The impact of early versus delayed cord clamping on hematological and cardiovascular changes in preterm newborns between 24 and 34 weeks' gestation: a randomized clinical trial

PURPOSE

This study aimed to   investigate hematological and cardiac changes after early (ECC) versus delayed cord clamping (DCC) in preterm infants at 24-34 weeks of gestation.

METHODS

Ninety-six healthy pregnant women were assigned randomly to the ECC (< 10 s postpartum, n = 49) or DCC (45-60 s postpartum, n = 47). Primary endpoint was evaluation of neonatal hemoglobin, hematocrit and bilirrubin levels within the first 7 days after birth. A postpartum blood test was performed in the mother and a neonatal echocardiography in the first week of life.

RESULTS

We found differences in hematological parameters during the first week of life. On admission, the DCC group had higher hemoglobin levels than the ECC group (18.7 ± 3.0 vs. 16.8 ± 2.4, p < 0.0014) and higher hematocrit values (53.9 ± 8.0 vs. 48.8 ± 6.4, p < 0.0011). Around day 7 of life, hemoglobin levels were also higher in the DCC group compared with the ECC group (16.4 ± 3.8 vs 13.9 ± 2.5, p < 0.005), as was the hematocrit (49.3 ± 12.7 vs 41.2 ± 8.4, p < 0.0087). The need of transfusion was lower in the DCC compared to the ECC (8.5% vs 24.5%; OR: 0.29, 95% CI: 0.09-0.97, p < 0.036). The need for phototherapy was also higher in the DCC (80.9% vs 63.3%; OR: 0.23, 95% CI: 0.06-0.84, p < 0.026). No differences in cardiac parameters or maternal blood tests.

CONCLUSION

DCC improved neonatal hematological parameters. No changes in cardiac function were found and maternal blood loss did not increase to require transfusion.

Cavity-mediated drag in double-layer graphene

We study the frictional drag between two graphene layers placed inside a cavity. We show that the drag has two contributions: the well-known Coulomb drag, and a novel photon-mediated drag. The latter arises from a cavity-mediated interaction in which the backscattering is not suppressed and the screening is relatively weak. As a result, the photon-mediated drag resistivity in the Fermi-liquid regime acquires corrections to the usual quadratic temperature dependence, has a slow decay as the interlayer separationdincreases, and depends on the carrier densitynasρD∼1/n2. Thus, whereas for smalldandnthe Coulomb drag dominates, as these parameters increase the drag transitions to a purely photon-mediated drag. The onset of this transition depends on the electromagnetic field enhancement inside the cavity.

Parvovirus B19 myocarditis in children: a diagnostic and therapeutic approach

Parvovirus B19 is one of the most frequent causes of pediatric myocarditis, associating high mortality rates or need for cardiac transplantation. The aim of this study is to describe the clinical course of Parvovirus B19 myocarditis in children with emphasis on the role of endomyocardial biopsy and cardiac magnetic resonance, and the use of an innovative therapeutic strategy. Eleven patients and 12 episodes of polymerase chain reaction (PCR)-confirmed Parvovirus B19 myocarditis were prospectively collected for 14 years. Diagnosis was confirmed either histopathologically or by magnetic resonance. A life-threatening clinical presentation is described, similar to previous series, but with 83.3% overall survival without transplantation. We also present a case of recurrent myocarditis, which is extraordinarily rare. Electrocardiographic patterns presented chiefly peaked p waves, low QRS voltages, and negative T waves on inferior or lateral leads. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance could be a useful diagnostic tool. A good concordance between myocardial and blood PCRs was observed. Seven patients received treatment with corticosteroids and beta interferon and all underwent a significant cardiac function improvement.

CONCLUSION

A severe clinical presentation is reported, similar to previous reports but with better outcomes. Endomyocardial biopsy is the gold standard diagnostic test; alternatively magnetic resonance may be used. Both blood and myocardium PCR can be used in children to establish the microbiological etiology. Steroids with IFNß could be a useful therapeutic option, although further multicenter studies are needed to confirm these results.

WHAT IS KNOWN

• Parvovirus B19 is one of the most frequent causes of myocarditis in children. It is associated with a fulminant clinical presentation. • Endomyocardial biopsy is the gold standard diagnostic test but it is an invasive procedure.

