Adrenal and plasma corticosterone levels in the pregnant, foetal and neonatal rat, in the perinatal period.

A group of pregnant control rats was sacrificed before parturition, in the morning, afternoon and evening of day 20 and 21 and in the morning of day 22. Another group was sacrificed during parturition, when 2 to 8 foetuses had been expelled. The onset of parturition occurred for the first rat in the afternoon of day 21 and for the last rat in the afternoon of day 22. Corticosterone was extracted from maternal, foetal and neonatal adrenals and plasma, and was assayed by a fluorometric procedure. The maternal adrenal and plasma corticosterone levels, before parturition, were lower in the morning than in the afternoon excepting day 22 when morning values were as high as those in the afternoon of day 21. Adrenal and plasma corticosterone concentrations were elevated during parturition in the mother but not the foetus. Plasma corticosterone values were raised in the newborn compared to their littermates in utero.     

Ovarian surface epithelium receptors during pregnancy and estrus cycle of rats with emphasis on steroids and gonadotropin fluctuation

The present study is designed to demonstrate the ovarian surface epithelial cells’ (OSE) estrogen receptor α (ERα) and progesterone receptor (PR) during pregnancy and estrous cycle in rat. Moreover, determination of the levels of plasma progesterone, estradiol, FSH and LH was also made. The levels of plasma progesterone, estradiol, FSH and LH concentrations were determined on days 7 (n = 5), 14 (n = 5), and 21 (n = 5) of pregnancy in three groups of rats and during the estrous cycle (n = 5) using an ELISA kit. Immunohistochemical method for PR and ERα expressions was also made on the ovary. During pregnancy, FSH and LH remained low except at term when LH levels began to increase from 16 ng/ml to 47 ng/ml. Progesterone levels significantly exceeded estradiol values in all pregnant rats with a peak value of 202 ng/ml on day 14. Elevated progesterone levels were associated negatively with LH and estradiol levels during pregnancy. The levels of estradiol surged significantly on day 21. Immunohistochemistry of the ovary showed low levels of OSE cells staining positive for ERα expression. ERα positive cells were absent on day 7 and 14 of pregnancy, only day 21 recorded a very low percentage of immunostaining (0.5%) within the nuclei of OSE cells. On the contrary, immunostaining of PR was not observed within the nuclei of OSE cells in all groups of study. In conclusion, these results may suggest that the progesterone effect during pregnancy seems to be overriding the positive effect of estrogens on OSE cells. High progesterone levels may have a direct negative effect on gonadotropin production and thereby it might inhibit events leading to both follicular development and OSE proliferation. Understanding the factors affecting OSE proliferation may help elucidating the mechanism(s) of assisted diseases such as ovarian cancer.Keyword: OSE pregnancy rat steroid receptors gonadotropins     

Relationship between plasma and muscle concentrations of ketone bodies and free fatty acids in fed, starved and alloxan-diabetic states

1. Concentrations of ketone bodies, free fatty acids and chloride in fed, 24–120h-starved and alloxan-diabetic rats were determined in plasma and striated muscle. Plasma glucose concentrations were also measured in these groups of animals. 2. Intracellular metabolite concentrations were calculated by using chloride as an endogenous marker of extracellular space. 3. The mean intracellular ketone-body concentrations (±s.e.m.) were 0.17±0.02, 0.76±0.11 and 2.82±0.50μmol/ml of water in fed, 48h-starved and alloxan-diabetic rats, respectively. Mean (intracellular water concentration)/(plasma water concentration) ratios were 0.47, 0.30 and 0.32 in fed, 48h-starved and alloxan-diabetic rats respectively. The relationship between ketone-body concentrations in the plasma and intracellular compartments appeared to follow an asymptotic pattern. 4. Only intracellular 3-hydroxybutyrate concentrations rose during starvation whereas concentrations of both 3-hydroxybutyrate and acetoacetate were elevated in the alloxan-diabetic state. 5. During starvation plasma glucose concentrations were lowest at 48h, and increased with further starvation. 6. There was no significant difference in the muscle intracellular free fatty acid concentrations of fed, starved and alloxan-diabetic rats. Mean free fatty acid intramuscular concentrations (±s.e.m.) were 0.81±0.08, 0.98±0.21 and 0.91±0.10μmol/ml in fed, 48h-starved and alloxan-diabetic states. 7. The intracellular ketosis of starvation and the stability of free fatty acid intracellular concentrations suggests that neither muscle membrane permeability nor concentrations of free fatty acids per se are major factors in limiting ketone-body oxidation in these states.     

