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Biomedical subjects

A F Tarantal

Publications and source records attributed to A F Tarantal.

At least 19 recordsLinked to original sources

Embryotoxicity studies of norfloxacin in cynomolgus monkeys. II. Role of progesterone.

Norfloxacin, an orally active fluoroquinolone antimicrobial, has been reported to be embryolethal but not teratogenic when administered to pregnant cynomolgus macaques prior to gestational day (GD) 36 at doses > or = 200 mg/kg/day. Additional studies have been performed in an effort to examine the mechanism responsible for this effect, particularly regarding the role of progesterone (P). The first study (Study I) investigated the effect of norfloxacin administration during early pregnancy (200 mg/kg/day; daily GD 20-30) in the absence of a functional corpus luteum (CL). The CL was surgically removed from 16 gravid females on GD 19 in order to focus on placental-derived P; ten were dosed with norfloxacin and six received vehicle only. Embryolethality was observed for 7/10 (70%) of the treated animals during GD 25-31 versus 0/6 (0%) for controls. A reduction in serum P was noted prior to embryonic loss, although no significant effects on chorionic gonadotropin (CG), 17 beta-estradiol (E2), or P or E urinary metabolites were observed. A second study (Study II) was performed in order to evaluate the capacity of norfloxacin (200 mg/kg) to reduce CL-derived P in both normally cycling and CG-stimulated nonpregnant females (ten treated, ten controls; daily for 8 days). No effects on P production or on luteal phase or menstrual cycle lengths were observed. The third study (Study III) was designed to examine the effect of norfloxacin on the metabolism and excretion of P in nonpregnant females. Silastic P implants were placed subcutaneously in order to maintain constant P levels during a 10 day treatment regimen (200 mg/kg/day; ten controls, nine treated). Five of the controls and four of the norfloxacin-treated females also received 14C-P intravenously within 1 hr of the last dose of norfloxacin in order to study excretory patterns. No significant differences between control and treated groups were observed. The results of these studies combined suggest that the developmental toxic effects observed in prior studies and Study I are specific to pregnancy and directly related to placental-derived P production.

Animals

Ultrasound evaluation of fetuses of zinc-deprived monkeys (Macaca mulatta).

Fetal body movements were studied in three groups of gravid rhesus macaques fed different amounts of dietary zinc (100 micrograms Zn/g diet, control, n = 12; 4 micrograms Zn/g diet, marginal deprivation, n = 7; 2 micrograms Zn/g diet, moderate deprivation, n = 11). Sonographic examinations were conducted during the third trimester in awake chair-restrained dams. Movement categories, derived from the human biophysical profile, were motor activity (trunk and limb movements), startle, and breathing movements. Moderately deprived fetuses were more active than controls on gestational day (GD) 115; maternal plasma zinc concentrations were significantly correlated with fetal activity at this time. In addition moderately deprived fetuses exhibited fewer breathing episodes on GDs 115-135. Biometrics measures indicated growth retardation in one moderately deprived fetus. These data suggest that moderate, but not marginal, dietary zinc deprivation influences fetal status as evaluated by sonography.

Animals

Acceleration of alveolar type II cell differentiation in fetal rhesus monkey lung by administration of EGF.

To examine the effect of epidermal growth factor (EGF) on lung parenchymal maturation in fetal rhesus monkey, recombinant human EGF was administered intraperitoneally (IP) at 66 mg/kg body wt over a 7-day period into the fetal peritoneal cavity alone or IP and into the amniotic fluid (AF) simultaneously. The saline carrier was injected IP and AF into control (CO) fetuses. The body weights of the IP + AF group were significantly larger than CO. Overall lung growth, measured as wet lung weight or fixed volume of the right cranial lobe, was unchanged. Fixed lung volume per gram body weight was significantly lower for both IP + AF and IP compared with CO. Morphogenesis of lung parenchyma, measured as percent parenchymal airspace or airspace size, was unchanged. Alveolar type II cell ultrastructure was significantly altered by EGF treatment; volume fraction of cytoplasmic glycogen was 50% less and lamellar bodies threefold greater for IP + AF and IP groups compared with CO. Total phospholipid content of AF was not altered, but relative percentages of different phospholipids were changed by EGF treatments; phosphatidylinositol was significantly reduced, and phosphatidylglycerol was significantly elevated. The lecithin-to-sphingomyelin ratio was unchanged. Surfactant apoprotein A concentration in AF was significantly elevated and was detected by immunoperoxidase in more cuboidal alveolar cells in EGF-treated animals when compared with CO. We conclude that exogenous EGF administered in the last trimester of pregnancy accelerates structural and functional cytodifferentiation of the alveolar type II cell in fetal primates. These maturational changes occur in the absence of significant alterations in overall lung growth or morphogenesis of the gas exchange area.

