Observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT): assessment and evaluation as predictive factor for acute postnatal outcome-a single center study.

Introduction: To assess the observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) and to explore its value as a potential predictive factor for postnatal outcome. Methods: A retrospective single-center study was conducted on pregnancies complicated by CAKUT between 2007 and 2018. The lung-to-head ratio (LHR) was calculated for each fetus by two independent observers. Correlations between O/E LHR and various perinatal outcome factors were assessed with Spearman's rank correlation. Furthermore, nominal logistic regression was performed to assess O/E LHR as predictive factor for respiratory distress in newborn. Results: Of 64 pregnancies complicated by CAKUT, 23 were terminated. In the 41 cases of continuation of pregnancy, newborn presenting respiratory distress with need for respiratory support in the delivery room showed earlier gestational age at onset of amniotic fluid abnormalities and at birth. Although median O/E LHR and median single deepest pocket (SDP) of amniotic fluid were significantly smaller in newborn that did develop respiratory distress with need of respiratory support in the delivery room, neither O/E LHR nor SDP were accurate predictors for the development of respiratory distress. Conclusions: Our data show that O/E LHR alone cannot serve as a predictive marker for fetal outcome in pregnancies complicated by CAKUT, though it might still be a helpful parameter together with detailed renal ultrasound evaluation, onset of amniotic fluid abnormality and SDP, particularly in its extreme values.

Fasciola hepatica fatty acid binding protein (Fh12) induces apoptosis and tolerogenic properties in murine bone marrow derived dendritic cells.

In a previous study we demonstrated that Fasciola hepatica fatty acid binding protein (Fh12) significantly suppress macrophage function by inhibiting IL-6, IL-1ß, tumor necrosis factor (TNF)-α and IL-12 production in TLR4-stimulated murine macrophages, an effect mediated through the signaling of CD14 co-receptor without affecting the viability of these cells. Given that dendritic cells (DCs) are immune cells that play a central role in the initiation of primary immune responses and that are the only antigen-presenting cells capable of stimulating naïve T-cells, in the present study we investigated the effect of Fh12 on DCs. We found that Fh12 exerts a strong suppressive effect on activation and function of DCs. However, in contrast to the effect observed on macrophages, Fh12 induces early and late apoptosis of DCs being this phenomenon dose-dependent and CD14-coreceptor independent. At low concentration Fh12 modulates the LPS-induced DCs maturation status by suppressing the MHC-II, and co-stimulatory molecules CD40 and CD80 surface expression together with the pro-inflammatory cytokines IL-12p70 and IL-6 production whereas increase the IL-10 levels. Besides, Fh12 decreased the ability of LPS-activated DCs to induce IFN-γ production against allogeneic splenocytes, while increasing IL-4 production. We have described for the first time the ability of Fh12 to modify selectively the viability of DCs by apoptosis induction. The selective diminution in DCs survival could be a F. hepatica strategy in order to prevent a host immune response during the earliest phases of infection.

Fh15 Blocks the Lipopolysaccharide-Induced Cytokine Storm While Modulating Peritoneal Macrophage Migration and CD38 Expression within Spleen Macrophages in a Mouse Model of Septic Shock.

Sepsis caused by Gram-negative bacteria is the consequence of an unrestrained infection that continuously releases lipopolysaccharide (LPS) into the bloodstream, which triggers an uncontrolled systemic inflammatory response leading to multiorgan failure and death. After scrutinizing the immune modulation exerted by a recombinant Fasciola hepatica fatty acid binding protein termed Fh15, our group demonstrated that addition of Fh15 to murine macrophages 1 h prior to LPS stimulation significantly suppresses the expression of proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-1ß (IL1-ß). The present study aimed to demonstrate that Fh15 could exert a similar anti-inflammatory effect in vivo using a mouse model of septic shock. Among the novel findings reported in this article, (i) Fh15 suppressed numerous serum proinflammatory cytokines/chemokines when injected intraperitoneally 1 h after exposure of animals to lethal doses of LPS, (ii) concurrently, Fh15 increased the population of large peritoneal macrophages (LPMs) in the peritoneal cavity (PerC) of LPS-injected animals, and (iii) Fh15 downregulated the expression on spleen macrophages of CD38, a cell surface ectoenzyme with a critical role during inflammation. These findings present the first evidence that the recombinant parasitic antigen Fh15 is an excellent modulator of the PerC cell content and in vivo macrophage activation, endorsing Fh15's potential as a drug candidate against sepsis-related inflammatory response.IMPORTANCE Sepsis is a potentially life-threatening complication of an infection. Sepsis is mostly the consequence of systemic bacterial infections leading to exacerbated activation of immune cells by bacterial products, resulting in enhanced release of inflammatory mediators. Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is a critical factor in the pathogenesis of sepsis, which is sensed by Toll-like receptor 4 (TLR4). The scientific community highly pursues the development of antagonists capable of blocking the cytokine storm by blocking TLR4. We report here that a recombinant molecule of 14.5 kDa belonging to the Fasciola hepatica fatty acid binding protein (Fh15) is capable of significantly suppressing the LPS-induced cytokine storm in a mouse model of septic shock when administered by the intraperitoneal route 1 h after a lethal LPS injection. These results suggest that Fh15 is an excellent candidate for drug development against endotoxemia.

