[Surgical wound infections in newborns: analysis of risk factors]

The incidence of surgical wound infections in neonates is high and it has an associated morbidity which extends hospital stay and gets a worse prognosis. The purpose of this study is to analyze the risk factors associated with the development of surgical wound infection and to identify susceptible patients with modifiable factors.

MATERIAL AND METHODS

Case-control study of 90 surgical procedures underwent in newborns. We analyze pre-, intra- and postoperative risk factors.

MAIN RESULTS

There are statically significant differences in terms of wound infection in dirty and contaminated surgery, reoperation, lavage of abdominal cavity, preoperative hospital stay longer than 8 days and wound closure with reabsorbable material. Furthermore, the surgical site infection is more likely in preterms patients, with a previous positive culture infection and the use of invasive devices as mechanical ventilation or central venous access. We found no relationship between wound infection and surgical time, bleeding during surgery and preoperative skin preparation with antiseptics.

CONCLUSIONS

Reoperative patients, in which dirty and contaminated surgery is performed, absorbable material for skin is used and who have a preoperative hospital stay longer than 8 days, are in risk of developping wound infection and they will require an aggressive antibiotic treatment and special postsurgical care.

An evolutionary test of the isoform switching hypothesis of functional progesterone withdrawal for parturition: humans have a weaker repressive effect of PR-A than mice

BACKGROUND

A decrease in maternal serum progesterone (P4) concentrations precedes the onset of labor in most placental mammals. Humans differ by maintaining high levels of P4 throughout birth. Parturition in humans probably includes mechanisms that undercut the pregnancy sustaining function of P4. One attractive hypothesis is the isoform switching hypothesis (ISH). ISH is supported by in vitro evidence that progesterone receptor isoform A (PR-A) inhibits PR-B and that the PR-A/PR-B ratio increases towards term.

MATERIALS AND METHODS

Here, we test the hypothesis that isoform switching is an adaptation to high levels of P4 at term, predicting that, in humans, PR-A mediated repression of PR-B is stronger than in mouse. We use reporter assays with human and mouse PRs to detect species differences in the repressive effects of PR-A.

RESULTS

We found that human PR-B is less sensitive to repression by human PR-A than mouse PR-B, contrary to our prediction. The difference between human and mouse PR-B sensitivity is most pronounced at PR-A/PR-B ratios typical for the preterm myometrium.

CONCLUSIONS

Our results are inconsistent with the ISH. We speculate that, instead, the lower sensitivity of human PR-B to PR-A may be relevant for the maintenance of pregnancy at high progesterone levels and increasing PR-A concentrations towards term.

The evolution of menstruation: a new model for genetic assimilation: explaining molecular origins of maternal responses to fetal invasiveness

Why do humans menstruate while most mammals do not? Here, we present our answer to this long-debated question, arguing that (i) menstruation occurs as a mechanistic consequence of hormone-induced differentiation of the endometrium (referred to as spontaneous decidualization, or SD); (ii) SD evolved because of maternal-fetal conflict; and (iii) SD evolved by genetic assimilation of the decidualization reaction, which is induced by the fetus in non-menstruating species. The idea that menstruation occurs as a consequence of SD has been proposed in the past, but here we present a novel hypothesis on how SD evolved. We argue that decidualization became genetically stabilized in menstruating lineages, allowing females to prepare for pregnancy without any signal from the fetus. We present three models for the evolution of SD by genetic assimilation, based on recent advances in our understanding of the mechanisms of endometrial differentiation and implantation. Testing these models will ultimately shed light on the evolutionary significance of menstruation, as well as on the etiology of human reproductive disorders like endometriosis and recurrent pregnancy loss.

Clinical validation of the European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) II criteria in an open-access unit: a prospective study

BACKGROUND AND STUDY AIMS

The European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE I) criteria were recently updated (EPAGE II), but no prospective studies have used these criteria in clinical practice. The aim of the current study was to validate the EPAGE II criteria in an open-access endoscopy unit.

