Further insights into diastolic dysfunction in first-trimester trisomy-21 fetuses

OBJECTIVE

To assess fetal cardiac function in first-trimester trisomy-21 fetuses as compared with fetuses with other aneuploidies, euploid fetuses with cardiac defects or isolated increased nuchal translucency (NT) and controls.

METHODS

During a 2.5-year period, NT, ductus venosus (DV) blood flow, diastolic filling time, early filling time, tricuspid flow, tricuspid and mitral valve E/A velocity ratios, left ventricle shortening fraction, left myocardial performance index and fetal heart rate were assessed in fetuses with a crown-rump length between 45 and 84 mm undergoing chorionic villus sampling at our center. Cardiac parameters among study groups were compared with the use of 95% CIs.

RESULTS

The study population comprised 28 fetuses with trisomy 21, 25 with other aneuploidies, 94 euploid fetuses with abnormal findings (27 with cardiac defects, 31 with other structural anomalies and 36 with isolated increased NT) and 271 controls. Trisomy-21 fetuses showed signs of diastolic dysfunction such as increased DV pulsatility index and E/A ratios together with a higher prevalence of tricuspid regurgitation. However, no differences were found in euploid fetuses with cardiac defects or isolated increased NT.

CONCLUSIONS

No signs of cardiac dysfunction were observed in euploid fetuses with increased NT or cardiac defects, while in trisomy-21 fetuses signs of diastolic dysfunction could be potentially attributed to volume overload.

Graphene-based absorber exploiting guided mode resonances in one-dimensional gratings

A one-dimensional dielectric grating, based on a simple geometry, is proposed and investigated to enhance light absorption in a monolayer graphene exploiting guided mode resonances. Numerical findings reveal that the optimized configuration is able to absorb up to 60% of the impinging light at normal incidence for both TE and TM polarizations resulting in a theoretical enhancement factor of about 26 with respect to the monolayer graphene absorption (≈2.3%). Experimental results confirm this behavior showing CVD graphene absorbance peaks up to about 40% over narrow bands of a few nanometers. The simple and flexible design points to a way to realize innovative, scalable and easy-to-fabricate graphene-based optical absorbers.

Stable planar mesoscopic photonic crystal cavities

Mesoscopic self-collimation (MSC) in mesoscopic photonic crystals with high reflectivity is exploited to realize a novel high Q-factor cavity by means of mesoscopic PhC planar mirrors. These mirrors efficiently confine a mode inside a planar Fabry-Perot-like cavity, that results from a beam focusing effect that stabilizes the cavity even for small beam sizes, resembling the focusing behavior of curved mirrors. Moreover, they show an improved reflectivity with respect to their standard distributed Bragg reflector counterparts that allows higher compactness. A Q-factor higher than 10⁴ has been achieved for an optimized 5-period-long mirror cavity. The optimization of the Q-factor and the performances in terms of energy storage, field enhancement, and confinement are detailed.

Is nuchal translucency a useful aneuploidy marker in fetuses with crown-rump length of 28-44 mm?

OBJECTIVE

To investigate whether increased nuchal translucency (NT) in fetuses with a crown-rump length (CRL) below 45 mm needs to be re-evaluated at a later stage, or whether the early NT measurement can be used effectively as an aneuploidy marker.

METHODS

This was a prospective cohort study including all singleton fetuses with a CRL between 28 and 44 mm, scanned in our center during 2002-2012. The CRL, NT, fetal karyotype (when available) and pregnancy outcome were recorded. NT reference ranges were constructed using the Lambda-Mu-Sigma (LMS) method in non-referred pregnancies after exclusion of chromosomal anomalies. The 95(th) percentile was used to calculate detection rates for chromosomally abnormal fetuses.

RESULTS

NT was successfully measured in 643 of 672 fetuses with a CRL of 28-44 mm. Subsequent cytogenetic analysis revealed 11 cases of trisomy 21, 14 cases of trisomy 13 or 18, three cases of monosomy X, three sex trisomies, three triploidies and 12 balanced anomalies. NT was above the 95(th) percentile in 64% of the fetuses with trisomy 21, in 71% with trisomy 13 or 18 and in all three cases of monosomy X.

CONCLUSION

NT appears to be useful as a marker for the early detection of fetal trisomies at 9-10 weeks' gestation (28-44 mm CRL).

Nonlinear control of absorption in one-dimensional photonic crystal with graphene-based defect

Perfect, narrow-band absorption is achieved in an asymmetric 1D photonic crystal with a monolayer graphene defect. Thanks to the large third-order nonlinearity of graphene and field localization in the defect layer we demonstrate the possibility to achieve controllable, saturable absorption for the pump frequency.

First-trimester detection of major cardiac defects with the use of ductus venosus blood flow

OBJECTIVE

To assess the best method of combining fetal nuchal translucency (NT) and ductus venosus (DV) blood flow measurements in the detection of major cardiac defects in chromosomally normal fetuses during the first-trimester scan.

