Human Menstrual Blood-Derived Mesenchymal Stem Cells as Potential Cell Carriers for Oncolytic Adenovirus.

Antitumor efficacy of systemically administered oncolytic adenoviruses (OAdv) is limited due to diverse factors such as liver sequestration, neutralizing interactions in blood, elimination by the immune system, and physical barriers in tumors. It is therefore of clinical relevance to improve OAdv bioavailability and tumor delivery. Among the variety of tumor-targeting strategies, the use of stem cells and specifically bone marrow-derived mesenchymal stem cells (BM-MSCs) is of particular interest due to their tumor tropism and immunomodulatory properties. Nonetheless, the invasive methods to obtain these cells, the low number of MSCs present in the bone marrow, and their restricted in vitro expansion represent major obstacles for their use in cancer treatments, pointing out the necessity to identify an alternative source of MSCs. Here, we have evaluated the use of menstrual blood-derived mesenchymal stem cells (MenSCs) as cell carriers for regional delivery of an OAdv in the tumor. Our results indicate that MenSCs can be isolated without invasive methods, they have an increased proliferation rate compared to BM-MSCs, and they can be efficiently infected with different serotype 5-based capsid-modified adenoviruses, leading to viral replication and release. In addition, our in vivo studies confirmed the tumor-homing properties of MenSCs after regional administration.

Insertion of exogenous epitopes in the E3-19K of oncolytic adenoviruses to enhance TAP-independent presentation and immunogenicity.

Oncolytic adenoviruses can promote immune responses against tumors by expressing and/or displaying tumor-associated antigens. However, the strong immunodominance of viral antigens mask responses against tumor epitopes. In addition, defects in major histocompatibility complex class I antigen presentation pathway such as the downregulation of the transporter-associated with antigen processing (TAP) are frequently associated with immune evasion of tumor cells. To promote the immunogenicity of exogenous epitopes in the context of an oncolytic adenovirus, we have taken advantage of the ER localization of the viral protein E3-19K. We have inserted tumor-associated epitopes after the N-terminal signal sequence for membrane insertion of this protein and flanked them with linkers cleavable by the protease furin to facilitate their TAP-independent presentation. This strategy allowed an enhanced presentation of the exogenous epitopes in TAP-deficient tumor cells in vitro and the generation of higher specific immune responses in vivo that were able to significantly control tumor growth.

Oxygen dependency as equivalent to bronchopulmonary dysplasia at different altitudes in newborns ⩽ 1500 g at birth from the SIBEN network.

OBJECTIVE: To compare the incidence of oxygen dependency in SIBEN neonatal units while adjusting for altitude. STUDY DESIGN: We reviewed the charts of infants who were ⩽ 1500 g at birth, admitted to six neonatal intensive care units (NICUs) near sea level and in seven NICUs at varying altitudes above sea level from the SIBEN network between 2008 and 2010. We defined bronchopulmonary dysplasia (BPD) as oxygen dependency at 28 days of life and at 36 weeks postmenstrual age. RESULT: There were 767 babies in the first group and 318 in the second group. BPD incidence was greater in hospitals at higher altitudes when it was not corrected for barometric pressure. After correction, there was a decrease in the incidence of oxygen dependency at 28 days of life (P<0.0002) and at 36 weeks corrected age. (P<0.0001) CONCLUSION: After correction for higher altitudes, the decrease in oxygen dependency as equivalent to BPD was significant. A proper classification of BPD for higher altitudes is urgently needed.

End of life, death and dying in neonatal intensive care units in Latin America.

AIM: Most analyses of end of life decisions in Neonatal Intensive Care Units (NICUs) have come from Europe/English-speaking countries. Would decisions be different in Latin American NICUs? Therefore, we aim to evaluate the approach to dying infants/families in NICUs in Latin America. METHODS: Multinational descriptive study of all deaths in babies born at >22 weeks in eight NICUs in five Latin American countries. Deaths were categorized as: (i) no Cardiopulmonary Resuscitation (CPR) or life support offered; (ii) life support initiated but do not resuscitate (DNR) orders written or no CPR provided; (iii) full life support and CPR; and (iv) unclassifiable. RESULTS: There were 100 deaths, 81% in >27 weeks. Seventeen infants received no CPR/life support at birth, 10 died in DR and seven in NICU. There were 27 infants in group 2, 54 in group three and two in group 4. No baby had care withdrawn or care withdrawn/CPR withheld. Thirty-two infants had 'do not resuscitate' order. Decisions without parents' involvement in 15%, both parents present at death 24% and sedatives/narcotics documented 14%. CONCLUSIONS: Latin American NICUs differ from those in Northern Europe/English-speaking countries. More deaths are accompanied by full life support and CPR. DNR orders are rare. Withdrawal of life support is virtually non-existent. Latin American's doctors are more likely to make decisions without the objections of family about withholding life-sustaining treatment.