PATIENTS AND METHODS

A prospective observational study was conducted in an open-access endoscopy unit at a tertiary care referral center. Consecutive outpatients (n = 1004; mean age 58.9 ± 13.1 years; 45 % men) were referred for diagnostic colonoscopy between September 2009 and February 2010. The appropriateness of colonoscopy was assessed based on EPAGE II criteria, and the relationship between appropriateness and both referral doctor and detection of significant lesions was examined. The effectiveness of EPAGE II criteria in assessing appropriateness was measured by means of sensitivity, specificity, and positive and negative predictive values for detecting significant lesions.

RESULTS

Colonoscopic cecal intubation was achieved in 956 patients (95.2 %). Most referral doctors were gastroenterologists (58.0 %) and the most common indication was colorectal cancer (CRC) screening (35.2 %). EPAGE II criteria were applicable in 968 patients (96.4 %); of these patients, the indication was appropriate in 778 (80.4 %), inappropriate in 102 (10.5 %), and uncertain in 88 (9.1 %). Patients with appropriate or uncertain indications based on EPAGE II criteria had more relevant endoscopic findings than those with inappropriate indications (38.8 % vs. 24.5 %; OR 1.95, 95 %CI 1.22 - 3.13; P < 0.005). Sensitivity and negative predictive value of EPAGE II criteria for detecting significant lesions were 93.1 % (95 %CI 90 % - 96 %) and 75.5 % (95 %CI 67 % - 84 %), respectively, whereas for advanced neoplastic lesions these values were 98.0 % (95 %CI 95 % - 100 %) and 98.0 % (95 % CI 95 % - 100 %), respectively. Adherence to EPAGE II recommendations was an independent predictor of finding a significant lesion (OR 1.93, 95 %CI 1.20 - 3.11; P = 0.007).

CONCLUSIONS

EPAGE II is a simple, valid score for detecting inappropriate colonoscopies in clinical practice.

Improving imbalanced scientific text classification using sampling strategies and dictionaries

Many real applications have the imbalanced class distribution problem, where one of the classes is represented by a very small number of cases compared to the other classes. One of the systems affected are those related to the recovery and classification of scientific documentation.

Sampling strategies such as Oversampling and Subsampling are popular in tackling the problem of class imbalance. In this work, we study their effects on three types of classifiers (Knn, SVM and Naive-Bayes) when they are applied to search on the PubMed scientific database.

Another purpose of this paper is to study the use of dictionaries in the classification of biomedical texts. Experiments are conducted with three different dictionaries (BioCreative, NLPBA, and an ad-hoc subset of the UniProt database named Protein) using the mentioned classifiers and sampling strategies.

Best results were obtained with NLPBA and Protein dictionaries and the SVM classifier using the Subsampling balancing technique. These results were compared with those ob- tained by other authors using the TREC Genomics 2005 public corpus.

Cross-linked ultra-high-molecular weight polyethylene liner and ceramic femoral head in total hip arthroplasty: a prospective study at 5 years follow-up

BACKGROUND

Recent data indicate that enhanced wear resistance can be obtained with new cross-linked ultra-high-molecular weight polyethylene (CL-UHMWPE) liners, in comparison with previous-generation liners. The current prospective, cohort study was undertaken to analyse whether the use of a new CL-UHMWPE (Rexpol) results in a lower wear rate than ultra-high-molecular weight polyethylene (UHMWPE) in a group of similar patients undergoing total hip arthroplasty (THA). This study provides the first clinical data with this particular CL-UHMWPE.

METHODS

Between January 2001 and December 2001, patients underwent THA with biconical threaded cups and ceramic femoral heads using either a CL-UHMWPE liner (n = 50) or a regular UHMWPE liner (n = 57). At the time of the final 5-year evaluation, there were 48 patients available in the CL-UHMWPE and 54 patients available in the UHMWPE group.

RESULTS

After a mean 5.6 years follow-up, there were no significant differences between the groups in Harris Hip Score outcomes. However, there was a 69.1% decrease in wear at 5 years for the CL-UHMWPE group in comparison with the UHMWPE group (p < 0.01).