Amniotic Fluid

Developmental toxicity of L-selenomethionine in Macaca fascicularis.

Forty pregnant long-tailed macaques were dosed via nasogastric intubation with 0, 25, 150, or 300 micrograms/kg of L-selenomethionine (Se) daily during organogenesis [Gestational Day (GD) 20-50]. Clinical examination of the dams, maternal body weights, sonographic evaluations, clinical chemistry screens, and measures of serum progesterone and urinary estrone conjugates were used as indicators of maternal and fetal status in all animals. The pregnancies of two to three dams from each dose group were followed until term (approximately GD 165); the remainder (N = 7/dose group) were scheduled for hysterotomy on GD 100 +/- 2. A standard teratologic evaluation was performed including visceral and skeletal examinations. Fetal liver, kidney, skin, and smooth, cardiac, and skeletal muscles were examined by light microscopy; heart muscle was also evaluated by transmission electron microscopy. Neonates delivered at term remained with the dams and were removed periodically for morphometric, neurologic, behavioral, and ophthalmologic assessments on Days 1, 8, 15, 22, and 30 of age. Dose-dependent maternal toxicity as evidenced by anorexia, vomiting, and a significant reduction in body weight increased with increasing duration of Se exposure. One growth-retarded fetus was recovered on GD 131 from a compromised dam exposed to 25 micrograms/kg-day; one early embryonic death (GD 35) and two fetal deaths [GD 68 (followed by maternal death) and GD 123] occurred among animals dosed with 300 micrograms/kg-day. Pregnancy loss among treated animals was not significantly different from concurrent or historical controls. No statistically significant treatment-related effects were observed at necropsy on GD 100 +/- 2. One infant exposed to 150 micrograms/kg-day prenatally exhibited a unilateral cortical cataract, which may have been a spontaneous occurrence. The limited developmental effects observed and reported teratogenesis in nonmammalian species suggest that comparative pharmacokinetic studies are required before the full public health significance of elevated Se is understood.

Animals

Effect of epidermal growth factor on the fetal development of the tracheobronchial secretory apparatus in rhesus monkey.

Fetal rhesus monkeys were treated with recombinant human epidermal growth factor (EGF) to determine if EGF can induce maturation of the tracheobronchial secretory apparatus. At 75% of gestation, EGF was administered simultaneously into both the amniotic fluid and fetal abdominal cavity at an average dose of 66 micrograms/kg body weight, by each route over a 7-d period. At the end of the treatment period, the fetuses were delivered and either euthanized immediately or after maintenance on ventilatory support for 6 h. The lungs were removed, and the trachea and one lobe of the right lung was fixed and embedded for light microscopy. The left lung was lavaged with saline, and the collected fluid was used to quantify released secretory product. Secretory product was also measured in amniotic fluid as well as in situ on histologic sections of tracheal epithelium. When the tracheas of EGF-treated monkeys were examined, the epithelium was found to be taller and to contain a greater proportion of secretory cells and a smaller proportion of intermediate cells than the control group. However, there was no significant change in the total number of cells per millimeter of basal lamina or in the proportion of the epithelial population made up of basal or ciliated cells. There was more secretory product stored in the epithelium and submucosal glands and increased quantities of respiratory secretions in both lung lavage and amniotic fluid of EGF-treated monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

The macaque model for in vitro fertilization: superovulation techniques and ultrasound-guided follicular aspiration.

