD 51), or a combination of both is responsible for disruption of collagen fibroblast interactions.

Repeated additions of hyaluronan alters granulation tissue deposition in sponge implants in mice.

The role for the metabolism of hyaluronic acid in the repair process is uncertain. Fetal dermal wounds do not heal by scarring and have sustained high levels of hyaluronic acid. In contrast, adult dermis is repaired by scarring and has less hyaluronic acid. Initially after injury, hyaluronic acid is elevated in both adult and fetal wounds, and although it remains elevated in fetal repair, it is rapidly degraded in adult wounds. The chronic addition of hyaluronic acid or hyaluronidase to polyvinyl alcohol sponge implants in adult mice was investigated in this study. Polyvinyl alcohol sponge implants containing a central reservoir were placed subcutaneously in the dorsum of adult male CD-1 mice. Mice were divided into three groups: a phosphate-buffered saline control, a 20 microgram hyaluronic acid treatment group, and a 10 U hyaluronidase treatment group. The central reservoir of each sponge implant received appropriate compound every 3 days for 2 weeks via transdermal injection and were then evaluated histologically. At 2 weeks, the cellular density and the quantity of granulation tissue deposition were the greatest in the hyaluronidase group and were lowest in the hyaluronic acid group. In addition, the organization of collagen fiber bundles was the most dense in the hyaluronidase group and least in the hyaluronic acid group. In a second experiment, polyvinyl alcohol sponge implants in mice received either phosphate-buffered saline solution or 20 microgram hyaluronic acid every 3 days for 1 week. On day 5, an aliquot of fluorescently tagged native collagen was injected into the sponges. Sponges were harvested at day 7, cryosections made, and the presence of autofluorescent collagen fibers assessed. The autofluorescent collagen fiber bundles in the phosphate-buffered saline solution group were organized in thick parallel bundles, whereas the collagen bundles from hyaluronic acid-treated implants were organized in fine lacelike structures. Chronic addition of hyaluronic acid appears to mimic the fetal dermal connective tissue matrix in which repair proceeds with diminished collagen deposition, organized in finer collagen fiber bundles in granulation tissue. On the other hand, the removal of hyaluronic acid by the chronic administration of hyaluronidase increases the amount of granulation tissue. Elevated levels of hyaluronic acid in granulation tissue appear to modulate the ability of resident fibroblasts to organize collagen fiber bundles.

Informed consent for cardiopulmonary resuscitation in elderly patients.

OBJECT: to determine if a semistructured interview would enable elderly patients to give adequately informed consent for cardiopulmonary resuscitation (CPR). METHOD: one hundred consecutive patients admitted to Wakari assessment and rehabilitation unit for the elderly, who satisfied study criteria, were randomly allocated to receive a detailed discussion on CPR or to act as controls. Subsequently knowledge about CPR was tested in both groups. RESULTS: of the 49 study subjects, 27 (55%) wished to have CPR in the event of a cardiac arrest. After the interview knowledge about the CPR was significantly better in the study group than the controls, but there was still a lack of appreciation of the possible complications and an overly optimistic view of the likely outcome. CONCLUSIONS: careful explanation of the procedures involved in CPR does increase knowledge and assist in making an informed decision. However, the decision may still be based on poor understanding of the likely outcome and possible complications.