Oluseyi Vanderpuye - Academia.edu (original) (raw)

Papers by Oluseyi Vanderpuye

Research paper thumbnail of Spice Synthetic Cannabinoid Drugs: Lung and Adrenal Cell Models

The FASEB Journal

‘Spice’ refers to designer drugs consisting of plant materials spiked with different synthetic mi... more ‘Spice’ refers to designer drugs consisting of plant materials spiked with different synthetic mimetics of delta tetrahydrocannabinol, a psychoactive compound in marijuana. The toxicology and bioactivity of many synthetic cannabinoids are unknown including Spice brands: Barely Legal, Brain Storm and Voodoo.It was hypothesized that the ‘Spice’ brands Barely Legal, Brain Storm and Voodoo Child contain different compounds, overlap in biological activities with delta THC and affect cell physiology and morphology. This study sought possible biomarkers for the effects of ‘Spice’. Fluorescence microscopy detected cannabinoid receptor type 2 proteins but not type 1 receptors on A549 and SW‐13 cells. The complement system regulatory proteins CD46 and CD59 but not CD55 were detected on A549 and SW‐13 cells. Glycoconjugate profiles on these cells were characterized by lectin binding. Exposure to delta THC and Barely Legal Spice caused stronger Con A lectin binding to A549 lung cells than did exposure to Brainstorm Spice or control media. This study is the first description of the complement regulatory protein profile of adrenal gland cells and provided carbohydrate structure profiles of A549 and SW‐13 cells as detected by lectin binding. The results will facilitate more detailed analysis of the toxicology and bioactivities of spice.

Research paper thumbnail of Evidence for the Binding of Synthetic Cannabinoids to Human and Bovine Serum Albumin

Research paper thumbnail of Llama Hemoglobin Binding to Heterologous Haptoglobins

Research paper thumbnail of Modeling metabolism of the synthetic cannabinoids Bay 59‐3074 and JWH‐015 by human liver microsomes and cytochrome p450

Research paper thumbnail of Lectin Binding Studies of Buccal Cell Glycoproteins

Research paper thumbnail of Comparison of Different DNA Extraction Methods for Forensic Samples

Journal of Natural Sciences Research, 2013

DNA analyses are important for different types of research in biomedical and forensic science and... more DNA analyses are important for different types of research in biomedical and forensic science and DNA isolation is an often required step. Because different DNA isolation kits are constantly becoming available, it is useful to compare their efficacies. This study compared kits of the QIAamp DNA Investigator (Qiagen), ZR Genomic DNA (Zymo Research) and AccuPrep Genomic DNA (Bioneer). Spectrophotometry showed the highest yield of DNA from 200 µl of blood was obtained by the Qiagen kit (5.6 µg) followed by the Bioneer kit (2.74 µg) and Zymo kit (2.39 µg). For purity measured by spectrophotometric A260/A280 nm ratio, DNA isolated by the Qiagen was the most pure and had a ratio of 1.85, closer to the ideal ratio than DNA isolated by Zymo (2.0) and Bioneer (1.03) ratios. Costs of isolation were 3.60/sampleforQiagen,3.60/sample for Qiagen, 3.60/sampleforQiagen,1.50/sample for Bionner and $0.72 for Zymo kits. The Zymo test took 25 minutes to isolate DNA, the Bioneer kit 35 minutes and the Qiagen kit 50 minutes. These findings ma...

Research paper thumbnail of Polymorphisms in UEA‐1 Lectin Binding to Human Buccal Cells and Salivary Fluid

Research paper thumbnail of Modulation of association of a 120 kda cell surface glycoprotein with ascites tumor microvillar microfilament cores

Research paper thumbnail of Cofactor Activity in Placental Microvilli for the Cleavage of Complement Component 3 by Factor I

Research paper thumbnail of Conservation of Binding of Llama and Other Animals’ Hemoglobins to Haptoglobins Across Species

