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Nishijo M, Pham TT, Pham NT, Duong HTT, Tran NN, Kondoh T, Nishino Y, Nishimaru H, Do QB, Nishijo H. Nutritional Intervention with Dried Bonito Broth for the Amelioration of Aggressive Behaviors in Children with Prenatal Exposure to Dioxins in Vietnam: A Pilot Study. Nutrients 2021; 13:nu13051455. [PMID: 33922941 PMCID: PMC8145378 DOI: 10.3390/nu13051455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 12/04/2022] Open
Abstract
Dioxins have been suggested to induce inflammation in the intestine and brain and to induce neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), partly due to deficits in parvalbumin-positive neurons in the brain that are sensitive to inflammatory stress. Previously, we reported ADHD traits with increased aggressiveness in children with prenatal exposure to dioxins in Vietnam, whereas dried bonito broth (DBB) has been reported to suppress inflammation and inhibit aggressive behavior in animal and human studies. In the present study, we investigated the association between dioxin exposure and the prevalence of children with highly aggressive behaviors (Study 1), as well as the effects of DBB on the prevalence of children with highly aggressive behaviors (Study 2). Methods: In Study 1, we investigated the effects of dioxin exposure on the prevalence of children with high aggression scores, which were assessed using the Children’s Scale of Hostility and Aggression: Reactive/Proactive (C-SHARP) in dioxin-contaminated areas. The data were analyzed using a logistic regression model after adjusting for confounding factors. In Study 2, we performed nutritional intervention by administering DBB for 60 days to ameliorate the aggressiveness of children with high scores on the C-SHARP aggression scale. The effects of DBB were assessed by comparing the prevalence of children with high C-SHARP scores between the pre- and post-intervention examinations. Results: In Study 1, only the prevalence of children with high covert aggression was significantly increased with an increase in dioxin exposure. In Study 2, in the full ingestion (>80% of goal ingestion volume) group, the prevalence of children with high covert aggression associated with dioxin exposure was significantly lower in the post-ingestion examination compared with in the pre-ingestion examination. However, in other ingestion (<20% and 20–79%) groups and a reference (no intervention) group, no difference in the prevalence of children with high covert aggression was found between the examinations before and after the same experimental period. Conclusions: The findings suggest that DBB ingestion may ameliorate children’s aggressive behavior, which is associated with perinatal dioxin exposure.
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Affiliation(s)
- Muneko Nishijo
- Department of Public Health, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan; (M.N.); (Y.N.)
| | - Tai The Pham
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Hanoi 193824, Vietnam; (T.T.P.); (N.T.P.); (Q.B.D.)
| | - Ngoc Thao Pham
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Hanoi 193824, Vietnam; (T.T.P.); (N.T.P.); (Q.B.D.)
| | | | - Ngoc Nghi Tran
- Ministry of Health, Vietnam Government, Hanoi 111000, Vietnam;
| | - Takashi Kondoh
- Department of Food Science and Nutrition, Faculty of Agriculture, Kindai University, Nara 631-8505, Japan;
| | - Yoshikazu Nishino
- Department of Public Health, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan; (M.N.); (Y.N.)
| | - Hiroshi Nishimaru
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan;
| | - Quyet Ba Do
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Hanoi 193824, Vietnam; (T.T.P.); (N.T.P.); (Q.B.D.)
