Multitude Of Molecules Research Articles

Exploring the Interplay between Calcium Oxalate Crystals and Renal Tubular Epithelial Cell Injury: Implications for the Formation and Prevention of Kidney Stones

Kidney stones are a prevalent and clinically significant disease that affects millions of individuals worldwide, which have emerged as a significant global public health concern. The majority of kidney stones are composed of calcium oxalate (CaOx). The mechanisms of stone formation and development are unclear, involving a complex interplay of physical and biochemical processes. The injury of tubular epithelial cells (TECs) represents a pivotal event in the pathogenesis of this condition, as it initiates oxidative stress and immune-inflammatory reactions. Macrophages play a pivotal role in the inflammatory process, interacting with a multitude of molecules and pathways, thereby influencing the stone formation. Furthermore, apoptosis and autophagy induce TECs injury and contribute to the pathogenesis of CaOx stones. The current treatment strategies mainly focus on the management of crystal-cell interactions and the protection of TECs, in conjunction with the application of antioxidants, anti-inflammatory agents, and inhibitors of apoptosis and autophagy. These strategies have demonstrated promising results. Future research will aim to modulate the immune-inflammatory response, offering hope for the effective prevention of stone recurrence.

Novel Intensified Alternatives for Purification of Levulinic Acid Recovered from Lignocellulosic Biomass

The development of a bio-based economy has its foundations in the development of efficient processes to optimize biomass potential. In this context there are a multitude of molecules that can be either synthetized or recovered from biomass, among those the so-called 12 building-blocks reported by the US Department of Energy. Even if their identification and importance is clearly defined, research efforts concerning the purification or separation of these platform molecules are limited. To fill this gap, different configurations for the purification of levulinic acid recovered from lignocellulosic biomass are examined and compared in this work. In particular, hybrid configurations obtained by the combination of liquid-liquid extraction and distillation have been considered. It was demonstrated how a deep understanding of the subspace including all extraction-assisted simple column distillation configurations represents a fundamental step in the synthesis of different process alternatives. From a separation efficiency and economic standpoint, the proposed intensified liquid-liquid thermally equivalent configuration (LL-TE) and liquid-liquid side stream column configuration (LL-SSC) are promising solutions. Nonetheless, their performances are deeply interrelated to the purity target defined by the designer.

Understanding Molecules that Mediate Leukocyte Extravasation

Getting leukocytes to the site of inflammation is extremely important for maintaining homeostasis. Over time, leukocyte extravasation is resolved; however, in the case of chronic inflammatory diseases, it is not. When left unresolved, persistent leukocyte infiltration is detrimental to the host. Understanding how leukocytes get out of circulation and into the tissue puts us closer to combating these diseases. This review focuses on the molecules regulating leukocyte extravasation. There are multiple pathways regulating leukocyte transmigration. Targeted recycling of membrane from the lateral border recycling compartment is required for leukocyte extravasation. Differences in leukocyte phenotypes may contribute to different transmigration rates and extent. Leukocyte transmigration is regulated by a multitude of molecules. How these molecules interact to coordinate the process is the subject of ongoing research. Characterization of these pathways will be useful in developing therapies for chronic inflammation.

Management of Pediatric Urolithiasis

Urolithiasis, the formation or presence of calculi in the urinary tract, is a broad term covering a multifaceted disease process with wide-ranging clinical and economic implications. Stones, often originating in the renal papillae, may be found from the renal parenchyma through the renal pelvis, ureter, or bladder. Stones can be composed of a multitude of molecules either in pure form or mixtures of several compounds. Historically considered a disease of adults, the prevalence of stones has increased among children. This review highlights pathophysiology of urolithiasis, common clinical presentations, work-up, and surgical and medical management of this increasingly common pediatric condition. The authors review the chemical pathways by which stones form, common stone types, common operative techniques, and epidemiology. This review contains 4 tables, and 59 references. Key Words: extracorporeal shockwave lithotripsy, kidney stones, lithotripsy, nephrolithiasis, percutaneous nephrolithotomy, pediatrics, renal calculi, ureteroscopy, urolithiasis

Abstract 542: Anti-CD19 therapy for precursor B-acute lymphoblastic leukemia: Response and resistance mechanisms