American Journal of Biochemistry and Biotechnology, 2018

The plasma protein haptoglobin binds hemoglobin released from lysed erythrocytes. It causes remov... more The plasma protein haptoglobin binds hemoglobin released from lysed erythrocytes. It causes removal of the free hemoglobin, thus preventing pathological oxidation of cells. Hemoglobin higher level structures are well conserved across animal species but primary structures can be as little as 50% homologous. Because of these differences, the question arose as to what extent hemoglobins can bind to haptoglobins from different species. The charge properties and binding to three genetic variants of human haptoglobin were compared by non-denaturing agarose gel electrophoresis, with llama, human, dog, pig, horse and goat hemoglobins. In this study, it was reported for the first time that llama and alpaca hemoglobins differed in electrophoretic mobility from hemoglobins from several animal species and humans. Llama hemoglobin was more positively charged than the other mammalian hemoglobins. Electrophoretic mobility changes of the animal hemoglobins in the presence of human plasma and two different purified human haptoglobin genetic variants suggested that hemoglobins from all animals in this study could bind all three genetic variants of human haptoglobin. In all cases, the llama hemoglobin-haptoglobin samples had lesser mobility than those of the other mammals. This study showed that the binding sites on hemoglobin and haptoglobin for each other have been evolutionarily conserved despite differences in primary structure and marked difference in the charge of llama hemoglobin from the other animal species and humans.

Research paper thumbnail of Redistribution of connexin 43 during cell division

Cell Biology International, 2016

Gap junction channels, once clustered into gap junction plaques, allow communication of essential... more Gap junction channels, once clustered into gap junction plaques, allow communication of essential metabolites between cells. Gap junction plaques have been reported to be lost from the cell surface during cell division. The mechanism involved in this loss of gap junction plaques during mitosis is unclear, but we hypothesize that an endoexocytotic mechanism that results in cytoplasmic double-membraned annular gap junction vesicles is involved. In this study, gap junction plaque changes in dividing cells were examined in SW-13 adrenocortical tumor cells. Endogenous gap junction protein, connexin 43 (Cx43), was detected with immunofluorescence, and live cell imaging was used to monitor green fluorescent protein-tagged Cx43 (Cx43-GFP). Mitotic stages were identified by Hoechst chromosomal staining. During interphase, large gap junction plaques were detected; however, the presence of these plaques decreased, whereas cytoplasmic puncta increased beginning with prophase. The cytoplasmic puncta were demonstrated with immunoelectron microscopy to be Cx43-positive annular gap junction vesicles. As gap junction plaques reformed at cleavage furrows between daughter cells, the number of annular gap junctions decreased during cytokinesis. The data are consistent with the mechanism of gap junction plaque loss during mitosis relying on an endoexocytotic process that results in annular gap junction vesicles formation. The rapid formation of gap junction plaques during cytokinesis points to the intriguing possibility of connexin recycling from annular gap junction vesicles to form gap junction plaques as mitosis is completed.

Research paper thumbnail of Isolation and partial characterization of ascites sialoglycoprotein-2 of the cell surface sialomucin complex of 13762 rat mammary adenocarcinoma cells

Biochemical Journal, 1990

Sialomucins are the dominant components of the cell surfaces of some carcinoma ascites cells and ... more Sialomucins are the dominant components of the cell surfaces of some carcinoma ascites cells and have been postulated to inhibit recognition of tumours by the immune system. The sialomucin ASGP-1 (ascites sialoglycoprotein-1) of the 13762 rat mammary adenocarcinoma is associated with the cell surface as a complex with a concanavalin-A-binding glycoprotein called ASGP-2. This sialomucin complex has been purified from ascites cell microvilli by extraction with Triton X-100 and CsCl density-gradient centrifugation. ASGP-1 (which has been purified previously) and ASGP-2 were dissociated in 6 M-guanidine hydrochloride and separated by gel filtration. The molecular mass of the undenatured detergent complex of ASGP-2, estimated by gel filtration and velocity sedimentation in Triton X-100, was 148 kDa. Since the apparent molecular mass by SDS/polyacrylamide-gel electrophoresis was about 120 kDa, ASGP-2 must be a monomer as extracted from the membrane. Studies of its chemical composition ind...