Placental transfer of stobadine in rabbits

Stobadine, a pyridoindole antioxidant, was investigated for its placental transfer and distribution in New Zealand white rabbits on the 27th day of gestation. The concentrations of stobadine were determined in maternal and foetal organs (plasma, brain, heart) at 30, 60, 120, and 360 minutes after oral administration of the drug in a dose of 5 mg/kg. The results obtained proved that after oral stobadine intake by rabbits at the stage of advanced pregnancy both maternal and foetal organs were under a certain drug level which could act protectively against oxidative stress--frequently occurring during late organogenesis, foetal stages and delivery, as well as during early postnatal development.     

Effect of Antioxidant Supplementation on Exercise-Induced Cardiac Troponin Release in Cyclists: A Randomized Trial

Background

Cardiac troponin is the biochemical gold standard to diagnose acute myocardial infarction. Interestingly however, elevated cardiac troponin concentrations are also frequently observed during and after endurance-type exercise. Oxidative stress associated with prolonged exercise has been proposed to contribute to cardiac troponin release. Therefore, the aim of this study was to assess the effect of 4 week astaxanthin supplementation (a potent cartenoid antioxidant) on antioxidant capacity and exercise-induced cardiac troponin release in cyclists.

Methods

Thirty-two well-trained male cyclists (age 25±5, weight 73±7 kg, maximum O₂ uptake 60±5 mL·kg⁻¹·min⁻¹, W_max 5.4±0.5 W·kg⁻¹; mean ± SD) were repeatedly subjected to a laboratory based standardized exercise protocol before and after 4 weeks of astaxanthin (20 mg/day), or placebo supplementation in a double-blind randomized manner. Blood samples were obtained at baseline, at 60 min of cycling and immediately post-exercise (≈ 120 min).

Results

The pre-supplementation cycling trial induced a significant rise of median cardiac troponin T concentrations from 3.2 (IQR 3.0–4.2) to 4.7 ng/L (IQR 3.7–6.7), immediately post-exercise (p<0.001). Four weeks of astaxanthin supplementation significantly increased mean basal plasma astaxanthin concentrations from non-detectable values to 175±86 µg·kg⁻¹. However, daily astaxanthin supplementation had no effect on exercise-induced cardiac troponin T release (p = 0.24), as measured by the incremental area under the curve. Furthermore, the elevation in basal plasma astaxanthin concentrations was not reflected in changes in antioxidant capacity markers (trolox equivalent antioxidant capacity, uric acid, and malondialdehyde). Markers of inflammation (high-sensitivity C-reactive protein) and exercise-induced skeletal muscle damage (creatine kinase) were equally unaffected by astaxanthin supplementation.

Conclusion

Despite substantial increases in plasma astaxanthin concentrations, astaxanthin supplementation did not improve antioxidant capacity in well-trained cyclists. Accordingly, exercise-induced cardiac troponin T concentrations were not affected by astaxanthin supplementation.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01241877","term_id":"NCT01241877"}}NCT01241877     

Effective lipid lowering diets including lean meat

The plasma lipid and lipoprotein responses to two modified isoenergetic diets including meat were studied in 15 free living men with hyperlipidaemia (mean plasma cholesterol and triglyceride concentrations 8·1 and 3·4 mmol/l). A reference diet (diet A, 42% energy from fat, ratio of polyunsaturated to saturated fatty acids (P:S ratio) 0·2) was compared with a fat reduced diet (diet B, 35% energy from fat, P:S ratio 0·5) and with a further fat modified diet supplemented with fibre (diet C, 27% energy from fat, P:S ratio 1·0). Daily intake of meat and meat products (180 g/day) was the same in each dietary period; that in diet A had a fat content typical of the average British diet, whereas that in diets B and C was based on very lean meat and meat products. During consumption of diet B the plasma cholesterol concentration fell by 8·6% and low density lipoprotein cholesterol by 11%. During consumption of diet C plasma cholesterol fell by 18·5% and low density lipoprotein cholesterol by 23·8%. Triglyceride and high density lipoprotein cholesterol concentrations and body weight did not change appreciably during the study.A modified diet including a moderate amount of lean meat and meat products is compatible with a reduced lipoprotein mediated risk of atherosclerotic heart disease.     