Influence of sleep state and respiratory pattern on cyclical fluctuations of cerebral blood flow velocity in healthy preterm infants.

To examine the influence of sleep state, respiratory pattern, and ventilation on cyclical fluctuations (CF) in cerebral blood flow (CBF) velocity (CBFV), we studied 21 'healthy' preterm infants: birth weight 1,790 +/- 162 g (SEM), study weight 1,960 +/- 165 g, gestational age 32 +/- 1 weeks, postnatal age 20 +/- 4 (range 8-57) days. The CBFV was measured using on-line pulsed Doppler ultrasound by insonating the middle cerebral artery. Breathing was measured using a flow through system. The sleep state was monitored according to conventional criteria. Three hundred and seventy-five epochs of 1 min each were analyzed; 207 during quiet sleep (QS) and 168 during rapid eye movement (REM) sleep. CFs in CBFV were detected in all babies. The frequency of CF ranged from 0.5 to 6 cycles/min. The proportion of epochs showing CF was similar during both sleep states (56% QS vs. 59% REM; p = NS). Although the mean CBFV (cm/s) was similar in these two sleep states, the mean coefficient of variation, a measure of CF amplitude, was significantly higher during REM as compared with QS (6 +/- 0.5 vs. 4.3 +/- 0.2%; p < 0.05). Similarly, the mean CBFVs were similar with various respiratory patterns, but the coefficient of variation was significantly higher in periodic and apneic patterns as compared with regular and irregular respiratory patterns (5.6 +/- 0.6% periodic, 5.6 +/- 0.3% apneic, 3.6 +/- 0.3% regular, and 4.1 +/- 0.5% irregular, p < 0.05). The amplitude of CF was associated with the variability of the heart rate (p < 0.05), but not with the variability of the respiratory measurements. These findings suggest: (1) REM sleep is associated with a greater CBF variability than QS, and (2) periodic and apneic breathing are associated with a greater CBF variability than regular or irregular breathing. We speculate that sleep state and respiratory pattern do not determine but modulate the CBF. Our data suggest that in studies involving interpretation of CBFV data using the Doppler technique, breathing patterns should be taken into account in addition to sleep state.

Effects of central apnea on cerebral blood flow velocity in healthy term infants.

We evaluated a new method of monitoring cerebral blood flow velocity (CBFV) and described changes in CBFV in relation to central apnea in 17 healthy term infants. The area under the velocity curve during apnea did not change, whereas area under the velocity curve per the waveform showed a significant difference, suggesting that stability is maintained through an increase in CBFV with each heartbeat. The maintenance of cerebral hemodynamics during isolated central apnea supports the assumption that these episodes are benign.

Inhaled nitric oxide monitoring.

UNLABELLED: Recently, inhaled nitric oxide (NO) became clinically available for the treatment of persistent pulmonary hypertension of the newborn. Such use requires administration and continuous monitoring of a very low concentration of NO to prevent potential toxicity. Since limited data on the reliability of NO monitoring devices are available, we evaluated the performance of a chemiluminescent and electrochemical sensor NO analyzer in a patient ventilator circuit. RESULTS: The chemiluminescence analyzer readings were significantly altered by the oxygen concentration in the ventilator circuit. When the FiO2 was increased from 0.21 to 1, a 4.5% +/- 0.3 decrease in the NO readings was found (p < 0.01). Similarly, adding humidity to the circuit, reduced the NO readings by 4.8% +/- 0.9 (p < 0.01). The effect of gas pressure was proportional to its magnitude but independent of whether a pulsatile or continuous gas flow was provided. At a mean airway pressure of 15 cm H2O, the NO readings increased by 3.94% +/- 0.05 (NO = 10 parts per million) and 3.97% +/- 0.02 (40 parts per million) (p < 0.01). The electrochemical sensor NO readings were directly proportional to the ventilator circuit pressure but independent of whether a pulsatile or continuous gas flow was provided. At a mean airway pressure of 15 cm H2O, the NO reading was increased by 25.39% +/- 0.04 (NO = 40 parts per million) (p < 0.01) and 1.07% +/- 0.16 (NO = 10 parts per million) (p NS). The greatest difference with NO = 10 parts per million from baseline was found at a mean airway pressure of 6 cm H2O (6.67% +/- 0.23; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Sighs and their relationship to apnea in the newborn infant.