Prior methods for macaque in vitro fertilization (IVF) have incorporated laparoscopy and/or laparotomy as the primary means for oocyte recovery. Sonographic techniques, as used with human IVF, have been applied to the macaque, both for monitoring the response to hyperstimulation and for follicular aspiration prior to ovulation. Pergonal (hMG) was administered for 7 or 8 days beginning on cycle day 1 or 2 or for 6 days beginning on cycle day 3. This was followed by Pregnyl (hCG) prior to follicular aspiration. The quality of oocytes recovered from the 6-day treatment group was considerably better than those treated for greater than or equal to 7 days. It was concluded that ultrasound can provide a reliable means for documenting the response to ovarian stimulation and the successful transabdominal aspiration of multiple follicles.

Animals

Developmental toxicity of temafloxacin hydrochloride in the long-tailed macaque (Macaca fascicularis).

The potential developmental toxicity of temafloxacin hydrochloride was studied in the long-tailed macaque (Macaca fascicularis). Ten animals in each of the three drug-treated groups (25, 50, and 100 mg/kg) were administered temafloxacin via nasogastric intubation during gestational days (GD) 20-50. A control group of ten animals received vehicle only. The dams were monitored daily for adverse physical signs and maternal blood samples were collected for analyses of serum progesterone (P), 17 beta-estradiol (E2), and chorionic gonadotropin (CG). In addition, the conceptus was monitored periodically by ultrasound during gestation to confirm growth and viability. Increased maternal toxicity (weight loss, anorexia, emesis) and embryolethality were observed at 100 mg/kg, and a no-observable-adverse-effect-level (NOAEL) of 50 mg/kg was established. The incidence of prenatal mortality was as follows: Control = 1/10 (10%); 25 mg/kg = 1/10 (10%); 50 mg/kg = 2/10 (20%); and 100 mg/kg = 5/10 (50%). Analysis of P, E2, and CG indicated no significant effect of treatment. In addition, no significant differences were observed in embryonic/fetal growth and development when compared to historical controls. No gross structural changes were observed in fetuses exposed to 50 or 100 mg/kg, although one fetus exposed to 25 mg/kg exhibited microphthalmia. This anomaly was considered spontaneous and, therefore, unrelated to treatment.

4-Quinolones

Interventional ultrasound in pregnant macaques: embryonic/fetal applications.

Similarities in developmental biology between human and nonhuman primates have resulted in the use of macaque species as models in perinatal research. Studies have frequently included invasive surgical procedures or may have required "blind" injections. Several techniques have been established in human subjects using ultrasound as a guide such as cordocentesis and fetal therapy. These techniques have been applied to the nonhuman primate laboratory setting, which significantly decreases the risk of pregnancy loss due to experimental intervention.

Amniocentesis

Intrauterine insemination with ultrasound guidance in the long-tailed macaque (Macaca fascicularis).

Techniques used for the artificial insemination of macaques have primarily involved instillation of the ejaculate into the vagina or cervical canal. Intrauterine insemination has been performed previously but only as a surgical procedure. The application of ultrasound-guided techniques for this purpose provides a method for efficiently inseminating macaques in a relatively noninvasive fashion. This report describes the successful transabdominal ultrasound-guided insemination of the long-tailed macaque and the potential application of this procedure to a variety of nonhuman primate species.

Animals

In-utero transplantation of fetal liver haemopoietic stem cells in monkeys.

To evaluate the potential of in-utero transplantation of fetal haemopoietic stem cells (HSCs) for permanent engraftment as a treatment of congenital haemoglobinopathies, fetal rhesus monkeys were transplanted with HSCs derived from fetal livers. Five pregnant monkeys (60-62 days' gestation) were given an in-utero intraperitoneal injection of fetal liver cells (10(8)-10(9) cells/kg estimated fetal recipient body weight) derived from opposite sex donors at 59-68 days' gestation. Engraftment was confirmed by karyotype analysis of peripheral blood leucocytes and bone marrow; cells of donor sex were found among the recipient cells. Donor cell engraftment was apparent in four of five in-utero HSC transplant recipients at birth. Engraftment involved lymphoid (2.9-8.0% donor cells), erythroid (5.3-12.5%), and myeloid (8.5-15.4%) lineages and has persisted for up to 2 years without evidence of graft-versus-host disease.

Age Factors

Ultrasound-guided transfundal uterine sperm recovery from Macaca fascicularis.

