Thesis (Ph. D.)--University of Wisconsin--Madison, 1942. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.A.)--University of Wisconsin--Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1941. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Texte remanié de: Dissertation--Philosophische Fakultät--Universität Zurich, 2005. / Bibliogr. p. 314-329.

Abstract The effect of Aloe vera (L.) Burm. f. (Aloe barbadensis Miller) gel and whole leaf extract on the permeability of Caco-2 cell monolayers was determined. Solutions of gel and the whole leaf extract were applied to the cell monolayers, and the transepithelial electrical resistance was monitored for 2 hours, which was then continued for another 2 hours after removal of the test solutions to measure reversibility of the effect. The transport of insulin in the presence and absence of the A. vera gel and whole leaf extract solutionswas also investigated. Both the A. vera gel and whole leaf extract were able to significantly reduce the transepithelial electrical resistance of the Caco-2 cell monolayers at concentrations above 0.5% w/ v and thereby showed the ability to open tight junctions between adjacent cells. This effect was fully reversible, as the electrical resistance of the cell monolayers returned to the original value upon removal of the test solutions. The A. vera gel and whole leaf extract solutions significantly enhanced the transport of insulin across the Caco- 2 cell monolayers compared with the control. The results suggest that these plant products have a high potential to be used as absorption enhancers in novel dosage forms for drugs with poor bioavailabilities when administered orally. On the other hand, an uncontrolled increase in the bioavailability of drugs that are taken simultaneously with A. vera gel and whole leaf extract products may result in adverse effects, and the potential exists that toxic blood plasma levels may be reached.

Many of the health benefits associated with Aloe vera have been attributed to the polysaccharides contained in the gel of the leaves. These biological activities include promotion of wound healing, antifungal activity, hypoglycemic or antidiabetic effects antiinflammatory, anticancer, immunomodulatory and gastroprotective properties. While the known biological activities of A. vera will be briefly discussed, it is the aim of this review to further highlight recently discovered effects and applications of the leaf gel. These effects include the potential of whole leaf or inner fillet gel liquid preparations of A. vera to enhance the intestinal absorption and bioavailability of co-administered compounds as well as enhancement of skin permeation. In addition, important pharmaceutical applications such as the use of the dried A. vera gel powder as an excipient in sustained release pharmaceutical dosage forms will be outlined.

