Sonographic diagnosis of conjoined twinning.
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Humans↗
Biomedical subjects
K Benirschke
Publications and source records attributed to K Benirschke.
Chromosomal rearrangements in a Somali wild ass pedigree, Equus africanus somaliensis (Perissodactyla, Equidae).
Chromosome analyses were conducted on 15 animals in a pedigree of Somali wild ass, Equus africanus somaliensis. G- and C-banded karyotypes are presented for the first time on this endangered species. The diploid number ranged from 62 to 64. Numerical chromosomal variation was the result of a centric fission which was accompanied by a heterochromatic deletion. The fission polymorphism involved acrocentric elements 19 and 21 as determined by G-banding. These autosomes are homologous to those involved in centric fission/fusion polymorphisms in other equids: E. asinus (domestic donkey), E. hemionus (onager), E. kiang (kiang), and E. burchelli (common zebra). Banding analyses also revealed a paracentric inversion polymorphism in submetacentric chromosome pair 2 of E. a. somaliensis. Both the centric fission and paracentric inversion polymorphisms involved heterochromatic regions. One individual was found to be heterozygous for two de novo chromosomal rearrangements: a centric fission (involving acrocentric elements 19 and 21) and a heterochromatic deletion of chromosome 2.
Animals↗
Maternal melanoma metastatic to the placenta: a case report and review of the literature.
Metastases of maternal cancer to the placenta and fetus are rare in cases of maternal primary malignancy. This report describes a case of malignant melanoma metastatic to the placenta, reviews the literature, and discusses the clinical significance. A 33-year-old woman presented at 30 weeks' gestation with multiple metastases from a malignant melanoma diagnosed 4 years previously. Rapid maternal deterioration necessitated premature cesarean delivery, and maternal death occurred 7 days later. The placenta showed multiple metastases of malignant melanoma. The infant, however, is alive and well at 7 months of age. Melanoma in pregnancy rarely results in metastasis to the conceptus, but when it does occur there may be fatal consequences to the fetus. Therefore, the placenta should be thoroughly examined for metastasis, which, if present, should alert the clinician to monitor the infant for development of malignant disease.
Adult↗
Gestational psittacosis: case report and literature review.
In Europe, Chlamydia psittaci is a relatively common cause of abortion in sheep and other mammals. Psittacosis in humans is typically described as a mild-to-moderate flu-like illness. If psittacosis is acquired during pregnancy, it can present as a severe, progressive, febrile illness, with headache, disseminated intravascular coagulation, abnormal liver enzyme studies, and impaired renal function. Only cases with significant fetomaternal morbidity and mortality have been reported. Recovery from this disease follows termination of pregnancy and appropriate antibiotic therapy. Direct exposure of gravid humans to infected products of conception is the most commonly reported mode of transmission. Diagnosis is suggested by the placental histopathologic findings, which consist of an intense, acute intervillositis, perivillous fibrin deposition with villous necrosis, and large irregular basophilic intracytoplasmic inclusions within the syncytiotrophoblast. Commercially available genus-specific monoclonal antichlamydial antibody is available for the rapid confirmation of the diagnosis. In the United States, only two cases of gestational psittacosis have been previously reported. In contrast to the experience in Europe, both cases were associated with psittacine birds. This is the first reported instance of ovine-related gestational psittacosis documented in the United States. Gravid patients should be warned to avoid contact with sheep and their products, particularly during the spring lambing period.
Adult↗
What's new in gestational trophoblastic disease?
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Diagnosis, Differential↗
Absence of the lateral philtral ridges: a clue to the structural basis of the philtrum.
This study compares philtral development in the normal fetus with philtral development in specimens lacking normal philtral landmarks. Distinct differences in the structure of the upper lip were discovered between the two groups using a histological comparison. A new mechanism for the structural basis of the philtrum is proposed on the basis of these differences.
Animals↗
Complete hydatidiform mole with a coexistent embryo.
We describe a case of a complete hydatidiform mole with a coexistent embryo. A 19-year-old Hispanic woman presented with an intrauterine pregnancy at 7 weeks gestational age. An ultrasound evaluation at that time showed a gestational sac and fetal heart activity was observed. Four weeks later, subsequent ultrasound study revealed no evidence of an embryo, and a pattern consistent with a hydatidiform mole. Dilation and curettage was subsequently performed that showed a classic hydatidiform mole on histological examination. Chromosome analysis revealed a normal 46,XX karyotype. DNA was extracted from the placental tissue, as well as maternal and paternal blood. Molecular genetic analysis was; performed with four variable number of tandem repeats (VNTR) probes and showed the placental tissue to consist of only paternal DNA with two genomic copies of each allele studied. These findings are consistent with the diagnosis of complete hydatidiform mole and its origin from an empty ovum fertilized by a single sperm. This is the first reported case of a living embryo coexistent with a complete hydatidiform mole documented by genetic analysis.
