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Silva LC, Angrimani DS, Regazzi FM, Lúcio CF, Veiga GA, Fernandes CB, Vannucchi CI. Exogenous surfactant replacement immediately at birth as preventive therapy for lung prematurity in neonatal lambs. Theriogenology 2021; 171:14-20. [PMID: 34000686 DOI: 10.1016/j.theriogenology.2021.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 11/26/2022]
Abstract
Surfactant treatment is a manner to reduce alveolar superficial tension and increase pulmonary compliance in premature neonates. Thus, we aimed to analyze the effect of exogenous surfactant treatment in combination with manual ventilation for preterm lambs. We used 15 ewes and their lambs (n = 16), prematurely born at 135 days. At birth, lambs were submitted to orotracheal intubation attached to a handheld resuscitation device and randomly allocated to: Control Group (n = 5; only manual ventilation), Single Surfactant Group (n = 5; manual ventilation coupled by intratracheal administration of 100 mg/kg surfactant) and Double Surfactant Group (n = 6; surfactant volume was divided into two doses (50 mg/kg + 50 mg/kg) administrated at birth and 30 min thereafter). A complete physical exam, arterial gas analysis, blood glucose, urea and creatinine concentration and chest radiographic assessment were performed at fixed times. All lambs had decreased body temperature until 20 min after birth. However, control and double surfactant groups reached a thermic plateau after 30 min. Regardless of the time-point, control lambs had higher heart rate in comparison to treated neonates, including bradycardia in Single Surfactant Group. Single instillation led to lower oxygenation degree, compared to the Double Surfactant Group, suggesting that surfactant treatment was not able to adequately spread within the alveoli. Lambs treated with surfactant had severe impairment of aerobic activity, leading to anaerobic metabolism. All groups had hypercapnia, which can be explained by inadequate respiratory pattern and pulmonary opacity (89% of the lambs had severe or moderate lung content). In conclusion, exogenous surfactant therapy in association with manual ventilation is ineffective in reverting pulmonary immaturity of the preterm lamb, leading to less vitality, hypoxemia, delayed pulmonary clearance and high mortality rate.
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Affiliation(s)
- Liege Cg Silva
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Daniel Sr Angrimani
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Fernanda M Regazzi
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Cristina F Lúcio
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Gisele Al Veiga
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Claudia B Fernandes
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil
| | - Camila I Vannucchi
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, University of São Paulo, Rua Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil.
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Kuma Y, Usumi-Fujita R, Hosomichi J, Oishi S, Maeda H, Nagai H, Shimizu Y, Kaneko S, Shitano C, Suzuki JI, Yoshida KI, Ono T. Impairment of nasal airway under intermittent hypoxia during growth period in rats. Arch Oral Biol 2014; 59:1139-45. [PMID: 25073088 DOI: 10.1016/j.archoralbio.2014.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 05/30/2014] [Accepted: 06/13/2014] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To clarify the influences of intermittent hypoxia (IH) on the growth and development of the midfacial area, including the nasal cavity, in growing rats. DESIGN Seven-week-old male Sprague-Dawley rats were divided into two groups: the experimental group (n=5), which was exposed to IH for 8h during light periods at a rate of 20 cycles/h (nadir, 4% O₂ to peak, 21% O₂ with 0% CO₂), and the control group (n=5), which was exposed to room air. After 3 weeks, the maxillofacial structures in both groups were evaluated with respect to the height, width, length, surface area, cross-sectional area, and volume of the nasal cavity using soft X-ray and micro-CT. RESULTS The experimental group showed a significantly smaller cross-sectional area and volume than did the control group. The surface area exhibited no significant differences between the two groups, although it tended to be smaller in the experimental group than in the control group. The nasal volume divided by the length of the tibia (for comparison with whole-body growth) was significantly smaller in the experimental group than in the control group. CONCLUSIONS These data suggest that IH exposure suppresses growth and development of the nasal cavity and may result in nasal breathing disturbance.
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Affiliation(s)
- Yoichiro Kuma
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Risa Usumi-Fujita
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Jun Hosomichi
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
| | - Shuji Oishi
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Hideyuki Maeda
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisashi Nagai
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasuhiro Shimizu
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Sawa Kaneko
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Chisa Shitano
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Jun-ichi Suzuki
- Department of Advanced Clinical Science and Therapeutics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ken-ichi Yoshida
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Ono
- Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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Abstract
The purpose of this review is to outline the physiological responses associated with the diving response, its functional significance, and its cardiorespiratory control. This review is separated into four major sections. Section one outlines the diving response and its physiology. Section two provides support for the hypothesis that the primary role of the diving response is the conservation of oxygen. The third section describes how the diving response is controlled and provides a model that illustrates the cardiorespiratory interaction. Finally, the fourth section illustrates potential adaptations that result after regular exposure to an asphyxic environment. The cardiovascular and endocrine responses associated with the diving response and apnea are bradycardia, vasoconstriction, and an increase in secretion of suprarenal catecholamines. These responses require the integration of both the cardiovascular system and the respiratory system. The primary role of the diving response is likely to conserve oxygen for sensitive brain and heart tissue and to lengthen the time before the onset of serious hypoxic damage. We suggest that future research should be focused towards understanding the role of altered ventilatory responses in human breath-hold athletes as well as in patients suffering from sleep-disordered breathing.
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Affiliation(s)
- G E Foster
- Health and Integrative Physiology Laboratory, School of Human Kinetics, University of British Columbia, Vancouver, BC, Canada
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