Abstract Introduction: CD19 is a transmembrane protein restricted to B-lineage cells and follicular dendritic cells. In conjunction with CD21, CD81, and CD225, CD19 acts as a B cell co-receptor to decrease the threshold for antigen receptor-dependent stimulation. CD19 trafficking and expression are orchestrated by a multitude of molecules. Resistance to blinatumomab (Blina, anti-CD19 therapy) in acute lymphoblastic leukemia (ALL) is thought to be due in part to the emergence of CD19-negative escape variants. Loss of expression of CD81 and/or CD21, which are required for CD19 trafficking, results in the lack of CD19 expression. In addition, alternative CD19 splicing and other non-CD19-mediated resistance mechanisms have been described. Therefore, we aimed to study CD19 trafficking and response to Blina in ALL patients. Methods: Peripheral blood was collected at our Center. Mononuclear cells (PBMCs) were isolated and viably frozen. Cells were then thawed and washed with PBS with 10% FBS, and viable cells were counted using trypan blue dye exclusion. 1x10^6 cells/test were stained for CD19, CD81 (BD Biosciences, San Jose, CA) and CD21 (Biolegend, San Diego, CA). After incubation, cells were washed 2x with FACs buffer, resuspended and acquired on a BD Canto II flow cytometer. Results: Blood was obtained from 10 patients with relapsed or refractory pre-B-ALL with blood blasts prior to Blina treatment. Five patients subsequently achieved complete remission (CR). Cells from four of these patients had CD21 expression on <5% of cells, but CD81 expression on >40% of cells. Of the 5 patients whose disease did not respond to Blina, four also had CD21 expression on <5% of cells and had CD81 expression on an average of 40% of cells. CD19 was expressed on >40% of cells in all samples. Conclusion: Although CD21 and CD81 are required for CD19 trafficking and expression, loss of either of these antigens measured by flow cytometry did not correlate with the response to Blina. PatientAge(years)DiagnosisKaryotypeCD19*CD21*CD81*Response to Blinatumomab176Pre-B-ALL46,XX,t(9;22)(q34.1;q11.2)53241Yes (CR)255Pre-B-ALL46, X,inv(Y)(p11.2q11.23), dic(9;12)(p13;p13), del20(q11.2)42146Yes (CR)347Pre-B-ALL46, XX,t(4;11)(q21;q23)941256Yes (CR)484Pre-B-ALL46,XX,i(9)Iq10)65372Yes (CR)551Pre-B-ALL46, XX, t(9;22)(q34.1;q11.2)77578Yes (CR)633Pre-B-ALL46, XY, +X, der(17;18)(q10;q10)67185No725Pre-B-ALL46, XY, der(20;21)(q10;q10),+2146432No825Pre-B-ALL46, Y, t(X;4)(p11.2;p15), der(9)t(9;14)(p21;q12) del(9)(p21),del(14)q13), +mar[cp14]742429No979Pre-B-ALL46, XY48123No1073Pre-B-ALL46, XY59129No*% cells; CR = complete remission Note: This abstract was not presented at the meeting. Citation Format: Firas El Chaer, Brandon Carter-Cooper, Rena G. Lapidus, Maria R. Baer, Zeba N. Singh, Ashkan Emadi. Anti-CD19 therapy for precursor B-acute lymphoblastic leukemia: Response and resistance mechanisms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 542.

Development of Inhibitors of PIP4K2 As a Treatment for Patients with Hematologic Malignancies