Adult↗
The biology of the twinning process: how placentation influences outcome.
Placentation of twins has important bearing on the fetal development and neonatal outcome. Because of limitation in space of the endometrial cavity, twin placentas frequently collide during their expansion. This may restrict their growth and also lead to a somewhat increased rate of placenta previa. Moreover, abnormal cord insertions such as marginal and velamentous cords are much more frequent in multiple gestation. Absence of one umbilical artery is also much more frequent in twins. The best prognosis is had when two independent placentas develop, the dichorionic separate organs. Fusion of two separate placentas does not lead to vascular anastomoses in human twins, whereas it often does in other species (marmoset, cattle). Blood vessel fusion occurs only in monochorionic twins, all of which are "identical" (monozygotic). Large anastomoses (usually artery-to-artery) allow blood to shift rapidly from one to the other. Thus, when one twins dies, the survivor may quickly exsanguinate into the dead twin, leading to hypotension and occasionally to cerebral palsy. Arteriovenous anastomoses are the basis for the twin transfusion syndrome. This results in severe prematurity and gross discordance of all sorts of physical parameters. Knowing this type of vascular shunts helped develop the prenatal laser obliteration with salvage of the twins. The worst prognosis occurs with the rarest type of placentation in twin, in which both reside in the same cavity. This is the monoamnionic-monochorionic twin placentation. By moving about, the twins often entangle their umbilical cords and some 40% to 50% may die in utero.
Animals↗
Observations on neonatal mortality of the Chacoan peccary, Catagonus wagneri.
The considerable neonatal mortality of a captive population of Chacoan peccaries, the taguá (Catagonus wagneri), in Paraguay was investigated with the examination of six newborn animals and one adult. Most deaths occur primarily because of restriction of space resulting in competition for space and nutrition. The adult had nonlethal inhalation pulmonary anthracosis. Neonatal pulmonary nocardiosis was noted in one infant and is believed to be related to the dust storms prevailing locally. Another neonate had a duplication of the pelvis, rear extremities, and one ovary, representing a type of conjoined twin classified as ischiopagus.
Abnormalities, Multiple↗
Anatomical relationship between fetus and mother.
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Female↗
Cytokine expression in the placenta. The role of interleukin 1 and interleukin 1 receptor antagonist expression in chorioamnionitis and parturition.
Interleukin 1 (IL-1) is known to be present in placental tissue and is implicated as an endogenous mediator of inflammation and parturition. This study was undertaken to assess the role of IL-1 receptor antagonist (IL-1ra) in the placenta. Placentas with acute chorioamnionitis, with meconium staining, and without significant inflammation were examined for immunohistochemical expression of IL-1 and IL-1ra. Interleukin 1 and IL-1ra immunoreactivity was variably noted in the amnion, trophoblast, vascular smooth muscle, stromal cells, fibrinoid, and decidua in all placentas. Interleukin 1 immunoreactivity was less intense than IL-1ra immunoreactivity, and both were generally more intense in acute chorioamnionitis. Interleukin 1 receptor antagonist was detected (approximately 5 to 6 ng/mL) in the amniotic fluid of pregnant women at term. Colocalization of IL-1 and IL-1ra in normal and inflamed placentas suggests that the balance between these proinflammatory and anti-inflammatory mediators plays a role in parturition as well as in the pathogenesis of acute inflammation. An increase and/or imbalance in the IL-1 and IL-1ra expression associated with chorioamnionitis may precipitate preterm labor.
Adolescent↗
Immunocytochemical localization of nonluteal ovarian relaxin.