METHODS

During an 8-year period NT and DV blood flow were routinely assessed at 11-14 weeks' gestation. Only chromosomally normal singleton pregnancies were included in the study. When a cardiac defect was suspected, or when increased fetal NT and/or absent or reversed (AR) A-wave in the DV was observed, early fetal echocardiography was offered. Data on routine second- and third-trimester scans, neonatal follow-up or postmortem examination were obtained from hospital records. The detection and false-positive rates for all major cardiac defects were calculated for several screening strategies, including: NT or DV pulsatility index for veins (DV-PIV) above a fixed normal centile; AR A-wave; risk based on NT and DV-PIV or A-wave velocity above a fixed normal centile; and combinations of these strategies.

RESULTS

The study population included 37 chromosomally normal fetuses with a major cardiac defect and 12 799 unaffected pregnancies. Fetal NT above the 95(th) or the 99(th) centile and AR A-wave was observed in 40, 27 and 39% of the fetuses with major cardiac defects, respectively. A 47% detection rate with a 2.7% false-positive rate was obtained when AR A-wave or NT above the 99(th) centile was used as the selection criterion.

CONCLUSIONS

Half of major fetal cardiac defects could be detected in the first trimester if NT and DV Doppler are used to select 2.7% of the general pregnant population for extended fetal echocardiography.

Clinical application of midtrimester non-invasive fetal RHD genotyping and identification of RHD variants in a mixed-ethnic population

OBJECTIVE

This study aims to assess the suitability of non-invasive prenatal RHD genotyping in non-immunized midtrimester pregnant women from a mixed ethnic population, to prevent unnecessary anti-D immunoglobulin prophylaxis and to identify RHD variants

METHODS

Rhesus D-negative pregnant women were offered fetal RHD genotyping at 24 gestational weeks. A total of 284 samples were tested for RHD status using multiplex rt-PCR amplification of exons 5 and 7 of the RHD gene and exons 6 and 10 in selected cases. Women carrying RHD-negative fetuses were counseled about their option to avoid routine antenatal anti-D immunoglobulin administration. Diagnostic accuracy of RHD genotyping was compared with postnatal Rhesus D serotyping.

RESULTS

A total of 184 positives (65%), 91 negatives (32%) and 7 cases (2.5%) compatibles with RHD variants were detected by RHD genotyping. No false negative results were found, and a single false positive was observed in a twin pregnancy. Genotyping was accepted when offered by 94% of women (284/302), and anti-D immunoglobulin was avoided in 95% (90/95) of RHD-negative fetuses.

CONCLUSIONS

Non-invasive routine antenatal RHD genotyping at 24 weeks of pregnancy is a highly accurate method, resulting in the avoidance of 95% of unnecessary administrations of anti-D immunoglobulin, with no false negative results.

Rectus sheath haematoma: are there prognostic risk factors of haemodynamic instability motivating an early operative treatment?

PURPOSE

Rectus sheath haematoma (RSH) is an uncommon condition caused by lesion of the superior or inferior epigastric arteries or their branches or by rupture of the rectus muscle. Treatment is usually supportive; however, if haemodynamic compromise develops, intravascular embolisation or surgery may be required. Furthermore, in some cases, bleeding may be so conspicuous that it can determine the patient's death before an adequate treatment is performed. We performed a retrospective study on 78 consecutive patients with the diagnosis of RSH admitted to the General Surgery Unit of our hospital between January 2000 and December 2010 in order to identify possible prognostic risk factors that could affect the operational approach before the onset of haemodynamic instability.

METHODS

Demographic characteristics, patient history, laboratory and diagnostic imaging examinations were investigated. The variables considered were: gender, age, anti-coagulation or anti-platelet therapy, trauma, international normalised ratio (INR) and bleeding time in the first 72 h of observation and concomitant diseases. The data were used for statistical analysis.

RESULTS

Sixty patients received a conservative treatment, while 18 underwent operative treatment for haemodynamic instability (embolisation in 2 patients and surgery in 16 patients). Three of these 18 patients (17 %) died for consumption coagulopathy after surgery. None of the variables included in the univariate statistical analysis was significant (p = ns).

CONCLUSION

Ultrasonography or computed tomography are the most common methods used to establish the diagnosis of RSH, so it is no longer a diagnostic dilemma. Most patients can be treated conservatively and an operative treatment is justified only in case of haemodynamic instability. Our retrospective study could not identify any prognostic risk factor of haemodynamic instability in RSH. We believe that only a close observation of the patients with RSH and "common sense" can prevent a possible fatal outcome.

First-trimester detection of structural abnormalities and the role of aneuploidy markers

OBJECTIVES

To determine the sensitivity of first-trimester ultrasound for diagnosing different structural anomalies in chromosomally normal pregnancies, and to establish the role of aneuploidy markers in the detection of abnormalities.