Phosphoinositide signaling is central to many cellular processes including the cell survival pathway known as autophagy. While there is evidence that autophagy can suppress tumorigenesis under certain circumstances, there is increasingly abundant evidence that autophagy promotes tumorigenesis and tumor cell survival in solid tumors and hematologic malignancies.Autophagy is a complex process that has evolved to promote survival of cells under a variety of stress or nutrient starvation conditions. There are a multitude of molecules and structures involved in initiating, promoting, and resolving the autophagy process. It is known that PI5P is an important component for the resolution of autophagy. PIP4K2α,β,γ are a family of lipid kinases that convert PI5P to PI(4,5)P2. These enzymes have recently been shown to be critical for the fusion of autophagosomes with lysosomes. This known activity, coupled with the observation that PIP4K2 activity is essential for the survival and leukemia initiating potential of human and mouse acute myeloid leukemia (AML) cells, suggest that the PIP4K2 family of enzymes may be a promising target for a new class of therapeutics for the treatment of hematologic malignancies.We have investigated the role of PIP4K2 enzymes in supporting the survival of cancer cells by developing potent and selective inhibitors of PIP4K2 enzymatic activity. A screen of human cancer cell lines show that potent and selective inhibitors of PIP4K2 are effective at inhibiting growth of a variety of hematologic cancers including leukemia- and lymphoma-derived lines. In vivo studies demonstrate that these inhibitors induce rapid regression of an AML tumor (MOLM-16) in a mouse xenograft model. These studies show a dose-dependent control of tumor growth with sustained regression of tumor volume with QD oral dosing of a prototype molecule. Body weights of the mice were stable over the course of the study suggesting that the molecule is well tolerated in this dosing protocol.A preliminary toxicity study in rats has not revealed any identifiable toxicity at doses up to 100 mg/Kg given QD/PO for 14 days. Additional in vitro safety studies suggest minimal safety concerns due to off-target activity.Exploration of the structure activity relationship of PIP4K2 inhibitors, using fragment and structure-based drug discovery, has led to highly potent and selective molecules with exceptional drug-like properties. A clinical development candidate has been selected and that candidate is currently in the late stages of preclinical studies preceding anticipated clinical entry in early 2019. DisclosuresMcElligott:Petra Pharma: Employment, Equity Ownership. Kesicki:Petra Pharma: Employment, Equity Ownership. Karukarichi:Petra Pharma: Employment, Equity Ownership. Shim:Petra Pharma: Employment, Equity Ownership. Wang:Petra Pharma: Employment, Equity Ownership. Yu:Petra Pharma: Employment, Equity Ownership. Zolfaghari:Petra Pharma: Employment, Equity Ownership. Linstrom:Sprint Bioscience: Employment, Equity Ownership. Persson:Sprint Bioscience: Employment, Equity Ownership. Hoglund:Sprint Bioscience: Employment, Equity Ownership. Ericsson:Sprint Bioscience: Employment, Equity Ownership. Trésaugues:Sprint Bioscience: Employment, Equity Ownership. Livendahl:Sprint Bioscience: Employment, Equity Ownership. Santangelo:Sprint Bioscience: Employment, Equity Ownership. Viklund:Sprint Bioscience: Employment, Equity Ownership. Pettersson:Sprint Bioscience: Employment, Equity Ownership. Wähling:Sprint Bioscience: Employment, Equity Ownership. Forsblom:Sprint Bioscience: Employment, Equity Ownership. Karlsson:Sprint Bioscience: Employment, Equity Ownership. Ginman:Sprint Bioscience: Employment, Equity Ownership. Braga:Sprint Bioscience: Employment, Equity Ownership. Henley:Sprint Bioscience: Employment, Equity Ownership. Talagas:Sprint Bioscience: Employment, Equity Ownership. Rahm:Sprint Bioscience: Employment, Equity Ownership. Johansson:Sprint Bioscience: Employment, Equity Ownership. Martinsson:Sprint Bioscience: Employment, Equity Ownership. Andersson:Sprint Bioscience: Employment, Equity Ownership. Cantley:Petra Pharma: Equity Ownership.

Galectin-3-binding protein: A multitask glycoprotein with innate immunity functions in viral and bacterial infections.

Galectin-3-binding protein (Gal-3BP) is a ubiquitous and multifunctional secreted glycoprotein originally identified and mainly studied in the context of neoplastic transformation and cancer progression. However, Gal-3BP expression is induced in viral infection and by a multitude of molecules that either mimic or are characteristic for an ongoing inflammation and microbial infection, such as IFN-α, IFN-β, IFN-γ, TNF-α, poly(I:C), dsRNA, and dsDNA. Furthermore, Gal-3BP belongs to the scavenger receptor cysteine-rich (SRCR) domain-containing protein family, by virtue of its N-terminal SRCR domain. The SRCR domain is found in soluble or membrane-associated innate immunity-related proteins and is implicated in self-nonself discrimination. This review summarizes the current knowledge of structural features of Gal-3BP and its proposed intracellular and extracellular innate immunity functions with special emphasis on viral and bacterial infections.

Exosomes in Extracellular Matrix Bone Biology.