Intravenous propofol,ketamine (ketofol) and rocuronium after sevoflurane induction provides long lasting anesthesia in ventilated rats

Rats are commonly used animals for laboratory experiments and many experiments require general anesthesia. However, the lack of published and reproducible intravenous anesthesia protocols for rats results in unnecessary animal use to establish new anesthesia techniques across institutions. We therefore developed an anesthesia protocol with propofol, ketamine, and rocuronium for mechanically ventilated rats, and evaluated vital parameters and plasma concentrations. 15 male Sprague-Dawley rats underwent inhalation induction with sevoflurane and tracheal, venous and arterial cannulation. After established venous access, sevoflurane was substituted by propofol and ketamine (ketofol). Rocuronium was added under mechanical ventilation for 7 h. Drug dosages were stepwise reduced to prevent accumulation. All animals survived the observation period and showed adequate depth of anesthesia. Mean arterial pressure and heart rate remained within normal ranges. Median propofol plasma concentrations remained stable: 1, 4, 7 h: 2.0 (interquartile range (IQR): 1.8–2.2), 2.1 (1.8–2.2), 1.8 (1.6–2.1) µg/ml, whereas median ketamine concentrations slightly differed after 7 h compared to 1 h: 1, 4, 7 h: 3.7 (IQR: 3.5–4.5), 3.8 (3.3–4.1), 3.8 (3.0–4.1) µg/ml. Median rocuronium plasma concentrations were lower after 4 and 7 h compared to 1 h: 1, 4, 7 h: 3.9 (IQR: 3.5–4.9), 3.2 (2.7–3.3), 3.0 (2.4–3.4) µg/ml. Our anesthesia protocol provides stable and reliable anesthesia in mechanically ventilated rats for several hours.     

Plasma gonadotrophins, prolactin and corticosterone concentrations in male mice exposed to high altitude

Groups of sexually-naive male NFR/N mice were maintained at sea level or exposed to simulated altitudes of 18 000 ft (5486 m) or 22 000 ft (6705 m) for 1, 3, 7, 14 or 28 days. Plasma LH concentrations were slightly but not significantly depressed after 1 day of hypoxia. Plasma FSH values were reduced (P < 0.05) after 1, 7, 14 and 28 days of exposure to 22 000 ft when compared to the values in the other groups. Prolactin concentrations fluctuated considerably, but were not uniformly affected by high altitude exposure. Exposure to 18 000 ft resulted in an elevation of plasma corticosterone concentration (P < 0.05) for 3 days, which was followed by a decline to control group values, whereas at 22 000 ft corticosterone levels remained elevated. These findings indicate that plasma LH values are transiently reduced during the initial 24 h of exposure to high altitude and that plasma FSH concentrations are depressed in a sustained manner during severe hypoxia.     

Effect of Maternal Probiotic Intervention on HPA Axis,Immunity and Gut Microbiota in a Rat Model of Irritable Bowel Syndrome

Objective

To examine whether maternal probiotic intervention influences the alterations in the brain-immune-gut axis induced by neonatal maternal separation (MS) and/or restraint stress in adulthood (AS) in Wistar rats.

Design

Dams had free access to drinking water supplemented with Bifidobacterium animalis subsp lactis BB-12® (3×10⁹ CFU/mL) and Propionibacterium jensenii 702 (8.0×10⁸ CFU/mL) from 10 days before conception until postnatal day (PND) 22 (weaning day), or to control ad lib water. Offspring were subjected to MS from PND 2 to 14 or left undisturbed. From PND 83 to 85, animals underwent 30 min/day AS, or were left undisturbed as controls. On PND 24 and 86, blood samples were collected for corticosterone, ACTH and IgA measurement. Colonic contents were analysed for the composition of microflora and luminal IgA levels.

