Search PubMed⌕ Search

Biomedical subjects

Halit Pinar

Publications and source records attributed to Halit Pinar.

At least 19 recordsLinked to original sources

Role of aspartyl-(asparaginyl) beta-hydroxylase in placental implantation: Relevance to early pregnancy loss.

Aspartyl-(asparaginyl) beta-hydroxylase (AAH) is a type 2 transmembrane protein with catalytic activity that hydroxylates epidermal growth factor-like domains of proteins that have a functional role in cell motility and invasion. Extravillous cytotrophoblasts (CTB) are motile and invasive unpolarized epithelial cells that mediate early implantation through interaction with the endometrium. This study characterizes the potential role of AAH in CTB implantation using human placentas from (1) terminated pregnancies (n = 11), (2) normal term deliveries (n = 21), (3) spontaneous abortuses (n = 21), and (4) small-for-gestational-age (SGA) term deliveries (n = 21). The SGA cases all had established clinical histories of intrauterine growth restriction or preeclampsia. Formalin-fixed, paraffin-embedded sections of placenta were immunostained using the 15C7 monoclonal antibody generated to recombinant AAH. In addition, snap-frozen or RNAlater-preserved specimens (Ambion, Austin, TX) were used for RNA analysis of AAH expression by real-time quantitative reverse transcriptase-polymerase chain reaction and protein analysis by Western blotting. The immunohistochemical staining studies demonstrated AAH expression in amniocytes, villous CTB, syncytiotrophoblast, extravillous CTB, decidua, and endometrial glands at all gestational ages and in all 4 groups. Higher levels of AAH immunoreactivity were observed in extravillous CTB compared with villous CTB. Immunohistochemical staining and RNA analysis demonstrated abundant AAH expression in placental trophoblastic cells as well as in decidua and endometrial glands, with reduced expression in spontaneous abortion and SGA, suggesting that AAH may serve as a biomarker of impaired implantation. The high levels of AAH in decidua and endometrial glands suggest a role for this molecule in "receptivity" of endometrium.

Abortion, Spontaneous↗

Musashi1 antigen expression in human fetal germinal matrix development.

Musashi1 is a highly conserved protein found in neural progenitor cells. We examined the expression dynamics of Musashi1 in conjunction with other representative neural progenitor antigenic determinants (Ki-67 and nestin) during 8 different stages of the developing human fetal germinal matrix. Our results indicate that Musashi1 is a useful marker for immature cells in periventricular areas inhabited by stem cells, progenitor cells, and differentiating cells.

Brain↗

Amniotic fluid infection syndrome and neonatal mortality caused by Eikenella corrodens.

Different microorganisms not commonly found in the female genital tract have been implicated as causative agents for amniotic fluid infections. Eikenella corrodens is part of the normal flora in the human oral cavity and upper respiratory tract. It is most commonly found in the clinical setting of polymicrobial infections involving human bite wounds, head and neck infections, and periodontitis. On rare occasions, E. corrodens has been reported as a cause of gynecologic infections. There are only 3 reports of documented E. corrodens chorioamnionitis of the placenta resulting in preterm labor, one of which is associated with early neonatal demise. We report a case of preterm delivery of twin infants at 23 weeks of gestation with documented E. corrodens infection in 1 twin who was not resuscitated.

Adolescent↗

Second-trimester maternal serum markers in twin pregnancy with complete mole: report of 2 cases.

We present second-trimester serum marker levels in cases of twin pregnancy with complete hydatidiform mole and a coexistent fetus (CHMCF). Second-trimester inhibin A (InhA) levels have not been previously reported in such cases. Second-trimester maternal serum screening, alpha-fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and InhA measurements combined with maternal age to estimate a patient's risk of Down syndrome during pregnancy was performed as a routine prenatal test in 2 cases of CHMCF. Hospital records containing serum marker data, patient history, pathology reports, and pregnancy outcome were reviewed. In cases of CHMCF, maternal serum AFP and uE3 levels were similar to those of a normal singleton pregnancy, whereas hCG and InhA levels were markedly increased. Second-trimester maternal serum marker profiles in cases of CHMCF are a composite of normal singleton and molar tissue secretions. We have found, for the first time, that second-trimester InhA levels are markedly increased in these cases. Serum marker levels may be useful in diagnosis of CHMCF, prenatal counseling, and evaluation of risk for persistent trophoblastic disease.

