Prediction of labor using non-invasive Laplacian EHG recordings

Non-invasive electrohysterogram (EHG) recordings could be used as an alternative technique for monitoring uterine dynamics. Bipolar recordings of EHG have proven to provide valuable information to predict labor. Recently it has been stated that uterine EHG bursts could also be identified in Laplacian recordings on abdominal surface. Taking into account that Laplacian potential technique permits to acquire more localized electrical activity than conventional recordings; these recordings could also be helpful for deducing uterine contraction efficiency. The aim of this paper is to examine the feasibility of Laplacian potential EHG recording for labor prediction and to compare it with monopolar recordings. To this purpose, a total of 42 EHG recordings were acquired from women of similar gestational age: 29 antepartum patients, and 13 patients in labor. Then linear and non-linear classifiers have been implemented using EHG burst parameters as input features. Experimental results show significant differences in temporal and spectral parameters in both monopolar and Laplacian potential recordings between the two groups. In addition, support vector machine based classifier achieved an accuracy of 93% for labor prediction for monopolar recordings, 92% for bipolar recordings and 91% for Laplacian potential.

[Influence of pregnancy on refractive parameters after LASIK surgery]

OBJECTIVES

Different ocular changes and complications of refractive surgery such as photorefractive keratectomy (PRK) due to pregnancy have been described in the last few years. However there is no information about the possible problems of laser in situ keratomileusis (LASIK) in pregnant women. Our objective was to study how physiological changes secondary to pregnancy could alter the refractive situation in pregnant women who have undergone LASIK surgery. We show the results obtained due to the changes between the first two trimesters of the pregnancy.

METHODS

A prospective and observational study was conducted in which one study group, made up of 9 patients who had undergone LASIK surgery before becoming pregnant, was compared with a control group of 9 patients with non-surgically corrected refractive problems. The following measurements were made in both groups in the first and second trimesters of the pregnancy; visual acuity, the best corrected visual acuity, tonometry, ocular anatomical characteristics by biometry, and refractive and corneal study by Pentacam(®).

RESULTS

Signicant changes were observed in the cylinder and spherical equivalent between the two trimesters in both groups. Visual acuity and spherical equivalent show a strong trend towards worsening, which was more significant in the study group. The patients of this group who had a larger pre-surgical defect showed lower modifications during the six first months of pregnancy.

CONCLUSIONS

The majority of women who require laser refractive surgery are are between 20-30 years old, thus in many cases corneal surgery is followed by at least one pregnancy, with different possible ophthalmological effects. The conclusions that may be derived from this study are that the assessment of the refractive changes in surgically operated corneas may be biomechanically weakened on being subjected to physiological hormone stimulation as happens during gestation.

Recording of electrohysterogram laplacian potential

Preterm birth is the main cause of the neonatal morbidity. Noninvasive recording of uterine myoelectrical activity (electrohysterogram, EHG) could be an alternative to the monitoring of uterine dynamics which are currently based on tocodynamometers (TOCO). The analysis of uterine electromyogram characteristics could help the early diagnosis of preterm birth. Laplacian recordings of other bioelectrical signals have proved to enhance spatial selectivity and to reduce interferences in comparison to monopolar and bipolar surface recordings. The main objective of this paper is to check the feasibility of the noninvasive recording of uterine myoelectrical activity by means of laplacian techniques. Four bipolar EHG signals, discrete laplacian obtained from five monopolar electrodes and the signals picked up by two active concentric-ringed-electrodes were recorded on 5 women with spontaneous or induced labor. Intrauterine pressure (IUP) and TOCO were also simultaneously recorded. To evaluate the uterine contraction detectability of the different noninvasive methods in comparison to IUP the contractions consistency index (CCI) was calculated. Results show that TOCO is less consistent (83%) than most EHG bipolar recording channels (91%, 83%, 87%, and 76%) to detect the uterine contractions identified in IUP. Moreover laplacian EHG signals picked up by ringed-electrodes proved to be as consistent (91%) as the best bipolar recordings in addition to significantly reduce ECG interference.

DIAGNOSIS, MANAGEMENT AND PROGNOSIS OF VAGINAL EROSION AFTER TRANSOBTURATOR SUBURETHRAL TAPE PROCEDURE USING A NONWOVEN THERMALLY BONDED POLYPROPYLENE MESH

PURPOSE

We studied the diagnosis, management and prognosis of vaginal mesh erosion using a thermally bonded nonwoven polypropylene mesh in a transobturator suburethral tape procedure for the surgical treatment of stress urinary incontinence in women.

