Precise calving monitoring is essential for minimizing the effects of dystocia in cows and calves. We conducted two studies in healthy cows that compared seven clinical signs (broad pelvic ligaments relaxation, vaginal secretion, udder hyperplasia, udder edema, teat filling, tail relaxation, and vulva edema) alone and in combination in order to predict the time of parturition. The relaxation of the broad pelvic ligaments combined with teat filling gave the best values for predicting either calving or no calving within 12 h. For the proposed parturition score (PS), a threshold of 4 PS points was identified below which calving within the next 12 h could be ruled out with a probability of 99.3% in cows (95.5% in heifers). Above this threshold, intermitted calving monitoring every 3 h and a progesterone rapid blood test (PRBT) would be recommended. By combining the PS and PRBT (if PS > or = 4), the prediction of calving within the next 12 h improved from 14.9% to 53.1%, and the probability of ruling out calving was 96.8%. The PRBT was compared to the results of an enzyme immunoassay (sensitivity, 90.2%; specificity, 74.9%). The standard operating procedure developed in this study that combines the PS and PRBT will enable veterinarians to rule out or predict calving within a 12 h period in cows with high accuracy under field conditions.
Animals ; Cattle/blood/*physiology ; Female ; Mammary Glands, Animal/physiology ; Parturition/*physiology ; Pregnancy ; Progesterone/blood ; ROC Curve ; Time Factors

Endocrine hormones are important factors in maintaining pregnancy as well as initiation of parturition. Progesterone is the major hormone maintaining myometrium quiescence, while glucocorticoids, prostaglandins and estrogen are among the major hormones involved in the initiation of parturition. Therefore progesterone withdrawal at the end of pregnancy is the prerequisite for the initiation of parturition. However, unlike most of the other species of mammals that the withdrawal of progesterone is achieved via reduction of progesterone synthesis or increased conversion of progesterone to estrogen, some mammals including the primates maintain high progesterone level throughout gestation and even during parturition. Accumulating lines of evidence indicate that the withdrawal of progesterone in human being is attained via the changes of the expression ratio of progesterone receptor subtypes and the changes of co-activators required for the activation of transcriptional activity of progesterone receptor. Here we reviewed the three major mechanisms, namely luteolysis, upregulation of placental P450c17 hydroxylase and changes of progesterone receptor functions, underlying progesterone withdrawal in late pregnancy in mammals.
Animals ; Female ; Humans ; Luteolysis ; physiology ; Parturition ; metabolism ; physiology ; Pregnancy ; Pregnancy Trimester, Third ; metabolism ; physiology ; Progesterone ; metabolism ; Receptors, Progesterone ; metabolism ; physiology ; Species Specificity ; Steroid 17-alpha-Hydroxylase ; metabolism

Pulmonary surfactant instillation is the treatment of choice in neonatal respiratory distress syndrome. The development of artificial surfactant has three decades of history. Animal-derived artificial surfactant is used in most countries and consists of 80% phospholipids and glycerol. 10% of the formulation is comprised of surfactant proteins, which have the critical role in surfactant function of lowering surface tension in the alveoli. Synthetic surfactants are made using synthetic peptide analogues as the surfactant protein counterparts. These are not the same as the human surfactant protein sequences; however, researchers are attempting to find the ideal synthetic peptide sequence for use in synthetic surfactants. Prophylactic and rescue surfactant therapy are two main therapeutic options. A recent recommendation emphasizes the importance of rescue therapy with continuous positive nasal airway pressure, rather than prophylactic use immediate after birth. This article briefly reviews the history and physiology of surfactant use, as well as clinical practice of surfactant and future studies.
Glycerol ; Humans ; Parturition ; Phospholipids ; Physiology ; Pulmonary Surfactants* ; Respiratory Distress Syndrome, Newborn ; Surface Tension ; Surface-Active Agents

BACKGROUND: Prenatal tongue development may affect oral-craniofacial structures, but this muscular organ has rarely been investigated. METHODS: In order to document the physiology of prenatal tongue growth, we histologically examined the facial and cranial base structures of 56 embryos and 106 fetuses. RESULTS: In Streeter's stages 13-14 (fertilization age [FA], 28 to 32 days), the tongue protruded into the stomodeal cavity from the retrohyoid space to the cartilaginous mesenchyme of the primitive cranial base, and in Streeter's stage 15 (FA, 33 to 36 days), the tongue rapidly swelled and compressed the cranial base to initiate spheno-occipital synchondrosis and continued to swell laterally to occupy most of the stomodeal cavity in Streeter's stage 16-17 (FA, 37 to 43 days). In Streeter's stage 18-20 (FA, 44 to 51 days), the tongue was vertically positioned and filled the posterior nasopharyngeal space. As the growth of the mandible and maxilla advanced, the tongue was pulled down and protruded anteriorly to form the linguomandibular complex. Angulation between the anterior cranial base (ACB) and the posterior cranial base (PCB) was formed by the emerging tongue at FA 4 weeks and became constant at approximately 124degrees-126degrees from FA 6 weeks until birth, which was consistent with angulations measured on adult cephalograms. CONCLUSIONS: The early clockwise growth of the ACB to the maxillary plane became harmonious with the counter-clockwise growth of the PCB to the tongue axis during the early prenatal period. These observations suggest that human embryonic tongue growth affects ACB and PCB angulation, stimulates maxillary growth, and induces mandibular movement to achieve the essential functions of oral and maxillofacial structures.
Adult ; Axis, Cervical Vertebra ; Embryonic Structures* ; Fetus* ; Humans ; Mandible ; Maxilla ; Mesoderm ; Parturition ; Physiology ; Skull Base ; Tongue*