Adolescent↗

Postmortem lung weight/body weight standards for term and preterm infants.

Assessment of lung development is a crucial component of the perinatal autopsy, especially in preterm infants. In current pathology practice, the diagnosis of lung hypoplasia in very premature infants (<28 weeks of gestation) is based on a lung weight/body weight ratio (LW/BW) of 1.5% or less. While useful to confirm the presence of marked pulmonary hypoplasia, the 1.5% threshold may be too stringent to detect more subtle degrees of pulmonary hypoplasia, as seen in association with rupture of membranes. The aim of this study was to establish reference values for postmortem LW/BW in preterm and term infants. To this end, we performed a retrospective analysis of fetuses and newborns (16-41 weeks of gestation) without known risk factors for pulmonary hypoplasia. Mean LW/BW ranged between 2.98-3.15% between 16-27 weeks, and decreased to 2.55% by 28-36 weeks and 1.79% at term. The 10th percentile for LW/BW was significantly higher in preterm infants (2.24% between 20-23 weeks, and 2.59% between 24-27 weeks) than in term infants (1.24% at >or=37 weeks, P < 0.01). We then correlated LW/BW of infants with risk factors for pulmonary hypoplasia with the newly established reference values. As expected, mean LW/BW of infants with congenital diaphragmatic hernia or severe renal anomalies was <1.5% (0.98% and 1.40%, respectively). Mean LW/BW of infants with prolonged (> 1 week) rupture of membranes (PROM) was 2.08%. Three of 12 (25%) preterm infants with PROM had pulmonary hypoplasia according to the traditional criteria (LW/BW <1.5%). However, an additional 4/12 (33%) infants with PROM had a LW/BW between 1.5% and the 10th percentile for age (2.2%), indicative of more subtle but potentially relevant pulmonary underdevelopment. In conclusion, we determined LW/BW reference values for preterm and term infants. Correlation of LW/BW with age-matched reference values at postmortem examination represents an invaluable additional tool to evaluate lung growth, particularly in preterm infants.

Body Weight↗

Effects of exogenous glucose on brain ischemia in ovine fetuses.

We examined the effects of prolonged moderate hyperglycemia with and without an additional rapid glucose injection on ischemic brain injury in the fetus. Twenty-five ewes (117-124 d of gestation) were assigned to one of four groups: 1) glucose-infused fetuses exposed to 30 min of carotid artery occlusion followed by 48 h of reperfusion (I/R-Glu, n = 8); 2) glucose-infused plus rapid glucose injection given 100 min before 30 min of occlusion followed by 48 h of reperfusion (I/R-GluR, n = 4); 3) placebo-infused exposed to 30 min of occlusion and 48 h of reperfusion (I/R-PL, n = 8); and 4) glucose-infused sham occlusion and 48 h of sham reperfusion (control, n = 5). After baseline measurements, fetuses were infused with glucose (9-16 mg/kg/min) for 48 h before and after carotid occlusion or sham treatment. The I/R-PL group received 0.9% NaCl. Brain pathologic outcome was determined. Serial sections stained with Luxol fast blue-hematoxylin and eosin were scored for white matter, cerebral cortical, and hippocampal lesions. These areas received graded pathologic scores of 0 to 5, reflecting the amount of injury, where 0 = 0%, 1 = 1-25%, 2 = 26-50%, 3 = 51-75%, 4 = 76-95%, and 5 = 96-100% of the area damaged. Comparisons of the pathologic scores for cerebral cortex (CC), white matter (WM), and hippocampus (H) demonstrated that the I/R-GluR (CC: 4.56 +/- 0.11, WM: 4.50 +/- 0.11, H: 3.44 +/- 0.48, mean +/- SEM) had more (p < 0.05) damage than the I/R-Glu (CC: 2.46 +/- 0.47, WM: 1.97 +/- 0.37, H: 1.81 +/- 0.36) and control (CC: 1.12 +/- 0.13, WM: 0.82 +/- 0.34, H: 0.80 +/- 0.34) groups. The pathologic scores in the I/R-Glu were (p < 0.05) greater than the control, but not the I/R-PL (CC: 2.12 +/- 0.35, WM: 2.20 +/- 0.44, H: 1.59 +/- 0.41) group. We conclude that exposure to prolonged moderate hyperglycemia before ischemia and during reperfusion does not affect the extent of brain injury, but exposure to an additional acute increase in plasma glucose concentration before ischemia is extremely detrimental to the fetal brain.