Research paper thumbnail of Proteins of the human placental microvillar cytoskeleton. α-Actinin

Biochemical Journal, 1986

The human placental syncytiotrophoblast microvilli are supported by an underlying cytoskeleton co... more The human placental syncytiotrophoblast microvilli are supported by an underlying cytoskeleton consisting mainly of actin microfilaments. The major proteins associated with the actin have Mr values of 105 000, 80 000 and 68 000. The 105 000-Mr protein is recognized by an antibody preparation raised to purified chicken gizzard alpha-actinin. Electron microscopy has shown that the human placental protein has dimensions similar to those reported for muscle alpha-actinin. About half of the placental microvillar alpha-actinin is released from the cytoskeleton in the presence of Ca2+. This effect occurs at concentrations of Ca2+ greater than 0.3 muM and has been used as the basis of a method for the purification of the placental alpha-actinin. This sensitivity to Ca2+ is not affected by trifluoperazine and is therefore likely to be a property of the alpha-actinin as such rather than being mediated via calmodulin.

Research paper thumbnail of A vitronectin-receptor-related molecule in human placental brush border membranes

Biochemical Journal, 1991

The heterodimeric vitronectin receptor (VNR) and platelet glycoprotein IIb/IIIa (GPIIb/IIIa) are ... more The heterodimeric vitronectin receptor (VNR) and platelet glycoprotein IIb/IIIa (GPIIb/IIIa) are two members of the integrin family of cell adhesion receptors that share the same beta subunit (GPIIIa). These proteins are involved in binding to vitronectin, fibrinogen and fibronectin and in cytoskeleton-membrane interactions. The present study shows that the human placental syncytiotrophoblast brush border membrane contains a heterodimer of subunit Mr values of 140,000 and 90,000 (non-reduced) or 125,000 and 100,000 (reduced). This protein was recognized by a monoclonal antibody to GPIIIa, rabbit antisera to the VNR and a human alloantiserum to GPIIIa. Brush border VNR-related protein bound to an immobilized peptide containing the Arg-Gly-Asp sequence and, less avidly, to immobilized fibrinogen. Only a small fraction of brush border VNR was associated with a cytoskeleton fraction. Membrane-bound brush border GPIIIa was distinct from that of platelets in its resistance to digestion by...

Research paper thumbnail of Structure of Human Placental Microvilli

Novartis Foundation Symposia, 2008

ABSTRACT Cytoskeletons have been prepared from microvilli isolated from the human placental syncy... more ABSTRACT Cytoskeletons have been prepared from microvilli isolated from the human placental syncytiotrophoblast. They contain actin and a protein similar to fimbrin. In addition, they contain calmodulin and a protein of relative molecular mass (Mr) 105 000, both of which can be released from the cytoskeletons by treatment with Ca2+. In this respect the 105 000 Mr protein is more similar to non-muscle alpha-actinin than to the intestinal microvillar protein with an Mr of 110 000. Human placental actin displays the anomalous properties of binding to phenyl-Sepharose and wheatgerm agglutinin-Sepharose, suggesting that one or more membrane glycoproteins is associated with the actin. Transferrin, presumably receptor-bound, has been identified in preparations of extensively washed placental microvillar cytoskeletons. These findings are discussed in terms of the earliest events in endocytosis and materno-fetal transfer.

Research paper thumbnail of Evaluation of Rubella Immunity in a Community Prenatal Clinic

ISRN Family Medicine, 2013

Since the introduction of the Rubella vaccine in 1969, prevalence of congenital Rubella syndrome ... more Since the introduction of the Rubella vaccine in 1969, prevalence of congenital Rubella syndrome (CRS) has greatly declined in the United States. However, reports of sporadic adult cases of the disease and frequent identification of non-Rubella immune (NRI) women in prenatal units may result in outbreak of CRS in susceptible communities. Identifying populations with high rates of NRI will assist in evidence-based public health intervention that may prevent epidemic of CRS in the United States. Method. This is a retrospective, cross-sectional study involving chart audit of Rubella screening results of 642 women who attended a high-risk prenatal care at a northwestern Iowa clinic between January 1 and December 31, 2007. Results. NRI was found in 6.9% of the study population. The highest prevalence rate of 10.2% was found among adolescents. NRI was highest among Native American women at 17.3%, compared to Whites 7.3%, African Americans 5.9%, and Hispanics 4.6%. Multivariate analysis de...