WHAT IS NEW

• Myocarditis may recur in pediatrics, even it is extraordinarily rare. • IFNβ with steroids may be a useful therapeutic option to improve the outcomes.

Fermi velocity reduction in graphene due to enhanced vacuum fluctuations

It is well known that the confinement of matter inside a microcavity can significantly enhance the light-matter interactions. As a result the vacuum fluctuations, induced by virtual photons, can occur in a volume much lower than the free-space diffraction limit. In this work we show that, for a single doped graphene plane inside a microcavity, these enhanced vacuum interactions can produce a significant reduction in the Fermi velocity of the electrons. The effect arises because the energies of the photons are much larger than the energies of the electrons in graphene, which implies that the vacuum exchange interaction is repulsive around the Fermi level. Consequently the quasiparticle Fermi velocity decreases, in contrast with the enhancement obtained in Hartree-Fock. For THz cavities, the reduction is highly localized around the Fermi level, and is practically independent of the carrier density in graphene.

P–626 A freeze-all strategy improves clinical pregnancy rate in patients with few available embryos

Study question

Is elective frozen blastocyst transfer an advantageous strategy for all patients?

Summary answer

A freeze-all strategy improves the outcomes in patients with few available embryos.

What is known already

With the aim of defining the best moment to perform embryo transfer, in recent years, relevance has been given to the understanding of the implantation window, however oocyte and embryo quality are key factors that are not to be disregarded.

It has been suggested that a freeze-all strategy and subsequent frozen embryo transfers improve pregnancy rates. However, it is unclear whether this strategy benefits all kind of patients (i.e. with or without surplus embryos, etc).

In this study, we aim to provide an answer on which patients may benefit of a freeze-all policy and a subsequent frozen embryo transfer.

Study design, size, duration

This retrospective cohort study includes infertile patients aged 21 to 44 years old, without previous history of recurrent failure of ART (including recurrent miscarriages). Enrolments took place between January 2015 and November 2019 and cycles with oocyte donation and PGT were excluded. Embryo transfers were performed in: 1) a fresh cycle (ET) or 2) a deferred cycle with surplus frozen embryos (FET) or embryos that were frozen in a freeze-all policy (FET-FA).

Participants/materials, setting, methods

Patients with blastocysts transfer were included. PGT cycles were excluded.

The number of cycles complying with the inclusion criteria were: 617 ICSI cycles. Fresh embryo transfers (ET) were performed in 396 cycles (43 with a subsequent Frozen embryo transfer, FET). Frozen embryo transfers following a freeze-all strategy (FET-FA) were performed in 221 cycles.

Clinical pregnancy rates (CPR) and Cumulative clinical pregnancy rates (CCPR) were calculated and compared among those groups.

Main results and the role of chance

Mean age of patients was 36.1 ± 3.7 years old (mean ± SD). In average, 1.83 ± 0.41 (mean ± SD) embryos were transferred.

Following the first transfer (either ET and FET-FA), CPR was 40.4% and 58.4% (ET and FET-FA, respectively). Following the subset analysis of 2 age groups (≤38 & &gt;38 years-old); in the ≤38-group, CPR was 45.2% and 58.9% (ET and FET-FA, respectively), while in &gt; 38-group, the rates were 30.8% and 54.8% (ET and FET-FA, respectively); p &lt; 0.05. CCPR were also significantly better in the FET-FA group: 51.3% vs 66.8% and 33.8% vs 58.1% in the ≤38-group and &gt;38-group, respectively.

Additionally, CPR was analysed independently for patients with ≤2 usable embryos (1 attempt) or ≥ 3 usable embryos (surplus embryos after first attempt).

When a single attempt was possible; in the ≤38-group, CPR was 36.1% and 56.9% (ET and FET-FA, respectively) while in the &gt;38-group, the rates were 24.7% and 63.6% (ET and FET-FA, respectively); p &lt; 0.05. When surplus embryos were available, no difference in CPR (or CCPR) between ET and FET-FA groups were observed. After first attempt CPR were 58.4% and 48.2% in the ≤38-group & &gt;38-group, respectively; while CCPR were 69.8% and 57.1% in the ≤38-group & &gt;38-group, respectively.