Relaxin has been demonstrated to be produced by the corpus luteum of the menstrual cycle and pregnancy and is also produced by the endometrium and decidua, although these nonluteal sources may not contribute to circulating relaxin concentrations. The reports of luteal production of relaxin have failed to consider nonluteal ovarian sources. To look for sources of nonluteal ovarian relaxin, human ovaries were collected from patients who underwent removal of the ovary for a variety of reasons. Tissues were fixed in formalin and embedded in paraffin. Two monoclonal antibodies were used for immunocytochemical staining, one directed against human relaxin and the other against the C peptide of prorelaxin. In addition to the expected staining of corpora lutea, the luteinized theca interna but not granulosa of developing follicles from ovaries with an active corpus luteum of the cycle also stained positive for both relaxin and prorelaxin. Ovaries from term pregnant women with luteinized theca also demonstrated staining for relaxin and prorelaxin. In addition to luteal and thecal cell staining, small clusters of pseudodecidual cells in the periphery of the ovary stained positive for relaxin and prorelaxin. These data indicate that the ovary contains theca interna-derived structural elements in addition to the corpus luteum that produce relaxin when a corpus luteum is active, while granulosa-derived elements do not. This suggests that luteal production of relaxin is from theca-derived elements and may explain instances of independent relaxin and progesterone secretion.
Adult↗
Obstetrically important lesions of the umbilical cord.
Many pathologic features of the umbilical cord affect fetal well-being adversely. Excessively long or short umbilical cords may be the cause of hematomas and thrombosis of cord vessels and the placental surface, thus causing fetal death and/or thrombocytopenia. In other cases, fetal hypoxia and central nervous system damage are possible outcomes. Thrombosis is also frequently induced by velamentous insertion of the cord, as are hemorrhages when the membranous vessels rupture during parturition. Entangling and knotting of the cord, especially of excessively long cords, may lead to similar lesions and fetal death. It was recognized recently that prolonged meconium exposure to the surface of the cord can cause partial necrosis of umbilical vessels and cord ulceration. The noxious moiety of meconium also causes contraction of the umbilical vessels, leading to fetal hypoperfusion and hypoxia. A stricture at the fetal end of the cord and excessive spiralling of a very long umbilical cord are often present in cases of unexplained fetal demise, especially in early pregnancy. Less common abnormalities are obstruction of the circulation by amnionic bands and varices.
Aneurysm↗
Extension of the cleft lip phenotype: the subepithelial cleft.
We present a previously undescribed occult malformation of the upper lip manifest by discontinuity of the orbicularis oris muscle. The relationship of this defect to our current concept of abnormal maxillary process development is discussed along with a proposal to extend the cleft lip phenotype.
Cleft Lip↗
Physical and behavioral findings in a pseudohermaphrodite American bison.
A pseudohermaphrodite American bison (Bison bison) behaved like an adult male when interacting with adult females, but like an adult female when interacting with adult males. Its chromosomes were a normal 60, XX and it had a uterus; but it had bilateral testes rather than ovaries. Skull measurements were intermediate between a bull and a cow. Gonadotrophin levels were typical of ovariectomized domestic cows or steers.
Animals↗
Intrauterine death of a twin: mechanisms, implications for surviving twin, and placental pathology.
In multiple gestations, intrauterine death of one fetus occurs frequently. Sonographic studies indicate that many twin pregnancies are converted in early pregnancy to singletons. The "vanished" twin is sometimes recognized as a fetus papyraceous (compressus) incorporated into the placenta of the survivor. Death of one twin later in pregnancy may have serious implications for the survivor, especially in cases of monochorionic twins. One postulated mechanism has been that thromboplastic proteins from the dead twin are transfused into the survivor's circulation, resulting in disseminated intravascular coagulation. More recently it has been proposed that massive blood loss may occur from the survivor into the more relaxed circulation of a dead monochorionic twin through vascular anastomoses. These mechanisms may explain the higher frequency of cerebral palsy in monochorionic twins. These concepts emphasize the importance of careful examination and thoughtful interpretation of twin placentas.
Brain Diseases↗
Effect of ACE inhibition on the fetal kidney: decreased renal blood flow.
The kidneys of nine fetuses whose mothers were chronically hypertensive were examined microscopically. Three of these mothers used antihypertensive agents throughout pregnancy including one who used an angiotensin-converting enzyme (ACE) inhibitor. The tubular defects found in these kidneys were compared to the kidneys of 20 normal controls, 13 fetuses with various multiple malformation syndromes and six cases of the twin to twin transfusion syndrome. Evidence from these cases as well as the literature suggest that the primary mechanism by which ACE inhibitors affect development of the fetal kidney is through decreased renal blood flow.
Abnormalities, Drug-Induced↗
The contribution of placental anastomoses to prenatal twin damage.
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Arteriovenous Anastomosis↗