Effective Structural Concrete Repair, Volume 3 of 3, Evaluation of Repair Materials for Use in Patching Damaged Concrete, March 2004

Structural concrete is one of the most commonly used construction materials in the United States. However, due to changes in design specifications, aging, vehicle impact, etc. – there is a need for new procedures for repairing concrete (reinforced or pretressed) superstructures and substructures. Thus, the overall objective of this investigation was to develop innovative cost effective repair methods for various concrete elements. In consultation with the project advisory committee, it was decided to evaluate the following three repair methods: • Carbon fiber reinforced polymers (CFRPs) for use in repairing damaged prestressed concrete bridges • Fiber reinforced polymers (FRPs) for preventing chloride penetration of bridge columns • Various patch materials The initial results of these evaluations are presented in this three volume final report. Each evaluation is briefly described in the following paragraphs. A more detailed abstract of each evaluation accompanies the volume on that particular investigation.

Portland Cement Concrete Patching Techniques vs. Performance and Traffic Delay, January 2004

Standards for the construction of full-depth patching in portland cement concrete pavement usually require replacement of all deteriorated based materials with crushed stone, up to the bottom of the existing pavement layer. In an effort to reduce the time of patch construction and costs, the Iowa Department of Transportation and the Department of Civil, Construction and Environmental Engineering at Iowa State University studied the use of extra concrete depth as an option for base construction. This report compares the impact of additional concrete patching material depth on rate of strength gain, potential for early opening to traffic, patching costs, and long-term patch performance. This report also compares those characteristics in terms of early setting and standard concrete mixes. The results have the potential to change the method of Portland cement concrete pavement patch construction in Iowa.

Neonatal Minimally Invasive Surgery for Congenital Diaphragmatic Hernias: a multicenter study using thoracoscopy or laparoscopy.

BACKGROUND: Minimally invasive surgery (MIS) for late-presenting congenital diaphragmatic hernia (CDH) has been described previously, but few neonatal cases of CDH have been reported. This study aimed to report the multicenter experience of these rare cases and to compare the laparoscopic and thoracoscopic approaches. METHODS: Using MIS procedures, 30 patients (16 boys and 14 girls) from nine centers underwent surgery for CDH within the first month of life, 26 before day 5. Only one patient had associated malformations. There were 10 preterm patients (32-36 weeks of gestational age). Their weight at birth ranged from 1,800 to 3,800 g, with three patients weighing less than 2,600 g. Of the 30 patients, 18 were intubated at birth. RESULTS: The MIS procedures were performed in 18 cases by a thoracoscopic approach and in 12 cases by a laparoscopic approach. No severe complication was observed. For 20 patients, reduction of the intrathoracic contents was achieved easily with 15 thoracoscopies and 5 laparoscopies. In six cases, the reduction was difficult, proving to be impossible for the four remaining patients: one treated with thoracoscopy and three with laparoscopy. The reasons for the inability to reduce the thoracic contents were difficulty of liver mobilization (1 left CDH and 2 right CDH) and the presence of a dilated stomach in the thorax. Reductions were easier for cases of wide diaphragmatic defects using thoracoscopy. There were 10 conversions (5 laparoscopies and 5 thoracoscopies). The reported reasons for conversion were inability to reduce (n = 4), need for a patch (n = 5), lack of adequate vision (n = 4), narrow working space (n = 1), associated bowel malrotation (n = 1), and an anesthetic problem (n = 1). Five defects were too large for direct closure and had to be closed with a patch. Four required conversion, with one performed through video-assisted thoracic surgery. The recurrences were detected after two primer thoracoscopic closures, one of which was managed by successful reoperation using thoracoscopy. CONCLUSIONS: In the neonatal period, CDH can be safely closed using MIS procedures. The overall success rate in this study was 67%. The indication for MIS is not related to weeks of gestational age, to weight at birth (if >2,600 g), or to the extent of the immediate neonatal care. Patients with no associated anomaly who are hemodynamically stabilized can benefit from MIS procedures. Reduction of the herniated organs is easier using thoracoscopy. Right CDH, liver lobe herniation, and the need for a patch closure are the most frequent reasons for conversion.