Limitations, reasons for caution

Although the authors consider that the patient population is of optimal size, a detailed analysis of the stimulation protocol and hormonal values (estradiol and progesterone) during treatment, and its potential relation to the outcomes, should follow.

Wider implications of the findings: In our setting, the data suggests that freeze-all strategy (with subsequent frozen embryo transfer) over fresh transfer is advantageous for patients with few available embryos (1 or 2 embryos for a single attempt). This increases the chances to pregnancy in 30.3% in the ≤38-group and 77.9% in the &gt;38-group.

Trial registration number

Not applicable

Heat capacity in doped graphene under magnetic fields: the role of spin splitting

We study the electronic heat capacity in doped graphene under magnetic fields. The partition function is calculated considering only the thermal excitations in the last occupied energy levels. Due to the large energy separation between the Landau levels (LLs) and the Zeeman splitting, at low temperatures the heat capacity is dominated by the spin excitations in the last occupied LL. Correspondingly the heat capacity oscillates with maximum amplitude at half filling of each LL. At higher temperatures the inter-LLs excitations dominate the heat capacity, with maximum amplitude at full filling factors. The oscillation amplitudes are compared with the phonon heat capacityCp. It is shown that the spin induced heat capacity oscillations have a maximum amplitude approaching 3% ofCp, whereas for the inter-LLs excitations the maximum amplitude is only 0.1% ofCp. These amplitudes decrease in the presence of impurities, although the effect is appreciable if the LLs broadening is bigger than the excitation energies.

Temperature effect on the magnetic oscillations in 2D materials

We study the magnetic oscillations (MO) in 2D materials with a buckled honeycomb lattice, considering a perpendicular electric and magnetic field. At zero temperature the MO consist of the sum of four sawtooth oscillations, with two unique frequencies and phases. The values of these frequencies depend on the Fermi energy and electric field, which in turn determine the condition for a beating phenomenon in the MO. We analyse the temperature effect in the MO by considering its local corrections over each magnetization peak, given by Fermi-Dirac like functions. We show that the width of these functions is related to the minimum temperature necessary to observe the spin and valley properties in the MO. In particular, we find that in order to observe the spin splitting, the width must be lower than the MO phase difference. Likewise, in order to observe valley mixing effects, the width must be lower than the MO period. We also show that at high temperatures, all the maxima and minima in the MO shift to a constant value, in which case we obtain a simple expression for the MO and its envelope. The results obtained show unique features in the MO in 2D materials, given by the interplay between the valley and spin.

Influence of temperature on the magnetic oscillations in graphene with spin splitting: a new approach

We analyze the magnetic oscillations (MO) due to the de Haas-van Alphen effect, in pristine graphene under a perpendicular magnetic field, taking into account the Zeeman effect. We consider a constant Fermi energy, such that the valence band is always full and only the conduction band is available. At zero temperature the MO consist of two sawtooth peaks, one for each spin. Both peaks have the same frequency, but different amplitude and phase. We show that, in order to observe the spin splitting in the MO, Fermi energy of about 0.1 eV is required. At low temperatures we obtain that the MO can be expressed as the MO at zero temperature, plus small Fermi-Dirac like functions, each centered around the MO peaks. Using this expression, we show that the spin splitting is observable in the MO only when the thermal energy is smaller than the Zeeman energy. We also analyze the shift of the MO extrema as the temperature increases. We show that it depends on the magnetic field, which implies a broken periodicity at nonzero temperature. Finally, we obtain an analytical expression for the MO envelope. The results obtained could be used to infer temperature changes from the MO extrema shift and vice versa.

Long-term experience with sodium chondroitin sulfate in patients with painful bladder syndrome

OBJECTIVE

To assess the response of patients diagnosed with painful bladder syndrome to treatment with instillations of sodium chondroitin sulfate.

MATERIAL AND METHODS

We present a series of cases of patients with painful bladder syndrome who followed a bladder instillation protocol with sodium chondroitin sulfate, according to our centre's regimen. The response to treatment was assessed with respect to pain, according to the Downie scale; urinary frequency, according to the voiding diary; and subjective improvement, according to the Patient Global Impression of Improvement (PGI-I) scale.