| | - Hisao Nishijo
- System Emotional Science, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan;
- Correspondence: ; Tel.: +81-764347215
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Pham NT, Nishijo M, Nghiem TTG, Pham TT, Tran NN, Le VQ, Vu TH, Tran HA, Phan HAV, Do Q, Takiguchi T, Nishino Y, Nishijo H. Effects of perinatal dioxin exposure on neonatal electroencephalography (EEG) activity of the quiet sleep stage in the most contaminated area from Agent Orange in Vietnam. Int J Hyg Environ Health 2020; 232:113661. [PMID: 33296778 DOI: 10.1016/j.ijheh.2020.113661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/23/2020] [Accepted: 11/01/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the effects of perinatal dioxin exposure indicated by dioxins in breast milk on neonatal electroencephalography (EEG) power in the quiet sleep stage, and associations with neurodevelopmental outcomes at 2 years of age. STUDY DESIGN Fifty-one mother-newborn pairs were enrolled for neonatal EEG analysis in the quiet sleep stage from a birth cohort recruited at a prefecture hospital in Bien Hoa city, Vietnam. Relative EEG power in intra-burst-intervals and high-voltage-bursts in the trace alternant pattern were computed from EEG data during the quiet sleep stage. Forty-three mother-child pairs participated in a 2-year follow-up survey to examine neurodevelopment using the Bayley-III scale and gaze behavior exhibited by fixation duration on the face of a child talking in videos. The general linear model and regression linear model were used for data analysis after adjusting for confounding factors. RESULTS Perinatal dioxin exposure, particularly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure, influenced relative EEG power values mainly in the intra-burst-interval part of the trace alternant pattern in the quiet sleep stage. In intra-burst-intervals, decreased frontal delta power and increased frontal and parietal alpha power values in the left hemisphere and temporal beta power values in the right hemisphere were associated with increased TCDD exposure, with significant dose-response relationships. Almost none of the relative power values in these brain regions were associated with Bayley III scores, but relative delta power values were significantly associated with face fixation duration in left frontal and parietal regions at 2 years of age. CONCLUSION Perinatal dioxin exposure influences neuronal activity in the quiet sleep stage, leading to poor communication ability indicated by gaze behavior in early childhood.
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Affiliation(s)
- Ngoc Thao Pham
- Department of Epidemiology and Public Health, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Muneko Nishijo
- Department of Epidemiology and Public Health, Kanazawa Medical University, Ishikawa, 920-0293, Japan.
| | - Thi Thuy Giang Nghiem
- System Emotional Science, Graduate School of Medicine, University of Toyama, Toyama, Japan
| | - The Tai Pham
- Vietnam Military Medical University, 160 Phung Hung, Ha Dong, Ha Noi, Viet Nam
| | - Ngoc Nghi Tran
- Ministry of Health, Vietnamese Government, Hanoi, Viet Nam
| | - Van Quan Le
- Vietnam Military Medical University, 160 Phung Hung, Ha Dong, Ha Noi, Viet Nam
| | - Thi Hoa Vu
- Department of Epidemiology and Public Health, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Hai Anh Tran
- Vietnam Military Medical University, 160 Phung Hung, Ha Dong, Ha Noi, Viet Nam
| | - Huy Anh Vu Phan
- Department of Health, Dongnai Prefectural Government, Bienhoa, Dongnai, Viet Nam
| | - Quyet Do
- Vietnam Military Medical University, 160 Phung Hung, Ha Dong, Ha Noi, Viet Nam
| | - Tomoya Takiguchi
- Department of Epidemiology and Public Health, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Yoshikazu Nishino
- Department of Epidemiology and Public Health, Kanazawa Medical University, Ishikawa, 920-0293, Japan
| | - Hisao Nishijo
- System Emotional Science, Graduate School of Medicine, University of Toyama, Toyama, Japan
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Pham NT, Nishijo M, Pham TT, Tran NN, Le VQ, Tran HA, Phan HAV, Nishino Y, Nishijo H. Perinatal dioxin exposure and neurodevelopment of 2-year-old Vietnamese children in the most contaminated area from Agent Orange in Vietnam. Sci Total Environ 2019; 678:217-226. [PMID: 31075589 DOI: 10.1016/j.scitotenv.2019.04.425] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/28/2019] [Accepted: 04/28/2019] [Indexed: 05/19/2023]
Abstract
Bien Hoa airbase is the most contaminated area of dioxin contamination from Agent Orange in Vietnam, but little is known about the neurodevelopmental effects of perinatal dioxin exposure on children living nearby. We recruited 210 mother-newborn resident pairs in 2012 and 78 pairs in 2015 and followed them for 2 years to assess the children's neurodevelopment. As a control group, we used 120 mother-child pairs recruited in 2014 in the Ha Dong district of Ha Noi City, an unexposed area. Perinatal dioxin exposure levels were indicated by levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and toxic equivalency values of polychlorodibenzodioxins, polychlorodibenzofurans, and nonortho-polychlorinated biphenyls (TEQ-PCDD/Fs/noPCBs) in maternal breast milk. The Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) were used to assess neurodevelopment, and scores in each domain were compared between children with different exposure levels using general linear regression models and stratification by sex. Decreased expressive and composite language scores in boys and gross motor scores in girls were found in children exposed to TCDD ≥ 5.5 (pg/g lipid) compared with children with TCDD < 1.8. However, in matched pair analysis between children with TCDD ≥ 5.5 and <1.8 (pg/g lipid), lower expressive and composite language scores in boys exposed to TCDD ≥ 5.5 were significant, but lower gross motor scores in girls did not reach statistical significance. In addition, significant association was found between levels of PCDD congeners other than TCDD and gross motor scores in boys. These findings suggest that perinatal exposure of TCDD and other PCDD congeners affects development of language and gross motor skills, respectively, in boys at 2 years of age exposed to dioxins originating from Agent Orange in Vietnam.