Exosomes are membrane vesicles that are released by most cell types into the extracellular environment. The purpose of this article is to discuss the main morphological features and contents of bone-derived exosomes, as well as their major isolation and physical characterization techniques. Furthermore, we present various scenarios and discuss potential clinical applications of bone-derived exosomes in bone repair and regeneration. Exosomes were believed to be nanosized vesicles derived from the multivesicular body. Reports now suggest that nanovesicles could bud directly from the plasma membrane. However, the exosome cargo is cell-type specific and is derived from the parent cell. In the bone matrix, several intracellular proteins lacking a signal peptide are transported to the ECM by exosomes. Besides proteins, several mRNA, miRNA, and lipids are exported to the ECM by bone cells and bone marrow stromal cells. Recent evidence suggests that several of the functional components in the cargo could regulate processes of bone formation, inhibit osteoclast activity, and promote fracture repair. Exosomes are powerful cellular molecular machines produced without human intervention and packaged with physiological cargo that could be utilized for molecular therapy in several skeletal disorders such as osteoporosis, osteogenesis imperfecta, and fracture healing. Although much work has been done, there is a lot of information that is still unknown, as exosomes contain a multitude of molecules whose identity and function have yet to be identified.

Involvement of Dihydrolipoyl Dehydrogenase in the Phagocytosis and Killing of Paracoccidioides brasiliensis by Macrophages.

Paracoccidioides brasiliensis and Paracoccidioides lutzii are fungi causing paracoccidioidomycosis (PCM), an autochthonous systemic mycosis found in Latin America. These microorganisms contain a multitude of molecules that may be associated with the complex interaction of the fungus with the host. Here, we identify the enzyme dihydrolipoyl dehydrogenase (DLD) as an exoantigen from P. brasiliensis (Pb18_Dld) by mass spectrometry. Interestingly, the DLD gene expression in yeast form showed higher expression levels than those in mycelial form and transitional phases. Pb18_Dld gene was cloned, and the recombinant protein (rPb18_Dld) was expressed and purified for subsequent studies and production of antibodies. Immunogold labeling and transmission electron microscopy revealed that the Pb18_Dld is also localized in mitochondria and cytoplasm of P. brasiliensis. Moreover, when macrophages were stimulated with rPb18Dld, there was an increase in the phagocytic and microbicidal activity of these cells, as compared with non-stimulated cells. These findings suggest that Pb18_Dld can be involved in the pathogen-host interaction, opening possibilities for studies of this protein in PCM.

The Systems Biology of Stem Cell Released Molecules—Based Therapeutics

Most therapeutics are based on the traditional method of reductionism where a clinically defined condition is broken down into a defined biochemical pathway underlying the condition, then a target in the pathway is identified, followed by developing a drug to interact with the target, modifying the target such that the disease is ameliorated. Biology acts as a system, therefore reductionist approaches to developing therapeutics are limited in therapeutic value because disease or traumatized tissue involves multiple underlying pathways, only a part of the pathways underlying the disease is manipulated by the traditional therapeutic. Much data regarding stem cells shows that their beneficial effects are not restricted to their ability to differentiate, but is more likely due in large part to their ability to release a multitude of molecules. Stem cells release potent combinations of factors that modulate the composition of the cellular milieu to evoke a multitude of responses from neighboring cells. Therefore, stem cells represent a natural systems-based biological factory for the production and release of a multitude of molecules that interact with the system of biomolecular circuits underlying an indication. Current research includes efforts to define, stimulate, enhance, and harness stem cell released molecules (SRM) to develop systems-therapeutics.

Novel and Bioactive Compounds from the Malayan Flora; Recent Findings and Challenges

Malaysia is one of the seventeen megadiverse countries in the world. Its flora is home to an estimated 15,000 higher plant species and it is widely known that plants are efficient manufacturers of compounds with highly diversed molecular structures and an unending array of biological activities. Therefore, it is logical to assume that a multitude of molecules and their activities are yet to be discovered from this beautiful and immense flora. In fact, our experience with plants from various families; Annonaceae, Apocynaceae, Lauraceae, Meliaceae and Rubiaceae, have evidenced that many types of interesting and unique compounds were synthesized by these plants; alkaloids, triterpenes, limonoids, lignans, coumarins and many others. In this presentation, recent findings on some novel and bioactive compounds from some higher plants shall be communicated which includes some mechanisms in their mode of action for example the novel malayanine A and B from Chisocheton erythrocarpus and the neuroprotective and acetylcholinesterase inhibiting mesuagenins isolated from Mesua species. In addition, as Natural Products and Drug Discovery is an important research area in Malaysia, the challenges and possible directions in this field shall be discussed briefly. For instance, how can we, the natural products scientists relate our findings and knowledge to the society and then further contribute to the enhancement of its well-being?

