Inferior Adrenal Artery PI in Fetuses with IUGR: Value Indicating Early Blood Redistribution and Steroidogenic Response

Objective To characterize the inferior adrenal artery (IAA) pulsatility index (PI) in intrauterine growth–restricted (IUGR) fetuses without brain sparing. Methods Twenty-three IUGR fetuses with a normal Doppler cerebroplacental ratio (CPR) and 23 normal controls were included in this prospective cross-sectional study. The PI of the IAA was recorded using routine transabdominal Doppler ultrasound. The differences in Doppler characteristics, perinatal outcomes, and steroidogenesis in the umbilical vein at birth (adrenocorticotropic hormone [ACTH] and cortisol [F] levels) were compared between the 2 groups. The correlations between IAA-PI and steroidogenesis were assessed in the IUGR group. Results IAA-PI was significantly lower in IUGR fetuses than in normal controls (0.85 vs 1.18 at first scan, 0.78 vs 0.92 at last scan; both P < 0.001). The plasma F and ACTH levels in IUGR cases were significantly higher than those of the normal controls (18.2 vs 12.4 µg/dL and 280.5 vs 125.6 pg/mL for F and ACTH, respectively; both P < 0.001). There were negative correlations between IAA-PI and plasma F values and between IAA-PI and ACTH values in the IUGR group (r = −0.774 and −0.82 at first scan, r = −0.525 and −0.45 at last scan, respectively; P < 0.001). Conclusion Increased adrenal gland blood flow with concomitant increases in ACTH and F levels were observed in IUGR fetuses. IAA-PI is useful to assess early blood redistribution and may be beneficial for evaluating the steroidogenic response in high-risk pregnancies.

The range of normative surface skin temperature changes in adolescents: prospective multicenter study

Aim We aimed to establish a normative range of surface skin temperature (SST) changes due to blood redistribution in adolescents and to register the time needed for complete postural change-related blood redistribution. Methods The healthy volunteers (age 15–18, n = 500, M 217, F 283) were recruited for this prospective multicenter study. The volunteers were asked to keep one extremity down and another extremity up in supine rest, sitting with straight legs, and upright rest. We obtained temperature readings being taken from the tips of the middle fingers and temperature readings from the tips of the first toes at the ambient temperature of 25 °C and 30 °C. The control group consisted of a 100 of adult volunteers. Results The resting temperature of the middle fingers for a sitting participant was 28.6 ± 0.8 °C. The physiological change of this temperature during body position changes was 4.5 ± 1.1 °C and for most of the participants remained within the 26.5–31.5 °C range at 25 °C. For the toe, physiological skin temperature range was 25.5–33 °C. At 30 °C, these ranges were 27–33 °C for the fingers and 27–34 °C for the toes. On average, 2–3 min were needed for such temperature changes. Conclusion At normal room temperature, the SST of thermoneutral adolescents may vary within a range of approximately 5 °C only due to the blood redistribution in the body. This range is specific for each person due to individual peculiarities of the vasomotor activity. This normative range of SSTs should be taken into account during investigations of thermoregulation.

Resveratrol mitigates hypercholesterolemia exacerbated hyperthermia in chronically heat-stressed rats

Background and Aim: Hypercholesterolemia (HC) is the major leading cause of cardiovascular disease worldwide. Such atherogenic aberration deeply impacts blood circulation. Resveratrol (R) is a polyphenol that has received attention as a hypolipidemic, antioxidant, and vascular agility advocate. Efficient blood redistribution is a key element in mammalian thermoregulation. We hypothesized that R treatment may aid in mitigating hyperthermic responses under both acute and chronic heat stress (HS) conditions in HC male rats. Materials and Methods: All rats were initially fitted with miniaturized thermologgers to measure core body temperature (Tcore). With a 2 × 2 factorial arrangement, four groups were randomly allotted, in which half of the animals ingested an HC diet (C+), while the other half ingested a control (C-) diet, throughout the whole study duration of 35 days. Seven rats from each dietary treatment, however, received R (R+; 13 mg/kg BW/day), while the rest received normal saline (R-) for 5 continuous days. All animals were maintained at thermoneutrality (TN; ambient temperature; Ta=23.15±0.04°C) for a period of 30 continuous days (days 0-29). On day 29, an acute HS (HS; Ta=35.86±0.37°C; for 9 nocturnal h) was imposed. Then, from day 29, a chronic HS protocol (Ta=32.28±1.00°C) was maintained until the past day of the trial (day 34), after which blood samples were drawn for analyses of platelet (PL) count, total antioxidant activity (TAO), total cholesterol (TC), triglycerides (TGs), and lipid peroxidation (LP). Results: Switching animals from TN to HS resulted in abrupt rises in Tcore. The HC diet induced a significant (p<0.01) hyperlipidemia over the control of diet-consuming rats. Interestingly, the hyperthermic response to acute HS was highly pronounced in the rats consuming the C- diet, while the C+ diet exacerbated the chronic HS-induced hyperthermia. Despite failure to improve TAO in the C+ diet, R+ treatment caused a marked (p<0.05) decline in nighttime - hyperthermia in C+ rats, likely by enhancing blood flow to extremities (for heat dissipation) as delineated by drastic downregulations of C+ related rises in PL, TC, TG, and LP (HC diet by R+ interaction; p<0.03). Conclusion: The hyperthermic response in C- groups was attributed to higher amount of feed intake than those consuming the C+ diet. Yet, the R+ improvement of thermoregulation in the C+ group was likely related to enhancement of vascular hemodynamics. Resveratrol intake mitigated chronic HS-evoked hyperthermia in rats. Such an approach is worthy to follow-up in other mammals and humans.

