A proposta deste estudo consistiu em avaliar, cefalometricamente, as alterações dentárias e esqueléticas promovidas pelos aparelhos MARA e Bionator, seguidos do aparelho ortodôntico fixo, no tratamento da má oclusão de Classe II, 1ª divisão. A amostra foi composta por 40 pacientes, divididos em dois grupos. O Grupo MARA foi composto por 18 jovens, 12 do gênero masculino e 6 do gênero feminino, sendo que, 22,22% apresentavam ½ Classe II, 38,89% ¾ de Classe II e 38,89% Classe II completa nos molares. A idade inicial variou entre 10,29 anos e 14,99 anos (média de 11,96 anos). Estes pacientes foram selecionados prospectivamente entre os jovens que procuraram tratamento ortodôntico na clínica de Ortodontia da Faculdade de Odontologia de Bauru Universidade de São Paulo, durante o ano de 2006 e tratados por meio do aparelho MARA seguido do aparelho ortodôntico fixo, por um período médio de 3,47 anos. O Grupo Bionator, composto por 22 jovens, sendo 13 do gênero masculino e 9 do gênero feminino, com idade inicial média de 11,38 anos, apresentavam 27,27% dos indivíduos com ½ Classe II, 27,27% ¾ de Classe II e 45,45% Classe II completa nos molares. Foram selecionados retrospectivamente a partir do acervo da Disciplina de Ortodontia da Faculdade de Odontologia de Bauru Universidade de São Paulo e tratados por meio do aparelho Bionator seguido do aparelho ortodôntico fixo, por um período médio de 3,95 anos. Para cada paciente foram utilizadas duas telerradiografias em norma lateral, uma na fase inicial e outra ao término do tratamento ortodôntico fixo. Utilizou-se o teste t de Student, para amostras independentes, a fim de se comparar as idades iniciais e finais, o tempo de tratamento, as variáveis cefalométricas iniciais e finais e as alterações médias reais na comparação intergrupos. O gênero dos jovens e a severidade da má oclusão entre os grupos foram avaliados pelo teste do Qui-quadrado. Para avaliar as alterações iniciais e finais dentro de cada grupo tratado, realizou-se o teste t para amostras dependentes. Os resultados revelaram que ambos os aparelhos proporcionaram alterações semelhantes no desenvolvimento maxilar e mandibular, na relação maxilomandibular, no padrão de crescimento, bem como no arco superior e nas relações dentárias. No arco inferior, os molares sofreram uma angulação distal significante do seu longo eixo nos dois grupos, porém com maior quantidade de angulação no Grupo Bionator. / This study aimed to evaluate, cephalometrically, dental and skeletal changes promoted by the MARA and Bionator, followed by fixed appliances on the treatment of Class II, Division 1 malocclusion. The sample comprised 40 young subjects, divided into two groups. MARA Group, was comprised 18 patients, 12 males and 6 females, among which 22.22% exhibited ½-cusp Class II, 38.89% ¾-cusp Class II, and 38.89% full-cusp Class II malocclusions (molar relationship). The initial age ranged from 10.29 years to 14.99 years (mean of 11.96 years). These patients were prospectively selected among young subjects who seek orthodontic treatment at the Orthodontic Department at Bauru Dental School, University of São Paulo, Brazil, during 2006 and treated with the MARA appliance followed by fixed appliances for a mean period of 3.47 years. Bionator Group, consisted of 22 patients, 13 males and 9 females, with initial mean age of 11.38 years; 27.27% exhibited ½-cusp Class II, 27.27% ¾-cusp Class II and 45.45% full-cusp Class II malocclusions (molar relationship). These patients were retrospectively selected from the files of the Orthodontic Department at Bauru Dental School, University of São Paulo, Brazil and treated with the Bionator followed by fixed appliances for a mean period of 3.95 years. The initial and final lateral cephalograms of individuals in the two groups were evaluated. The Student t test for independent samples was applied to compare the initial and final ages, the period of treatment, the initial and final cephalometric variables and the actual mean changes between the two groups. The distribution of genders and the severity of malocclusion between the groups were evaluated by the chi-square test. The changes between the initial and final stages of each group were evaluated by the t test for dependent samples. The results showed that, for both appliances, there was no significant change in maxillary and mandibular development, in the maxillomandibular relationship, the growth pattern, as well as in the maxillary arch and dental relationships. The mandibular molars presented significant distal angulation in both groups, with greater angulation in the Bionator Group.