An Overview of Immunologic Adjuvants - A Review

With the onset of antigen production using biosynthetic and rDNA techniques, the need to administer adjuvants along with vaccines has increased remarkably. This search for accompanying adjuvants has resulted in a multitude of molecules from mineral salts to bacterial polysaccharides and Immuno stimulatory complexes that range considerably in efficacy. Moreover, the adjuvant molecule is specific to its antigen molecule and hence has to be tailored suitably to maximise efficacy and safety, maintaining the cost at a minimum. This paper explores the characteristics of these molecules, their mode of action and the advancements in the field.

The structure and functioning of the couplon in the mammalian cardiomyocyte

The couplons of the cardiomyocyte form nanospaces within the cell that place the L-type calcium channel (Ca(v)1.2), situated on the plasmalemma, in opposition to the type 2 ryanodine receptor (RyR2), situated on the sarcoplasmic reticulum. These two molecules, which form the basis of excitation-contraction coupling, are separated by a very limited space, which allows a few Ca(2+) ions passing through Ca(v)1.2 to activate the RyR2 at concentration levels that would be deleterious to the whole cell. The limited space also allows Ca(2+) inactivation of Ca(v)1.2. We have found that not all couplons are the same and that their properties are likely determined by their molecular partners which, in turn, determine their excitability. In particular, there are a class of couplons that lie outside the RyR2-Ca(v)1.2 dyad; in this case, the RyR2 is close to caveolin-3 rather than Ca(v)1.2. These extra-dyadic couplons are probably controlled by the multitude of molecules associated with caveolin-3 and may modulate contractile force under situations such as stress. It has long been assumed that like the skeletal muscle, the RyR2 in the couplon are arranged in a structured array with the RyR2 interacting with each other via domain 6 of the RyR2 molecule. This arrangement was thought to provide local control of RyR2 excitability. Using 3D electron tomography of the couplon, we show that the RyR2 in the couplon do not form an ordered pattern, but are scattered throughout it. Relatively few are in a checkerboard pattern--many RyR2 sit edge-to-edge, a configuration which might preclude their controlling each other's excitability. The discovery of this structure makes many models of cardiac couplon function moot and is a current avenue of further research.

Cadmium and transport of ions and substances across cell membranes and epithelia

Toxic metals such as cadmium (Cd(2+)) pose serious risks to human health. However, even though the importance of Cd(2+) as environmental health hazards is now widely appreciated, the specific mechanisms by which it produces its adverse effects have yet to be fully elucidated. Cd(2+) is known to enter cells, it binds and interacts with a multitude of molecules, it may indirectly induce oxidative stress and interfere with gene expression and repair of DNA. It also interacts with transport across cell membranes and epithelia and may therefore disturb the cell's homeostasis and function. Interaction with epithelial transport, especially in the kidney and the liver, may have serious consequences in general health. A lot of research still needs to be done to understand the exact way in which Cd(2+) interferes with these transport phenomena. It is not always clear whether Cd(2+) has primary or secondary effects on cell membrane transport. In the present review we try to summarize the work that has been done up to now and to critically discuss the relevance of the experimental work in vitro with respect to the in vivo situation.

Abstract 3703: Nanoparticle-induced targeted pro-apoptotic peptide in glioblastoma

Abstract Glioblastomas multiforme (GBM) are the most common and lethal form of intracranial tumors. They account for approximately 70% of the 22,500 new cases of malignant primary brain tumors that are diagnosed in adults in the United States each year. Although relatively uncommon, malignant gliomas are associated with disproportionately high morbidity and mortality (median survival is only 12 to 15 months). Malignant gliomas are among the most vascular of human tumors. Tumor vasculature has proven to be particularly well suited as a site for receptor-based targeting. It expresses a multitude of molecules that are not expressed in the vessels of normal tissues. Our laboratory screens phage-displayed peptide libraries in vivo and ex vivo to discover specific targets in tumor vessels. One of the peptides, CGKRK (1) binds to the blood vessels in various kinds of tumors. Initial experiments showed that intravenously injected CGKRK peptide effectively homes to lentiviral (H-RasV12-sip53)-induced glioma in mice. We coupled the CGKRK peptide to the alpha-helical amphipathic peptide D[KLAKLAK]2, which is toxic to eukaryotic cells if it internalized into the cells (2). The chimeric peptide, when added to actively growing HUVEC or U87 glioma cells colocalized with mitochondria, whereas D[KLAKLAK]2 did not. Iron oxide nanoworms (NW) coated with the chimeric D[KLAKLAK]2-CGKRK peptide were 100-200-fold more toxic to the HUVEC and U87 cells than the free peptide in vitro and specifically accumulated in the blood vessels of glioma. Treatment of lentiviral induced glioma in mice with the D[KLAKLAK]2-CGKRK-PEG-NW inhibited tumor growth and showed a significant survival increase compared to control-treated mice. 1. Hoffman, J.A., et al. Progressive vascular changes in a transgenic mouse model of squamous cell carcinoma. Cancer Cell 4, 383-391 (2003). 2. Ellerby, H.M., et al. Anti-cancer activity of targeted pro-apoptotic peptides. Nat Med 5, 1032-1038 (1999). *These authors contributed equally to this work Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3703.