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Affiliation(s)
- Ngoc Thao Pham
- Department of Public Health, Kanazawa Medical University, Japan; Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Viet Nam
| | - Muneko Nishijo
- Department of Public Health, Kanazawa Medical University, Japan.
| | - The Tai Pham
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Viet Nam
| | | | - Van Quan Le
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Viet Nam
| | - Hai Anh Tran
- Biomedical and Pharmaceutical Research Center, Vietnamese Military Medical University, Viet Nam
| | - Huy Anh Vu Phan
- Department of Health, Dong Nai Prefecture Government, Bien Hoa, Viet Nam
| | | | - Hisao Nishijo
- System Emotional Science, Graduate School of Medicine, University of Toyama, Japan
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Nishijo M, Pham TT, Nguyen ATN, Tran NN, Nakagawa H, Hoang LV, Tran AH, Morikawa Y, Ho MD, Kido T, Nguyen MN, Nguyen HM, Nishijo H. 2,3,7,8-Tetrachlorodibenzo-p-dioxin in breast milk increases autistic traits of 3-year-old children in Vietnam. Mol Psychiatry 2014; 19:1220-6. [PMID: 24637425 DOI: 10.1038/mp.2014.18] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/18/2014] [Accepted: 02/03/2014] [Indexed: 01/29/2023]
Abstract
Dioxin levels in the breast milk of mothers residing near a contaminated former airbase in Vietnam remain much higher than in unsprayed areas, suggesting high perinatal dioxin exposure for their infants. The present study investigated the association of perinatal dioxin exposure with autistic traits in 153 3-year-old children living in a contaminated area in Vietnam. The children were followed up from birth using the neurodevelopmental battery Bayley-III. The high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposed groups (⩾3.5 pg per g fat) showed significantly higher Autism Spectrum Rating Scale (ASRS) scores for both boys and girls than the mild-TCDD exposed groups, without differences in neurodevelopmental scores. In contrast, the high total dioxin-exposed group, indicated by polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs)--the toxic equivalents (TEQ) levels⩾17.9 pg-TEQ per g fat, had significantly lower neurodevelopmental scores than the mild-exposed group in boys, but there was no difference in the ASRS scores. The present study demonstrates a specific impact of perinatal TCDD on autistic traits in childhood, which is different from the neurotoxicity of total dioxins (PCDDs/Fs).