A proposta deste estudo consistiu em avaliar, cefalometricamente, as alterações dentárias e esqueléticas promovidas pelos aparelhos MARA e Bionator, seguidos do aparelho ortodôntico fixo, no tratamento da má oclusão de Classe II, 1ª divisão. A amostra foi composta por 40 pacientes, divididos em dois grupos. O Grupo MARA foi composto por 18 jovens, 12 do gênero masculino e 6 do gênero feminino, sendo que, 22,22% apresentavam ½ Classe II, 38,89% ¾ de Classe II e 38,89% Classe II completa nos molares. A idade inicial variou entre 10,29 anos e 14,99 anos (média de 11,96 anos). Estes pacientes foram selecionados prospectivamente entre os jovens que procuraram tratamento ortodôntico na clínica de Ortodontia da Faculdade de Odontologia de Bauru Universidade de São Paulo, durante o ano de 2006 e tratados por meio do aparelho MARA seguido do aparelho ortodôntico fixo, por um período médio de 3,47 anos. O Grupo Bionator, composto por 22 jovens, sendo 13 do gênero masculino e 9 do gênero feminino, com idade inicial média de 11,38 anos, apresentavam 27,27% dos indivíduos com ½ Classe II, 27,27% ¾ de Classe II e 45,45% Classe II completa nos molares. Foram selecionados retrospectivamente a partir do acervo da Disciplina de Ortodontia da Faculdade de Odontologia de Bauru Universidade de São Paulo e tratados por meio do aparelho Bionator seguido do aparelho ortodôntico fixo, por um período médio de 3,95 anos. Para cada paciente foram utilizadas duas telerradiografias em norma lateral, uma na fase inicial e outra ao término do tratamento ortodôntico fixo. Utilizou-se o teste t de Student, para amostras independentes, a fim de se comparar as idades iniciais e finais, o tempo de tratamento, as variáveis cefalométricas iniciais e finais e as alterações médias reais na comparação intergrupos. O gênero dos jovens e a severidade da má oclusão entre os grupos foram avaliados pelo teste do Qui-quadrado. Para avaliar as alterações iniciais e finais dentro de cada grupo tratado, realizou-se o teste t para amostras dependentes. Os resultados revelaram que ambos os aparelhos proporcionaram alterações semelhantes no desenvolvimento maxilar e mandibular, na relação maxilomandibular, no padrão de crescimento, bem como no arco superior e nas relações dentárias. No arco inferior, os molares sofreram uma angulação distal significante do seu longo eixo nos dois grupos, porém com maior quantidade de angulação no Grupo Bionator. / This study aimed to evaluate, cephalometrically, dental and skeletal changes promoted by the MARA and Bionator, followed by fixed appliances on the treatment of Class II, Division 1 malocclusion. The sample comprised 40 young subjects, divided into two groups. MARA Group, was comprised 18 patients, 12 males and 6 females, among which 22.22% exhibited ½-cusp Class II, 38.89% ¾-cusp Class II, and 38.89% full-cusp Class II malocclusions (molar relationship). The initial age ranged from 10.29 years to 14.99 years (mean of 11.96 years). These patients were prospectively selected among young subjects who seek orthodontic treatment at the Orthodontic Department at Bauru Dental School, University of São Paulo, Brazil, during 2006 and treated with the MARA appliance followed by fixed appliances for a mean period of 3.47 years. Bionator Group, consisted of 22 patients, 13 males and 9 females, with initial mean age of 11.38 years; 27.27% exhibited ½-cusp Class II, 27.27% ¾-cusp Class II and 45.45% full-cusp Class II malocclusions (molar relationship). These patients were retrospectively selected from the files of the Orthodontic Department at Bauru Dental School, University of São Paulo, Brazil and treated with the Bionator followed by fixed appliances for a mean period of 3.95 years. The initial and final lateral cephalograms of individuals in the two groups were evaluated. The Student t test for independent samples was applied to compare the initial and final ages, the period of treatment, the initial and final cephalometric variables and the actual mean changes between the two groups. The distribution of genders and the severity of malocclusion between the groups were evaluated by the chi-square test. The changes between the initial and final stages of each group were evaluated by the t test for dependent samples. The results showed that, for both appliances, there was no significant change in maxillary and mandibular development, in the maxillomandibular relationship, the growth pattern, as well as in the maxillary arch and dental relationships. The mandibular molars presented significant distal angulation in both groups, with greater angulation in the Bionator Group.