Characterization of the immune response elicited by the vaccinia virus L3 protein delivered as naked DNA.

Poxviruses are complex dsDNA viruses with over 200 genes, many of them with unknown role in the stimulation of immune responses. Among these, the vaccinia virus (VACV) L3L ORF encodes an essential protein for the transcription of the VACV early genes. To the best of our knowledge, the immune response elicited by L3 has not been characterized. In this regard, our data describes a DNA L3-coding plasmid (pL3L) that stimulates both, humoral- and cell-mediated immune responses in a mouse model. Cell-mediated immune responses were measured by IFN-γ and IL-4 ELISPOT assays. We performed CD8+ cells depletion and flow cytometry analysis to account for the contribution of cytotoxic T lymphocytes in the IFN-γ production. Moreover, results from ELISPOT were confirmed by measuring the concentration of IL-4 and IFN-γ in supernatant of antigen-stimulated splenocytes by cytokine ELISA. Additionally, dominant antigenic regions of L3 protein were identified by epitope mapping analysis. Humoral immune responses were assessed by ELISA. Specifically, the production of total IgG, IgG1 (TH-2) and IgG2a (TH-1) were determined one week after the final immunization. Our ELISPOT data shows pL3L-immunized animals to produce significantly higher frequencies of IFN-γ Spot-Forming Cells (SFC) versus controls. IL-4 levels remained unchanged in all three groups, demonstrating the increase in antigen-specific IFN-γ releasing cells. Flow cytometry assay results showed that CD8+ T cells are a major contributor to the production of IFN-γ. Moreover, our formulation enhances the production of total IgG, predominantly IgG2a isotype. Immunization with pL3L promotes a robust cytotoxic immune response, crucial against viral pathogens. In addition, our vaccine candidate promotes an increase in IgG levels, especially IgG2a (TH-1 type). Our data encourages further studies of L3 as a novel antigen in vaccine development against poxviruses.

Gradients of the signaling lipid S1P in lymph nodes position natural killer cells and regulate their interferon-γ response.

The lymph node periphery is an important site for many immunological functions, from pathogen containment to the differentiation of helper T cells, yet the cues that position cells in this region are largely undefined. Here, through the use of a reporter for the signaling lipid S1P (sphingosine 1-phosphate), we found that cells sensed higher concentrations of S1P in the medullary cords than in the T cell zone and that the S1P transporter SPNS2 on lymphatic endothelial cells generated this gradient. Natural killer (NK) cells are located at the periphery of the lymph node, predominantly in the medulla, and we found that expression of SPNS2, expression of the S1P receptor S1PR5 on NK cells, and expression of the chemokine receptor CXCR4 were all required for NK cell localization during homeostasis and rapid production of interferon-γ by NK cells after challenge. Our findings elucidate the spatial cues for NK cell organization and reveal a previously unknown role for S1P in positioning cells within the medulla.

A map of the distribution of sphingosine 1-phosphate in the spleen.

Despite the importance of signaling lipids, many questions remain about their function because few tools are available for charting lipid gradients in vivo. Here we generated a sphingosine 1-phosphate (S1P) reporter mouse and used this mouse to define the distribution of S1P in the spleen. Unexpectedly, the presence of blood did not serve as a predictor of the concentration of signaling-available S1P. Large areas of the red pulp had low concentrations of S1P, while S1P was sensed by cells inside the white pulp near the marginal sinus. The lipid phosphate phosphatase LPP3 maintained low S1P concentrations in the spleen and enabled efficient shuttling of marginal zone B cells. The exquisitely tight regulation of S1P availability might explain how a single lipid can simultaneously orchestrate the movements of many cells of the immune system.