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Affiliation(s)
- M Nishijo
- Department of Public Health, Kanazawa Medical University, Ishikawa, Japan
| | - T T Pham
- Biomedical and Pharmaceutical Research Center, Vietnam Military Medical University, Ha Noi, Vietnam
| | - A T N Nguyen
- Department of Public Health, Kanazawa Medical University, Ishikawa, Japan
| | - N N Tran
- Department of Public Health, Kanazawa Medical University, Ishikawa, Japan
| | - H Nakagawa
- Department of Public Health, Kanazawa Medical University, Ishikawa, Japan
| | - L V Hoang
- Biomedical and Pharmaceutical Research Center, Vietnam Military Medical University, Ha Noi, Vietnam
| | - A H Tran
- Biomedical and Pharmaceutical Research Center, Vietnam Military Medical University, Ha Noi, Vietnam
| | - Y Morikawa
- School of Nursing, Kanazawa Medical University, Ishikawa, Japan
| | - M D Ho
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa, Japan
| | - T Kido
- Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa, Japan
| | - M N Nguyen
- 1] Biomedical and Pharmaceutical Research Center, Vietnam Military Medical University, Ha Noi, Vietnam [2] System Emotional Science, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan
| | - H M Nguyen
- 1] Biomedical and Pharmaceutical Research Center, Vietnam Military Medical University, Ha Noi, Vietnam [2] System Emotional Science, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan
| | - H Nishijo
- System Emotional Science, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan
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Robert A, Tran NN, Giummelly P, Atkinson J, Capdeville-Atkinson C. Sensitivity of norepinephrine-evoked vasoconstriction to pertussis toxin in the old rat. Am J Physiol 1998; 274:R1604-12. [PMID: 9608014 DOI: 10.1152/ajpregu.1998.274.6.r1604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In male Wistar rats, the in vitro vasoconstrictor response of the perfused tail artery elicited by norepinephrine or serotonin decreased with age (24 mo old vs. 3 mo old), whereas the fluorescent signal (fura 2) produced by intracellular calcium (Ca2+i) mobilization increased. Both vasoconstriction and the increase in intracellular calcium concentration elicited by a high-K+, depolarizing solution were unaffected by aging. Pertussis toxin, a G protein inhibitor, had no effect on vasoconstriction induced by high K+ but diminished vasoconstrictor responses to norepinephrine in 3- and 12-mo-old animals but not in 24-mo-old animals. Pertussis toxin had no effect on Ca2+i mobilization. The sensitivity of receptor activation to pertussis toxin in tail arteries from 24-mo-old animals was restored by pretreatment with the alpha-adrenoceptor antagonist nicergoline. Nicergoline had no effect on vasoconstriction induced by high K+. Plasma norepinephrine concentration rose with age; nicergoline had no effect on this rise. We suggest that aging leads to a decrease in the intracellular G protein-modulated amplification of vasoconstriction produced by receptor activation and that this could be linked to the hyperadrenergic state. Ca2+ sensitivity can be restored by chronic treatment with an alpha-adrenoceptor antagonist.
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Affiliation(s)
- A Robert
- Laboratoire de Pharmacologie Cardio-vasculaire, Universite Henri Poincare, Faculte de Pharmacie, 54001 Nancy Cedex, France
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Tran NN, Spitzbarth E, Robert A, Giummelly P, Atkinson J, Capdeville-Atkinson C. Nitric oxide lowers the calcium sensitivity of tension in the rat tail artery. J Physiol 1998; 507 ( Pt 1):163-74. [PMID: 9490833 PMCID: PMC2230774 DOI: 10.1111/j.1469-7793.1998.163bu.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
1. Controversy exists as to whether a fall in the intracellular Ca2+ concentration ([Ca2+]i) is a requisite element of the vasodilatory response to nitric oxide (NO). 2. We studied the effect of NO on the coupling between [Ca2+]i and vasoconstriction in arterial segments loaded with the [Ca2+]i-sensitive, intracellular dye fura-2. As data interpretation is equivocal when fura-2 is loaded into both endothelial and smooth muscle cells, we compared results from in vitro experiments on segments of the rat tail artery in which fura-2 and noradrenaline were applied on the luminal or adventitial side, and endothelium was removed 'physically' (rubbing or air) or 'functionally' (Nomega-nitro-L-arginine methyl ester). The use of air perfusion to remove endothelium is of considerable benefit since it allows paired observations in a single tissue. 3. Fura-2 loaded into endothelial cells but endothelial 'contamination' of the smooth muscle cell [Ca2+]i signal was minimal. 4. Endogenous NO decreased vasoconstrictor responses to noradrenaline but had no effect on [Ca2+]i. 5. Nitroglycerine decreased vasoconstrictor responses in a concentration-dependent fashion but had no effect on [Ca2+]i. 6. In conclusion, NO causes vasodilatation via a mechanism which is downstream of [Ca2+]i mobilization.