Animals↗

Reference values for valve circumferences and ventricular wall thicknesses of fetal and neonatal hearts.

To evaluate valvular stenosis, cardiac dilation, and/or cardiac hypertrophy, measurements of valve circumference and ventricular wall thickness are of importance. To establish reference values in fetuses and neonates, we reviewed pathology reports at Women and Infants Hospital from 1978 through 2002 and found measurements in 776 cases that were suitable for analysis. Gestational ages (GA) ranged from 15 to 42 wk. The tabulated data include the mean, standard deviation, and 10th and 90th percentile values for foot length, body weight, body length, heart weight, valve measurements, and ventricular wall thicknesses for each week of GA. In cases in which clinical dating is not reliable, we estimated the GA by the mean value nearest that of the observed foot length. All linear measurements increased in a linear fashion throughout the second and third trimesters of development. The circumferences of cardiac valves at all ages, in descending order of magnitude, are: tricuspid, mitral, pulmonary, and aortic. Mean left ventricular (LV) wall thickness is greater than mean right ventricular (RV) wall thickness throughout gestation. The tables offer a means of determining valvular stenosis, or cardiac dilation and/or hypertrophy, based on various gestational ages.

Fetal Heart↗

A new weight-bearing meniscal test and a comparison with McMurray's test and joint line tenderness.

PURPOSE: The purpose of this study was to describe a new weight-bearing McMurray's test (Ege's test) and to compare its diagnostic value with McMurray's test and joint line tenderness (JLT). We also aimed to determine if associated lesions had any effect on the diagnostic values of the 3 tests. TYPE OF STUDY: Prospective controlled trial, clinical study. METHODS: The study group consisted of 150 consecutive patients who had had symptoms related to intra-articular knee pathology, and arthroscopic diagnoses were used as the gold standard. RESULTS: There were a total of 211 diagnoses on arthroscopy. A meniscus tear was found in 127 of the 150 patients; 90 had medial, 28 had lateral, and 9 had tears of both menisci. There were no statistically significant differences between the 3 tests in detecting a meniscal tear ( P > .05). However, better accuracy, sensitivity, and specificity rates were obtained with Ege's test for medial meniscal lesions (71%, 67%, and 81%, respectively). JLT also gave superior accuracy rates (71%), but the specificity of Ege's test was apparently higher than JLT (81% v 44%). The highest positive predictive value was also obtained with Ege's test (86%), whereas a superior negative predictive value was obtained with JLT (67%) in medial meniscal tears. Lateral meniscal tears were diagnosed more accurately than medial meniscal tears, and Ege's test gave results superior to the others (84%, 64%, 90% for accuracy, sensitivity, and specificity, respectively). Higher positive predictive values were obtained with McMurray's and Ege's tests than with JLT, but similar negative predictive values were achieved in all. A torn anterior cruciate ligament did not decrease the diagnostic values of the 3 tests, whereas the number of associated lesions in the knee negatively affected the diagnostic capabilities of the tests. CONCLUSIONS: Accuracies of traditional clinical meniscus tests may be improved by including Ege's test in the clinical examination. LEVEL OF EVIDENCE: Level II, diagnostic.

Adolescent↗

Severe umbilical cord inflammation-a predictor of periventricular leukomalacia in very low birth weight infants.

Chorioamnionitis has been associated with periventricular leukomalacia (PVL) in very low birth weight (VLBW) infants. We examined the association between the pathological severity of chorioamnionitis and PVL in VLBW infants. Thirty-four VLBW infants with PVL and 34 control infants matched for gestational age without a diagnosis of PVL or intraventricular hemorrhage were obtained from the Women and Infants' Hospital of Rhode Island's Neonatal Follow-up Clinic database. Placental samples, including the amnion/chorion, chorionic plate, and umbilical cord, were examined microscopically. Statistical analysis included Mantel-Haenszel chi-square, and Student's t-test. Severe inflammation in the umbilical cord was observed in 53% of infants with PVL and 32% without PVL (p<0.05). Severe umbilical cord inflammation is one of the risk factors associated with the development of PVL in VLBW infants.