Erythroid progenitor cells of the abnormal clone in polycythemia vera (PV) are capable of colony formation in vitro without the addition of erythropoietin, the regulatory hormone required for normal in vivo and-in vitro erythropoiesis. This property of "erythropoietin-independent" colony formation has been considered a marker for the abnormal clone in PV, although recent studies indicate that not all erythropoietic members of the clone may be capable of exhibiting this abnormal phenotype. The present studies were undertaken to investigate the level of maturation at which establishment of an erythropoietin-independent phenotype might be determined. A series of experiments was performed on the replated progeny of single primitive hemopoietic cells already committed to erythropoiesis (primitive BFU-E). First, conditions were established to maximize the number of erythroid colonies obtainable in secondary assays of replated primary colonies of primitive BFU-E origin. Time course studies and experiments with irradiated peripheral blood "feeder" cells treated in different ways established that results were best when primary colonies were allowed to grow for 9 days prior to replating and when 9 day old feeders stored at 4°C were included in the secondary assay medium. Second, a technique was developed for dividing such colonies between 2 secondary assay cultures. Experiments with normal primary colonies transferred to 2 secondary assays, both containing erythropoietin, showed that the variation between true replicates was random, indicating that the procedure used divided each primary colony equally. Third, it was shown that secondary assays to which no erythropoietin was added failed to support erythroid colony formation by progenitors present in normal 9 day old primary colonies. Finally, the distribution of erythropoietin-dependent and erythropoietin-independent phenotypes in individual colonies derived from primitive BFU-E from 5 patients with. PV was assessed by replating experiments. Most of the replated colonies from PV cultures that yielded erythroid colonies in secondary assays containing 3 units of erythropoietin per ml also produced some erythroid colonies in the paired replicate that contained < 0.01 units of erythropoietin per ml. However, fewer colonies were consistently obtained in the low erythropoietin cultures. These results indicate that in PV, most of the primitive erythroid bursts that generate phenotypically abnormal progeny capable of erythroid colony formation under conditions which are non-permissive for normal cells also produce significant numbers of progeny that are phenotypically normal in this respect. It is concluded that the capacity for erythropoietin-independent growth and maturation exhibited in vitro by terminally differentiating members of the abnormal clone in PV is not commonly fixed at or prior to the primitive BFU-E stage of erythropoietic cell development. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Introducción: El acemanano presente en las hojas de Aloe vera, es un polisacárido que posee una gran actividad en la regeneración celular y modulación del sistema inmune. Objetivo: Determinar el efecto regenerador óseo del extracto acuoso liofilizado de hojas de Aloe vera (Sábila) sobre la osteotomía mandibular inducida en cobayo. Diseño: Experimental. Lugar: Laboratorio de Farmacología, Facultad de Medicina Humana - UNMSM. Intervenciones: Se utilizó 40 cobayos machos con un peso corporal 1000±120g, se formó 5 grupos aleatoriamente de 8 animales; grupo I: Suero fisiológico al 0,9% (2mL/kg), grupo II: alendronato (0.5mg/kg), los grupos III, IV y V: extracto acuoso liofilizado de hojas de Aloe vera a dosis de 50mg/kg, 250mg/kg y 500mg/kg, respectivamente. Los cobayos fueron sometidos a osteotomía mandibular unilateral. Principales medidas de resultados: Recuento de células por campo, niveles de fosfatasa alcalina. Resultados: Se evidencia incremento significativo de fosfatasa alcalina, osteoclastos y osteocitos (p<0,05) a los 15 y 30 días en los grupos que recibieron alendronato y Aloe vera; también aumento de fibroblastos a los 15 días en los grupos III y IV; no se encontró diferencia significativa (p>0,05) en el recuento de linfocitos ni osteoblastos a los 15 y 30 días. Conclusiones: El extracto acuoso liofilizado de Aloe vera posee efecto regenerador óseo. Palabras clave: Regeneración ósea, Aloe vera, alendronato / --- Introduction: The acemannan present in the leaves of Aloe vera, is a polysaccharide having a high activity in cell regeneration and modulating the immune system. Objetive: To determine bone regenerative effect of the lyophilized aqueous extract of leaves of Aloe vera on the mandibular osteotomy induced in guinea pigs. Design: Experimental. Location: Laboratory of Pharmacology, Faculty of Human Medicine - UNMSM. Interventions: 40 male guinea pigs was used with a 1000±120g body weight, 5 groups of 8 animals randomly formed; Group I: 0.9% physiological saline (2mL/kg), group II: Alendronate (0.5mg/kg), the groups III, IV and V: lyophilized aqueous extract of Aloe vera leaves at doses of 50mg/kg, 250mg/kg and 500mg/kg respectively. The guinea pigs were undergoing unilateral mandibular osteotomy. Main outcome measures: Count cells per field, and alkaline phosphatase levels. Results: Significant increase in alkaline phosphatase, osteoclasts and osteocytes (p <0.05) at 15 and 30 days in the groups receiving alendronate and Aloe vera is evident; fibroblasts also increased to 15 days in groups III and IV; no significant difference (p> 0.05) was found in the lymphocyte count or osteoblasts at 15 and 30 days. Conclusions: The dried aqueous extract of Aloe vera has bone regenerative effect. Keywords: Bone regeneration, Aloe vera, alendronate / Tesis

Reproduction de : Thèse d'exercice : Pharmacie : Nantes : 2008. / Bibliogr.

Zugl.: Duisburg, Essen, University, Diss., 2008.