Primary nontrophoblastic tumors of the placenta

Looking from histogenetical point of view primary neoplastic alterations of placenta and umbilical cord can be divided in two main groups. First group consists of neoplasms of trophoblastic disease's origin: placental site trophoblastic tumor, choriocarcinoma and hydatidiform mole, according to most authors it not belonging to neoplasms. The second group consists of nontrophoblastic tumors, like: chorioangioma and teratoma. Hepatocellular adenoma and leiomyoma are also enclosed to the nontrophoblastic tumors. It hasn't been defined yet whether all nontrophoblastic changes in placenta or in umbilical cord should be considered as neoplasms or like pseudoneoplastic changes. Comparing to neoplasms of trophoblastic disease's origin nontrophoblastic tumors are not frequent changes to be observed, moreover they are always benign tumors. In some cases these neoplasms are asymptomatic, however clinical course of some of them may become severe. The influence of nontrophoblastic tumors on pregnancy and delivery is often underestimated. It could be observed that studies on these neoplasms are performed very seldom what may be result of their infrequent appearance and because of their asymptomatic natural history. In this study we presented an up-to date opinions about the histopathogenesis of the nontrophoblastic tumors and also their histopathological characteristics and the most common symptoms which can accompany the development of these neoplasms. An important notice is that these tumors can remain undetected during macroscopic examination of secundines.     

Endometrial stromal sarcoma involving the placenta

The two pest control agents, buprofezin and petroleum oil (Super Royal), were tested to evaluate their potential mutagenicity, in comparison with the organophosphorus insecticide profenofos. Chromosomal aberration analysis was used in both somatic and germ cells of male mice. Single oral treatment at three different dose levels (1/16, 1/8 and 1/4 LD50) for each insecticide induced an increase in the percentage of chromosomal aberrations in bone-marrow cells 24 h post-treatment, indicating a dose-dependent relationship. The percentage of chromosomal aberrations reached 23 +/- 0.73, 10.5 +/- 0.64 and 15 +/- 1.4 after treatment with the highest tested dose of profenofos, buprofezin and Super Royal, respectively. Such percentages did not exceed the corresponding value of the positive control, mitomycin C (29.2 +/- 0.69). The percentage of chromosomal aberrations induced by the different doses of profenofos was still highly significant even after excluding gaps. The same trend of results was noticed only at the highest tested dose of buprofezin and Super Royal. With respect to germ cells, profenofos is also a potent inducer of chromosomal aberrations in 1ry spermatocytes, giving percentages of 14 +/- 1.3 and 19 +/- 1.6 at the two higher doses of 4.25 and 8.5 mg kg(-1) body wt., respectively. Buprofezin and Super Royal had no significant effect on mouse spermatocytes at the tested concentrations. The various types of induced aberrations were examined and recorded in both somatic and germ cells. In conclusion, the present investigation indicates that the two pest control agents buprofezin and Super Royal are relatively much safer compounds than the conventional organophosphorus insecticides.     

Globoside expression within the human placenta

PURPOSE: To validate a computer-based area calculation method of quantification of rectal evacuation by using defecography videotapes and to use that method to compare evacuation in constipated patients with that in control subjects. MATERIALS AND METHODS: For validation of the method, simultaneous defecography and weight measurements were compared in 36 patients with constipation or incontinence. Evacuation was calculated as the rate of change of the contrast medium-covered rectal area (percentage per second) or of the evacuated amount of contrast medium (percentage per second [relative] and grams per second [absolute]). After method validation, from a series of 215 consecutive constipated patients, individuals with an isolated radiologic diagnosis of intussusception greater than 0.6 cm (n = 27), rectocele greater than 2 cm (n = 19), enterocele (n = 12), or paradoxic puborectal muscle contraction (n = 12) were selected. Rectal evacuation in these groups was compared with that in 30 control subjects. RESULTS: Rectal evacuation rates measured at defecography correlated well with weighed amounts of evacuated contrast medium during the initial and total evacuation periods in 21 patients without contrast medium leak (r = 0.92, P < .001). Constipation overall, a rectocele greater than 2 cm, or paradoxic puborectal muscle contraction were associated with impaired evacuation (P < .001). CONCLUSION: Area calculations of rectal evacuation reflect rectal emptying. A rectocele greater than 2 cm or a paradoxic puborectal muscle contraction may be associated with obstructed defecation.     