Results

Exposure to MS significantly increased ACTH levels and neonatal fecal counts of aerobic and anaerobic bacteria, E. coli, enterococci and clostridia, but reduced plasma IgA levels compared with non-MS animals. Animals exposed to AS exhibited significantly increased ACTH and corticosterone levels, decreased aerobic bacteria and bifidobacteria, and increased Bacteroides and E. coli counts compared to non-AS animals. MS coupled with AS induced significantly decreased anaerobes and clostridia compared with the non-stress adult controls. Maternal probiotic intervention significantly increased neonatal corticosterone levels which persisted until at least week 12 in females only, and also resulted in elevated adult ACTH levels and altered neonatal microflora comparable to that of MS. However, it improved plasma IgA responses, increased enterococci and clostridia in MS adults, increased luminal IgA levels, and restored anaerobes, bifidobacteria and E. coli to normal in adults.

Conclusion

Maternal probiotic intervention induced activation of neonatal stress pathways and an imbalance in gut microflora. Importantly however, it improved the immune environment of stressed animals and protected, in part, against stress-induced disturbances in adult gut microflora.     

Plasma prostaglandin levels during early neonatal life following term and pre-term delivery

The concentrations of prostaglandin E (PGE), prostaglandin F (PGF) and 13,14-dihydro-15-oxo-PGF (PGFM) have been measured by sensitive and specific radioimmunoassays in neonatal plasma after term and pre-term delivery. Blood samples were taken in the term delivery group from the umbilical artery at birth and on the sixth post-natal day and after pre-term delivery at 2–4 days, on the sixth day, at 2–4 weeks and at 5–8 weeks after birth. The levels of prostaglandins circulating during the first month of life were far greater than those found in normal adults. In neonates delivered at term the plasma concentration of PGE was significantly lower six days after delivery compared with the concentration at delivery whereas the concentrations of PGF and PGFM were essentially unchanged. Following pre-term delivery prostaglandin concentrations declined with increasing neonatal age although only levels of PGE at 5–8 weeks of age were within the normal range of adult values. Comparison of prostaglandin levels six days after delivery between neonates born at term and pre-term showed no significant differences. These results suggest that prematurity is not associated with marked abnormalities in the ability of the neonate to synthesize or metabolize prostaglandins.     

Hydrogel-Forming Microneedles Prepared from “Super Swelling” Polymers Combined with Lyophilised Wafers for Transdermal Drug Delivery

We describe, for the first time, hydrogel-forming microneedle arrays prepared from “super swelling” polymeric compositions. We produced a microneedle formulation with enhanced swelling capabilities from aqueous blends containing 20% w/w Gantrez S-97, 7.5% w/w PEG 10,000 and 3% w/w Na₂CO₃ and utilised a drug reservoir of a lyophilised wafer-like design. These microneedle-lyophilised wafer compositions were robust and effectively penetrated skin, swelling extensively, but being removed intact. In in vitro delivery experiments across excised neonatal porcine skin, approximately 44 mg of the model high dose small molecule drug ibuprofen sodium was delivered in 24 h, equating to 37% of the loading in the lyophilised reservoir. The super swelling microneedles delivered approximately 1.24 mg of the model protein ovalbumin over 24 h, equivalent to a delivery efficiency of approximately 49%. The integrated microneedle-lyophilised wafer delivery system produced a progressive increase in plasma concentrations of ibuprofen sodium in rats over 6 h, with a maximal concentration of approximately 179 µg/ml achieved in this time. The plasma concentration had fallen to 71±6.7 µg/ml by 24 h. Ovalbumin levels peaked in rat plasma after only 1 hour at 42.36±17.01 ng/ml. Ovalbumin plasma levels then remained almost constant up to 6 h, dropping somewhat at 24 h, when 23.61±4.84 ng/ml was detected. This work represents a significant advancement on conventional microneedle systems, which are presently only suitable for bolus delivery of very potent drugs and vaccines. Once fully developed, such technology may greatly expand the range of drugs that can be delivered transdermally, to the benefit of patients and industry. Accordingly, we are currently progressing towards clinical evaluations with a range of candidate molecules.     