Free intra-osseous muscle transfer for treatment of chronic osteomyelitis.

BACKGROUND: Chronic osteomyelitis is still a big reconstructive challenge. Even with standard care, therapeutic failures and recurrences are common. Multiple techniques of tissue transfer have increased the success rate. This study recommends free muscle transfers into the intramedullary bone cavities for treatment of chronic osteomyelitis. PATIENTS AND METHODS: The review included 29 patients that were treated for chronic osteomyelitis. Osteomyelitis was located at the femur in four patients, the tibia in 22 patients, and the foot in three patients. Dead bone and scar tissue were replaced with durable free muscle flap with special attention to fill the dead space. RESULTS: The average age of these patients was 48.5 years old (range = 23-70 years old). The average duration of osteomyelitis was 8.2 years (range = 1-45 years). Gracilis was applied in 20 cases (69%), latissimus dorsi was used in five cases (17.2%), and rectus abdominis was performed in four cases (13.8%). There was one flap failure, one partial superficial flap necrosis, two arterial thrombosis, and one venous thrombosis. All the remaining 28 muscle flaps survived. From 1-10 years follow-up, there was one recurrence of the osteomyelitis in the distal end of the intra-medullary cavity of a femur after reconstructing using the gracilis flap. CONCLUSION: The present study demonstrated that free intramedullary muscle transfers are effective in providing a high rate of success in the treatment of chronic osteomyelitis. The secondary filling of the intramedullary cavity after extensive removal of all infected bony sequesters has proven to give a long-term arrest of chronic osteomyelitis.

[Characteristics of violence during teenage pregnancy in Lima, Peru]. / Características de la violencia durante el embarazo en adolescentes de Lima, Perú

OBJECTIVES: To determine the characteristics of violence seen in pregnant teenagers who were treated at the Instituto Nacional Materno Perinatal (INMP) in Lima, Peru. MATERIALS AND METHODS: A cross-sectional study was carried out by INMP between January and March, 2010 using a probabilistic and systematic sampling. The study unit comprises every hospitalized teenager who had just given birth and who lived in Lima. A semi-structured interview was conducted. History of violence was operationalized into: verbal violence (insults, ridicule, and humiliation), physical violence (arm pulling, hair pulling, pushes), direct aggression (slaps, kicking, burns) and sexual violence (sexual intercourse without consent). RESULTS: 292 teenage mothers aged 16,5 ± 1 in average took part in the study. 47.9% lived with their partners and 51.4% were single. In 97.3% of the cases, they got pregnant as a result of a conserted sexual relationship, while 2.7% got pregnant as a result of rape. 90.1% of teenage mothers reported not having planned the pregnancy. Conserning history of violence: 48.1% had had verbal violence, 17.1% physical violence, 8.2% direct aggression and 6.8% sexual violence. CONCLUSIONS: Violence during teenage pregnancy is not an isolated event; actually, it is rather common in any of its forms.

Características de la violencia durante el embarazo en adolescentes de Lima, Perú / Characteristics of violence during teenage pregnancy in Lima, Peru

Objetivos. Determinar las características de la violencia durante el embarazo en adolescentes atendidas en el Instituto Nacional Materno Perinatal (INMP) de Lima, Perú. Materiales y métodos. Estudio transversal llevado a cabo en el INMP entre enero a marzo de 2010. Se trabajó con una muestra probabilística y un muestreo sistemático. La unidad de estudio fue toda adolescente hospitalizada después de la atención del parto y residente en Lima. Se realizó una entrevista semiestructurada. El antecedente de violencia se operacionalizó en: violencia verbal (insultos, ridiculizaciones, humillación); violencia física (jalones del brazo, jalones de los cabellos, empujones); agresión directa (puñetes, cachetadas, patadas, quemaduras), y violencia sexual (relaciones sexuales sin consentimiento). Resultados. Se incluyeron 292 madres adolescentes. La edad promedio fue de 16,5 ± 1 año. En cuanto a estado civil, el 47,9% era conviviente y el 51,4% soltera. El motivo del embarazo fue por relación consentida en el 97,3% y por violación sexual en el 2,7%. El 90,1% de las madres adolescentes refirió no haber planificado el embarazo. El antecedente de violencia reportado fue en 48,1% de violencia verbal; 17,1% violencia física; 8,2% agresión directa, y 6,8% de violencia sexual. Conclusiones. La violencia durante el embarazo adolescente no es un hecho aislado, sino que es altamente frecuente en cualquiera de sus formas.