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Affiliation(s)
- N N Tran
- Laboratoire de Pharmacologie Cardio-vasculaire, Faculte de Pharmacie, Universite Henri Poincare-Nancy I, 5 rue Albert Lebrun, 54001 Nancy Cedex, France
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Tran NN, Robert A, Atkinson J, Capdeville-Atkinson C. Inhibition of oxidative phosphorylation, vascular tone, and [Ca2+]i in the perfused rat tail artery. Am J Physiol 1997; 273:C834-42. [PMID: 9316403 DOI: 10.1152/ajpcell.1997.273.3.c834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the possibility that the inhibition of oxidative phosphorylation in vascular smooth muscle attenuates norepinephrine- or KCl-evoked vasoconstriction with no change in mobilization of intracellular calcium concentration ([Ca2+]i). Experiments were performed in perfused segments of the rat tail artery loaded with the intracellular calcium dye fura 2, in the absence and presence of dinitrophenol or sodium cyanide; inhibition of oxidative phosphorylation was evaluated from the fall in intracellular ATP levels. The metabolic inhibitors reduced vasoconstriction with no change in [Ca2+]i handling, suggesting that 1) inhibition of oxidative phosphorylation attenuates vasoconstriction via a mechanism downstream of [Ca2+]i, and 2) [Ca2+]i homeostasis (both increases and decreases in [Ca2+]i) can be maintained in the presence of inhibitors of oxidative phosphorylation.
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Affiliation(s)
- N N Tran
- Laboratoire de Pharmacologie Cardio-vasculaire, Faculté de Pharmacie, Université Henri Poincaré-Nancy 1, France
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Abstract
Evidence of surfactant inactivation by meconium has led to the use of exogenous surfactant therapy in the management of meconium aspiration syndrome (MAS). Liquid assisted ventilation has been shown to improve the cardiopulmonary function in lungs with high surface tension. We compared exogenous surfactant therapy with liquid assisted ventilation in the management of experimental acute meconium aspiration injury. Thirty-two newborn lambs were ventilated at peak inspiratory pressures of 13-16 cm H2O, positive end expiratory pressure of 3-4 cm H2O, fractional inspired oxygen concentration (FiO2) of 1.0, and a respiratory frequency range between 30 and 35 breaths/min. Baseline arterial blood gases, pulmonary function, and arterial blood pressure measurements were taken. All lambs were given 2-3 ml/kg of an unfiltered 25% meconium solution. Lambs were then randomized into either gas-ventilated meconium control, or one of three treatment groups: 1) surfactant; 2) partial liquid ventilation (PLV); or 3) total liquid ventilation (TLV) for 4 hours after meconium injury. All treated groups demonstrated a significant increase in arterial oxygenation (P < 0.05); surfactant and PLV-treated lambs demonstrated significantly decreased arterial PCO2 (P < 0.05). Compliance in all groups increased compared with injury values; compliance of the TLV group increased more than in all other treatment groups (P < 0.05). In addition, lung histology of the TLV group demonstrated clear, intact alveolar epithelium and homogeneously expanded alveoli, while no such improvement was evident in the other groups. These data suggest roles for both exogenous surfactant therapy and liquid assisted ventilation techniques in the management of MAS.