Ultra-Thin PCC Overlays, January 2005

· Evaluate conventional methods of slab removal and asphalt surface preparation for subsequent overlays of portland cement concrete (PCC) in the “remove and replace” areas. · Evaluate existing asphaltic concrete surface under the “remove and patch” areas of rehabilitation areas and evaluate joint formation in the areas of patching. · Evaluate polypropylene fiber enhanced concrete at the three-inch depth to determine the cost/benefit of its inclusion. · Evaluate the performance of the rehabilitated ultra-thin whitetopping sections and the extended performance of the existing ultra-thin sections with and without patching. · Validate existing ultra-thin whitetopping design procedures of the Portland Cement Association (PCA) and American Concrete Pavement Association (ACPA) for application in Iowa.

Cricotracheal resection for laryngeal invasion by thyroid carcinoma: our experience.

Invasion of the laryngeal framework by thyroid carcinoma requires specific surgical techniques and carries a higher rate of complications that deserve to be highlighted. We reviewed our data from 1995 to 2012 and found six patients with laryngotracheal invasion by thyroid carcinoma. All underwent total thyroidectomy and single-stage cricotracheal resection, plus anterolateral neck dissection. Three had airway obstruction that necessitated prior endoscopic debulking. None of the patients needed a tracheotomy. There were four cases of papillary carcinoma, and two cases of undifferentiated carcinoma. One patient died of complications of the procedure (anastomotic dehiscence and tracheo-innominate artery fistula). Another died 2 months after the procedure from local recurrence and aspiration pneumonia. One case presented recurrence at 15 months, which was managed by re-excision and adjuvant radiotherapy; after 26 months of follow-up, he has no evidence of locoregional recurrence. The three other patients are alive without evidence of disease at 6, 18 and 41 months, respectively. Cricotracheal resection for subglottic invasion by thyroid carcinoma is an effective procedure, but carries significant risks of complications. This could be attributed to the devascularisation of the tracheal wall due to the simultaneous neck dissection, sacrifice of the strap muscles or of a patch of oesophageal muscle layer. We advocate a sternocleidomastoid flap to cover the anastomosis. Cricotracheal resection for subglottic invasion can be curative with good functional outcomes, even for the advanced stages of thyroid cancer. Endoscopic debulking of the airway prior to the procedure avoids tracheotomy.

Gene-flow in a mosaic hybrid zone: is local introgression adaptive?

Genome-wide scans of genetic differentiation between hybridizing taxa can identify genome regions with unusual rates of introgression. Regions of high differentiation might represent barriers to gene flow, while regions of low differentiation might indicate adaptive introgression-the spread of selectively beneficial alleles between reproductively isolated genetic backgrounds. Here we conduct a scan for unusual patterns of differentiation in a mosaic hybrid zone between two mussel species, Mytilus edulis and M. galloprovincialis. One outlying locus, mac-1, showed a characteristic footprint of local introgression, with abnormally high frequency of edulis-derived alleles in a patch of M. galloprovincialis enclosed within the mosaic zone, but low frequencies outside of the zone. Further analysis of DNA sequences showed that almost all of the edulis allelic diversity had introgressed into the M. galloprovincialis background in this patch. We then used a variety of approaches to test the hypothesis that there had been adaptive introgression at mac-1. Simulations and model fitting with maximum-likelihood and approximate Bayesian computation approaches suggested that adaptive introgression could generate a "soft sweep," which was qualitatively consistent with our data. Although the migration rate required was high, it was compatible with the functioning of an effective barrier to gene flow as revealed by demographic inferences. As such, adaptive introgression could explain both the reduced intraspecific differentiation around mac-1 and the high diversity of introgressed alleles, although a localized change in barrier strength may also be invoked. Together, our results emphasize the need to account for the complex history of secondary contacts in interpreting outlier loci.

Utilisation d'EMLA® (lidocaïne/prilocaïne)de façon routinière lors de vaccinations chez l'enfant : anodin?

L'utilisation d'EMLA 5%®, une association de deux anesthésiques locaux, la lidocaïne et la prilocaïne, sous forme de crème ou de patch, s'est répandue de façon assez générale. Son utilisation lors de gestes invasifs, tels que ponctions veineuses ou injections intramusculaires, petite chirurgie comme ablation de verrues plantaires ou biopsies cutanées, s'est étendue à toutes sortes d'indications, telles qu'administration de vaccins ou, en dehors d'une indication médicale, lors de piercing ou de pose de boucles d'oreilles. S'il est vrai que l'accent a été mis ces dernières années sur l'importance d'une bonne antalgie, en particulier chez les jeunes enfants, la généralisation de l'utilisation d'anesthésiques topiques pour des gestes anodins doit faire évoquer les risques potentiels associés à de telles molécules.