Previous studies from this center have indicated that the cynomolgus macaque (Macaca fascicularis) may serve as a model for human sperm interaction with the cervix and uterus. In some macaque species, transcervical aspiration of the uterine contents carries a significant risk of disturbing the cervical milieu due to the serpentine nature of the cervix. The only alternatives have been surgical procedures such as laparotomy or laparoscopy. In this paper, we report our experience with a new technique for ultrasound-guided sampling of spermatozoa in the macaque uterus. Twenty adult female cynomolgus macaques were monitored for menses (first day of menses = day 1), and one mating per cycle was allowed on day 10, 11, or 12. In one group of ten animals, cervical mucus was sampled at 3 or 18 hr postcoitus (pc) and ultrasound-guided uterine aspiration was performed at 24 hours pc. In a second group of ten monkeys, uterine aspiration was at six hr pc and sperm numbers and motility were counted in the uterine fluid. Uterine fluid was obtained from fourteen of twenty monkeys. Pregnancy occurred in ten of the twenty experimental cycles. Ultrasound-guided uterine aspiration appears to be a reliable method for the evaluation of sperm transport in female macaques. The correlations between uterine sperm recovery and cervical mucus sperm populations are discussed. The high conception rate in treatment cycles indicates that this procedure can be performed without apparent risk to pregnancy.

Animals

Embryotoxicity studies of norfloxacin in cynomolgus monkeys: I. Teratology studies and norfloxacin plasma concentration in pregnant and nonpregnant monkeys.

Norfloxacin, a new orally active antibiotic, was investigated in cynomolgus monkeys for potential developmental toxicity. Fifty-seven monkeys were administered a control vehicle or norfloxacin by nasogastric gavage during the major period of organogenesis on gestational days (GD) 21 through 50 at doses of 0, 50, 100, 150, or 200/300 mg/kg/day. There was no evidence of teratogenicity at any dose level. Maternotoxicity and a significant increase in embryolethality occurred following doses of 200/300 mg/kg/day. The maternotoxicity was not expected based on range-finding studies in nonpregnant female monkeys, which showed no signs of toxicity in doses up to 500 mg/kg/day. Additional studies were conducted to determine if norfloxacin caused similar toxicity later in gestation. Forty-six pregnant monkeys were dosed with a control vehicle or 200 mg/kg/day norfloxacin for one of three 10-day periods on GD 36-45, 71-80, or 111-120. There were no maternotoxic, embryotoxic, or fetotoxic effects observed. Plasma concentrations of norfloxacin in five cynomolgus monkeys following 50 and 200 mg/kg oral doses were not dose-proportionate. However, at a given dose, administered in cross-over fashion, plasma concentrations of norfloxacin were higher in nonpregnant females (approximately 20-40%) than during pregnancy when the same subject was compared. At the no-observed-effect dose for maternal and embryotoxicity (50 mg/kg), peak plasma concentrations of norfloxacin in pregnant cynomolgus monkeys are approximately threefold higher than those observed in human volunteers receiving norfloxacin at the maximum recommended therapeutic dose of 400 mg (5.7 mg/kg based on 70 kg body weight) twice per day.

Animals

Evaluation of the bioeffects of prenatal ultrasound exposure in the cynomolgus macaque (Macaca fascicularis): I. Neonatal/infant observations.

The frequency of use of ultrasonography for evaluating the developing embryo/fetus has continued to rise although the possible risks from exposure still remain uncertain. The cynomolgus macaque (Macaca fascicularis) is currently being used in our laboratory as a model to assess these risks. In utero exposure was performed utilizing a commercial real-time mechanical sector scanner with a 7.5 MHz scanhead (ATL, MK 600). Maximum acoustic power output for this unit is as follows: I(SPTA) = 12.0 mW/cm2, I(SPPA) = 98 W/cm2, and Im = 137 W/cm2. Animals exposed to ultrasound (N = 16) were scanned five times weekly on gestational days (GD) 21-35 +/- 2 for 10 minutes/exam (m/e), three times weekly on GD 36-60 +/- 2 for 10 m/e, and once weekly on GD 61-150 +/- 2 for 20 m/e. Controls (N = 14) were "scanned" with the unit placed on standby. Assessment of simian Apgar scores at 1, 5, and 10 minutes of life revealed higher scores for treated animals at 10 minutes (P less than or equal to 0.045); greater scores in muscle tone (P less than or equal to 0.013) and color (P less than or equal to 0.016) were observed. Evaluation of morphometrics at birth including weight, biparietal diameter, occipitofrontal diameter, head circumference, hand and foot lengths, humerus and femur lengths, arm circumference, chest circumference, tail length, skinfold thickness, and crown-rump length (CRL) indicated a significant reduction in only two parameters, birth weight (P less than or equal to 0.027) and CRL (P less than or equal to 0.033). Hematologic analysis at 2 +/- 1, 9 +/- 1, and 16 +/- 1 days of life revealed a significant difference in white blood cell counts (WBCs). Treated animals displayed lower WBCs with reductions in numbers of segmented neutrophils and monocytes at all ages observed. Hematologic differences were not significant by 5-6 months of age. No abortions, gross malformations, or stillbirths were observed in the exposed animals.