Endocrine Changes in Premature Labour

Plasma oestradiol and progesterone levels in peripheral blood have been studied before and during premature labour of unknown aetiology. Hormones were measured by radio-immunoassay using specific antisera. Levels in patients who delivered prematurely were compared with levels measured serially in 33 primigravidae during normal pregnancy and labour.In 19 out of 25 patients admitted in progressive premature labour the plasma oestradiol level was two standard deviations or more above the mean for the control patients of similar gestational age. The mean (± S.E. of mean) plasma oestradiol in premature labour was 19·1 ± 1·1 ng/ml, similar to levels found in labour at term (18·5 ± 1·4 ng/ml). In contrast, in over 50% of cases levels of plasma progesterone during premature labour lay below the mean for gestation though within the normal range. In six patients studied serially oestradiol levels rose dramatically, high values being detected one to 10 days before the onset of premature labour. Serial progesterone levels gave no consistent trend though one patient showed steadily decreasing values.These studies suggest that the onset of premature labour is preceded by a marked increase in peripheral plasma oestradiol levels, which may be of value not only in the prediction of premature labour but also in its prevention by suppression of the premature oestradiol surge.     

Serum and Urinary Folate in Liver Disease

During the active phase of viral hepatitis urinary folate loss was found to be 8·0 to 48·3 (mean 31·1) μg./day, compared with a normal urinary folate excretion of 0·1 to 18·0 (mean 9·5) μg./day. In cirrhosis and cardiac failure with congestive hepatomegaly the corresponding values were 25·8 to 55·0 (mean 35·7) μg./day and 2·5 to 61·6 (mean 26·9) μg./day, respectively. Urinary folate loss may be a significant factor in the aetiology of folate deficiency of chronic liver disease, particularly when dietary intake is poor.After prolonged dialysis in Visking casing urinary folate was almost totally dialysable, but an appreciable fraction of serum folate was not, even after 72 hours. The dialysable (free) folate fraction of serum and urine disappeared maximally during the first six hours'' dialysis, and was virtually cleared after 24 hours'' dialysis; clearance curves in normal individuals and in liver disease were comparable. The non-dialysable serum folate fraction was of similar magnitude in all subjects studied, in spite of marked variation in total folate, and probably represented protein-bound folate.     

Postnatal development of β-galactosidase activity in the small intestine of the rat. Effect of adrenalectomy and diet

1. β-Galactosidase activity was studied in homogenates of the proximal and distal thirds of the small intestine from adult and infant rats. o-Nitrophenyl β-d-galactoside served as the substrate. 2. Activity in suckling rats is highest in the distal part of the small intestine. 3. The pH optimum was 3·5 in the distal third of the small intestine in rats aged 5 and 15 days, whereas in the proximal third the maximum was not clearly defined. 4. Activity was higher in both thirds in newborn than in adult rats, expressed per wet wt. or per wt. of protein. In the proximal third activity continually decreases with age, whereas in the distal part there is a rise up to day 15 and then a sudden decrease. Total β-galactosidase activity changes very little in the proximal third during postnatal development; the greatest changes occur in the distal third. 5. Adrenalectomy performed on day 15 postnatally slows down the decrease in β-galactosidase activity, particularly in the distal part. 6. Feeding a lactose diet to infant rats from day 14 postnatally in the presence of the mother rat also slows down the decrease in β-galactosidase activity and this is not found with a diet containing glucose and galactose instead of lactose.     

Progesterone and the initiation of parturition in the goat

The corpora lutea were surgically removed from 6 goats between 134 and 136 days of pregnancy and progesterone was administered daily. Pregnancy was prolonged past normal term in 4 goats receiving 25 mgs. of progesterone daily as a split dose. However, eventual delivery following progesterone withdrawal was abnormal and foetal mortality high.The progesterone therapy regime maintained maternal jugular plasma concentrations of progesterone in excess of 3 ng/ml. In normal untreated goats, maternal plasma concentrations of progesterone declined over the last 6 days of gestation. In treated goats, plasma concentrations of progesterone fell only after the cessation of therapy. Maternal plasma concentrations of estrogen rose within 24 hours of parturition in normal untreated goats. In the 4 goats in which pregnancy was prolonged, by progesterone administration, maternal plasma concentrations of estrogen were elevated for several days in the period before eventual foetal delivery.     