CONCLUSION

The use of CL-UHMWPE significantly reduced the risk of polyethylene wear in patients undergoing THA with biconical threaded cups and ceramic femoral heads. Further follow-up is needed to determine how this will influence long-term outcomes.

The contribution of order to the phase stability of β-Cu-Zn-Al

We report the lower stability temperatures, T(β), of the body centred cubic (bcc) β phase for several alloys along the line of compositions Cu(0.76-0.5x)-Zn(x)-Al(0.24-0.5x), corresponding to a constant electron to atom ratio e/a = 1.48. The results have been obtained by means of differential scanning calorimetry measurements at various heating rates. The influence of atomic ordering on the stability of the bcc structure was evaluated using a mixed approach involving Monte Carlo simulations and the cluster variation method. It was found that the chemical short- and long-range ordering contributes to the free energy of the alloy by an amount of around 200k(B).

[Cold-knife retrograde endoscopic endopyelotomy (Cutting-Balloon) in children with ureteropelvic junction obstruction: early results]

BACKGROUND

To present our early experience in the use of Cutting-Balloon for the treatment of resistant or relapsed ureteropelvic junction obstruction (UPJO) after a prior endourological retrograde high-pressure balloon dilatation (RHPBD).

MATERIALS AND METHODS

Patients with progressive hydronephrosis and impaired drainage of the renal pelvis on a diuretic renal scan were treated with RHPBD. In those patients with resistant UPJO (waist persistence after dilatation) or relapsed UPJO, we consider using a Cutting-Balloon as an alternative to our current protocol (second RHPBD or open surgery). A JJ stent was placed following the procedure, and removed at 4-6 weeks. Outcomes were evaluated 3 and 6 months after stent removal, and every 6 months thereafter, repeating renal ultrasonography and diuretic renal scan.

RESULTS

Between 2008 and 2010 we treated with Cutting-balloon 5 patients (4 male, 1 woman) with UPJO (left side: 3 cases, right side: 1 case, bilateral: 1 case) with a mean age of 3 months (range, 10 days to 7 months). Four cases had resistant UPJO and 1 case relapsed UPJO. After the procedure, and during the follow-up period of 12 months (range, 9-18 months), no further treatment was necessary. Four patients had improvement of hydronephrosis, with normal relative renal function (RRF). One patient (RRF 18% before treatment) did not improve. No periprocedural complications occurred.

CONCLUSIONS

Cutting-balloon retrograde endopyelotomy seems to be a treatment with encouraging early results for resistant and relapsed UPJO, after a prior RHPBD. We believe that further clinical evaluation is needed to confirm these findings.

[Role of peritoneal drainage in necrotizing enterocolitis in critical infants with extremely low birth weight]

INTRODUCTION

Peritoneal drainage is one of the options for treatment in necrotizing enterocolitis (NEC). Currently its role is controversial as an alternative to laparotomy in low birthweight and mortality associated with both procedures is high (35-55%).

MATERIAL AND METHODS

We reviewed 30 low-weight premature (< 1000 g) with NEC treated surgically. We evaluate the hemodynamic, respiratory and metabolic status of the patients, as well as multi-organ involvement and the need for inotropic drugs. These data were analyzed previos to surgery and at 6 and 12 hours. We divided the sample into two groups: those who underwent peritoneal drainage (PD) input or laparotomy (LAP).

RESULTS

In the series the average birth weight was 754 +/- 156 g and gestational age was 26.1 +/- 2.1 weeks. We carry on 10 peritoneal drainage and 20 laparotomies. The DP group before the intervention showed increased heart rate, FiO2 and acidosis (p < 0.05). The needs of dopamine were similar in both groups. Following the peritoneal drainage, we found breathing improvement (adequate ventilation and oxygenation, decreased FiO2) and hemodynamic improvement (blood pressure maintained, reduced heart rate, reduced requirements for dopamine) at 6 and 12 h. DP was not the definitive treatment in any of the patiens, and all survivors (80%) of this group required further laparotomy. 62% of them died. Overall mortality was 47% (70% DP and 35% LAP, p = 0.07).