Animals

Evaluation of the bioeffects of prenatal ultrasound exposure in the cynomolgus macaque (Macaca fascicularis): II. Growth and behavior during the first year.

The extensive use of ultrasonography for the prenatal assessment of growth and development continues to present questions regarding biological effects. We are currently evaluating a nonhuman primate model (Macaca fascicularis) exposed to ultrasound from gestational day (GD) 21 to 152 +/- 2. Exposures were performed with a commercial real-time sector scanner (ATL, MK 600); animals were scanned five times weekly on GD 21-35 +/- 2, three times weekly on GD 36-60 +/- 2, and once weekly on GD 61-150 +/- 2. The length of exposure was approximately the same as human exposure (GD 21-60 +/- 2 = 10 min/exam and GD 61-150 +/- 2 = 20 min/exam) although the frequency of the examinations was considerably greater. Initial reports indicated differences between control and treated animals including lower birth weight, higher simian Apgar scores, and changes in select hematologic parameters. Follow-up evaluations of growth during the first year included measurements of body weight, hand and foot lengths, humerus and femur lengths, biparietal and occipitofrontal diameters, head circumference, arm circumference, chest circumference, skinfold thickness, and crown-rump length. Results indicated a significant reduction in body weight in treated animals during the first three months, with nonsignificant differences during the following nine months. Hematologic analysis including complete blood counts (CBC) and clinical biochemistry at 6, 9, and 12 months of age were not significantly different. A series of behavioral evaluations including a neurobehavioral test battery (NBT) and tests assessing motor and cognitive skills were included. The NBT revealed increased muscle tone in treated animals at one, two, and four days. In an observation cage (week 1-14) more quiet activities were displayed by treated animals. Group differences in performance of motor and cognitive tasks were observed and may be attributable to agitation and difficulties in adjusting to test environments. There were no group differences observed in discrimination learning. When considering the possible implications to the human population, it is important to consider the amount of exposure these animals received, and the fact that most of the effects observed appeared to be transitory. Although human epidemiological studies have not revealed any significant bioeffects, the "prudent use" of diagnostic ultrasound should still be kept in mind. This is especially significant with the current rise in the use of endovaginal scanning and pulsed Doppler.

Animals

The effect of the anti-progestin RU 486 on early pregnancy in the long-tailed macaque (Macaca fascicularis).

The efficacy of various doses of RU 486 in terminating pregnancy before and after the luteal-placental shift (LPS) in the long-tailed macaque (Macaca fascicularis) was assessed through sonographic examination and measurements of steroid hormones and their metabolites. Intramuscular injection of 1.0, 2.5, 12.5, or 25.0 mg/kg was administered either from gestational day (GD) 15-18 (Group 1; N = 11) or GD 23-26 (Group 2; N = 9). The timing of treatment was determined by the detection of the preovulatory estrogen peak via daily urinary estrone conjugate (E1C) measurements. In Group 1, a 90.9% pregnancy loss was observed (10/11); seven animals aborted during GD 15-20, two animals indicated early embryonic death with retained gestational sacs, one animal aborted on GD 56, and one pregnancy was maintained. In Group 2, an 88.9% pregnancy loss was observed (8/9); eight animals aborted between GD 26-29, and one pregnancy was unaffected. Hormone profiles appeared to fall secondarily to the loss of trophoblast function. These results indicate: (a) RU 486 was more effective after the LPS; and (b) the primary effect of RU 486 appeared to be at the level of the products of conception.

Abortifacient Agents