Hexokinase isoenzymes in the rat placenta

The phosphorylation of glucose to glucose-6-phosphate, the first enzymatic step for glucose utilization is catalysed by a family of four hexokinase isoenzymes (HKI-IV) which display a tissue-specific distribution. The expression of HK isoenzymes was investigated in the rat placenta. High levels of HKI and HKII mRNA were found in the junctional and the labyrinthine zones. HKIII mRNA was present at low levels in the junctional zone and glucokinase (HKIV) mRNA was not detected, indicating that HKI and HKII are the two major placental HK isoenzymes. HKII activity was increased in placenta of insulinopenic diabetic rats. This regulation is likely to support the increase in glucose utilization and storage characteristics of the enlarged placentae of diabetic rats.     

Gestational drive and the green-bearded placenta

A "green beard" refers to a gene, or group of genes, that is able to recognize itself in other individuals and direct benefits to these individuals. Green-beard effects have been dismissed as implausible by authors who have implicitly assumed sophisticated mechanisms of perception and complex behavioral responses. However, many simple mechanisms for genes to "recognize" themselves exist at the maternal-fetal interface of viviparous organisms. Homophilic cell adhesion molecules, for example, are able to interact with copies of themselves on other cells. Thus, the necessary components of a green-beard effect -- feature, recognition, and response -- can be different aspects of the phenotype of a single gene. Other green-beard effects could involve coalitions of genes at closely linked loci. In fact, any form of epistasis between a locus expressed in a mother and a closely linked locus expressed in the fetus has the property of "self-recognition." Green-beard effects have many formal similarities to systems of meiotic drive and, like them, can be a source of intragenomic conflict.     

Spatiotemporal expression of C-CAM in the rat placenta

We investigated the expression of the immunoglobulin superfamily cell adhesion molecule, C-CAM, in developing and mature rat placenta. By immunohistochemical staining at the light microscopic level, no C-CAM-expression was seen before Day 9 of gestation, when it appeared in the trophoblasts of ectoplacental cones. On Day 10.5, spongiotrophoblasts and invasive trophoblasts around the maternal vessels of the decidua basalis were stained positively. On Day 12.5, C-CAM was detected in the spongiotrophoblasts of the junctional layer, but labyrinth trophoblasts and secondary giant trophoblasts were not stained. On Day 17.5, C-CAM was found only in the labyrinth and lacunae of the junctional layer. At this stage, both the labyrinth cytotrophoblasts of the maternal blood vessels and the endothelial cells of the embryonic capillaries were strongly stained. Placental tissues from gestational Days 12.5 and 17.5 were analyzed by immunoelectron microscopy to determine the location of C-CAM at the subcellular level. On Day 12.5, positive staining of the spongiotrophoblasts was observed, mainly on surface membranes and microvilli between loosely associated cells. On Day 17.5, staining was found primarily on the microvilli of the maternal luminal surfaces of the labyrinth cytotrophoblasts, and both on the luminal surface and in the cytoplasm of endothelial cells of the embryonic vessels. RT-PCR analysis and Southern blotting of the PCR products revealed expression of mRNA species for both of the major isoforms, C-CAM1 and C-CAM2. Immunoblotting analysis of C-CAM isolated from 12.5-day and 14.5-day placentae showed that it appeared as a broad band with an apparent molecular mass of 110-170 kD. In summary, C-CAM was strongly expressed in a specific spatiotemporal pattern in trophoblasts actively involved in formation of the placental tissue, suggesting an important role in placental development. In the mature placenta, C-CAM expression was confined to the trophoblastic and endothelial cells lining the maternal and embryonic vessels, respectively, suggesting important functions in placental physiology.     