Objectives. To determine the characteristics of violence seen in pregnant teenagers who were treated at the Instituto Nacional Materno Perinatal (INMP) in Lima, Peru. Materials and methods. A cross-sectional study was carried out by INMP between January and March, 2010 using a probabilistic and systematic sampling. The study unit comprises every hospitalized teenager who had just given birth and who lived in Lima. A semi-structured interview was conducted. History of violence was operationalized into: verbal violence (insults, ridicule, and humiliation), physical violence (arm pulling, hair pulling, pushes), direct aggression (slaps, kicking, burns) and sexual violence (sexual intercourse without consent). Results. 292 teenage mothers aged 16,5 ± 1 in average took part in the study. 47.9% lived with their partners and 51.4% were single. In 97.3% of the cases, they got pregnant as a result of a conserted sexual relationship, while 2.7% got pregnant as a result of rape. 90.1% of teenage mothers reported not having planned the pregnancy. Conserning history of violence: 48.1% had had verbal violence, 17.1% physical violence, 8.2% direct aggression and 6.8% sexual violence. Conclusions. Violence during teenage pregnancy is not an isolated event; actually, it is rather common in any of its forms.

Toxic shock syndrome due to group A beta-hemolytic streptococcus presenting with purpura fulminans and limb ischemia in a pediatric patient treated with early microsurgical arteriolysis.

We describe a 2.5 year-old child with toxic shock syndrome due to group A beta-hemolytic streptococcus (GABHS) who presented with purpura fulminans and limb ischemia treated with early microsurgical arteriolysis. The clinical picture of toxic shock syndrome (TSS) presenting with purpura fulminans and limb ischemia is an exceptionally uncommon finding in sepsis due to GABHS. This is the first case of purpura fulminans caused by GABHS reported in Europe and the third one described in the literature (Dhodapkar et al., 2000[1]; Renaud et a., 2011[2]).

The transporter Spns2 is required for secretion of lymph but not plasma sphingosine-1-phosphate.

Plasma sphingosine-1-phosphate (S1P) regulates vascular permeability, and plasma and lymph S1P guide lymphocyte egress from lymphoid organs. S1P is made intracellularly, and little is known about how S1P is delivered into circulatory fluids. Here, we find that mice without the major facilitator superfamily transporter Spns2 have a profound reduction in lymph S1P, but only a minor decrease in plasma S1P. Spns2-deficient mice have a redistribution of lymphocytes from the spleen to lymph nodes and a loss of circulating lymphocytes, consistent with normal egress from the spleen directed by plasma S1P and blocked egress from lymph nodes directed by lymph S1P. Spns2 is needed in endothelial cells to supply lymph S1P and support lymphocyte circulation. As a differential requirement for lymph and blood S1P, Spns2 may be an attractive target for immune suppressive drugs.

Lipid phosphate phosphatase 3 enables efficient thymic egress.

The signaling lipid sphingosine-1-phosphate (S1P) stabilizes the vasculature, directs lymphocyte egress from lymphoid organs, and shapes inflammatory responses. However, little is known about how S1P distribution is controlled in vivo, and it is not clear how a ubiquitously made lipid functions as a signal that requires precise spatial and temporal control. We have found that lipid phosphate phosphatase 3 (LPP3) enables efficient export of mature T cells from the thymus into circulation, and several lines of evidence suggest that LPP3 promotes exit by destroying thymic S1P. Although five additional S1P-degrading enzymes are expressed in the thymus, they cannot compensate for the loss of LPP3. Moreover, conditional deletion of LPP3 in either epithelial cells or endothelial cells is sufficient to inhibit egress. These results suggest that S1P generation and destruction are tightly regulated and that LPP3 is essential to establish the balance.

Minimizing limb amputations in meningococcal sepsis by early microsurgical arteriolysis.

PURPOSE: Surgical treatment of children with meningococcal sepsis has mainly involved debridement of necrotic skin and amputation of limbs. This resulted in major functional impairment. On the contrary, when early microsurgical arteriolysis was performed, freeing up the blood vessels, the impaired blood flow could be restored, thereby significantly reducing the amputation levels. METHODS: We prospectively evaluated 14 patients affected by meningococcal sepsis. In 7 patients, microsurgical arteriolysis was performed; standard sepsis treatment was performed on the remaining 7. Ischemia levels on admission were compared with permanent amputation levels after 1 year. RESULTS: Statistically significant decreases (P = .005) in ischemia values were achieved by the arteriolysis, in comparison with final amputation percentages. The functional impairment of the affected limbs was highly reduced compared with the probable loss of function observed on admission. CONCLUSIONS: Our findings show that early microsurgical arteriolysis is a reliable method to reduce the devastating amputations normally found in patients with meningococcal sepsis. This significantly improves the functional outcome in severely ischemic limbs in meningococcal induced septic children.