Made available in DSpace on 2014-06-11T19:31:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-27Bitstream added on 2014-06-13T19:20:03Z : No. of bitstreams: 1 pinto_prs_dr_arafo.pdf: 1147214 bytes, checksum: f6c2e1b004c27589634b2b9982a04229 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução: O presente trabalho foi consubstanciado em três capítulos como se seguem: Capítulo I - Crescimento mandibular e desenvolvimento dentoalveolar no tratamento da Classe II, divisão 1, com bionator de Balters em função da maturidade esquelética; Capítulo II - Influência da época de tratamento, no processo de crescimento e desenvolvimento mandibular e dentoalveolar, durante a correção da má oclusão de Classe II, divisão 1, com a utilização do bionator de Balters e, 3- Influência do Bionator de Balters no processo de crescimento e desenvolvimento mandibular e dentoalveolar, durante a correção da má oclusão de Classe II, divisão 1. Material e Método: Na realização dos três capítulos do trabalho, foram utilizadas telerradiografias laterais em 45 graus de crianças Classe II divisão 1, com retrusão mandibular acompanhadas sem tratamento ou durante o tratamento com o aparelho bionator de Balters. Superposições mandibulares orientadas por referências fixas e estáveis representadas por implantes metálicos de tântalo inseridos na região anterior e posterior do corpo da mandíbula foram utilizadas para avaliação das mudanças no crescimento da mandíbula (corpo, ramo e base) e mudanças na erupção dos dentes decíduos e permanentes. Capítulo I: Foram avaliados 3 grupos de crianças Classe II divisão 1, dois tratados pelo período de um ano com o aparelho bionator de Balters (Grupo 1: 6 crianças com 7 a 8 anos e Grupo 2: 10 crianças com 9 a 10 anos) e um sem tratamento (Grupo controle: 7 crianças com 8 a 9 anos). Capítulo II - Foram avaliados 4 grupos em diferentes tempos de tratamento: Grupos 1 e 2, pacientes com idades esqueléticas variando de 7 a 8,5 anos de idade (10pacientes) e dos 9,3 aos 10,7 anos (10pacientes) respectivamente, tratados por 1 ano com o bionator de Balters. Grupos 3 e 4, pacientes com idades esqueléticas variando... / Introduction: The actual study was structured in three chapters. Chapter I: Mandibular growth and dentoalveolar development in the treatment of the Class II division 1 malocclusion with the bionator of Balters according to the skeletal maturation. Chapter II: Influence of the bionator of Balters treatment phase, in the process of mandibular and dentoalveolar growth and development, during the correction of the Class II, division 1 malocclusion. Chapter III: Evaluation of the Bionator of Balters influence in the mandibular and dentoalveolar growth and development process, during the correction of Class II division 1 malocclusion. Material e Method: It was used in the three chapters, lateral 45 degree cephalometric radiographs of Class II division 1 children with mandibular deficiency, followed without treatment or during the treatment with the orthopedic appliance bionator of Balters. Mandibular superposition using tantalun metallic implants as fixed and stable references positioned in the anterior and posterior mandibular body were used for evaluation of the growth modifications of the mandible (condyle, ramus and base of the mandible) and of the eruption changes of the deciduous and permanent teeth. Chapter I: Three groups of children with Class II division 1 malocclusion were evaluated. Two of them were treated for one year with the bionator of Balters appliance in different skeletal ages (Group 1: 6 children 7 to 8 years old and Group 2: 10 children 9 to 10 years old) and the other one was followed without treatment (Control Group: 7 children 8 to 9 years old). Chapter II: Four groups of children with Class II division 1 treated with the bionator of Balters were evaluated: Groups 1 and 2 – Patients with skeletal age ranging from 7 to 8,5 years(10patients) and 9,3 to 10,7 years(10patients) respectively, treated for the first year with the appliance... (Complete abstract click electronic access below)

This thesis addresses the problem healthcare facilities are having in maintaining proper food temperatures while transporting meals to patients after food has left the kitchen area. Induction heat has been a known method for generating heat for many years. The commercial food industry currently uses this technology, which is beginning to appear in the residential sector as well because of developments made by manufacturers. This study focuses on the top commercial brand models of induction heaters and the supporting materials currently used to create heat sources to maintain food temperatures in hospitals and long term care facilities. The research in this thesis includes data recorded from 6,000 total induction cycles from the 3 leading induction heating models. The focus of the research was to gather data concerning the models’ reliability to consistently create the intended inducement of radio frequency waves as well as deliver consistent temperature reactions from the recorded induction cycles. There