Case-Control Studies↗

Postmortem findings in term neonates.

Neonatal deaths in infants born at term are relatively rare in the USA, occurring in 0.9/1000 live births. Congenital malformations, perinatal asphyxia, infections and inborn errors of metabolism are the leading causes. Chromosomal malformation syndromes, congenital heart disease, pulmonary hypoplasia and severe neural tube defects comprise the majority of lethal malformations. Several skeletal dysplasias are lethal in the newborn infant. Group B Streptococcus still plays a major role in neonatal mortality while deaths due to other infectious agents have decreased. Hypoxic ischaemic encephalopathy is a significant cause of neonatal death. Inborn errors of metabolism have variable presentations but some, such as the fatty acid oxidation disorders, may present in neonates and cause sudden death.

Asphyxia Neonatorum↗

The histologic fetoplacental inflammatory response in fatal perinatal group B-streptococcus infection.

OBJECTIVE: To determine the rate of histologic fetoplacental inflammation in fetuses and newborns with fatal perinatal Group B-Streptococcus (GBS) infection. STUDY DESIGN: Autopsy files (1990 to 2002) were searched for fetuses and newborns with GBS-positive post-mortem blood and/or lung cultures. The rate of histological fetoplacental inflammation in preterm (< 36 weeks gestational age) and term (> or =36 weeks) fetuses/infants was compared using chi(2) test. RESULTS: GBS infection was diagnosed in 4.9% (61/1236) of perinatal autopsies and was considered the exclusive cause of death in 58 cases (16 to 41 weeks gestation, median: 26 weeks). A total of 43 fetuses/infants (74%) were preterm, 24 (41%) were male and 33 (57%) stillborn. The histologic fetoplacental inflammatory response was age-dependent for the following variables: acute chorioamnionitis (seen in 67% of preterm vs 33% of term fetuses/infants, p < 0.05), multiple-vessel umbilical vasculitis (37 vs 7%, p < 0.05), funisitis (37 vs 13%, p < 0.05), and the presence of neutrophils in the gastrointestinal tract (35% vs none, p < 0.05). Neutrophils in the pulmonary airspaces (47 vs 33%) and pneumonia (16 vs 27%) were found with similar frequency in both groups. CONCLUSION: Histologic fetoplacental inflammation is a poor indicator of perinatal GBS infection; the sensitivity is 67% in preterm and 33% in term fetuses/newborns (overall sensitivity 59%). The higher rate of histologic inflammation in preterm fetuses/newborns suggests age-specific interactions between microorganism, host and placenta.

Chorioamnionitis↗

[Anterior knee pain in the absence of patellofemoral instability].

A wide range of disorders other than patellofemoral instability may be responsible for anterior knee pain and should therefore be included in the differential diagnosis in children and adolescents. The role of overuse and repetitive trauma is of utmost importance in these disorders. Moreover, systemic or local malignancies, referred pain especially from the hip, and psychiatric features specific to this age group should always be kept in mind. This article revisits anterior knee pain in the absence of patellofemoral instability with regard to etiology, examination methods, diagnosis, and treatment in the light of recent data and clinical experience.

Adolescent↗

Analysis of meniscal and chondral lesions accompanying anterior cruciate ligament tears: relationship with age, time from injury, and level of sport.

The purposes of this multi-center study were: (a) to document the location and type of meniscal and chondral lesions that accompany anterior cruciate ligament (ACL) tears, and (b) to test for possible relationships between these lesions and patient age, time from initial injury (TFI), and sports level (i.e., recreation, amateur, professional, and national). The cases of 764 patients with ACL tears who underwent arthroscopy for the first time were retrospectively analyzed. The group included 684 males and 80 females of mean age 27 years (range 14-59 years). The mean TFI was 19.8 months (range 0.2-360 months). Eighty-seven percent of the group engaged in regular sporting activity. Thirty-seven percent had medial meniscal tears, 16% had lateral meniscal tears, and 20% had tears of both menisci. The most common tear types were longitudinal tears in the posterior and middle horns of both menisci. Tears of the lateral meniscus were more centrally located than those of the medial meniscus. Incomplete tears and radial tears were significantly more common in the lateral meniscus. Nineteen percent of the knees had one or more chondral lesions. Sixty percent of the chondral lesions were located in the medial tibio-femoral compartment. Patient age was statistically associated with presence of a medial meniscal tear, presence of a grade 3 or 4 chondral lesion, and presence of a complex tear of the medial meniscus. Sports level was not statistically related to any of the parameters studied. The odds of having a medial meniscal tear at 2 to 5 years TFI were 2.2 times higher than the odds in the first year post-injury, and the odds at >5 years were 5.9 times higher than at 0 to 12 months TFI. The frequency of lateral meniscal tear remained fairly constant at 2 years TFI. The odds of having a grade 3 or 4 chondral lesion were 2.7 times greater at 2 to 5 years TFI than they were at 1 year post-injury, and these odds increased to 4.7 when patients at >5 years TFI were compared to those in the 2 to 5 years category. Multivariate analysis demonstrated that TFI and age were equally important predictors of lateral meniscal tears and of grade 3 or 4 chondral lesions; however, TFI was the better predictor of medial meniscal tear.