The tissue content and turnover rates of intermediates in the biosynthesis of glycosaminoglycans in young rat skin

1. The tissue contents of hexose monophosphate, N-acetylglucosamine 6-phosphate, UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, UDP-N-acetylgalactosamine and UDP-glucuronic acid were determined in the skin of young rats less than 1 day post partum. Tissue-space determinations were used to calculate their average cellular concentrations. 2. The incorporation of [U-¹⁴C]-glucose into the intermediates was recorded with time and their rates of turnover were calculated. The results demonstrated product–precursor relationships along the pathway of hexosamine synthesis and that of hexuronic acid synthesis. The rates of synthesis of UDP-N-acetylhexosamine and UDP-glucuronic acid were 1·5±0·3 and 0·24±0·03mμmoles/min./g. of tissue respectively. These results indicated the average turnover time of the total tissue glycosaminoglycans to be about 5 days.     

Losartan reduces oxidative damage to renal DNA and conserves plasma antioxidant capacity in diabetic rats

Increased reactive oxygen species (ROS) levels produced by hyperglycemia and angiotensin-II (AT-II) are considered among the pathogenic factors in the malignant transformation of diabetic renal cells. We aimed to investigate the potential role of AT-II in the increased cancer risk seen in diabetes; measuring oxidative damage to renal DNA and protective antioxidant defenses, including adiponectin (Adp) and plasma antioxidant capacity by the Ferric Reducing Ability of Plasma (FRAP) method. In the kidney of streptozotocin (STZ)-induced (55 mg/kg) diabetic rats either treated or not treated for 3 weeks with losartan, an AT-II type 1 receptor antagonist (20 mg/kg/day); we measured 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) levels, as an index of oxidative DNA damage, circulating Adp and FRAP. Diabetic rats showed significantly higher 8-oxodGuo levels in renal DNA (8.48 ± 0.98 × 10⁻⁶ dG, mean ± SEM n = 11) than normoglycemic ones (1.18 ± 0.04 × 10⁻⁶ dG, mean ± SEM, n=7) and lower plasma Adp and FRAP levels in comparison to normoglycemics. The treatment of diabetic rats with losartan significantly (P < 0.01) reduced 8-oxodGuo levels (5.4 ± 0.58 × 10⁻⁶ dG, mean ± SEM n=9) in renal DNA and conserved FRAP values. Moreover, an inverse correlation was found between 8-oxodGuo in kidney DNA and circulating Adp levels in normoglycemic and diabetic rats. Losartan treatment preserves FRAP levels, reduces DNA oxidative injury and thus the carcinogenesis risk. Furthermore, our results indicate that Adp plasma levels are a further marker of oxidative injury to the kidney and confirm that it is an important part of the plasma antioxidant defense.     

Lysosomal enzyme changes in growing and regressing mammary tumours

Rat mammary tumours induced by 7,12-dimethylbenz[a]anthracene can undergo repeated growth and regression during successive pregnancies. In a 10-day period after birth about half of the tumours regressed 50% or more. The concentrations of the lysosomal enzymes increased in regressing mammary tumours to the following multiples of the initial values: β-glucuronidase, 7·7; β-galactosidase, 3·9; cathepsin, 2·9; acid ribonuclease, 2·1; arylsulphatase A, 1·5; acid phosphatase, 1·4. In contrast, several non-lysosomal enzymes failed to increase. Activities in the post-partum uterus increased to the following multiples of the initial values: β-glucuronidase, 5·8; cathepsin, 5·5; acid ribonuclease, 4·3; β-galactosidase, 2·2; acid phosphatase, 1·8. Arylsulphatase A in the post-partum uterus decreased significantly, suggesting a non-lysosomal distribution or a special function related to pregnancy. No other significant changes were observed in the lysosomal or non-lysosomal enzymes in the hormone-independent liver or hormone-dependent normal mammary gland. The ratio of free to bound arylsulphatase A and acid ribonuclease decreased slightly 1–3 days after birth because of problems in homogenizing the tumours. At days 4–8, however, there was a dramatic increase in the ratio of the free to bound activities. The results can be explained in terms of the lysosomal theory of intracellular digestion.     