Amphotericin B: 50 Years of Chemistry and Biochemistry

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Understanding the Drug Development Process

In the United States, new drug development is a complex, highly regulated process that often involves academic institutions, the pharmaceutical industry, and government agencies. Much of the primary and clinical research conducted in the United States is funded by the National Institutes of Health. The Food and Drug Administration (FDA) provides regulatory review and oversight of the drug development process. The Investigational New Drug application is the primary mechanism that the FDA uses to regulate clinical testing in humans. A New Drug Application summarizing all of the data necessary to perform risk/benefit analysis of the new drug is submitted to the FDA for review and approval once sufficient testing has been completed. Recent research into the pathogenesis of inflammatory bowel disease has yielded numerous drug targets resulting in a multitude of molecules and biologic agents under varying stages of development and a consequent need for clinical testing. A thorough understanding of the regulatory development process and the National Institutes of Health funding process is necessary for any investigator involved in clinical trials.

Fibrin Is a Many Splendored Thing

The many splendors of fibrin go far beyond its intrinsic role in hemostasis. Fibrin indirectly contributes to the healing of injured tissue through its ability to bind proenzymes, enzyme inhibitors, extracellular matrix molecules and cells (Clark, 2001). In this issue of the JournalGreer and Andreadis (2003) extend the multiplicity of fibrin functions during wound repair. They demonstrate that by its capacity to bind plasminogen, fibrin indirectly promotes epidermal cell migration. This concept is especially attractive since epidermal cells do not express a receptor for fibrin (Kubo et al, 2001), yet fibrin has been reported to facilitate epithelialization in vitro (Greer et al, 2002) and in vivo (Horch et al, 1998;Pellegrini et al, 1999). To better appreciate the multitude of molecules that can interact with the fibrin clot, a brief overview of the structure and function of fibrinogen and fibrin is warranted.

Modulators of neuronal migration and neurite growth

A multitude of molecules have been identified over the past few years that promote neurite outgrowth in vitro. The concept that these molecules work mainly by providing an adhesive surface for neuronal growth cones has been challenged by evidence from recent experiments. Some of the substrate molecules have diverse actions on cell migration and neurite growth. In addition, there is now evidence that there are molecules that specifically inhibit growth cone locomotion. This has given rise to the hypothesis that growth cones integrate a variety of growth-promoting and inhibitory signals and translate them into directed locomotion.

Congenital Abnormalities Induced by Heterologous Antisera Directed Against Rat Kidney Glycoproteins Isolated by Concanavalin A Affinity Chromatography

It has been well established that heterologous antisera against whole rat kidney homogenate when injected into pregnant rats during the embryonic organogenetic period may induce abnormal embryonic development. Attempts were made to isolate the active components from soluble rat kidney extract by ammonium sulfate precipitation, anion-exchange chromatography, and concanavalin A-Sepharose 4B affinity chromatography. The glycoproteins isolated were capable of stimulating the production of potent rabbit antisera. When injected ip into the 9th day pregnant rats, these antisera induced embryonic death, congenital abnormalities, and fetal growth retardation. Eighty-four surviving fetuses were examined, all of them were malformed. The most frequently observed congenital defects were anophthalmia and microphthalmia. Attempts were made to analyze the glycoprotein fraction by discontinuous and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The results indicate that the glycoproteins were of high molecular weight and could be dissociated by SDS into a multitude of molecules or subunits. Although double immunodiffusion indicated that there were one major and two minor antigens in the glycoprotein fraction, attempts to identify the antigens as to their size by analytical gel electrophoresis have not been successful. Electron microscopic study seemed to suggest that the glycoproteins might tend to aggregate to form particulates. The underlying mechanism whereby the antisera to these glycoproteins induce abnormal embryonic development is not understood. The hypotheses to explain the possible sites of teratogenic antibody interaction are discussed.