Role of glucagon in disposal of an amino acid load.

Amino acids stimulate the release of glucagon and insulin. To assess the role of aminogenic hyperglucagonemia, we have studied, in healthy young males, the effects of basal (less than 100 pg/ml) and high (200-400 pg/ml) plasma glucagon concentrations on amino acid metabolism during intravenous infusion (0.5 g.h-1.4 h) of a mixture of 15 amino acids. Basal plasma glucagon concentrations were obtained by infusion of somatostatin (0.5 mg/h) plus glucagon (0.25 ng.kg-1.min-1) and high plasma glucagon concentrations by infusion of somatostatin plus glucagon (3.0 ng.kg-1.min-1) or by infusion of amino acids alone. All studies were performed under conditions of euglycemic (83-91 mg/dl) hyperinsulinemia (50-80 microU/ml). Hyperglucagonemia significantly increased 1) net amino acid transport from the extracellular into the intracellular space (by approximately 4%), 2) net degradation of amino acids entering the intracellular space (by approximately 40%), and 3) conversion of degraded amino acids into glucose from 0-10% (basal glucagon) to 70-100% (high glucagon). Hyperglucagonemia did not affect the amount of amino acids excreted in the urine (approximately 4%). We conclude that glucagon plays an important role in the disposition of amino acids by increasing their inward transport, their degradation, and their conversion into glucose.

Lower thigh subcutaneous and higher visceral abdominal adipose tissue content both contribute to insulin resistance.

It is well known that visceral adipose tissue (VAT) is associated with insulin resistance (IR). Considerable debate remains concerning the potential positive effect of thigh subcutaneous adipose tissue (TSAT). Our objective was to observe whether VAT and TSAT are opposite, synergistic or additive for both peripheral and hepatic IR. Fifty-two volunteers (21 male/31 female) between 30 and 75 years old were recruited from the general population. All subjects were sedentary overweight or obese (mean BMI 33.0 ± 3.4 kg/m(2)). Insulin sensitivity was determined by a 4-h hyperinsulinemic-euglycemic clamp with stable isotope tracer dilution. Total body fat and lean body mass were determined by dual X-ray absorptiometry. Abdominal and mid-thigh adiposity was determined by computed tomography. VAT was negatively associated with peripheral insulin sensitivity, while TSAT, in contrast, was positively associated with peripheral insulin sensitivity. Subjects with a combination of low VAT and high TSAT had the highest insulin sensitivity, subjects with a combination of high VAT and low TSAT were the most insulin resistant. These associations remained significant after adjusting for age and gender. These data confirm that visceral excess abdominal adiposity is associated with IR across a range of middle-age to older men and women, and further suggest that higher thigh subcutaneous fat is favorably associated with better insulin sensitivity. This strongly suggests that these two distinct fat distribution phenotypes should both be considered in IR as important determinants of cardiometabolic risk.

Partial gene deletion of endothelial nitric oxide synthase predisposes to exaggerated high-fat diet-induced insulin resistance and arterial hypertension.

Nitric oxide (NO) plays a major role in the regulation of cardiovascular and metabolic homeostasis, as evidenced by insulin resistance and arterial hypertension in endothelial NO synthase (eNOS) null mice. Extrapolation of these findings to humans is difficult, however, because eNOS gene deficiency has not been reported. eNOS gene polymorphism and impaired NO synthesis, however, have been reported in several cardiovascular disease states and could predispose to insulin resistance. High-fat diet induces insulin resistance and arterial hypertension in normal mice. To test whether partial eNOS deficiency facilitates the development of insulin resistance and arterial hypertension during metabolic stress, we examined effects of an 8-week high-fat diet on insulin sensitivity (euglycemic clamp) and arterial pressure in eNOS(+/-) mice. When fed a normal diet, these mice had normal insulin sensitivity and were normotensive. When fed a high-fat diet, however, eNOS(+/-) mice developed exaggerated arterial hypertension and had fasting hyperinsulinemia and a 35% lower insulin-stimulated glucose utilization than control mice. The partial deletion of the eNOS gene does not alter insulin sensitivity or blood pressure in mice. When challenged with nutritional stress, however, partial eNOS deficiency facilitates the development of insulin resistance and arterial hypertension, providing further evidence for the importance of this gene in linking metabolic and cardiovascular disease.