METHODS

This was a retrospective study of chromosomally normal singleton pregnancies with an 11-14-week scan performed in our center during 2002-2009. The ultrasound examination included an early fetal anatomy survey and assessment of nuchal translucency, ductus venosus blood flow and nasal bone.

RESULTS

Among 13 723 scanned first-trimester pregnancies with no genetic anomalies and complete follow-up, 439 fetuses (3.2%) were found to present with structural anomalies (194 with major anomalies and 245 with only minor anomalies). Forty-nine per cent of major structural anomalies were detected during the first-trimester scan, the highest rates corresponding to acrania (17/17), holoprosencephaly (three of three), hypoplastic left heart syndrome (10/10), omphalocele (six of six), megacystis (seven of eight) and hydrops (eight of nine). Higher than expected detection rates were obtained for skeletal (69%) and cardiac (57%) defects, coincidentally showing the highest presence of an increased nuchal translucency or abnormal ductus venosus blood flow (38% and 52%, respectively). The finding of an absent nasal bone did not appear to be associated with structural defects.

CONCLUSION

About half of major structural abnormalities can be diagnosed in the first trimester. Increased nuchal translucency or abnormal ductus venosus blood flow appear to be associated with cardiac and skeletal defects and may facilitate early detection.

Focus on abdominal rectopexy for full-thickness rectal prolapse: meta-analysis of literature

BACKGROUND

Laparoscopic rectopexy to treat full-thickness rectal prolapse has proven short-term benefits, but there are few long-term follow-up and functional outcome data available. Using meta-analysis techniques, this study was designed to evaluate long-term results of open and laparoscopic abdominal procedures to treat full-thickness rectal prolapse in adults.

METHODS

A literature review was performed using the National Library of Medicine's PubMed database. All articles on abdominal rectopexy patients with a follow-up longer than 16 months were considered. The primary end point was recurrence of rectal prolapse, and the secondary end points were improvement in incontinence and constipation. A random effect model was used to aggregate the studies reporting these outcomes, and heterogeneity was assessed.

RESULTS

Eight comparative studies, consisting of a total of 467 patients (275 open and 192 laparoscopic), were included. Analysis of the data suggested that there is no significant difference in recurrence, incontinence and constipation improvement between laparoscopic abdominal rectopexy and open abdominal rectopexy. Considering non-comparative trials, the event rate for recurrence was similar in open and laparoscopic suture rectopexy studies and in open and laparoscopic mesh rectopexy trials. Improvement in constipation after the intervention was not statistically significant except for open mesh repair; postoperative improvement in incontinence was statistically significant after laparoscopic procedures and open mesh rectopexy.

CONCLUSIONS

Laparoscopic abdominal rectopexy is a safe and feasible procedure, which may compare equally with the open technique with regard to recurrence, incontinence and constipation. However, large-scale randomized trials, with comparative, strong methodology, are still needed to identify outcome measures accurately.

New trends in nutritional status assessment of cancer patients

BACKGROUND

Nutritional status assessment and support should be considered a valuable measure within the overall oncology strategy. Despite extensive research in the field of clinical nutrition, definite guidelines to base rational nutritional assessment and support in cancer patients are still debated. This review examines different approaches to nutritional status in cancer patients.

DESIGN

The assessment of nutritional status is usually based on anthropometric measures, biochemical or laboratory tests, clinical indicators and dietary assessment. At present, body composition (BC) is rarely measured in the clinical setting because it is thought to be too unmanageable and time-consuming. However, using new technologies, the estimation of fat, lean and body fluids, that is significant in the management of nutrition therapies in oncology, has become easy. The present study evaluates the different methods of nutrition assessment today available, especially body composition (BC) measurements. Furthermore, nutrition assessment, relevance of nutritional support and choice of nutritional strategy, in surgical patients, are discussed.

DISCUSSION

Given the clinical relevance of nutritional intervention in patients' quality of life, the nutritional status assessment has a key role in oncological and surgical practice and should include BC assessment in order to tailor nutritional treatment to patients' individual requirements. Furthermore, administration of the supplemented diet before and after surgery seemed to be the best strategy to reduce complications and length of hospital stay.

[Endometriosis: aetiopathogenetic basis]

Endometriosis, defined by the presence of endometrial tissue outside the uterine cavity, is a common condition affecting 10% of women in the reproductive age. Menstrual factors reported to increase risk include dysmenorrhea, early menarche, and shorter cycle lengths. The theory of retrograde menstruation with implantation of endometrial fragments, in conjunction with peritoneal factors to stimulate cell growth is the most widely accepted. There is a growing body of evidence that immunological factors and angiogenesis play a key role in the pathogenesis of endometriosis. In women with endometriosis, there appears to be an alteration in the function of peritoneal macrophages, natural killer cells and lymphocytes, with production of growth factors and inflammatory mediators in the peritoneal fluid. Survival, adhesion, proliferation, invasion and vascularization of endometrial tissue in abdominal cavity may be the consequence of retrograde menstruation and referred to as implantation theory.