were 18,000 temperature data points recorded during different time intervals for each of the induction cycles for the entire study. The results indicate the current technology not only is reliable in creating inductions fields but also in delivering consistent temperatures in the supporting materials being heated. Induction has been used historically as a fast heating process to treat large metal products and requires no direct contact to create or transfer heat to a surface (Rudnev et al., 2003). The speed and consistent application of heat transfer that has been derived by modern manufacturing induction practices makes it a logical use of existing technology to be applied in maintaining temperatures of food in the healthcare market. However, the focus for commercial equipment manufacturers has been to market products that can consistently maintain desired food temperatures, particularly in the healthcare industry. Traditionally, heating foods was accomplished by physically applying heat to areas where food is stored, in order to reach a certain temperature, and then working to deliver that food to the patient in a timely manner or before it cooled to temperatures that would be deemed too cold for consumption. If the food was too cold, before it was served to the patient, then it was typically micro waved in order to reheat the food. However, reheating food in the microwave is not only detrimental, but it also degrades food quality, texture, and visual presentation (Harvard Health, 2015). As a result, the effort demanded to deliver all foods to all patients, while the food is still at an ideal temperature, has resulted in an increased cost of labor. This is because healthcare facilities have had to hire additional workers to meet the demands placed on the nutrition department related to safe temperatures and speed of food delivery (Aladdin, 2013).

A fatty acid amide is precisely as the name suggests: A fatty acid (CHn-COOH), in which the hydroxyl group of the carboxylic acid is displaced by an amine functional group from a biogenic amine (R-NH2), ultimately forming an amide bond. Furthermore, these fatty acid amides can be composed of a variety of different acyl chain lengths donated by the fatty acid and a myriad of different biogenic amines. Thus, these molecules can be subdivided in a number of different ways including the separation of short chain (acetyl to heptanoyl) and long chain (palmitoyl to arachidonoyl) and also based off the biogenic amine type. The long chain fatty acid amides quickly gained the interest of the scientific community through the discovery of anandamide (N-arachidonoylethanolamide), which was found to be the endogenous ligand for the cannabinoid receptor-1 (CB1) found in the mammalian brain. This particular neural molecule is an N-acylethanolamide, which is one specific classification of long chain fatty acid amide. However, there exist other types of long chain fatty acid amides including the N-acylglycines, primary fatty acid amides (PFAMs) and N-acylarylalkylamides. Yet, despite the type of fatty acid amide, it has been shown many of these types of molecules are synthesized using a type of N-acyltransferase. These N-acyltransferases are believed to be members of the GCN5-related superfamily of N-acyltransferases (GNAT), which share the feature of being able to accept acyl-CoA thioester substrates. This dissertation will discuss and demonstrate the extraction of all types of the aforementioned classifications of long chain fatty acid amides but will have a particular focus on the N-acylarylalkylamides. Elucidating more about the biosynthetic pathways and metabolic routes of the long chain fatty acid amides could lead to the development of potential therapeutics and pest control agents. We have determined Drosophila melanogaster arylalkylamine N-acyltransferase like 2 is responsible for the in vivo biosynthesis of N-acyldopamines. We have also demonstrated Bombyx mori is another suitable model systems for the study of long chain fatty acid amides, as three insect arylalkylamine N-acyltrasnferase from Bombyx mori (Bm-iAANAT) were found to share some homology in primary sequence (25-29%) to AAANTL2 in Drosophila melanogaster. We show herein that one of these enzymes is able to catalyze the formation of long chain N-acylarylalkylamides in vivo. The change in the transcription of these enzymes was tracked to try and understand if these enzymes serve a focused purpose in the physiological development of the insect. If it is found one of these Bm-iAANAT are crucial for growth, it may elucidate a general function of the enzyme, which may be able to inhibit growth of specific insects that are known pests, while not targeting endangered insects like Apis melliferra (honey bee). Understanding this would help in the eventual creation of targeted insecticides on specific insect pests Furthermore, a novel panel of fatty acid amides was characterized and quantified in extracts from this organism via LC-QToF-MS, ultimately showing it is very possible the Bm-iAANATs are performing this catalysis in vivo.

