Measurements have been made of the peripheral vascular factors influencing venous return, and hence cardiac output, in the fetus. These measurements show the fetus maintains a high venous return by means of a high mean systemic pressure, or driving pressure for venous return, and a low resistance to venous return. Increases in fetal blood volume cause increases in mean systemic pressure with no change in resistance to venous return and, as a result, venous return is increased. These studies show the possible importance of peripheral vascular factors in the control of cardiac output.
{"title":"Determinants of venous return in the fetal lamb.","authors":"R D Gilbert","doi":"10.1159/000301088","DOIUrl":"https://doi.org/10.1159/000301088","url":null,"abstract":"<p><p>Measurements have been made of the peripheral vascular factors influencing venous return, and hence cardiac output, in the fetus. These measurements show the fetus maintains a high venous return by means of a high mean systemic pressure, or driving pressure for venous return, and a low resistance to venous return. Increases in fetal blood volume cause increases in mean systemic pressure with no change in resistance to venous return and, as a result, venous return is increased. These studies show the possible importance of peripheral vascular factors in the control of cardiac output.</p>","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 5-6","pages":"233-45"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11814387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthesis of proteins in the placenta.","authors":"C A Villee","doi":"10.1159/000301047","DOIUrl":"https://doi.org/10.1159/000301047","url":null,"abstract":"","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 3-4","pages":"145-61"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11418893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
4 70. Biological Membranes (JDC 470.) Spring. 3(3-0) BCH 401. Interdepartmental with the departments of Microbiolop,y and Public Health, and Physio(ogy. Administered by the Department of Physiology. Thtt chemistry, physics and mathematics of the permeabilitv. energy transductions and snrfacc functions o{ differentiated cell membranes and membranous organelles are compared. A brief discussion of theoretical and experimental models is included.
{"title":"Nucleic acid structure and function.","authors":"C A Villee","doi":"10.1159/000301045","DOIUrl":"https://doi.org/10.1159/000301045","url":null,"abstract":"4 70. Biological Membranes (JDC 470.) Spring. 3(3-0) BCH 401. Interdepartmental with the departments of Microbiolop,y and Public Health, and Physio(ogy. Administered by the Department of Physiology. Thtt chemistry, physics and mathematics of the permeabilitv. energy transductions and snrfacc functions o{ differentiated cell membranes and membranous organelles are compared. A brief discussion of theoretical and experimental models is included.","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 3-4","pages":"139-44"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11808837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
10 fetal lambs prepared with sampling catheters in the common umbilical vein and distal aorta were studied at 2 h, 2 and 4 days postoperatively. Umbilical blood flow was measured by a diffusion equilibrium method. Oxygen, lactate, pyruvate, glucose and alpha-amino nitrogen concentrations were determined on umbilical arterial (UA) and umbilical vein (UV) blood. Fetal oxygen consumption averaged 10.4, 10.6 and 1.0 ml.kg-1.min-1 for the three study periods. Lactate/pyruvate ratios were higher in UV than in UA in 17 of 20 experiments. Significant reductions (p less than 0.05) in (1) maternal mixed venous-UA glucose concentration difference, and (2) UA glucose concentrations occurred at 2 and 4 days compared to the 2-hour period. Fetal alpha-amino nitrogen balance was negative at the 2-hour period, but positive 2 days and 4 days postoperatively.
{"title":"Fetal metabolism during recovery from surgical stress.","authors":"J F Clapp, R M Abrams, N Patel","doi":"10.1159/000301106","DOIUrl":"https://doi.org/10.1159/000301106","url":null,"abstract":"<p><p>10 fetal lambs prepared with sampling catheters in the common umbilical vein and distal aorta were studied at 2 h, 2 and 4 days postoperatively. Umbilical blood flow was measured by a diffusion equilibrium method. Oxygen, lactate, pyruvate, glucose and alpha-amino nitrogen concentrations were determined on umbilical arterial (UA) and umbilical vein (UV) blood. Fetal oxygen consumption averaged 10.4, 10.6 and 1.0 ml.kg-1.min-1 for the three study periods. Lactate/pyruvate ratios were higher in UV than in UA in 17 of 20 experiments. Significant reductions (p less than 0.05) in (1) maternal mixed venous-UA glucose concentration difference, and (2) UA glucose concentrations occurred at 2 and 4 days compared to the 2-hour period. Fetal alpha-amino nitrogen balance was negative at the 2-hour period, but positive 2 days and 4 days postoperatively.</p>","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 5-6","pages":"299-306"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11817581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Role of nucleic acids in the regulation of human placental lactogen synthesis.","authors":"D J Gusseck","doi":"10.1159/000301049","DOIUrl":"https://doi.org/10.1159/000301049","url":null,"abstract":"","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 3-4","pages":"162-82"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11418894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Measurement of changes in the constituents of nucleic acids (total DNA and RNA) in the placenta during the course of pregnancy.","authors":"T T Hayashi","doi":"10.1159/000301051","DOIUrl":"https://doi.org/10.1159/000301051","url":null,"abstract":"","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"8 3-4","pages":"183-94"},"PeriodicalIF":0.0,"publicationDate":"1977-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11552638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In vitro perfusion studies of glucose transport in the human placenta show saturation kinetics at high glucose concentrations and competitive inhibition of glucose transfer by the nonmetablizable glucose analog 3-O-methyl-alpha-D glucopyranoside. These characteristics provide further evidence that glucose is transported by a facilitated diffusion process in the human placenta.