CONCLUSIONS

Peritoneal drainage allowed the stabilization of low-weight premature in critical condition. The hemodynamic and respiratory stabilization was transient and did not prevent the definitive surgical treatment, although it improved the conditions for doing so. In our series, the peritoneal drainage did not improve long-term survival, questioning its role as an alternative to surgery for NEC.

Vaginal progesterone reduces the rate of preterm birth in women with a sonographic short cervix: a multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVES

Women with a sonographic short cervix in the mid-trimester are at increased risk for preterm delivery. This study was undertaken to determine the efficacy and safety of using micronized vaginal progesterone gel to reduce the risk of preterm birth and associated neonatal complications in women with a sonographic short cervix.

METHODS

This was a multicenter, randomized, double-blind, placebo-controlled trial that enrolled asymptomatic women with a singleton pregnancy and a sonographic short cervix (10-20 mm) at 19 + 0 to 23 + 6 weeks of gestation. Women were allocated randomly to receive vaginal progesterone gel or placebo daily starting from 20 to 23 + 6 weeks until 36 + 6 weeks, rupture of membranes or delivery, whichever occurred first. Randomization sequence was stratified by center and history of a previous preterm birth. The primary endpoint was preterm birth before 33 weeks of gestation. Analysis was by intention to treat.

RESULTS

Of 465 women randomized, seven were lost to follow-up and 458 (vaginal progesterone gel, n=235; placebo, n=223) were included in the analysis. Women allocated to receive vaginal progesterone had a lower rate of preterm birth before 33 weeks than did those allocated to placebo (8.9% (n=21) vs 16.1% (n=36); relative risk (RR), 0.55; 95% CI, 0.33-0.92; P=0.02). The effect remained significant after adjustment for covariables (adjusted RR, 0.52; 95% CI, 0.31-0.91; P=0.02). Vaginal progesterone was also associated with a significant reduction in the rate of preterm birth before 28 weeks (5.1% vs 10.3%; RR, 0.50; 95% CI, 0.25-0.97; P=0.04) and 35 weeks (14.5% vs 23.3%; RR, 0.62; 95% CI, 0.42-0.92; P=0.02), respiratory distress syndrome (3.0% vs 7.6%; RR, 0.39; 95% CI, 0.17-0.92; P=0.03), any neonatal morbidity or mortality event (7.7% vs 13.5%; RR, 0.57; 95% CI, 0.33-0.99; P=0.04) and birth weight < 1500 g (6.4% (15/234) vs 13.6% (30/220); RR, 0.47; 95% CI, 0.26-0.85; P=0.01). There were no differences in the incidence of treatment-related adverse events between the groups.

CONCLUSIONS

The administration of vaginal progesterone gel to women with a sonographic short cervix in the mid-trimester is associated with a 45% reduction in the rate of preterm birth before 33 weeks of gestation and with improved neonatal outcome.

[Simplification of the surgical treatment of a hidden penis]

INTRODUCTION

The treatment of a hidden penis consists of completely and effectively exteriorizing the penile shaft from a functional and aesthetic point of view.

PATIENTS AND METHODS

Over a period of 15 months (02/2008-05/2009), we treated 7 children (mean age 4.6 years) with hidden penis (five had a buried penis, one had a webbed penis and another a trapped penis) using the Borsellino reconstruction technique modified with an "S" dorsal incision. We performed a pubic lipectomy in one patient through the same incision. Surgical indication was for aesthetic reasons in all the cases, secondary phimosis in four, repeated balanitis in one and pain in another.

RESULTS

Hospital stay was 24 hours. With a short-term follow-up (1-12 months), we detected the following complications: partial recurrence, post-surgical lymphedema and hypertrophic scarring, each of them in one case. Patients and parents were satisfied with the result.

CONCLUSIONS

The technique that we present achieves good cosmetic results and has few immediate complications. The substitution of the two dorsal incisions with one "S" incision allows simultaneous lipectomy without the need for another incision.