Mechanisms of drug transfer across the human placenta

In this review we summarized literature data on the mechanisms of human placental drug transport studied in the isolated perfused placental cotyledon, placental membrane vesicles or trophoblastic cell cultures. Overall human placental drug transport rarely exceeds the transfer of flow-dependent and membrane-limited marker compounds. Interestingly, relatively often placental drug transfer appeared to be much smaller, indicating impaired trans-placental transport, depending on the physico-chemical characteristics of the drug or placental factors such as tissue binding or metabolism. Although in perfusion studies overall human placental drug transport occurs by simple diffusion, at the membrane level several drug transport systems have been found, mainly for drugs structurally related to endogenous compounds.     

Pathological features of the placenta in fetal death

Few studies of the histopathological features of the placenta in cases of fetal death are available. We will describe the placental findings from 24 midtrimester spontaneous abortions and 54 stillborn infants of more than 28 weeks' gestation. In almost 100% of midtrimester abortions and in 48% of the placentas from stillborn infants of more than 28 weeks' gestation, chorioamnionitis, deciduitis, and/or villitis were present. Because of this very high percentage of lesions, which suggests an infectious causation, it is mandatory that studies be performed that might identify pathogens. One third of the stillborn infants of more than 28 weeks' gestation were associated with maternal complications (diabetes, preeclampsia, and urinary tract infection), in addition to placental fetal vasculopathy, ischemia, infarcts, and chorangiosis (villous capillary hyperplasia). We emphasize the use of the placenta for the recognition of maternal diabetes.     

Macroscopic examination of the placenta immediately following birth

Macroscopic examination of the placenta can be performed readily by the healthcare providers present at the time of birth. It can be accomplished with a basic knowledge of placental pathology and a general understanding of the abnormalities and variations that affect the placenta. These observations can easily be entered into the medical record and may often provide information about intrauterine life that will help the future care of both mother and infant.     

Placental lactogen-like proteins in the rabbit placenta

Rabbit placentae and embryos at days 11 and 12 were analyzed by two-dimensional gel electrophoresis and by light microscopic histology for the presence of placental lactogen-like proteins. Immunoblotting and immunohistochemistry were performed by using a goat anti-human placental lactogen serum as well as a monoclonal mouse anti-human prolactin immunoglobulin; the results were similar. In the gel electrophoresis of placental tissue, three protein spots at pH 5.6 and 43, 39, and 35 kDa were immunostained; they were absent in the embryo. Immunoresponse was restricted to the cytotrophoblast. Immunofluorescent cells were mainly found on the proximal parts of the placental trabeculae.     

Expression of vascular endothelial growth factor and placenta growth factor in human placenta

Normal development and function of the placenta requires invasion of the maternal decidua by trophoblasts, followed by abundant and organized vascular growth. Little is known of the significance and function of the vascular endothelial growth factor (VEGF) family, which includes VEGF, VEGF-B, and VEGF-C, and of placenta growth factor (PIGF) in these processes. In this study we have analyzed the expression of VEGF and PIGF mRNAs and their protein products in placental tissue obtained from noncomplicated pregnancies. Expression of VEGF and PIGF mRNA was observed by in situ hybridization in the chorionic mesenchyme and villous trophoblasts, respectively. Immunostaining localized the VEGF and PIGF proteins in the vascular endothelium, which was defined by staining for von Willebrand factor and for the Tie receptor tyrosine kinase, an early endothelial cell marker. VEGF-B and VEGF-C mRNAs were strongly expressed in human placenta as evidenced by Northern blot analysis. These data imply that VEGF and PIGF are produced by different cells but that both target the endothelial cells of normal human term placenta.     

In vitro perfusion studies of the human placenta. IV. Some characteristics of the glucose transport system in the human placenta

Cross infection has become a serious risk to hospitalized patients. Potential sources of infection by anaesthetic apparatus and equipment and the danger arising from disregard of proper asepsis are discussed. Prophylactic and hygienic measures to minimize these hazards are reviewed. Since patients receiving intensive therapy are particularly are risk very high hygienic standards are a "must" in these units. The need for thoroughly and regularly checking all equipment for contamination is emphasized.