人胎盘中葡萄糖转运的体外灌注研究显示，高葡萄糖浓度下的饱和动力学和不可代谢的葡萄糖类似物3- o -甲基- α - d葡萄糖吡喃苷对葡萄糖转运的竞争性抑制。这些特征提供了进一步的证据，证明葡萄糖是通过一个易于扩散的过程在人胎盘中运输的。
{"title":"In vitro perfusion studies of the human placenta. IV. Some characteristics of the glucose transport system in the human placenta.","authors":"P. A. Rice, J. E. Rourke, E. L. Nesbitt","doi":"10.1159/000301396","DOIUrl":"https://doi.org/10.1159/000301396","url":null,"abstract":"In vitro perfusion studies of glucose transport in the human placenta show saturation kinetics at high glucose concentrations and competitive inhibition of glucose transfer by the nonmetablizable glucose analog 3-O-methyl-alpha-D glucopyranoside. These characteristics provide further evidence that glucose is transported by a facilitated diffusion process in the human placenta.","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"7 4 1","pages":"213-21"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301396","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65433977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bulk water flows across term human amnio-chorion are studied in vitro. The hydrodynamic permeability is found to vary with both hydrostatic and osmotic pressure. The coefficient characterizing flows generated by hydrostatic pressure is substantially larger than that characterizing osmotic flows. The measurements are utilised to predict in vivo bulk flows across the amnio-chorion. These lead to the prediction that at most a flux of 34-83 ml/day may occur across amnio-chorion directed outwards from the amniotic cavity, the principal contribution to this arising from the effects of hydrostatic pressure.
{"title":"Bulk flows through human fetal membranes.","authors":"D R Abramovich, K R Page, L Jandial","doi":"10.1159/000301331","DOIUrl":"https://doi.org/10.1159/000301331","url":null,"abstract":"<p><p>Bulk water flows across term human amnio-chorion are studied in vitro. The hydrodynamic permeability is found to vary with both hydrostatic and osmotic pressure. The coefficient characterizing flows generated by hydrostatic pressure is substantially larger than that characterizing osmotic flows. The measurements are utilised to predict in vivo bulk flows across the amnio-chorion. These lead to the prediction that at most a flux of 34-83 ml/day may occur across amnio-chorion directed outwards from the amniotic cavity, the principal contribution to this arising from the effects of hydrostatic pressure.</p>","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"7 3","pages":"157-64"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301331","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12146403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human umbilical vein and artery diameters reduce significantly during the first 2 min after delivery, whereas blood gas tensions do not change significantly. Gas tension changes, therefore, cannot account for the reduction in the umbilical vessel diameters which occurs during this time.
{"title":"Human umbilical vessel diameters and bloodgas tensions in the first two minutes after delivery.","authors":"W D McCallum, R M McAreavey","doi":"10.1159/000301383","DOIUrl":"https://doi.org/10.1159/000301383","url":null,"abstract":"<p><p>Human umbilical vein and artery diameters reduce significantly during the first 2 min after delivery, whereas blood gas tensions do not change significantly. Gas tension changes, therefore, cannot account for the reduction in the umbilical vessel diameters which occurs during this time.</p>","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"7 4","pages":"201-12"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301383","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11981922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The simultaneous diffusion of 14C-succinylcholine and p-amino hippurate across human placental tissue in vitro was measured. Column chromatographic purification of the radioactivity followed by paper chromatographic analysis showed little alteration of the succinylcholine during the course of these experiments. Similar chloroform-buffer partition coefficients for the two solutes were measured. Thus in these experiments, the nearly identical transfer rates of these two similar sized, lipid-insoluble compounds indicated that succinylcholine crosses human placental tissue in quantitites compatible with its molecular size and lipophobic nature, and that the diffusion rate is not significantly influenced by its increased molecular charge.
{"title":"Permeability of chorion laeve to succinylcholine in vitro.","authors":"B C Eichhorst, A E Seeds","doi":"10.1159/000301378","DOIUrl":"https://doi.org/10.1159/000301378","url":null,"abstract":"<p><p>The simultaneous diffusion of 14C-succinylcholine and p-amino hippurate across human placental tissue in vitro was measured. Column chromatographic purification of the radioactivity followed by paper chromatographic analysis showed little alteration of the succinylcholine during the course of these experiments. Similar chloroform-buffer partition coefficients for the two solutes were measured. Thus in these experiments, the nearly identical transfer rates of these two similar sized, lipid-insoluble compounds indicated that succinylcholine crosses human placental tissue in quantitites compatible with its molecular size and lipophobic nature, and that the diffusion rate is not significantly influenced by its increased molecular charge.</p>","PeriodicalId":75889,"journal":{"name":"Gynecologic investigation","volume":"7 3","pages":"176-81"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000301378","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12146404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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