Research paper thumbnail of Characterization of cofactor activity for factor I: Cleavage of complement C4 in human syncytiotrophoblast microvilli

Placenta, 1994

To coexist with complement, human tissues express membrane-integrated regulatory proteins that in... more To coexist with complement, human tissues express membrane-integrated regulatory proteins that inhibit the activity of autologous complement on cell suoCaces. Certain of these complement regulatory proteins act as obligatory cofaaors for proteolytic inactivation of activated C4(C4b) by factor I. Extraembryonic tissues and in particular trophoblasts constitute an interface at risk from maternal complement during pregnancy. The present study examined syncytiotrophoblast plasma membrane (STM) cofactor activity for cleavage of immobilized methylamine-treated complement component C4 (C4ma), a C4b analog by factor L Membrane cofactor protein (MCP or CD46) provided most of the cofactor activity in STM preparations. Minor cofactor activity was derived from C4 binding protein that was firmly bound to STM. Cofactor activity for cleavage of C4ma at its two sites for factor I was enhanced at higher concentrations of STM and at lower concentrations cleavage at a C terminal site predominated. Soluble cofactor activity was present in STM preparations and was provided by 65 KDa, 55 KDa and 50 KDa soluble species of MCP that lacked amphiphilic properties. These results are consistent with a major role for MCP in regulation of C4 activity on the maternalfacing surfaces of extraembryonic tissues during human development. Soluble MCP may provide additional fluid phase complement regulatory activity in the maternotrophoblastic zone.

Research paper thumbnail of Transferrin receptors in the basal plasma membrane of the human placental syncytiotrophoblast

Placenta, 1986

Transferrin was identified in a preparation of human syncytiotrophoblast basal plasma membrane. S... more Transferrin was identified in a preparation of human syncytiotrophoblast basal plasma membrane. Such transferrin was shown to be bound to an amphiphilic membrane protein of subunit mol.wt 94 000 by crossed hydrophobic interaction immunoelectrophoresis and immunoprecipitation with antibodies to transferrin. Basal plasma membrane bound 125I-labelled transferrin in a saturable, reversible manner with high affinity (Kd = 2.5 +/- 0.6 X 10(-9) M). The maximum binding capacity (0.9 +/- 0.2 pmol transferrin/mg membrane protein) was approximately a half of that of microvillous membrane. The basal membrane transferrin receptors were similar to microvillous receptors in that their affinity for diferric transferrin was higher than that for apo-transferrin and transferrin dissociation was negligible at pH 5.0 but rapid at pH 7.4. We conclude that syncytiotrophoblast basal plasma membrane possesses a receptor similar, if not identical, to that on the microvillous membrane. These receptors are thus in a position to participate in iron transfer to the fetus or potentially to have alternative functions in the syncytiotrophoblast.

Research paper thumbnail of Proteins of the apical and basal plasma membranes of the human placental syncytiotrophoblast: Immunochemical and electrophoretic studies

Research paper thumbnail of Syncytiotrophoblast brush border proteins recognized by monoclonal antibody TRA-210 and rabbit anti-TLX sera

Placenta, 1991

Different subsets of placental trophoblast epithelium are directly exposed to the maternal immune... more Different subsets of placental trophoblast epithelium are directly exposed to the maternal immune system during pregnancy and consequently represent major elements in allogeneic interactions. It has been proposed that the trophoblast--lymphocyte cross-reactive (TLX) alloantigen system is involved in maternal allogeneic recognition during pregnancy. Monoclonal antibody TRA-2-10 putatively recognizes TLX antigens, but its reactivity with trophoblast and normal tissues has not been documented in detail. In this report, immunohistological investigations revealed that TRA-2-10 recognizes all subsets of trophoblast in addition to amniotic and seminal vesicle epithelia. Immunoblotting demonstrated reactivity with glycoproteins of 55,000 and 65,000 mol. mass under non-reducing conditions on various cell types. These proteins displayed tissue-specific size variations and individuals varied in the amounts expressed of the two species. On the basis of blocking and immunoprecipitation experiments, TRA-2-10 reactive antigens are recognized by rabbit anti-TLX sera and are potential TLX antigen candidates. However, TLX antigens are found in seminal plasma whilst TRA-2-10 reactive antigens are not. Both TLX and TRA-2-10 antigens appear related if not identical to membrane cofactor protein (MCP) by virtue of shared molecular characteristics and blocking of lymphocyte binding of monoclonals to MCP by polyclonal anti-TLX. Extra-embryonic membranes are thus richly endowed with a complement regulatory protein which could facilitate their roles in protection of the fetus by avoidance of harmful maternal immune response amplification.