Multi-faceted functions of secretory IgA at mucosal surfaces.

Secretory IgA (SIgA) plays an important role in the protection and homeostatic regulation of intestinal, respiratory, and urogenital mucosal epithelia separating the outside environment from the inside of the body. This primary function of SIgA is referred to as immune exclusion, a process that limits the access of numerous microorganisms and mucosal antigens to these thin and vulnerable mucosal barriers. SIgA has been shown to be involved in avoiding opportunistic pathogens to enter and disseminate in the systemic compartment, as well as tightly controlling the necessary symbiotic relationship existing between commensals and the host. Clearance by peristalsis appears thus as one of the numerous mechanisms whereby SIgA fulfills its function at mucosal surfaces. Sampling of antigen-SIgA complexes by microfold (M) cells, intimate contact occurring with Peyer's patch dendritic cells (DC), down-regulation of inflammatory processes, modulation of epithelial, and DC responsiveness are some of the recently identified processes to which the contribution of SIgA has been underscored. This review aims at presenting, with emphasis at the biochemical level, how the molecular complexity of SIgA can serve these multiple and non-redundant modes of action.

Clustering of cardiovascular risk factors mimicking the human metabolic syndrome X in eNOS null mice.

AIMS/HYPOTHESIS: The metabolic syndrome comprises a clustering of cardiovascular risk factors but the underlying mechanism is not known. Mice with targeted disruption of endothelial nitric oxide synthase (eNOS) are hypertensive and insulin resistant. We wondered, whether eNOS deficiency in mice is associated with a phenotype mimicking the human metabolic syndrome. METHODS AND RESULTS: In addition to arterial pressure and insulin sensitivity (euglycaemic hyperinsulinaemic clamp), we measured the plasma concentration of leptin, insulin, cholesterol, triglycerides, free fatty acids, fibrinogen and uric acid in 10 to 12 week old eNOS-/- and wild type mice. We also assessed glucose tolerance under basal conditions and following a metabolic stress with a high fat diet. As expected eNOS-/- mice were hypertensive and insulin resistant, as evidenced by fasting hyperinsulinaemia and a roughly 30 percent lower steady state glucose infusion rate during the clamp. eNOS-/- mice had a 1.5 to 2-fold elevation of the cholesterol, triglyceride and free fatty acid plasma concentration. Even though body weight was comparable, the leptin plasma level was 30% higher in eNOS-/- than in wild type mice. Finally, uric acid and fibrinogen were elevated in the eNOS-/- mice. Whereas under basal conditions, glucose tolerance was comparable in knock out and control mice, on a high fat diet, knock out mice became significantly more glucose intolerant than control mice. CONCLUSIONS: A single gene defect, eNOS deficiency, causes a clustering of cardiovascular risk factors in young mice. We speculate that defective nitric oxide synthesis could trigger many of the abnormalities making up the metabolic syndrome in humans.

Aortobronchial and aortoesophageal fistulae as risk factors in surgery of descending thoracic aortic aneurysms.

OBJECTIVE: Assess outcome of patients with descending thoracic aortic aneurysms complicated by aortobronchial and aortoesophageal fistulae in comparison to patients undergoing repair of aortic aneurysms without fistulae. METHODS: In a consecutive series of 145 patients (age 60 +/- 12 years) with repair of descending thoracic and thoracoabdominal aortic aneurysms, 11 patients (8%; age 63 +/- 9; NS) primarily presented for hematemesis and/or hemoptysis. In 8/11 patients (73%) an aortobronchial fistula was identified, and 3/11 patients (27%) suffered from an aortoesophageal fistula. Five of 11 patients (45%) had undergone previous aortic surgery in the same region. RESULTS: Extent of aortic segments (range 1-8) replaced was 3.1 +/- 1.4 for all versus 2.6 +/- 0.9 for fistulae (NS). Aortic cross clamp time was 38 +/- 22 min for all versus 45 +/- 15 min for fistulae (NS). Mortality at 30 days was 18/145 (12%) for all versus 16/134 (12%) without fistulae versus 2/11 (18%) with fistulae (NS). Paraparesis and or paraplegia was observed in 11/145 (8%) for all versus 10/134 (7%) without fistulae versus 1/11 (9%) for cases with fistulae (NS). Nine additional patients died after hospital discharge, seven without fistulae and two with fistulae (days 80, and 120) bringing the 1-year mortality up to 23/134 (17%) without fistulae versus 4/11 (36%) with fistulae (NS). Further analysis shows that the 1-year mortality accounts for 1/8 patients (13%) with aorto-bronchial fistulae versus to 3/3 patients (100%) with aorto-esophageal fistulae (esophageal versus bronchial fistula: P = 0.018; esophageal versus no fistula: P = 0.006). CONCLUSIONS: Outcome of patients suffering from descending thoracic aortic aneurysms complicated by aorto-bronchial fistulae can be similar to that without fistulae, whereas for cases complicated by aorto-esophageal fistulae the prognosis seems to remain poor even after successful hospital discharge.