The fetus is completely dependent on mother for glucose and other nutrient transfer across the placenta. At birth, when the maternal supply is discontinued, the neonate must adjust to an independent existence. The changes in the neonate's glucose homeostasis during this transition to the extrauterine environment are influenced by the mother's metabolism and intrinsic fetal and placental problems. Maturation of carbohydrate homeostasis results from a balance between substrate availability and coordination of developing hormonal, enzymatic, and neural systems. These mechanisms may not be fully developed in neonates, so the neonate is vulnerable to carbohydrate disequilibrium resulting in damage to the central nervous system. Hypoglycemia is a relatively common metabolic problem seen during newborn care. However its definition, management and long term sequalae remain controversial. Hyporglycemia occurs frequently as a transient disorder with excellent prognosis. It also may persist and recur and cause permanent neurological complications. Although the key to effective treatment of hypoglycemia is diagnostic specific, the maintenance of euglycemia is critical to the preservation of central nervous system function. This article discusses physiology of perinatal glucose homeostasis, focusing on evaluation and treatment of hypoglycemia.
Central Nervous System ; Fetus ; Glucose* ; Homeostasis ; Humans ; Hypoglycemia* ; Infant, Newborn* ; Metabolism* ; Mothers ; Parturition ; Physiology ; Placenta ; Prognosis

Preterm delivery is defined as delivering a fetus or fetuses before 37th gestational week. The incidence of preterm delivery has been reported to be 8-10% but is associated with 75% of perinatal mortality and morbidity, and long term sequelae such as cerebral palsy. The rates of preterm deliveries have actually increased in recent years for complex reasons despite widespread efforts to address the problem. A major drawback for the development of beneficial interventions of preterm delivery is the poor understanding of the normal physiology of human parturition. However, research efforts to elucidate this problem have risen substantially over the past decades, and there have been great advances in the understanding of the molecular and cellular pathways. This understanding has led to the development of several therapeutic strategies in terms of delaying the delivery and reducing the perinatal complications. Thus, we will discuss on the recent developments in therapeutic strategies in preterm labor and preterm premature rupture of membranes including antibiotics treatment, antenatal corticosteroid therapy and various tocolytic agents.
Anti-Bacterial Agents ; Cerebral Palsy ; Female ; Fetus ; Humans ; Incidence ; Membranes ; Obstetric Labor, Premature ; Parturition ; Perinatal Mortality ; Physiology ; Pregnancy ; Rupture ; Tocolytic Agents

OBJECTIVE: Leptin, the protein encoded by the Ob gene in the adipose cell, is produced by the placenta during pregnancy and materanal serum leptin is increased in preeclampsia. The objective of this study was to compare umbilical cord plasma leptin level between infants of mothers who experienced preeclampsia and infants of control subjects and to understand the physiology of leptin. METHODS: Leptin concentrations were measured in cord blood at birth using a specific radioimmunoassay employing human recombinant leptin (Human leptin RIA kit; Linco Research, Inc. U.S.A.). We compared cord plasma leptin between preeclamptic (n=17 women) and normal pregnancies (n=21 women). RESULTS: Gestational age is the only one significant variable among the demographic variables (P=0.011). There was no statistically significant difference in cord plasma leptin level between infants of mothers who experienced preeclampsia and infants of control subjects, but preeclampsia group had slightly lower leptin levels than control subjects (Control subjects: 4.8 [3.7-7.9] ng/ml, Preeclamptic women: 2.7 [2.3-6.8] ng/ml, P=0.142). There was also no difference in the leptin value adjusted for different gestational age, or ratio between cord plasma leptin level and gestational age (Control subjects: 0.017 [0.013-0.018], Preeclamptic women: 0.010 [0.008-0.025], P=0.131). CONCLUSION: We found no difference between umbilical cord plasma leptin in infants of mothers who had preeclampsia and umbilical cord plasma leptin in infants of control subjects, but insignificantly lower levels of umbilical cord plasma leptin in infants of mothers who had preeclampsia. It suggest that maternal serum concentration do not correlate with cord leptin concentration and dysregulation of leptin metabolism and/or function in the placenta may be implicated in the pathogenesis of preeclampsia.
Female ; Fetal Blood ; Gestational Age ; Humans ; Infant ; Leptin* ; Metabolism ; Mothers ; Parturition ; Physiology ; Placenta ; Plasma* ; Pre-Eclampsia ; Pregnancy ; Pregnant Women* ; Radioimmunoassay ; Umbilical Cord*