Dispersal, recruitment and migratory behaviour in a hawksbill sea turtle aggregation.

We investigated the dispersal, recruitment and migratory behaviour of the hawksbill sea turtle (Eretmochelys imbricata), among different life-history stages and demographic segments of the large hawksbill turtle aggregation at Mona Island, Puerto Rico. There were significant differences in both mitochondrial DNA (mtDNA) haplotype diversity and haplotype frequencies among the adult males, females and juveniles examined, but little evidence for temporal heterogeneity within these same groups sampled across years. Consistent with previous studies and the hypothesis of strong natal homing, there were striking mtDNA haplotype differences between nesting females on Mona Island and nesting females in other major Caribbean rookeries. Breeding males also showed strong, albeit weaker, genetic evidence of natal homing. Overall, Bayesian mixed-stock analysis suggests that Mona Island was the natal rookery for 79% (65-94%) of males in the aggregation. In contrast, the Mona Island rookery accounted for only a small subset of the new juvenile recruits to the foraging grounds or in the population of older juvenile hawksbills turtles on Mona. Instead, both new recruits and the older juvenile hawksbill turtles on Mona more likely recruited from other Caribbean rookeries, suggesting that a mechanism besides natal homing must be influencing recruitment to feeding habitats. The difference in the apparent degree of natal homing behaviour among the different life-history stages of hawksbill turtles at Mona Island underscores the complexity of the species' life-history dynamics and highlights the need for both local and regional conservation efforts.

A study of perfusion of the distal free-TRAM flap using laser Doppler flowmetry.

The aim of this study was to characterise microcirculatory changes in the distal part of a flap and to evaluate whether measurement of the microcirculation may predict flap complications (FC). In this prospective study, 30 patients undergoing a delayed breast reconstruction were included. Perioperative data were recorded and with the laser Doppler flowmetry (LDF; Perimed) blood flow was recorded in the central part (zone I) and the distal part (zone IV) of the flap. A lower blood flow was observed in zone IV of patients with flap complications compared to patients without flap complications (P=0.013). In addition, LDF demonstrated different flow trends in zone I compared to zone IV indicating a delayed opening of the choke vessels connecting the angiosomes in the distal part of the flap. The LDF has proven to be a useful investigative tool to monitor microcirculatory changes. In future studies it will be used to evaluate interventions aimed at decreasing distal ischaemia and reducing flap complications.

Risk factors and blood flow in the free transverse rectus abdominis (TRAM) flap: smoking and high flap weight impair the free TRAM flap microcirculation.

Mastectomy patients may have significant psychologic-related problems. Breast reconstruction provides in these cases substantial benefits in restoring body image and health-related quality of live. Autologous free tissue transfer is the treatment of choice due to excellent outcome. The purpose of this study was to elucidate the effect of the risk factors on the microcirculation and clinical outcome. In this prospective study, 21 patients with a free transverse rectus abdominis (TRAM) flap breast reconstruction were included. Patient demographics and flap characteristics were recorded. Blood flow was recorded in the central part (zone I) and the distal part (zone IV) of the flap with the laser Doppler flowmetry (LDF; Perimed). In this study, increased flap complications were seen in smokers when compared with nonsmokers (P < 0.000). LDF was higher in the older patient population (P = 0.008) in zone IV. Smoking, especially in combination with a high flap weight (HFW), revealed lower blood-flow values (P = 0.020) in zone IV. Other possible influencing risk factors such as a HFW and history of radio- and chemotherapy did not alter the microcirculation. Patients with smoking and a HFW did also show decreased blood flow but also more severe flap complications.Smoking, especially in patients with a HFW, impairs the free TRAM flap microcirculation in zone IV. In our opinion, these patients can still be included for reconstruction. However, extra care has to be taken during flap design to minimize disturbed wound healing.

Is the treatment of keloid scars still a challenge in 2006?