RESULTS

A total of 28 patients with a median age of 59 years (range 22-90) followed this protocol. From the medical histories, 19.4% had suffered an infection of the urinary tract, 3.8% had suffered urinary tuberculosis, 7.6% received pelvic radiation therapy and 26.9% had taken anticholinergic drugs for overactive bladder syndrome. We evaluated the response to treatment at 0, 3, 6 and 12 months and found that at the end of treatment 72.3% of the patients had improved bladder pain and 75% were significantly better.

CONCLUSIONS

Treatment with sodium chondroitin sulfate through endovesical instillation in painful bladder syndrome improves pain, voiding frequency and quality of life in the long term.

Respiratory infection in congenital cardiac disease. Hospitalizations in young children in Spain during 2004 and 2005: the CIVIC Epidemiologic Study

OBJECTIVES

To evaluate the rate of hospitalization for acute respiratory tract infection in children less than 24 months with haemodynamically significant congenital cardiac disease, and to describe associated risk factors, preventive measures, aetiology, and clinical course.

MATERIALS AND METHODS

We followed 760 subjects from October 2004 through April 2005 in an epidemiological, multicentric, observational, follow-up, prospective study involving 53 Spanish hospitals.

RESULTS

Of our cohort, 79 patients (10.4%, 95% CI: 8.2%-12.6%) required a total of 105 admissions to hospital related to respiratory infections. The incidence rate was 21.4 new admissions per 1000 patients-months. Significant associated risk factors for hospitalization included, with odds ratios and 95% confidence intervals shown in parentheses: 22q11 deletion (8.2, 2.5-26.3), weight below the 10th centile (5.2, 1.6-17.4), previous respiratory disease (4.5, 2.3-8.6), incomplete immunoprophylaxis against respiratory syncytial virus (2.2, 1.2-3.9), trisomy 21 (2.1, 1.1-4.2), cardiopulmonary bypass (2.0, 1.1-3.4), and siblings aged less than 11 years old (1.7, 1.1-2.9). Bronchiolitis (51.4%), upper respiratory tract infections (25.7%), and pneumonia (20%) were the main diagnoses. An infectious agent was found in 37 cases (35.2%): respiratory syncytial virus in 25, Streptococcus pneumoniae in 5, and Haemophilus influenzae in 4. The odds ratio for hospitalization due to infection by the respiratory syncytial virus increases by 3.05 (95% CI: 2.14 to 4.35) in patients with incomplete prophylaxis. The median length of hospitalization was 7 days. In 18 patients (17.1%), the clinical course of respiratory infection was complicated and 2 died.

CONCLUSIONS

Hospital admissions for respiratory infection in young children with haemodynamically significant congenital cardiac disease are mainly associated with non-cardiac conditions, which may be genetic, malnutrition, or respiratory, and to cardiopulmonary bypass. Respiratory syncytial virus was the most commonly identified infectious agent. Incomplete immunoprophylaxis against the virus increased the risk of hospitalization.

Factors associated with discontinuation rates of the copper T380A IUD in a Peruvian public hospital

The objectives of this study were to evaluate performance and causes of discontinuation of the Copper T380A IUD by users at the Family Planning Service at Hospital Arzobispo Loayza in Lima, Peru, during a period of three years. The study included 3167 acceptors of the CuT380A attending the service during 1992-1994. IUDs were inserted during interval timing. Follow-up was at 1, 12, 24 and 36 months after insertion. The following events were recorded: number of pregnancies, expulsions and all causes of discontinuation. The cumulative rates per 100 woman-years using the life-table method was calculated. Also calculated were the relative risks for expulsion and for pregnancy. At the end of the study, 361 women had discontinued the method for various reasons, whereas 1667 women continued using the method. The lost-to-follow-up proportion increased over time from 35.9 per 100 woman-years for the first year to 38.2 for the third year. The cumulative discontinuation rate over three years was 22.6 +/- 1.3 (cumulative rate +/- standard error) per 100 woman-years. The cumulative pregnancy rate for three years was 1.2 +/- 0.4 per 100 woman-years, whereas the cumulative rate of expulsion was 4.9 +/- 0.4 for the first, 6.4 for the second and 6.8 for the third year. The main cause of discontinuation during the first year of use was expulsion (4.9 per 100 woman-years) followed by personal reasons (2.1 per 100 woman-years). At the end of the third year, the main cause was personal reasons (11.4) and the second cause was expulsion (6.8). A higher probability of expulsion, pregnancy and discontinuation for bleeding and/or pain was associated with age less than 20 years. In conclusion, the effectiveness of the CuT380A IUD after three years of use was 98.8 per 100 woman-years, whereas continuation was 39.2, and loss to follow-up increased over time.