A New Method to Derive Fetal Heart Rate from Maternal Abdominal Electrocardiogram: Monitoring Fetal Heart Rate during Cesarean Section

BackgroundMonitoring of fetal heart rate (FHR) is important during labor since it is a sensitive marker to obtain significant information about fetal condition. To take immediate response during cesarean section (CS), we noninvasively derive FHR from maternal abdominal ECG.MethodsWe recruited 17 pregnant women delivered by elective cesarean section, with abdominal ECG obtained before and during the entire CS. First, a QRS-template is created by averaging all the maternal ECG heart beats. Then, Hilbert transform was applied to QRS-template to generate the other basis which is orthogonal to the QRS-template. Second, maternal QRS, P and T waves were adaptively subtracted from the composited ECG. Third, Gabor transformation was applied to obtain time-frequency spectrogram of FHR. Heart rate variability (HRV) parameters including standard deviation of normal-to-normal intervals (SDNN), 0V, 1V, 2V derived from symbolic dynamics of HRV and SD1, SD2 derived from Poincareé plot. Three emphasized stages includes: (1) before anesthesia, (2) 5 minutes after anesthesia and (3) 5 minutes before CS delivery.ResultsFHRs were successfully derived from all maternal abdominal ECGs. FHR increased 5 minutes after anesthesia and 5 minutes before delivery. As for HRV parameters, SDNN increased both 5 minutes after anesthesia and 5 minutes before delivery (21.30±9.05 vs. 13.01±6.89, P < 0.001 and 22.88±12.01 vs. 13.01±6.89, P < 0.05). SD1 did not change during anesthesia, while SD2 increased significantly 5 minutes after anesthesia (27.92±12.28 vs. 16.18±10.01, P < 0.001) and both SD2 and 0V percentage increased significantly 5 minutes before delivery (30.54±15.88 vs. 16.18±10.01, P < 0.05; 0.39±0.14 vs. 0.30±0.13, P < 0.05).ConclusionsWe developed a novel method to automatically derive FHR from maternal abdominal ECGs and proved that it is feasible during CS.     

myo-Inositol homeostasis in foetal rabbit lung

In several species, lung maturation is accompanied by a decline in the phosphatidylinositol content of lung surfactant and a concomitant increase in its phosphatidylglycerol content. To examine the possibility that this developmental change is influenced by the availability of myo-inositol, potential sources of myo-inositol for the developing rabbit lung were investigated. On day 28 of gestation the myo-inositol content of foetal rabbit lung tissue (2.3±0.5μmol/g of tissue) was not significantly different from that of adult lung tissue but the activity of d-glucose 6-phosphate:1l-myo-inositol 1-phosphate cyclase (cyclase) in foetal lung tissue (81.0±9.0nmol·h⁻¹·g of tissue⁻¹) was higher than that found in adult lung tissue (23.2±1.0nmol·h⁻¹·g of tissue⁻¹). Day 28 foetal rabbit lung tissue was found also to take up myo-inositol by a specific, energy-dependent, Na⁺-requiring mechanism. Half-maximal uptake of myo-inositol by foetal rabbit lung slices was observed when the concentration of myo-inositol in the incubation medium was 85μm. When the myo-inositol concentration was 1mm (but not 100μm) the addition of glucose (5.5mm) stimulated myo-inositol uptake. myo-Inositol uptake was observed also in adult rabbit lung and was found to be sub-maximal at the concentration of myo-inositol found in adult rabbit serum. The concentration of myo-inositol in the serum of pregnant adult rabbits (47.5±5.5μm) was significantly lower than that of non-pregnant adult female rabbits (77.9±9.2μm). On day 28 of gestation the concentration of myo-inositol in foetal serum (175.1±12.0μm) was much less than on day 25, but more than that found on day 30. A transient post-partum increase in the concentration of myo-inositol in serum was followed by a rapid decline. Much of the myo-inositol in foetal rabbit serum probably originates from the placenta, where on day 28 of gestation a high cyclase activity (527±64nmol·h⁻¹·g of tissue⁻¹) was measured. The gestational decline in serum myo-inositol concentration, together with the decreasing cyclase activity of the lungs, is consistent with the view that maturation of the lungs is accompanied by decreased availability of myo-inositol to this tissue.