Background: Adherent-invasive Escherichia coli (AIEC) is a pathogen isolated from the ileum of patients with CD. IFNγ is a key mediator of immunity, which regulates inflammatory responses to microbial infections. Previously, we showed enterohemorrhagic E. coli prevents STAT1 activation. Aims: To determine; 1) whether activation of STAT1 by IFNγ was prevented following AIEC infection, and 2) define the mechanisms used. Methods: Human epithelial cells were infected with AIEC strains or other pathogenic and commensal E. coli strains. Following infection, cells were stimulated with IFNγ. Activation of STAT1, was monitored by immunoblotting. Results: AIEC strains prevented STAT1 phosphorylation in response to IFNγ. Effect required live bacteria with active protein synthesis. A bacterial product was responsible for blocking STAT1 signalling and interfered with downstream signalling cascades. Conclusion: Suppression of epithelial cell STAT1 signal transduction by AIEC strains represents a novel mechanism by which the pathogen evades host immune responses to the infection.

Background: Adherent-invasive Escherichia coli (AIEC) is a pathogen isolated from the ileum of patients with CD. IFNγ is a key mediator of immunity, which regulates inflammatory responses to microbial infections. Previously, we showed enterohemorrhagic E. coli prevents STAT1 activation. Aims: To determine; 1) whether activation of STAT1 by IFNγ was prevented following AIEC infection, and 2) define the mechanisms used. Methods: Human epithelial cells were infected with AIEC strains or other pathogenic and commensal E. coli strains. Following infection, cells were stimulated with IFNγ. Activation of STAT1, was monitored by immunoblotting. Results: AIEC strains prevented STAT1 phosphorylation in response to IFNγ. Effect required live bacteria with active protein synthesis. A bacterial product was responsible for blocking STAT1 signalling and interfered with downstream signalling cascades. Conclusion: Suppression of epithelial cell STAT1 signal transduction by AIEC strains represents a novel mechanism by which the pathogen evades host immune responses to the infection.

Preeclampsia results from incomplete trophoblast invasion of the spiral arteries during early pregnancy. Vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) are critical factors involved in angiogenesis, invasion and hemostasis at the maternal-fetal interface. Both factors are transcriptionally regulated by hypoxia inducible factor (HIF), a heterodimeric complex consisting of HIF-1[beta] and either HIF-1[alpha] or -2[alpha] whose specificity or redundancy in gene regulation is cell-type specific. This study uses siRNA technology to dissect the mechanisms of hypoxia-mediated regulation of PAI-1 and VEGF expression in first trimester trophoblasts. Immortalized first trimester human extravillous trophoblasts (HTR8/SVneo cells) were maintained in serum-free and serum-containing media for 4h (n=3-4), 8h (n=6), 24h (n=5) and 48h (n=5) under normoxic (21% O2) and hypoxic (1-2% O2) conditions to determine a time of maximum induction of both VEGF and PAI-1. Subsequently, cells were maintained for 48h in the presence or absence of siRNA for HIF-1[alpha], HIF-2[alpha], HIF-1[alpha] + -2[alpha], a non-targeting (NT) sequence or Cyclophilin B (CB). Media were then removed, cells lysed, and Western blotting used to assess HIF-[alpha] knockdown. VEGF and PAI-1 levels in the media were quantified by ELISA and results expressed as pg or ng/[micro]g protein. Results from 3 to 8 independent experiments were analyzed using unpaired t-tests. Under hypoxic conditions treatment of cells with HIF-1[alpha], HIF-2[alpha] or HIF -1[alpha] + -2[alpha] siRNA resulted in >90% HIF-Ñ protein knockdown as determined by Western blotting. 48h of hypoxic treatment caused a statistically significant increase in PAI-1 levels (p<0.01) and VEGF levels (p<0.001) compared to normoxic controls. Under hypoxic conditions, PAI-1 levels were 4.75 [plus-minus] 0.46 ng/[micro]g protein and VEGF levels were 7.27 [plus-minus] 1.08 pg/[micro]g protein. Treatment with siRNA to HIF-1[alpha], HIF-2[alpha] and HIF-1[alpha] + -2[alpha] significantly reduced PAI-1 levels to 3.3 [plus-minus] 0.35 (p<0.02), 3.1 [plus-minus] 0.38 (p<0.03) and 2.4 [plus-minus] 0.19 (p<0.003), respectively. No significant difference in PAI-1 reduction was noted between the three HIF siRNA conditions. Under hypoxic conditions, levels of VEGF