BACKGROUND: Several options are described to treat keloid scars, none of them being 100% successful. Radiotherapy is suggested to have the most significant effect on recurrence rate. OBJECTIVES: The aim of the study is to confirm the effectiveness of iridium brachytherapy combined with surgery and to evaluate patient satisfaction. PATIENTS AND METHODS: We retrospectively enrolled 24 patients with 30 keloids, treated by surgical excision and iridium 192 high-dose-rate (HDR) brachytherapy. RESULTS: We observed a significant difference in scar thickness before and after the treatment (P < 0.001). With regard to patient satisfaction and complaints, 79.1% of them had no pain and irritation after treatment, 79.2% of patients would recommend this treatment to other patients, and 87.5% would undergo this treatment again if necessary. CONCLUSIONS: Our results confirm the effectiveness of surgical keloid excision followed by HDR brachytherapy in primary treatment or if other alternative methods have failed.

The role of free flaps in the treatment of persistent scalp osteomyelitis.

OBJECTIVE: To evaluate the efficacy of the combination of an extensive surgical debridement and simultaneous free flap repair in case of troublesome cranial osteomyelitis. METHODS: Five patients with persistent, frontal bone osteomyelitis were treated with surgical debridement of the infected bone and reconstruction with a free flap. In all patients, osteomyelitis occurred after neurosurgical procedures and lasted from 1 to 7 years. A latissimus dorsi muscle flap with a split skin graft has been performed. RESULTS: No flap failure occurred and donor site morbidity was negligible. No signs of osteomyelitis or soft tissue infection were observed during the mean follow-up period of 3.2 years. Furthermore, the contour of the cranium could be preserved without a need for bone grafts or implants. CONCLUSION: In our experience, the combination of an extensive surgical debridement and a free flap transfer is demonstrated to be an effective treatment for "chronic" osteomyelitis of the cranium.

Infected chronic wounds show different local and systemic arginine conversion compared with acute wounds.

BACKGROUND: Several experimental studies have shown the importance of arginine in wound healing. However, little is known about its role in human wound healing. In this study, we investigated arginine metabolism in impaired wound healing. MATERIALS AND METHODS: Twenty patients with chronic wounds and 10 patients with acute wounds were included in a prospective study. Amino acids, nitrate/nitrite, and arginase concentrations were determined in plasma and wound fluid using high-performance liquid chromatography and enzyme-linked immunosorbent assay. Chronic wounds were divided into two groups: noninfected chronic wounds (n = 11) and infected chronic wounds (n = 9), based on quantitative bacterial analysis of wound fluid samples. RESULTS: Plasma arginine levels, next to total plasma amino acid levels, were significantly decreased in patients with infected chronic wounds compared with patients having acute or noninfected wounds. Citrulline and ornithine levels were significantly increased in infected chronic wounds and related to decreased nitrate/nitrite levels, whereas wound fluid arginine levels were similar in all groups. In addition, wound fluid arginase levels of infected chronic wounds were significantly enhanced. CONCLUSIONS: This study demonstrates that patients with infected chronic wounds have decreased plasma arginine levels and suggests enhanced arginine conversion in the wound. In contrast to noninfected chronic wounds, arginine seems to be mainly metabolized by arginase in infected chronic wounds. In conclusion, our hypothesis is that impaired wound healing is related to an altered arginine usage.

Preservation of rat cremaster muscle microcirculation after prolonged cold storage and transplantation.

BACKGROUND: Microvascular surgery for the reconstruction of complex defects involves an ischemic period, which may cause flap failure as the result of ischemia/reperfusion injury. We assessed the microvascular consequences of rat cremaster muscle transplantation after prolonged periods of cold storage in HTK-Bretschneider solution (HTK). MATERIALS AND METHODS: Cremaster muscle transplantations were performed immediately or after 8 or 24 h of cold storage (4 degrees C) in HTK or saline. Intravital microscopy was used to quantify capillary perfusion and venular leukocyte-endothelium interactions following transplantation. RESULTS: The transplantation procedure itself resulted in 50-65 min of ischemia. After direct transplantation, capillary perfusion was 90% of control. Transplantation after 8 h of cold storage in either HTK or saline did not deteriorate capillary perfusion. When the tissue was stored for 24 h, HTK was superior to saline in preserving capillary perfusion (HTK: 76-83% of control, saline: 30%). Immediate transplantation induced a small increase in leukocyte adhesion. Prolonged cold storage in either fluid resulted in reduced flow velocities (qualitative observations) and edema formation, which hampered quantification of leukocyte-endothelium interactions. CONCLUSIONS: Even after 8 or 24 h of cold storage in HTK, transplantation of rat cremaster muscle was successful with good capillary perfusion. Capillary perfusion was better preserved in HTK than in saline.