A comparative trial of labor induction with misoprostol versus oxytocin

OBJECTIVE

To determine the efficacy and safety of intravaginal misoprostol compared with intravenous oxytocin in cervical ripening and labor induction.

METHOD

The study was carried out at the Department of Obstetrics and Gynecology at the Hospital Loayza, Lima, Peru. The sample included 123 pregnant women with any indication for labor induction. The study was prospective and randomized. We compared the effect of 50 micrograms of intravaginal misoprostol administered every 4 h up to 600 micrograms with that observed using the standard protocol of oxytocin by continuous infusion.

RESULTS

57 patients with misoprostol (group 1) and 63 with oxytocin (group 2) were enrolled. Delivery occurred in 45 patients (78.9%) in group 1 and in 37 (58.7%) in group 2 (P < 0.017). Complications including tachysystole, uterine hypertony and hyperstimulation were higher in group 1, 21.1% than in group 2, 7.9% (P < 0.04). The incidence of cesarean section in both groups was similar to the overall incidence in our center. No differences were observed between groups in perinatal and postpartum adverse outcomes. The interval from start of induction to vaginal delivery was significantly shorter in the oxytocin group (8.4 +/- 4.1 vs. 11.3 +/- 6.9 h, P < 0.005).

CONCLUSION

Intravaginal administration of misoprostol is a safe and effective alternative for cervical ripening and labor induction. Maternal and neonatal complications did not increase significantly.

Hormone profile during the menstrual cycle at high altitude

OBJECTIVES

To determine the hormone profile during the menstrual cycle in women at sea level and at high altitude, and whether the time between the gonadotropin peak and ovulation is different at high altitude from that at sea level.

METHODS

The study was carried out in Lima (150 m) and Cerro de Pasco (4340 m), Peru. The hormone profile of 10 adult regularly menstruating women at sea level and 10 women at high altitude was assessed. Ovulation was identified by vaginal ultrasonography.

RESULTS

The pre-ovulatory follicle diameter was lower (P < 0.001) at high altitude than at sea level. Ovulation after LH peak occurred earlier at high altitude than at sea level. Serum FSH levels were higher at late luteal phase and early follicular phase at high altitude than at sea level (P < 0.05). The serum LH and FSH peaks were similar in women at sea level and at high altitude. During the early follicular phase serum estradiol levels were significantly higher at high altitude than at sea level (P < 0.05). During the late follicular phase the production of estradiol was higher at sea level than at high altitude (P < 0.05). The peak of serum estradiol was at day -1 in Lima and in day 0 at high altitude. At ovulation, the serum estradiol levels in women at sea level were 55.1% of the peak, but remained at high levels (80% of the peak) in women at high altitude (P < 0.05). The second increase of serum estradiol occurred earlier at sea level than at high altitude. From days +12 to +15, there was a significant decline in serum estradiol levels in women at sea level (P < 0.05) but not in those from high altitude (P > 0.05). Serum progesterone levels at days +5, and +8 to +12 were significantly higher at sea level than at high altitude.

CONCLUSION

Our data suggest that hormone profile during menstrual cycle is different at high altitude than at sea level, probably as an effect of low barometric pressure.

[Treatment of puerperal endometritis. Evaluation of the efficacy and safety of clindamycin + gentamycin vs. penicillin + chloramphenicol + gentamycin]