Fetal “Aortic Coarctation” and Different Neonatal Follow-Up in 3 Cases

Heart defects which includes narrowing of aortic isthmus - aortic coarctation (CoA) are one of the most prevalent birth defects. Making a correct prenatal diagnosis of CoA is very difficult and problematic. We are still observing many false (+) and false (-) diagnoses. In presenting 3 cases with prenatal suspicion of CoA only one patient confirmed this defect in the postnatal life. In the fetal echocardiography inappropriate dimensions of great vessels and PA/Ao ratio are very relevant in the CoA diagnostics. Based on such suspicion before delivery we can select a group in which birth in the tertiary center, prostin infusion, control ECHO examinations and planned cardiac surgery will be needed. But wide differential diagnosis including pulmonary dilatation (due to pulmonary hypertension or fetal blood redistribution due to possible infection) is required.

Transient fetal blood redistribution associated with maternal supine position

Objective:To investigate whether fetal blood circulation is influenced by the maternal supine position.Methods:The inclusion criteria were good health, a singleton pregnancy, maternal age between 18 and 40 years, gestational age between 36 and 40 weeks, and an agreement to participate in the study. Each participant (n=20) was initially asked to adopt the left lateral position for 5 min, while fetal Doppler measurements were taken of the fetal middle cerebral artery (MCA), umbilical artery (UA), and umbilical vein (UV). Subsequently, they were asked to change to the supine position for Doppler measurements at 5 and at 10 min.Results:When a woman remained in the supine position for 5 min, there was a significant reduction in fetal MCA-pulsatility index (PI) (median 1.70 vs. 1.42, P=0.003). This reduction did not persist after 10 min (median 1.70 vs. 1.65 P=1.0). There was no significant difference between the left lateral and the supine position at 5 and at 10 min in terms of UA-PI (0.853 vs. 0.870 vs. 0.858, P=0.850), UV flow (217 vs. 242 vs. 236 mL/min, P=0.263), and normalized UV flow (72.2 vs. 80.8 vs. 78.8 mL/min/kg, P=0.271).Conclusions:Changing maternal position from the left lateral to the supine position caused a reduction in resistance in fetal MCA and no changes in UA or UV indices. However, despite the changes in cerebral circulation which occurred at 5 min by shifting position, they did not remain for 10 min. The changes may be related to reduction in maternal oxygen saturation as there was no decrease in UV blood flow.

A new hemodynamic model for the study of cerebral venous outflow

We developed a mathematical model of the cerebral venous outflow for the simulation of the average blood flows and pressures in the main drainage vessels of the brain. The main features of the model are that it includes a validated model for the simulation of the intracranial circulation and it accounts for the dependence of the hydraulic properties of the jugular veins with respect to the gravity field, which makes it an useful tool for the study of the correlations between extracranial blood redistributions and changes in the intracranial environment. The model is able to simulate the average pressures and flows in different points of the jugular ducts, taking into account the amount of blood coming from the anastomotic connections; simulate how the blood redistribution due to change of posture affects flows and pressures in specific points of the system; and simulate redistributions due to stenotic patterns. Sensitivity analysis to check the robustness of the model was performed. The model reproduces average physiologic behavior of the jugular, vertebral, and cerebral ducts in terms of pressures and flows. In fact, jugular flow drops from ∼11.7 to ∼1.4 ml/s in the passage from supine to standing. At the same time, vertebral flow increases from 0.8 to 3.4 ml/s, while cerebral blood flow, venous sinuses pressure, and intracranial pressure are constant around the average value of 12.5 ml/s, 6 mmHg, and 10 mmHg, respectively. All these values are in agreement with literature data.