Research paper thumbnail of Spice Synthetic Cannabinoid Drugs: Lung and Adrenal Cell Models

The FASEB Journal

‘Spice’ refers to designer drugs consisting of plant materials spiked with different synthetic mi... more ‘Spice’ refers to designer drugs consisting of plant materials spiked with different synthetic mimetics of delta tetrahydrocannabinol, a psychoactive compound in marijuana. The toxicology and bioactivity of many synthetic cannabinoids are unknown including Spice brands: Barely Legal, Brain Storm and Voodoo.It was hypothesized that the ‘Spice’ brands Barely Legal, Brain Storm and Voodoo Child contain different compounds, overlap in biological activities with delta THC and affect cell physiology and morphology. This study sought possible biomarkers for the effects of ‘Spice’. Fluorescence microscopy detected cannabinoid receptor type 2 proteins but not type 1 receptors on A549 and SW‐13 cells. The complement system regulatory proteins CD46 and CD59 but not CD55 were detected on A549 and SW‐13 cells. Glycoconjugate profiles on these cells were characterized by lectin binding. Exposure to delta THC and Barely Legal Spice caused stronger Con A lectin binding to A549 lung cells than did exposure to Brainstorm Spice or control media. This study is the first description of the complement regulatory protein profile of adrenal gland cells and provided carbohydrate structure profiles of A549 and SW‐13 cells as detected by lectin binding. The results will facilitate more detailed analysis of the toxicology and bioactivities of spice.

Research paper thumbnail of Evidence for the Binding of Synthetic Cannabinoids to Human and Bovine Serum Albumin

Research paper thumbnail of Llama Hemoglobin Binding to Heterologous Haptoglobins

Research paper thumbnail of Modeling metabolism of the synthetic cannabinoids Bay 59‐3074 and JWH‐015 by human liver microsomes and cytochrome p450

Research paper thumbnail of Lectin Binding Studies of Buccal Cell Glycoproteins

Research paper thumbnail of Comparison of Different DNA Extraction Methods for Forensic Samples

Journal of Natural Sciences Research, 2013

DNA analyses are important for different types of research in biomedical and forensic science and... more DNA analyses are important for different types of research in biomedical and forensic science and DNA isolation is an often required step. Because different DNA isolation kits are constantly becoming available, it is useful to compare their efficacies. This study compared kits of the QIAamp DNA Investigator (Qiagen), ZR Genomic DNA (Zymo Research) and AccuPrep Genomic DNA (Bioneer). Spectrophotometry showed the highest yield of DNA from 200 µl of blood was obtained by the Qiagen kit (5.6 µg) followed by the Bioneer kit (2.74 µg) and Zymo kit (2.39 µg). For purity measured by spectrophotometric A260/A280 nm ratio, DNA isolated by the Qiagen was the most pure and had a ratio of 1.85, closer to the ideal ratio than DNA isolated by Zymo (2.0) and Bioneer (1.03) ratios. Costs of isolation were 3.60/sampleforQiagen,3.60/sample for Qiagen, 3.60/sampleforQiagen,1.50/sample for Bionner and $0.72 for Zymo kits. The Zymo test took 25 minutes to isolate DNA, the Bioneer kit 35 minutes and the Qiagen kit 50 minutes. These findings ma...

Research paper thumbnail of Polymorphisms in UEA‐1 Lectin Binding to Human Buccal Cells and Salivary Fluid

Research paper thumbnail of Modulation of association of a 120 kda cell surface glycoprotein with ascites tumor microvillar microfilament cores

Research paper thumbnail of Cofactor Activity in Placental Microvilli for the Cleavage of Complement Component 3 by Factor I

Research paper thumbnail of Conservation of Binding of Llama and Other Animals’ Hemoglobins to Haptoglobins Across Species

