Effects of prenatal carbon monoxide exposure on cardiac development

Neuroglobin, cytoglobin, and transcriptional profiling of hypoxia-related genes in the rat cerebellum after prenatal chronic very mild carbon monoxide exposure (25 ppm)

The expression of neuroglobin (Ngb) and cytoglobin (Cygb), two recently discovered globins with a potential neuroprotective activity against hypoxia and oxidative stress, was investigated in the cerebellum of young rats (postnatal day 20) after being exposed to chronic mild carbon monoxide (CO) at 25 ppm during prenatal (group A), prenatal and postnatal (group B), the postnatal period only (group C), and air (group D). The expression of genes associated with hypoxia signaling pathways was also investigated in the rat cerebella by real-time RT-PCR after CO exposure. Ngb and Cygb mRNAs did not change in any CO-exposed group. Quantitative immunohistochemistry showed no significant change in Ngb protein; however, there was a significant increase of Cygb protein in rats from groups A, B, and C when compared with group D. In group B, genes related to the generation of reactive oxygen species (Nos2) and lipid metabolism (Apat2) were upregulated. In contrast, no changes were found in the expression of 8 genes typically upregulated by hypoxic conditions (Angptl4, Arnt2, Casp1, Crebbp, Hif1a, Hif3a, Mt3, or Vegfa) in any CO-exposed group, suggesting that hypoxia-related gene expression is not altered by this mild CO exposure. Cygb but not Ngb may protect cerebellar cells from the chronic presence of CO exposure during prenatal and postnatal development.

Burns in pregnancy

Pregnancy complicated by a thermal injury must be aggressively managed to provide a favorable outcome for the mother and her developing fetus. The MEDLINE database was used to search for English-language papers published after 1980 to evaluate the classification, complications, and treatment of thermal injuries in pregnancy. Additional sources were identified through cross-referencing. We reviewed these sources with particular attention to classification, complications, and treatment options. The incidence of serious thermal injury in pregnancy is low. Maternal and perinatal mortality increases significantly when greater than 50 percent of the total body surface area is burned. However, pregnancy does not seem to alter maternal outcome, and maternal survival is often accompanied by fetal survival. The delivery of a term infant is likely when the mother recovers from a thermal injury, and there is no evidence of fetal jeopardy or labor in the first week postburn. Acute management of thermal injuries in pregnancy is essential for maternal and fetal well-being. Obstetrical management should be individualized.

Urgent delivery, the treatment of choice in term pregnant women with extended burn injury

Two pregnant patients at term, suffering from major burn wounds, were treated in our burn unit during the year 1995, both were delivered immediately after admission by caesarean section. One of them had smoke inhalation injury which needed mechanical ventilation, both mothers and newborns survived. In spite of low maternal carboxyhaemoglobin the fetal cord blood carboxyhaemaglobin was high, supporting an objective physiological basis for the previous empirical conclusion of early delivery in pregnant patients at term with extensive burn injury (50 per cent TBSA and more). This obvious favourable outcome highlights the importance of urgent delivery in term pregnant women suffering a major burn injury.

Trauma in pregnancy

Trauma is a major cause of maternal death in pregnancy. The pregnant woman who has been involved in an episode leading to her arrival in an accident and emergency department presents with specific problems that often require specialist attention. The correct initial management of such patients should not be beyond the capabilities of an average trauma team and such management is clearly taught as part of the Advanced Trauma Life Support course now available in the UK. This review outlines the physiological changes associated with pregnancy that become important during resuscitation and definitive care. It discusses the presentation and management of specific problems, and the safety--or otherwise--of commonly administered drugs. Only the initial resuscitation of the patient is considered; specialist obstetric care is beyond the scope of the article.

Moderate prenatal carbon monoxide exposure produces persistent, and apparently permanent, memory deficits in rats

The effects of moderate (150 +/- 2 ppm) prenatal carbon monoxide (CO) exposure (maternal HbCO concentrations of 15.6 +/- 1.1%) on learning and memory were assessed in young and aged adult rats using a two-way active avoidance paradigm. In experiment 1, the prenatal CO-exposed rats at 120 days of age acquired a conditioned avoidance response equally well as control animals in a 100-trial session. However, following a 24-hr interval the CO-exposed rats failed to demonstrate significant retention of the task as indicated by the absence of significant improvement in performance over the indicated by the absence of significant improvement in performance over the previous day; control subjects did show significant retention. In experiment 2, in which 120-day-old animals received 50 training trials per day until a criterion of ten consecutive avoidance responses was met, the prenatal CO-exposed subjects again acquired the task as well as control animals. When tested for retention 28 days later, a significant memory impairment was again observed in terms of trials required to reattain the avoidance criterion as well as in total percent avoidance responding. In neither experiment did an analysis of initial or average latency to escape the footshock stimulus reveal any significant alterations. These latter results suggest that the observed performance impairment reflected a memory deficit and not a disruption of sensory, motor, or motivational factors. In experiment 3, prenatal CO-exposed rats approximately 1 year of age (300-360 days of age) showed impairment relative to air-exposed controls in both the original learning and retention of the two-way avoidance response. Again, however, there was no evidence for alterations in performance factors per se. Collectively these data indicate that while young adult rats prenatally exposed to 150 ppm CO demonstrate an associative deficit restricted to memory impairment, aged adults similarly exposed during the prenatal period display a more pronounced deficit similar to that recently reported for animals tested as juveniles. The importance of parametric manipulations in uncovering long-term toxicity is also discussed.