MATERIALS AND METHODS

A total of 65 patients diagnosed with stress urinary incontinence underwent a transobturator suburethral tape procedure with a fusion welded, nonwoven, nonknitted polypropylene mesh, with or without a central silicone coated section, at our institution. All women were followed and if vaginal erosion was diagnosed, cystoscopy and vaginoscopy were performed, the mesh was partially or completely removed and, if necessary, posterior cough test and urodynamic study were performed.

RESULTS

Of the 65 patients 9 (13.8%) were diagnosed with vaginal erosion at the vaginal incision during a relatively long postoperative period (mean 290 days). All presented with vaginal discharge and 1 had a severe complication (obturator abscess). Complete mesh removal was necessary in 8 patients and only 2 (22%) had recurrent stress urinary incontinence.

CONCLUSIONS

A 13.8% rate of vaginal mesh erosion using a nonwoven thermally bonded polypropylene mesh was reported. This complication was probably due to the characteristics of the mesh and not to the transobturator approach. Complete removal of the tape is recommended and the continence status prognosis is good (78%).

Epstein-Barr virus positivity in primary vaginal lymphoma

BACKGROUND

Primary non-Hodgkin lymphoma (NHL) of the vagina is a rare location. Its association with the Epstein-Barr virus (EBV) has been only reported in another case. We present a new case, emphasizing the oncogenetic relevance of EBV.

CASE REPORT

A 45-year-old woman with a pelvic pain revealed in her vaginal inspection a thick and hard vaginal plug with a "paving stone" appearance. The biopsy reported a vaginal non-Hodgkin lymphoma type B of intermediate cell, with positive result for EBV. After treatment, a complete remission was obtained.

CONCLUSION

The EBV is the main responsible for the non-Hodgkin lymphoma; classified as a group I carcinogen, it has been associated with a variety of neoplastic tumors, although it is unusual with extranodal type B diffuse lymphoma.

Antibody response and antigen-specific gamma-interferon profiles of vaccinated and unvaccinated pregnant sheep experimentally infected with Brucella melitensis

It is well known that the immune response in sheep against Brucella melitensis is subject to individual variation, depending on diverse factors. It bears asking whether these factors (e.g. clinical disease, active infection, state of previous immunity), when affecting a group, can cause variation in the performance of different diagnostic tests. To clarify some of the circumstances in which this immune response can vary, we examine the immune-response profile of sheep protected against the clinical disease by prior vaccination with strain Rev. 1 in comparison with the profile of unprotected females showing the classical brucellosis symptoms. An experimental infection was provoked at midpregnancy under controlled conditions of both non-vaccinated (n=7) and previously Rev.1-vaccinated ewes (n=5). Their immune response was monitored from 7 to 9 weeks before abortion or normal birth to 30 weeks afterwards. Antibody response was assessed by classical tests (Rose Bengal test, complement fixation test (CFT)) in comparison with other diagnostic tests (indirect ELISA (iELISA), competitive ELISA (cELISA), fluorescence polarization assay (FPA), immunocapture test (ICT)). In addition, the cell-mediated immune response was indirectly evaluated by the in vitro antigen-specific release of gamma-interferon. The antibody levels and antigen-specific gamma-IFN profile of the non-vaccinated ewes having the disease and excreting the pathogen was notably high and differed significantly (P<0.05 or P<0.01) from those of vaccinated ewes that neither contracted brucellosis nor excreted the pathogen. In general, all the tests detect the infection in the non-vaccinated ewes with substantial effectiveness. It can be concluded that the high levels of circulating antibodies and of antigen-specific gamma-IFN are related to active Brucella infection. Similarly, the state of protection against the disease, but not necessarily against infection, due to a previous immunization with the Rev. 1 vaccination, appears to be responsible for a low level of detectable immune response. Nevertheless, the design of the study limits conclusions to pregnant ewes and cannot be extrapolated to non-pregnant ewes or rams. Likewise, the study provides no information on animals which are carriers of B. melitensis.

Duration of ruptured membranes and extended labor are risk factors for HIV transmission

OBJECTIVES

To determine the effects of duration of ruptured membranes (DRM) and duration of labor in HIV transmission.