This was a prospective, single-blind, comparative study in patients with diagnosis of puerperal endometritis, carried out at the Loayza Hospital in Lima, Peru. The objective of this study was to evaluate the efficacy and safety of clindamycin and gentamicin in the management of endometritis vs. penicillin, chloramphenicol and gentamicin for 10 days. Sixty-five patients were enrolled and 62 were evaluable for efficacy. Both treatment groups were comparable in the pre-treatment period in terms of age, history of pregnancies, controls by gynecologist, days of disease and fever, clinical symptoms like fever, pelvic pain, pulse, uterine size and in laboratory, in hematocrit and leukocytes count. In the culture of endometrium tissue, 27/32 patients (84.4%) in Group A (penicillin + CAF + gentamicin) and 27/30 patients (90%) in Group B (clindamycin + gentamicin) had positive cultures at baseline; 18 and 22 patients showed anaerobes; 8 and 4 patients showed anaerobes plus aerobes and, one patient in each treatment group showed aerobes only. Peptostreptococcus and Bacteroides fragilis were the most frequently isolated pathogens. Improvement in lochia fetidity was more rapid in Group B, it turned transparent and not fetid since day 3. Complete cure was significantly better in Group B 24/30 (80%) in comparison with Group A 16/32 (50%) (p = 0.02). Partial response was found in 15 patients (43.3%) in Group A and 5 patients (16.6%) in Group B. Only one case was considered as bacteriological failure in Group A and only one patient in Group B was considered as failure and required an additional operation due to residual abscess.(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy rate in an oocyte donation program

Oocyte donation programs offer an alternative treatment for infertile women with ovarian failure or abnormal ovarian function. Seventeen cycles of in vitro fertilization and embryo transfer with donated oocytes were performed in 13 women, with a mean age of 34.8 years. The hormonal replacement therapy consisted of a fixed dose of oral estradiol valerate, 6 mg daily, and intramuscular progesterone in oil, 100 mg daily. Estrogen and progesterone were continued for 10 more weeks after embryo transfer if pregnancy was established. After 13 embryo transfers, 8 pregnancies were obtained, for a pregnancy rate per transfer of 61.5%. Today seven pregnancies are progressing normally, including one set of twins. This results suggest that an oocyte donation program using a fixed and simple hormonal replacement therapy is an adequate treatment for these infertile couples.

Deletion of chromosome 4: 46,XY, del(4) (q31.3) after gamete intrafallopian transfer and in vitro fertilization-embryo transfer

It seems that assisted reproduction technology does not increase the rate of chromosome abnormalities, and up to now, a few cases have been reported. The case we describe here is the first one of monosomy 4q31 in a full-term liveborn after a combined GIFT-IVF procedure. Once more, this case raises the question of whether pregnancies resulting from IVF should be monitored for chromosome abnormalities or not.

Inhibitory action of tumor-promoting phorbol esters upon beta-adrenergic agonist stimulation of cyclic AMP accumulation in rat prostatic epithelial cells

The pretreatment of rat prostatic epithelial cells with 4 beta-phorbol 12-myristate 13-acetate resulted in an attenuation of beta-adrenergic stimulated cyclic AMP accumulation. The effect was dependent on time and concentration. The maximal extent of isoproterenol stimulation of cyclic AMP production was reduced by 35% after 15-min pretreatment with the phorbol ester at 25 degrees C. Since a similar action was exerted by other protein kinase C stimulators, present results suggest the involvement of this enzyme in a process of desensitization to beta-adrenergic agonists of the adenylate cyclase system in rat prostatic epithelium.

Tumor-promoting phorbol esters interfere with the vasoactive intestinal peptide receptor/effector system in rat prostatic epithelial cells

Pretreatment of rat prostatic epithelial cells with the tumor-promoting phorbol ester 4 beta-phorbol 12-myristate 13-acetate resulted in a decrease of both the potency of vasoactive intestinal peptide (VIP) upon the stimulation of cyclic AMP accumulation and the affinity of the receptors of this peptide. These effects were dose-dependent and could be reproduced by other stimulators of protein kinase C (PKC). Thus, it is conceivably that phosphorylation of VIP receptors by PKC regulates VIP receptor function in the prostate gland.

Somatostatin inhibits VIP- and isoproterenol-stimulated cyclic AMP accumulation in rat prostatic epithelial cells

The dual regulation of cyclic AMP accumulation was studied in rat prostatic epithelial cells incubated with somatostatin, vasoactive intestinal peptide (VIP), and the beta-adrenergic agent isoproterenol. Somatostatin noncompetitively inhibited the stimulatory effect of VIP and isoproterenol, but it did not alter basal cyclic AMP levels. In addition to the multifactorial regulation of the cyclic AMP system in rat prostatic epithelium, these results suggest that somatostatin may play a physiological role at this level.