American Journal of Biochemistry and Biotechnology, 2018

The plasma protein haptoglobin binds hemoglobin released from lysed erythrocytes. It causes remov... more The plasma protein haptoglobin binds hemoglobin released from lysed erythrocytes. It causes removal of the free hemoglobin, thus preventing pathological oxidation of cells. Hemoglobin higher level structures are well conserved across animal species but primary structures can be as little as 50% homologous. Because of these differences, the question arose as to what extent hemoglobins can bind to haptoglobins from different species. The charge properties and binding to three genetic variants of human haptoglobin were compared by non-denaturing agarose gel electrophoresis, with llama, human, dog, pig, horse and goat hemoglobins. In this study, it was reported for the first time that llama and alpaca hemoglobins differed in electrophoretic mobility from hemoglobins from several animal species and humans. Llama hemoglobin was more positively charged than the other mammalian hemoglobins. Electrophoretic mobility changes of the animal hemoglobins in the presence of human plasma and two different purified human haptoglobin genetic variants suggested that hemoglobins from all animals in this study could bind all three genetic variants of human haptoglobin. In all cases, the llama hemoglobin-haptoglobin samples had lesser mobility than those of the other mammals. This study showed that the binding sites on hemoglobin and haptoglobin for each other have been evolutionarily conserved despite differences in primary structure and marked difference in the charge of llama hemoglobin from the other animal species and humans.

Research paper thumbnail of Redistribution of connexin 43 during cell division

Cell Biology International, 2016

Gap junction channels, once clustered into gap junction plaques, allow communication of essential... more Gap junction channels, once clustered into gap junction plaques, allow communication of essential metabolites between cells. Gap junction plaques have been reported to be lost from the cell surface during cell division. The mechanism involved in this loss of gap junction plaques during mitosis is unclear, but we hypothesize that an endoexocytotic mechanism that results in cytoplasmic double-membraned annular gap junction vesicles is involved. In this study, gap junction plaque changes in dividing cells were examined in SW-13 adrenocortical tumor cells. Endogenous gap junction protein, connexin 43 (Cx43), was detected with immunofluorescence, and live cell imaging was used to monitor green fluorescent protein-tagged Cx43 (Cx43-GFP). Mitotic stages were identified by Hoechst chromosomal staining. During interphase, large gap junction plaques were detected; however, the presence of these plaques decreased, whereas cytoplasmic puncta increased beginning with prophase. The cytoplasmic puncta were demonstrated with immunoelectron microscopy to be Cx43-positive annular gap junction vesicles. As gap junction plaques reformed at cleavage furrows between daughter cells, the number of annular gap junctions decreased during cytokinesis. The data are consistent with the mechanism of gap junction plaque loss during mitosis relying on an endoexocytotic process that results in annular gap junction vesicles formation. The rapid formation of gap junction plaques during cytokinesis points to the intriguing possibility of connexin recycling from annular gap junction vesicles to form gap junction plaques as mitosis is completed.

Research paper thumbnail of Isolation and partial characterization of ascites sialoglycoprotein-2 of the cell surface sialomucin complex of 13762 rat mammary adenocarcinoma cells

Biochemical Journal, 1990

Sialomucins are the dominant components of the cell surfaces of some carcinoma ascites cells and ... more Sialomucins are the dominant components of the cell surfaces of some carcinoma ascites cells and have been postulated to inhibit recognition of tumours by the immune system. The sialomucin ASGP-1 (ascites sialoglycoprotein-1) of the 13762 rat mammary adenocarcinoma is associated with the cell surface as a complex with a concanavalin-A-binding glycoprotein called ASGP-2. This sialomucin complex has been purified from ascites cell microvilli by extraction with Triton X-100 and CsCl density-gradient centrifugation. ASGP-1 (which has been purified previously) and ASGP-2 were dissociated in 6 M-guanidine hydrochloride and separated by gel filtration. The molecular mass of the undenatured detergent complex of ASGP-2, estimated by gel filtration and velocity sedimentation in Triton X-100, was 148 kDa. Since the apparent molecular mass by SDS/polyacrylamide-gel electrophoresis was about 120 kDa, ASGP-2 must be a monomer as extracted from the membrane. Studies of its chemical composition ind...