METHODS

A retrospective cohort study of 366 HIV-infected pregnant women and their infants analyzed the effects of these two variables; the cut-off point for transmission increase was estimated using a ROC curve. A multivariate analysis was performed with the most important risk factors according to the literature: maternal age, lymphocyte count, use of invasive procedures during gestation, antiretroviral treatment during pregnancy and labor, mode of delivery, newborn weight, DRM, labor duration, and the interaction of these last two factors.

RESULTS

The cut-off points were estimated at 6 h for DRM and at 5 h for labor duration. A lymphocyte count below 500 cells/ml, use of invasive procedures, use of antiretroviral treatment during pregnancy and interaction between DRM, and labor duration remained significant in perinatal HIV transmission (P<0.05).

CONCLUSIONS

An increased DRM increased perinatal HIV transmission when it was associated with prolonged labor.

Comparison between two strategies for umbilical cord blood collection

The use of cord blood (CB) for transplantation has increased greatly in recent years. The collection strategy is the first step in collecting good-quality CB units. There are two main techniques for collecting CB from the umbilical vein: in the delivery room while the placenta is still in the uterus by midwives and obstetricians or in an adjacent room after placental delivery by CB bank trained personnel. In this study, the benefits and disadvantages between the two different CB collection strategies were evaluated, in order to improve CB bank methodology. Valencia CB bank maintains the two different collection strategies. CB was obtained from 569 vaginal and 70 caesarean deliveries and obstetrical and clinical charts were reviewed. Before processing CB units, volume was calculated and samples were drawn for cell counts. After processing and before cryopreservation samples were drawn for cell counts, CD34+cell analysis, viability, clonogenic assays and microbiology were drawn directly from the bags. We compared the efficiency of the two collection techniques. Obstetric data and umbilical CB were obtained from 569 vaginal (264 collected in utero and 305 collected ex utero) and 70 caesarean deliveries. The proportion of excluded CB units before processing was 33% for vaginal ex utero, 25% for vaginal in utero and 46% for caesarean deliveries. Differences were statistically significant. For vaginal deliveries a larger volume and a higher number of nucleated cells, percentage of CD34+ cells and colony-forming units (CFUs) were harvested in the in utero collection group. There was no statistical difference between CB collected after placental expulsion from vaginal and caesarean deliveries. Comparison between all vaginal and caesarean deliveries did not show any difference. We conclude that the mode of collection influences the haematopoietic content of CB donations. Collection before placental delivery is the best approach to CB collection and allows optimisation of CB bank methodology. Caesarean deliveries seem to contain similar progenitor content to vaginal deliveries.

Bifurcations and global stability of synchronized stationary states in the Kuramoto model for oscillator populations

Bistability between synchronized stationary states is shown to occur in large populations of nonlinearly coupled random oscillators (Kuramoto model), governed by trimodal natural frequency distributions. Numerical simulations and a numerical investigation of bifurcating states provide evidence of global stability of such states, subject to unimodal, bimodal, and trimodal frequency distributions. All this may be important in the framework of large superconducting Josephson junctions arrays, as well as of neural networks.

Effects of prandial glycemic changes on objective fetal heart rate parameters

BACKGROUND

There is confusion in the literature about the potential effect of maternal glucose levels on the fetal heart rate (FHR) cardiotocographic interpretation.

METHODS

STUDY DESIGN

prospective clinical descriptive study.

SUBJECTS

21 pregnant women with diabetes mellitus, 23 women with gestational diabetes and 18 healthy non-diabetic pregnant volunteers (control group).

TREATMENT

maternal capillary glucose measurement and objective FHR analysis (Oxford System 8002) pre- and 1 h post-meal.

STATISTICAL ANALYSIS

descriptive statistics. Student t-tests and Pearson correlation studies.

RESULTS

Maternal capillary glucose levels ranged between 2.7-10.5 mmol/l pre-meal and 4.2 14.8 mmol/l post-meal. The differences between objective FHR parameters pre- and postmeal were not significant in any of the groups of women studied. No correlation was found between prandial glycemic and FHR changes. Women with optimal and suboptimal glycemic control exhibited similar objective FHR parameters pre- and post-meal. Women with gestational diabetes showed similar prandial cardiotocographic changes irrespective of whether they were on insulin therapy or on hypoglycemic diet only.

CONCLUSIONS

Objective FHR parameters are unaffected by prandial glycemic changes over a wide range of maternal glucose levels. Timing the non-stress test in relation to the meals seems irrelevant in clinical practice.