To test the hypothesis that sighs are mechanistically important in triggering apnea, we studied 10 preterm infants, group 1: body weight 1.8 +/- 0.1 kg, gestational age 33 +/- 1 weeks, postnatal age 21 +/- 4 days, and 10 term infants, group 2: body weight 3.9 +/- 0.15 kg, gestational age 40 +/- 0.4 weeks, postnatal age 1.4 +/- 0.2 days. Instantaneous ventilatory changes associated with a sigh were studied in another 10 preterm infants, group 3: body weight 1.6 +/- 0.11 kg, gestational age 32 +/- 0.4 weeks, postnatal age 25 +/- 4 days. Ventilation was measured using a nosepiece and a flow-through system. Sleep states were recorded. Sighs were more frequent in preterm than in term infants (0.4 +/- 0.04 vs. 0.18 +/- 0.03 sighs/min; p = 0.03) and in rapid eye movement than in quiet sleep (0.5 +/- 0.05 vs. 0.3 +/- 0.05 sighs/min; p = 0.05). Of 722 apneas, 235 (33%) were associated with a sigh; of these, 113 (48%) preceded and 122 (52%) followed a sigh. Sighs induced with airway occlusion (groups 1 and 2) were more frequent after occlusion on 21 than on 35% O2, particularly when O2 saturation was low and negative airway pressure high. Instantaneous ventilation measured over 10 breaths preceding a sigh did not show any trend indicating the possible appearance of a sigh. Tidal volume increased from 7.5 +/- 0.7 before the sigh to 18.9 +/- 0.7 ml/kg (p < 0.01) during a sigh, with a significant increase in inspiratory drive. Ventilation increased from 0.327 +/- 0.041 to 0.660 +/- 0.073 l/min/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of dopamine on failure of indomethacin to close the patent ductus arteriosus.

To test the hypotheses that administering dopamine before and concurrently with indomethacin therapy would (1) increase successful ductal closure rate, (2) act by maintaining a diuresis, and (3) prevent oliguria or high serum creatinine concentrations, we conducted a randomized, controlled trial in infants whose gestational age was <36 weeks and who had hemodynamically significant ductus arteriosus. Thirty-six infants were selected to receive a continuous infusion of either placebo or dopamine at either a low dosage of 2 micrograms/kg per minute or a higher dosage of 5 micrograms/kg per minute, beginning 6 hours before the use of indomethacin and continuing until 12 hours after the third dose of indomethacin. A total of 12 patients were selected to receive placebo, 14 were selected to receive "low dopamine," and 10 were selected to receive "high dopamine." The three groups were similar in their initial characteristics. Serum creatinine concentrations, urine output, and fractional excretion of sodium were not different in the three groups after indomethacin treatment. Two patients receiving placebo required a second course of indomethacin compared with four patients in the low-dopamine group and one in the high-dopamine group. The proportion of failures of medical treatment was not statistically different among the three groups. We conclude that concomitant dopamine therapy neither decreases the failure rate in indomethacin-treated infants nor reduces the magnitude of the indomethacin-induced oliguria.

Recovery of intralipid from lumbar puncture after migration of saphenous vein catheter.

A term female infant was admitted to the intensive care unit with the diagnosis of tetralogy of Fallot with critical pulmonary stenosis. On the seventh day of life a long saphenous line was inserted that remained without complications until seven days later when the infant appeared septic. A lumbar puncture demonstrated the presence of intra-lipid in the cerebrospinal fluid that we interpreted as due to migration of the saphenous catheter. The child had an uneventful recovery.

The effect of 10% O2 on the continuous breathing induced by O2 or O2 plus cord occlusion in the fetal sheep.

Although the administration of 100% O2 alone or combined with umbilical cord occlusion induces continuous breathing and arousal in the fetal sheep (Baier, Hasan, Cates, Hooper, Nowaczyk & Rigatto, 1990a), the individual contribution of O2 and cord occlusion to the response have not been determined. We hypothesized that if O2 is an important factor in the induction of continuous breathing, administration of O2 low enough (10%) to bring fetal arterial PO2 to about 20 torr while the fetus is breathing continuously should reverse these changes. Thus we subjected 12 chronically instrumented fetal sheep to 10% O2 for 10 minutes after the establishment of continuous breathing by O2 (4 fetuses; 137 +/- 1 days) or by O2 plus umbilical cord occlusion (8 fetuses; 134 +/- 1 days). Arterial PO2 decreased from about 250 torr to 20 torr during 10% O2. This induced a significant decrease in breathing output (EMGdi x f) related primarily to a decrease in frequency (f). In 3/5 experiments in 4 fetuses, with O2 alone, apnoea developed within 4 +/- 0.6 min; in 12/13 experiments in 8 fetuses, with added cord occlusion it developed at 5 +/- 0.6 min. With the decrease in PaO2, electrocortical activity (ECoG) switched from low to high-voltage within 6 minutes in 5/5 experiments (O2 alone) and in 11/13 (O2 plus cord occlusion). The findings suggest that umbilical cord occlusion alone is not sufficient to maintain breathing continuously and an increased PaO2 is needed. We speculate that in the fetus there is a vital link between PaO2, breathing and ECoG with low PaO2 inhibiting and high PaO2 favouring breathing and arousal.