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Affiliation(s)
- R Foust
- Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Tran NN, Leroy P, Bellucci L, Robert A, Nicolas A, Atkinson J, Capdeville-Atkinson C. Intracellular concentrations of fura-2 and fura-2/am in vascular smooth muscle cells following perfusion loading of fura-2/am in arterial segments. Cell Calcium 1995; 18:420-8. [PMID: 8581970 DOI: 10.1016/0143-4160(95)90057-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A new method for the determination of tissue concentrations of Fura-2 and Fura-2/AM was developed based upon acetonitrile extraction followed by RP-HPLC separation (using tetrahexylammonium as counter-ion), post-column alkaline hydrolysis of Fura-2/AM, and fluorimetric detection. The detection limit was 1.2 nM and 1 nM for Fura-2 and Fura-2/AM, respectively. When this technique was applied to perfusion-loaded segments of the rat tail artery, intracellular concentrations of Fura-2 determined by tissue disruption were 10 times those obtained by comparing the increase in fluorescence at the isoemissive point (following loading), with a calibration curve for Fura-2. Loading conditions of 90 min at [Fura-2/AM]e = 5 microM were optimal in terms of [Fura-2]i which attained a concentration not significantly different from [Fura-2/AM]e. Under such conditions, however, Fura-2/AM also accumulated in the arterial wall. Although incompletely de-esterified, Fura-2/AM metabolites produced by in vitro incubation of Fura-2/AM with pig liver esterases could be easily detected, fluorescent forms of Fura-2 with a different sensitivity for calcium were not detected in arterial extracts.
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Affiliation(s)
- N N Tran
- Laboratoire de Pharmacologie Cardio-vasculaire, URA CNRS 597, Faculté des Sciences Pharmaceutiques et Biologiques, Université Henri Poincaré-Nancy 1, France
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Wolfson MR, Durrant JD, Tran NN, Bhutani VK, Shaffer TH. Emergence of the brain-stem auditory evoked potential in the premature lamb. Electroencephalogr Clin Neurophysiol 1990; 75:242-50. [PMID: 1689647 DOI: 10.1016/0013-4694(90)90177-l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Brain-stem auditory evoked potentials (BAEPs) were elicited by bone conducted stimuli in the very immature lamb following delivery, wherein liquid ventilation techniques were utilized to control cardiopulmonary and acid-base conditions, independent of umbilical-placenta support. Unlike previous studies of the in utero fetal lamb in which the BAEP could not be elicited by earphone delivered stimuli until 117 days gestation, our results demonstrate that the BAEP emerges at least as early as 106 days gestation in the lamb and consists of a full complement of readily discernible and reproducible wave forms. In addition, the results demonstrate substantial maturation of the BAEP from 106 to 122 days gestation during which time there is a significant decrease in absolute and interpeak latencies with an increase in developmental age. It is concluded that the ability to elicit the BAEP utilizing bone conduction at this early stage of gestation is related to improved stimuli delivery. Furthermore, this study demonstrates the feasibility and flexibility afforded by liquid ventilation and bone conduction BAEP techniques to study brain-stem function at particularly vulnerable stages of development.
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Affiliation(s)
- M R Wolfson
- Department of Physiology, Temple University School of Medicine, Philadelphia, PA 19140
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Abstract
The inherent mechanical characteristics of the airways are determined in part by their elastic and viscoelastic properties. As compliant structures during early development, the airways are susceptible to significant distention and collapse, depending on the proportionality between airway volume and transmural pressure. To characterize the age-related changes in airway mechanical properties, the elastic and viscoelastic behavior of in vivo tracheal segments were evaluated in preterm and newborn lambs over a wide range of developmental age (108 to 154 days postconceptional age). Tracheal pressure-vol relationships and concomitant airway compliance measurements were used to determine elastic behavior. Calculations of the tracheal relaxation time constant on the same tracheal segments were used to evaluate airway viscoelastic behavior. Data demonstrated a significant (p less than 0.01) correlation with developmental age. With increasing age, the airways were found to be less compliant, and the tracheal relaxation time constant was observed to decrease. The difference in elastic properties of the trachea, in vivo compared to in vitro, suggest that neural-humoral and surrounding connective tissue factors may affect the elasticity of the developing airway. Although the modulating effects of smooth muscle tone and supporting connective tissue assist in the control of airway dimension and resistance to airflow in the intact airway, the age-related differences in the elastic properties may be a factor that predisposes the more immature airway to positive pressure-induced damage.
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Affiliation(s)
- T H Shaffer
- Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
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