Intrapartum fetal invasive procedures and perinatal transmission of HIV

OBJECTIVE

To study the effect of intrapartum use of fetal invasive procedures (scalp electrodes or scalp pH sampling) on perinatal transmission rate of HIV.

STUDY DESIGN

We compared the perinatal transmission of 57 HIV pregnancies in which invasive procedures (IP) were performed with a control group of 214 pregnancies without IP. We controlled for potentially risk factors (maternal CD4 level, gestational age, antiretroviral therapy use, duration of rupture of membranes (ROM), length of labor and mode of delivery) by stratification and logistic regression.

RESULTS

Transmission rate in the group with IP was 26.3% (15/57) versus 13.6% (29/214) in the control group, relative risk (RR) 1.9, 95% CI (1.1-3.4). By logistic regression we observed three significant factors involved in transmission of HIV: low maternal CD4 level (odds ratio (OR)=3.3, 95% CI=1.2-9.4), duration of ROM (OR=2.9, 95% CI=1.1-7.9) and IP use (OR=3.5, CI 95%=1.2-9.6). Interaction between duration of ROM and IP are also significant (OR=5.1, CI 95%=1.5-17.5).

CONCLUSIONS

Intrapartum use of fetal scalp electrodes or fetal scalp pH sampling increases the perinatal transmission of HIV and should therefore be avoided in HIV patients.

Prospective double-arm study of fibrinolysis in surgical patients

BACKGROUND

During surgery, the balance between thrombosis and fibrinolysis is altered. Methods reported to increase fibrinolysis, such as compression devices, may reduce venous thrombosis. However, there are no prospective studies comparing methods and the effect on fibrinolysis.

MATERIALS AND METHODS

In a prospective study, general surgical patients were randomized to either sequential compression devices (Group 1) or subcutaneous heparin (Group 2), and fibrinolysis factors were measured in order to determine the effect on the fibrinolysis system. Blood samples were drawn at a similar time of the day with the tourniquet off. Specifically, t-PA antigen, plasminogen activator inhibitor-1 (PAI-1), and D-dimer were measured preoperatively (preop) and on Postoperative Days (POD) 1 and 7 by the ELISA method. Fibrinolysis factors were reported as the mean +/- SD and as percentage change from preoperative values. Noninvasive vascular studies were performed preop, and on POD 1, 7, and 30, by an examination of the infrainguinal venous system and external iliac veins in bilateral lower extremities. Nonambulatory patients were excluded from the study and DVT prophylaxis methods were initiated at surgery and used through POD 2.

RESULTS

For the 136 patients in the study, there were no differences in clinical characteristics such as age, surgical time (all > 60 min), anesthesia type (general or spinal), type of surgical procedure, or other risk factors for DVT. Two DVTs occurred at POD 1 and 30 (both Group 2), and one pulmonary embolism in each group (POD 7 for Group 1; POD 1 for Group 2). For subjects without thrombosis, D-dimer changes were parallel for both groups, increasing through POD 7. Similarly, t-PA antigen levels rose from baseline on POD 1 in both groups, with a return toward baseline by POD 7. The PAI-1 levels increased on POD 1 in both groups, but severalfold more in Group 1 (compression devices). The elevation in PAI-1 decreased by 50% in Group 1 by POD 7, while values returned to normal in Group 2. These changes were not significant using the Mann-Whitney test. Only three patients had thrombotic episodes so that data on changes in fibrinolysis factors are difficult to compare with the larger group.

CONCLUSIONS

This is the first report of a prospective, randomized comparison of fibrinolysis factors using sequential compression devices in comparison to low dose unfractionated heparin in general surgical patients, and comparing postoperative values to preop. Both groups showed an enhanced fibrinolysis by elevation in t-PA antigen and D-dimer on POD 1, as expected when fibrinolysis occurs. While PAI-1 and t-PA work in parallel, the marked elevation of PAI-1 on POD 1 (although only slightly above reference values) and continuing into POD 7 for subjects using compression devices requires further inquiry. The elevation of PAI-1 in the face of elevated t-PA and D-dimer has been reported, but the comparison between patients using sequential compression devices and mini-dose heparin has not been reported. The reason for the elevation requires additional study into other influences on the synthesis, secretion, and/or function of PAI-1 that do not affect t-PA.