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M Panigel

Publications and source records attributed to M Panigel.

At least 37 records · Page 2Linked to original sources
PubMed1982

Transfer of ritodrine and norepinephrine in human placenta: in vitro study.

The placental transfer from maternal to fetal circulation of ritodrine, a tocolytic agent used in obstetrics and of a structurally related physiologic catecholamine, norepinephrine was studied in vitro using dual perfusion of isolated human placental lobules. The clearances of ritodrine and norepinephrine represent 34 and 24% respectively of tritiated water clearance taken as reference. The relatively low ritodrine clearance may be explained by its small molecular weight and hydrosoluble nature, but not that of norepinephrine. For the latter, a strong membrane limitation and efficient placental catabolism may be implicated. We conclude that some of the fetal effects of maternal infusion of these amines are the result of the method in which the drug is transferred.

Biological Transport, Active↗
PubMed1981

Transfer of Salbutamol in the human placenta in vitro.

The maternal-fetal transfer of Salbutamol was studied in vitro, in dual perfusion of isolated human placental lobules. The fraction of drug transferred to the fetal side was compared to reference substances:((14)C)-antipyrine and ((3H)-inulin. Salbutamol transfer (12%) represents about 39% of antipyrine and five times of inulin transfer. Studies with varying Salbutamol concentrations in the maternal arterial perfusate revealed that the drug transfer to the fetal side was effected by a flow-dependent diffusion process. We conclude that the reported effects on the fetus following a maternal drug infusion are mediated by the drug transferred across the placenta.

Albuterol↗
PubMed1979

In vitro computed tomography of the human placenta.

A plastic holding device has been devised to allow in vitro computed tomography of term human placentas. Graded dilutions of iodinated contrast medium have been injected into the fetal placental circulation and into the intervillous space of placental lobules perfused with normal saline solution. Computed tomography in different orientations has imaged Borell's "jets" on the maternal side and cotyledonary vascular "puffs" on the fetal side of the placenta. Attenuation coefficients, before and after injection of contrast medium may be used for quantitative investigation of the physiological placental circulation and possibly for diagnosing placental pathology.

Humans↗
PubMed1978

[The microvascularity of human placental villi].

Scanning electron microscopic observation of plastic casts of human chorionic villi vasculature has demonstrated that in the area of placental exchange two blood capillary networks are present: the paravascular and the villous capillary networks. S.E.M. provides precise information on the shape and anatomical relations of these blood capillary networks.

Capillaries↗
PubMed1976

Surface ultrastructure of preimplantation baboon embryos.

Scanning and transmission electron microscopy were used to study baboon preimplantation embryos 3 to 5 days E.F.A. (estimated fertilization age), ranging from about 16 to more than 60 cells. The peripheral blastomers were covered with microvilli scattered on the convex outer surface and along the borders of the intercellular furrows. In younger morulae, some longer microvilli may bridge over the furrow separating contiguous blastomeres. A few blastomeres showed poorly developed microvilli. Blastomeres of smaller diameter than the others may arise from more recent cleavage. Cell junctions as well as small intercellular spaces were noted at the apposition of the blastomere plasma membranes whereas surface intercellular ridges were not observed.

Animals↗
PubMed1975

Ultrastructure of cleavage stages and preimplantation embryos of the baboon.

The baboon preimplantation stages were examined using light and electron microscopy. Six cases were studied at 2, 3, 4, 5, 7 and 8 days estimated fertilization age. The first 3 specimens were composed of 2, 8 and 24 blastomeres respectively. At 5 days, 30 to 40 cells were counted and more than 60 cells in later stages. Primitive "trophoblast cells" differentiate at 7 days and a crescentic blastocoele appears at 8 days. Shedding of the zona pellucida is not observed in the 7 and 8 day specimens. The preimplantation period is longer in the baboon than in man. C-type viruses are observed in the zona pellucida, in the perivitelline and interblastomeric spaces. Microvilli and caveolae cover ther periphery of the baboon conceptus. As in many other mammals, transformation of the mitochondria, changes in the ribosomes distribution, multivesicular bodies, myelin figures, nucleoli and intranuclear clusters of granules are described in the baboon. Cytoplasmic fibrous strands are not present as in the mouse. Experiments on the influence of hormones and drugs on ultrastructural changes would help to evaluate the importance of biohazards during the early development of primates.

Animals↗
PubMed1975

Radionuclide and angiographic studies of placental circulation in man and rhesus monkey.

Imaging maternal and fetal circulation during perfusion of isolated human placental lobules was performed. Radionuclide and contrast angiograms, specimen scans, and histologic preparations obtained on human material during in vitro investigations were compared to the results obtained in vivo on pregnant rhesus monkeys. The distribution of maternal blood flow within the placenta appeared similar in both human and rhesus studies. The 'spurts' of radiopaque medium shown on the contrast angiograms correlated with the appearance of areas of increased radioactivity. These 'hot spots' are located where the uteroplacental spiral arteries open into the intervillous space or where the perfusion cannulae irrigate the maternal side of the placenta. Time-radioactivity curves reached an early peak and remained the same as did their distribution on delayed scans. The 15 to 30 micron microspheres injected into the intervillous spaces are not removed onto the venous side by maternal flow through arteriovenous communications (or 'shunts') but are retained in localized areas of the intervillous space adjacent to the spiral arteries. Many of these microspheres adhere to the 'brush border' of the chorionic villi syncytiotrophoblast. These comparative studies confirm that rhesus monkeys and perfused human placental lobules are relevant models to investigate uteroplacental hemodynamics.

Animals↗
PubMed1975

Type-C virus particles in placenta of the cottontop marmoset (Saguinus oedipus).

Electron microscopy of near-term placentas of two cottontop marmosets (Saguinus oedipus) revealed, in one placenta, the presence of budding and mature C-type virus particles associated with the basal trophoblast. The particles were morphologically similar to those observed by other investigators in placentas of other primate species.

Animals↗
PubMed1975

A comparative study on the presence of C-type viral particles in placentas from primates and other animals.

C-type particles are found in human, baboon, marmoset, rhesus, patas, and cynomolgus monkeys. A cebus monkey and two chimpanzee placentas have failed thus far to show the presence of these particles. Of the nonprimate tissues examined one mouse and one guinea pig placenta were positive whereas a rabbit placenta was negative. Variations in number of particles present in tissues as well as number of animals of a given species containing particles are noted. The isolation of foamyviruses from placenta cultures makes critical evaluation and interpretation of findings imperative. Several considerations suggest that the presence of foamyviruses is coincidental.

Animals↗
PubMed1975

A-type particles in placentas of four mouse strains.

A-type particles have been detected by electron microscopy in placentas from four strains of mice: AKR, Balb/c, C3H, and DBA/2N. Complete structures were observed within rough endoplasmic reticulum cisternae of the placental labyrinth cytotrophoblasts. A marked prevalence of such particles was observed in the DBA/2 N mice. Similar particles were also found in small cytotrophoblastic elements of the junctional zone (located between labyrinth and maternal decidua) of all mouse strains studied. The numbers of junctional zone particles in all four strains were roughly equivalent.

Animals↗