Adolescent↗

Clinical and arthroscopic features of meniscal tears and a search for the role of infection in histologically confirmed meniscal mucoid degeneration.

Mucoid degeneration (MD) of the meniscus has received little attention. The pathology deserves special interest as it may lead to loss of the meniscus even in very young individuals. The cause of MD and the clinical features of meniscal tears due to that pathology have not been understood. This study analyzed the age profile and the role of trauma in patients with torn menisci with MD, examined meniscal tear patterns and clinical features, and investigated the role of bacterial infection in causing MD. Meniscal samples obtained from 27 consecutive patients during arthroscopic resection of torn menisci considered to be due to MD (typical yellow color) underwent pathological investigation. The samples were scored according to the light microscopic criteria of Copenhaver; 24 menisci (23 patients) with stage 2-3 MD comprised the study group. Magnetic resonance imaging obtained in 11 patients typically revealed increased intrasubstance signal intensity that extended to at least one of the meniscal surfaces. Pieces of resected meniscal tissue were also subject to PCR investigation to search for presence of bacteria. Of the 24 knees 21 (87%) had no history of trauma. Mean Tegner activity level was 4 (1 and 7). Mean duration of symptoms was 11.6 months (1-36). Pain was the most frequent symptom ( n=22). Joint line tenderness and McMurray's test (pain and/or clicking) were present in 22 and 16 knees, respectively. Medial meniscus was affected in 16 and lateral meniscus in 8. Meniscal cyst and incomplete discoid meniscus was present in 5 and 2 of the lateral menisci. All of the torn menisci were degenerated and yellow in color. The most common tear patterns were radial and/or flap, and longitudinal-horizontal tears. PCR study revealed no bacteria. Mucoid degeneration of the meniscus does not seem to be related to the aging process. Clinical findings of torn such menisci are insidious compared to traumatic tears. Lack of history of trauma may delay the diagnosis. Bacterial infection has no role in the cause.

Adolescent↗

Partial deletions of the long arm of chromosome 13 associated with holoprosencephaly and the Dandy-Walker malformation.

Two patients with partial deletions of the long arm of chromosome 13, del(13)(13q21-q34) and del(13)(13q22-q33), respectively, multiple congenital anomalies including holoprosencephaly (HPE) and the Dandy-Walker malformation (DWM) are described. The occurrence of HPE and the DWM in both of these patients suggests that, in addition to ZIC2, which is important for normal development of the forebrain, there is at least one other dosage-sensitive gene in 13q22-q33 that plays an important role in brain development. The DWM is anatomically and developmentally distinct from HPE. The presence of a DWM in each of these two patients with partial deletions of the long arm of chromosome 13 suggests that haploinsufficiency at a locus in 13q22-q33 may cause this anomaly. These findings suggest that microdeletions in 13q22-q33 may be found in a proportion of patients with an apparently isolated DWM. Therefore, careful high-resolution cytogenetic analysis (550 band level or greater) of 13q22-q33 may be considered in these patients. Furthermore, future molecular studies of this region may reveal candidate gene loci for the DWM.

Chromosome Banding↗

Reference values for second trimester fetal and neonatal organ weights and measurements.