Research paper thumbnail of Proteins of the human placental microvillar cytoskeleton. α-Actinin

Biochemical Journal, 1986

The human placental syncytiotrophoblast microvilli are supported by an underlying cytoskeleton co... more The human placental syncytiotrophoblast microvilli are supported by an underlying cytoskeleton consisting mainly of actin microfilaments. The major proteins associated with the actin have Mr values of 105 000, 80 000 and 68 000. The 105 000-Mr protein is recognized by an antibody preparation raised to purified chicken gizzard alpha-actinin. Electron microscopy has shown that the human placental protein has dimensions similar to those reported for muscle alpha-actinin. About half of the placental microvillar alpha-actinin is released from the cytoskeleton in the presence of Ca2+. This effect occurs at concentrations of Ca2+ greater than 0.3 muM and has been used as the basis of a method for the purification of the placental alpha-actinin. This sensitivity to Ca2+ is not affected by trifluoperazine and is therefore likely to be a property of the alpha-actinin as such rather than being mediated via calmodulin.

Research paper thumbnail of A vitronectin-receptor-related molecule in human placental brush border membranes

Biochemical Journal, 1991

The heterodimeric vitronectin receptor (VNR) and platelet glycoprotein IIb/IIIa (GPIIb/IIIa) are ... more The heterodimeric vitronectin receptor (VNR) and platelet glycoprotein IIb/IIIa (GPIIb/IIIa) are two members of the integrin family of cell adhesion receptors that share the same beta subunit (GPIIIa). These proteins are involved in binding to vitronectin, fibrinogen and fibronectin and in cytoskeleton-membrane interactions. The present study shows that the human placental syncytiotrophoblast brush border membrane contains a heterodimer of subunit Mr values of 140,000 and 90,000 (non-reduced) or 125,000 and 100,000 (reduced). This protein was recognized by a monoclonal antibody to GPIIIa, rabbit antisera to the VNR and a human alloantiserum to GPIIIa. Brush border VNR-related protein bound to an immobilized peptide containing the Arg-Gly-Asp sequence and, less avidly, to immobilized fibrinogen. Only a small fraction of brush border VNR was associated with a cytoskeleton fraction. Membrane-bound brush border GPIIIa was distinct from that of platelets in its resistance to digestion by...

Research paper thumbnail of Structure of Human Placental Microvilli

Novartis Foundation Symposia, 2008

ABSTRACT Cytoskeletons have been prepared from microvilli isolated from the human placental syncy... more ABSTRACT Cytoskeletons have been prepared from microvilli isolated from the human placental syncytiotrophoblast. They contain actin and a protein similar to fimbrin. In addition, they contain calmodulin and a protein of relative molecular mass (Mr) 105 000, both of which can be released from the cytoskeletons by treatment with Ca2+. In this respect the 105 000 Mr protein is more similar to non-muscle alpha-actinin than to the intestinal microvillar protein with an Mr of 110 000. Human placental actin displays the anomalous properties of binding to phenyl-Sepharose and wheatgerm agglutinin-Sepharose, suggesting that one or more membrane glycoproteins is associated with the actin. Transferrin, presumably receptor-bound, has been identified in preparations of extensively washed placental microvillar cytoskeletons. These findings are discussed in terms of the earliest events in endocytosis and materno-fetal transfer.

Research paper thumbnail of Evaluation of Rubella Immunity in a Community Prenatal Clinic

ISRN Family Medicine, 2013

Since the introduction of the Rubella vaccine in 1969, prevalence of congenital Rubella syndrome ... more Since the introduction of the Rubella vaccine in 1969, prevalence of congenital Rubella syndrome (CRS) has greatly declined in the United States. However, reports of sporadic adult cases of the disease and frequent identification of non-Rubella immune (NRI) women in prenatal units may result in outbreak of CRS in susceptible communities. Identifying populations with high rates of NRI will assist in evidence-based public health intervention that may prevent epidemic of CRS in the United States. Method. This is a retrospective, cross-sectional study involving chart audit of Rubella screening results of 642 women who attended a high-risk prenatal care at a northwestern Iowa clinic between January 1 and December 31, 2007. Results. NRI was found in 6.9% of the study population. The highest prevalence rate of 10.2% was found among adolescents. NRI was highest among Native American women at 17.3%, compared to Whites 7.3%, African Americans 5.9%, and Hispanics 4.6%. Multivariate analysis de...