Gated myocardial SPECT and attenuation correction gave birth to new insights into the pathophysiology of ischemic myocardial perfusion and function in clinical routine practice. Gated myocardial Tc-99m-compound SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls as well as myocardial perfusion at the same time. Quantitative and qualitative assessement of myocardial performance and perfusion let us to understand the myocardial physiology in ischemia and infarction. In every patient who underwent gated perfusion SPECT, we will find ejection fraction, left ventricular volumes and regional wall motion. There are hopes to use gated T1-201 SPECT for the same purpose and to use gated SPECT for evaluation of wall motion and thickening at stress or immediate post-stress. Attenuation correction could improve diagnostic accuracy mainly by increasing normalcy ratio or performance of non-expert physicians. Both gated methods and attenuation correction improved specificity of non-expert physicians in diagnosing patients with moderate pretest likelihood. New imaging techniques will fill the desire of cardiologists examine function and perfusion, and possibly metabolism in their clinical routine practice.
Coronary Artery Disease ; Hope ; Humans ; Infarction ; Ischemia ; Linear Energy Transfer ; Metabolism ; Parturition ; Perfusion* ; Physiology ; Sensitivity and Specificity ; Tomography, Emission-Computed, Single-Photon*

BACKGROUND AND OBJECTIVES: Detailed information on how an epithelial differentiation and elastic structures occurred in the developing eustachian tube would be helpful in understanding both normal physiology and pathology of the tubotympanum. This study was undertaken to establish elastic structures such as cartilage, elastic fiber, and collagen fiber in the embryonic mouse eustachian tube at a stage when epithelial differentiation is taking place. MATERIALS AND METHOD: Thirty four mice (BALB/c mouse), aged from gestational day 11 to postnatal day 21, were investigated using Verhoeff stain, Masson trichrome stain and alpha-1 antitrypsin immunohistochemistry. RESULTS: The cartilage-like structures were first found after birth, however, matured cartilages appeared at postnatal day 7. The elastic fibers and collagen fibers surrounding cartilage were abundantly found about 5 days after birth. alpha-1 antitrypsin, which is an strong inhibitor of elastase, began to be immunolabelled at gestational day 16. Its expression has been significantly increased after birth. CONCLUSION: Although the epithelial differentiation and maturation in eustachian tube occured at late embryonal stage, the elastic structures have developed and matured after birth. These findings might be a explanation to why young children are highly susceptible to otitis media.
Animals ; Cartilage ; Child ; Collagen ; Elastic Cartilage ; Elastic Tissue ; Elasticity ; Eustachian Tube* ; Humans ; Immunohistochemistry ; Mice ; Otitis Media ; Pancreatic Elastase ; Parturition ; Pathology ; Physiology

Thyroid hormone is important in brain development. Thus, thyroid hormone deficiency during the critical period of brain development results in severe cognitive and motor dysfunctions. Along with the development of intensive care for premature infants, the survival rates of premature babies and the long-term complications associated with neurodevelopment and motor function have increased. Premature infants differ from full-term infants in terms of the change in thyroid hormone level after birth because of the immaturity of their hypothalamus-pituitary-thyroid axis. Therefore, the diagnostic and therapeutic criteria for hypothyroidism in premature infants still remain unclear. In addition, as the thyroid function of premature infants can be affected by various diseases or drugs, periodic thyroid function tests are required. Although transient hypothyroxinemia is known to spontaneously recover in most infants, some studies have shown further complications associated with neurodevelopmental disorders. Accordingly, although thyroid hormone therapy in preterm infants has been introduced, its efficacy is yet controversial. In order to understand the thyroid abnormalities observed in premature infants or patients in neonatal intensive care units, this article intends to present a comprehensive review of the physiology of the thyroid gland, transient hypothyroxinemia/delayed thyroidstimulating hormone elevation, and euthyroid sick syndrome that affects thyroid function.
Axis, Cervical Vertebra ; Brain ; Critical Period (Psychology) ; Euthyroid Sick Syndromes ; Humans ; Hypothyroidism ; Infant ; Infant, Newborn* ; Infant, Premature ; Critical Care ; Intensive Care Units, Neonatal ; Parturition ; Physiology ; Survival Rate ; Thyroid Diseases ; Thyroid Function Tests ; Thyroid Gland*