To establish accurate reference ranges for the entire second trimester, we documented organ weights, body weight, and linear measurements for 597 fetuses and neonates with gestational ages ranging from 12 to 26 wk. We determined the mean and standard deviation for weights and measurements at each week of gestation using the StatView trade mark SE + Graphics statistical program. The analyses revealed a linear correlation between the gestational age and, respectively, the toe-heel length, crown-rump length, and crown-heel length. Body and organ weights increase at varying rates throughout the second trimester. The data correlate well with weights and measurements previously published for the latter half of the second trimester, and extend these reference ranges to encompass the entire second trimester.

Crown-Rump Length↗

Inter-alpha inhibitor proteins in infants and decreased levels in neonatal sepsis.

OBJECTIVE: Adjunctive tests are needed to predict sepsis in the newborn and to lower the rate or duration of unnecessary antibiotic use. We evaluated the normal Inter-alpha inhibitor protein (IaIp) values in infants and the association of plasma levels of IaIp with sepsis in term and preterm newborns. METHODS: Plasma IaIp levels were measured by enzyme-linked immunosorbent assay in samples from 135 newborn infants at a wide range of gestational ages (24-42 weeks). IaIp levels were also determined in 19 infants undergoing prospective evaluation for sepsis. RESULTS: IaIp levels in umbilical cord blood and circulating peripheral blood of healthy newborn infants (525+/-66 mg/L) were not significantly different from the level in healthy adults (691+/-80 mg/L). IaIp levels were similar in infants between 24 and 42 weeks gestational age. There was a significant reduction in IaIp levels in infants with sepsis compared with nonseptic controls (169+/-126 mg/L vs 613+/-286 mg/L, P<.0001). CONCLUSIONS: IaIp levels in the blood of newborns are independent of gestational age and similar to adults. IaIp levels are significantly reduced in infants with bacterial sepsis and might serve as an adjunctive diagnostic marker to allow prospective reduction of antibiotic use.

Alpha-Globulins↗

Effects of antenatal steroids on ischemic brain injury in near-term ovine fetuses.

BACKGROUND: Hypoxia/ischemia in utero can result in brain damage to the fetus and newborn. Antenatal steroids are a routine part of the management of women who develop premature labor. Pretreatment of young postnatal rats with dexamethasone before hypoxic/ischemic insults has been reported to attenuate brain injury. However, the effects of antenatal steroids on ischemic brain injury in fetuses have not been investigated. OBJECTIVE: We examined the effects of maternally administered antenatal corticosteroids on ischemic brain injury in near-term ovine fetuses. METHODS: Chronically instrumented fetuses at 122 days of gestation were studied 12 h after the last of four 4 mg dexamethasone, or placebo injections were given over 48 h to the ewes. Groups were dexamethasone/ischemic, placebo/ischemic and sham-treated control. Fetuses were exposed to 30 min of carotid occlusion (ischemia) or no occlusion (control) and 72 h of reperfusion. Whole brain coronal sections stained with Luxol fast blue-hematoxylin-eosin were scored for white matter and cerebral cortical lesions. Both areas received pathological scores of 0 to 5 reflecting the degree of injury (0=0%, 1=1-10%, 2=11-50%, 3=51-90%, 4=91-99% and 5=100%). Bilateral carotid blood flow also was measured before, during and after brain ischemia in the dexamethasone/ischemic and placebo/ischemic groups. RESULTS: White matter (WM) and cerebral cortical scores did not differ between the dexamethasone/ischemic and placebo/ischemic (WM: 3.0+/-1.9 and 2.9+/-1.7; cortex: 3.1+/-1.7 and 2.6+/-1.8, mean+/-S.D.) groups. White matter and cerebral cortical scores were higher in the dexamethasone/ischemic (WM: 3.0+/-1.9, P<0.02; cortex: 3.1+/-1.7, P<0.005) and placebo/ischemic (WM: 2.9+/-1.7, P<0.006; cortex: 2.6+/-1.8, P<0.007) than control (WM: 0.2+/-0.4; cortex: 0.2+/-0.4) group. Carotid blood flow was relatively higher (P<0.05) after 24, 48 and 72 h of reperfusion in the dexamethasone/ischemic than placebo/ischemic group. CONCLUSIONS: We conclude that maternal pretreatment with antenatal dexamethasone did not attenuate ischemic brain injury in the fetus, and that carotid blood flow was higher during reperfusion in fetuses of dexamethasone than placebo-treated ewes, most likely secondary to decreases in arterial oxygen tension.

Animals↗