Research paper thumbnail of Characterization of cofactor activity for factor I: Cleavage of complement C4 in human syncytiotrophoblast microvilli

Placenta, 1994

To coexist with complement, human tissues express membrane-integrated regulatory proteins that in... more To coexist with complement, human tissues express membrane-integrated regulatory proteins that inhibit the activity of autologous complement on cell suoCaces. Certain of these complement regulatory proteins act as obligatory cofaaors for proteolytic inactivation of activated C4(C4b) by factor I. Extraembryonic tissues and in particular trophoblasts constitute an interface at risk from maternal complement during pregnancy. The present study examined syncytiotrophoblast plasma membrane (STM) cofactor activity for cleavage of immobilized methylamine-treated complement component C4 (C4ma), a C4b analog by factor L Membrane cofactor protein (MCP or CD46) provided most of the cofactor activity in STM preparations. Minor cofactor activity was derived from C4 binding protein that was firmly bound to STM. Cofactor activity for cleavage of C4ma at its two sites for factor I was enhanced at higher concentrations of STM and at lower concentrations cleavage at a C terminal site predominated. Soluble cofactor activity was present in STM preparations and was provided by 65 KDa, 55 KDa and 50 KDa soluble species of MCP that lacked amphiphilic properties. These results are consistent with a major role for MCP in regulation of C4 activity on the maternalfacing surfaces of extraembryonic tissues during human development. Soluble MCP may provide additional fluid phase complement regulatory activity in the maternotrophoblastic zone.

Research paper thumbnail of Transferrin receptors in the basal plasma membrane of the human placental syncytiotrophoblast

Placenta, 1986

Transferrin was identified in a preparation of human syncytiotrophoblast basal plasma membrane. S... more Transferrin was identified in a preparation of human syncytiotrophoblast basal plasma membrane. Such transferrin was shown to be bound to an amphiphilic membrane protein of subunit mol.wt 94 000 by crossed hydrophobic interaction immunoelectrophoresis and immunoprecipitation with antibodies to transferrin. Basal plasma membrane bound 125I-labelled transferrin in a saturable, reversible manner with high affinity (Kd = 2.5 +/- 0.6 X 10(-9) M). The maximum binding capacity (0.9 +/- 0.2 pmol transferrin/mg membrane protein) was approximately a half of that of microvillous membrane. The basal membrane transferrin receptors were similar to microvillous receptors in that their affinity for diferric transferrin was higher than that for apo-transferrin and transferrin dissociation was negligible at pH 5.0 but rapid at pH 7.4. We conclude that syncytiotrophoblast basal plasma membrane possesses a receptor similar, if not identical, to that on the microvillous membrane. These receptors are thus in a position to participate in iron transfer to the fetus or potentially to have alternative functions in the syncytiotrophoblast.

Research paper thumbnail of Proteins of the apical and basal plasma membranes of the human placental syncytiotrophoblast: Immunochemical and electrophoretic studies

Research paper thumbnail of Syncytiotrophoblast brush border proteins recognized by monoclonal antibody TRA-210 and rabbit anti-TLX sera

Placenta, 1991

Different subsets of placental trophoblast epithelium are directly exposed to the maternal immune... more Different subsets of placental trophoblast epithelium are directly exposed to the maternal immune system during pregnancy and consequently represent major elements in allogeneic interactions. It has been proposed that the trophoblast--lymphocyte cross-reactive (TLX) alloantigen system is involved in maternal allogeneic recognition during pregnancy. Monoclonal antibody TRA-2-10 putatively recognizes TLX antigens, but its reactivity with trophoblast and normal tissues has not been documented in detail. In this report, immunohistological investigations revealed that TRA-2-10 recognizes all subsets of trophoblast in addition to amniotic and seminal vesicle epithelia. Immunoblotting demonstrated reactivity with glycoproteins of 55,000 and 65,000 mol. mass under non-reducing conditions on various cell types. These proteins displayed tissue-specific size variations and individuals varied in the amounts expressed of the two species. On the basis of blocking and immunoprecipitation experiments, TRA-2-10 reactive antigens are recognized by rabbit anti-TLX sera and are potential TLX antigen candidates. However, TLX antigens are found in seminal plasma whilst TRA-2-10 reactive antigens are not. Both TLX and TRA-2-10 antigens appear related if not identical to membrane cofactor protein (MCP) by virtue of shared molecular characteristics and blocking of lymphocyte binding of monoclonals to MCP by polyclonal anti-TLX. Extra-embryonic membranes are thus richly endowed with a complement regulatory protein which could facilitate their roles in protection of the fetus by avoidance of harmful maternal immune response amplification.