Melatonin improves glucose homeostasis and endothelial vascular function in high-fat diet-fed insulin-resistant mice.

Obesity and insulin resistance represent a problem of utmost clinical significance worldwide. Insulin-resistant states are characterized by the inability of insulin to induce proper signal transduction leading to defective glucose uptake in skeletal muscle tissue and impaired insulin-induced vasodilation. In various pathophysiological models, melatonin interacts with crucial molecules of the insulin signaling pathway, but its effects on glucose homeostasis are not known. In a diet-induced mouse model of insulin resistance and normal chow-fed control mice, we sought to assess the effects of an 8-wk oral treatment with melatonin on insulin and glucose tolerance and to understand underlying mechanisms. In high-fat diet-fed mice, but not in normal chow-fed control mice, melatonin significantly improved insulin sensitivity and glucose tolerance, as evidenced by a higher rate of glucose infusion to maintain euglycemia during hyperinsulinemic clamp studies and an attenuated hyperglycemic response to an ip glucose challenge. Regarding underlying mechanisms, we found that melatonin restored insulin-induced vasodilation to skeletal muscle, a major site of glucose utilization. This was due, at least in part, to the improvement of insulin signal transduction in the vasculature, as evidenced by increased insulin-induced phosphorylation of Akt and endoethelial nitric oxide synthase in aortas harvested from melatonin-treated high-fat diet-fed mice. In contrast, melatonin had no effect on the ability of insulin to promote glucose uptake in skeletal muscle tissue in vitro. These data demonstrate for the first time that in a diet-induced rodent model of insulin resistance, melatonin improves glucose homeostasis by restoring the vascular action of insulin.

A new alternative method for testing skin irritation using a human skin model: a pilot study.

Studies assessing skin irritation to chemicals have traditionally used laboratory animals; however, such methods are questionable regarding their relevance for humans. New in vitro methods have been validated, such as the reconstructed human epidermis (RHE) model (Episkin®, Epiderm®). The comparison (accuracy) with in vivo results such as the 4-h human patch test (HPT) is 76% at best (Epiderm®). There is a need to develop an in vitro method that better simulates the anatomo-pathological changes encountered in vivo. To develop an in vitro method to determine skin irritation using human viable skin through histopathology, and compare the results of 4 tested substances to the main in vitro methods and in vivo animal method (Draize test). Human skin removed during surgery was dermatomed and mounted on an in vitro flow-through diffusion cell system. Ten chemicals with known non-irritant (heptylbutyrate, hexylsalicylate, butylmethacrylate, isoproturon, bentazon, DEHP and methylisothiazolinone (MI)) and irritant properties (folpet, 1-bromohexane and methylchloroisothiazolinone (MCI/MI)), a negative control (sodiumchloride) and a positive control (sodiumlaurylsulphate) were applied. The skin was exposed at least for 4h. Histopathology was performed to investigate irritation signs (spongiosis, necrosis, vacuolization). We obtained 100% accuracy with the HPT model; 75% with the RHE models and 50% with the Draize test for 4 tested substances. The coefficients of variation (CV) between our three test batches were <0.1, showing good reproducibility. Furthermore, we reported objectively histopathological irritation signs (irritation scale): strong (folpet), significant (1-bromohexane), slight (MCI/MI at 750/250ppm) and none (isoproturon, bentazon, DEHP and MI). This new in vitro test method presented effective results for the tested chemicals. It should be further validated using a greater number of substances; and tested in different laboratories in order to suitably evaluate reproducibility.