in cells treated with siRNA to HIF-1[alpha] (5.79 [plus-minus] 0.55), HIF-2[alpha] (5.50 [plus-minus] 1.24) and HIF-1[alpha] + -2[alpha] (4.24 [plus-minus] 0.93) were reduced compared to the hypoxic control (7.27 [plus-minus] 1.08), yet these effects did not reach statistical significance. However, when compared with the levels observed in cells treated with NT siRNA (9.90 [plus-minus] .98), all HIF siRNA treatments promoted a significant reduction in VEGF expression (p<0.003, p<0.02 and p<0.003 for HIF-1[alpha], HIF-2[alpha] and HIF-1[alpha]+ -2[alpha], respectively). In conclusion, these results indicate that hypoxia-mediated changes in PAI-1 and VEGF expression in trophoblasts are regulated similarly by both HIF-1[alpha] and HIF-2[alpha]. This provides important insight into the molecular mechanisms regulating hemostasis and trophoblast invasion as well as their potential dysfunction in pregnancies complicated by preeclampsia

Cytokine and growth factor signaling pathways involving STAT3 are frequently constitutively activated in many human primary tumors, and are known for the transcriptional role they play in controlling cell growth and cell cycle progression. However, the extent of STAT3's reach on transcriptional control of the genome as a whole remains an important question. We predicted that this persistent STAT3 signaling affects a wide variety of cellular functions, many of which still remain to be characterized. We took a broad approach to identify novel STAT3 regulated genes by examining changes in the genome-wide gene expression profile by microarray, using cells expressing constitutively-activated STAT3. Using computational analysis, we were able to define the gene expression profiles of cells containing activated STAT3 and identify candidate target genes with a wide range of biological functions. Among these genes we identified Necdin, a negative growth regulator, as a novel STAT3 target gene, whose expression is down-regulated at the mRNA and protein levels when STAT3 is constitutively active. This repression is STAT3 dependent, since inhibition of STAT3 using siRNA restores Necdin expression. A STAT3 DNA-binding site was identified in the Necdin promoter and both EMSA and chromatin immunoprecipitation confirm binding of STAT3 to this region. Necdin expression has previously been shown to be down-regulated in a melanoma and a drug-resistant ovarian cancer cell line. Further analysis of Necdin expression demonstrated repression in a STAT3-dependent manner in human melanoma, prostate and breast cancer cell lines. These results suggest that STAT3 coordinates expression of genes involved in multiple metabolic and biosynthetic pathways, integrating signals that lead to global transcriptional changes and oncogenesis. STAT3 may exert its oncogenic effect by up-regulating transcription of genes involved in promoting growth and proliferation, but also by down-regulating expression of negative regulators of the same cellular processes, such as Necdin.

A double sandwich enzyme-linked immunosorbent assay (ELISA) was developed to quantify the proteinaceous inhibitor of tissue plasminogen activator (t-PA) which occur in the tissue of Erythrina caffra Thunb. Using the ELISA the t-PA inhibitor could be detected in nanogramme quantities on the micro titer plate. The concentration of the t-PA inhibitor was determined in different tissues of Erythrina caffra. t-PA inhibitor concentrations in the order of 1 000 microgrammes per gramme protein were found in the seeds. Relatively small quantities of t - PA inhibitor, in the order of 10 to 50 microgrammes per gramme protein, occurred in root, shoot, leaf and living bark material. The t-PA inhibitor was found to accumulate in a similar way to the storage proteins in developing seeds. The accumulation of the inhibitor is at a relatively low level during the early period of seed development but increases exponentially just before the seeds reach their maximum size. The t-PA inhibitor content of the cotyledons decreased drastically during the process of germination and subsequent seedling development. The disappearance of the inhibitor be the result of total degradation of the molecule can or partial proteolysis with the modified molecule still being present in the tissue. An attempt was made to increase the t-PA inhibitor content of excised leaves of Erythrina caffra with protein inducing substances such as polyamines, precursors of ethylene and phytic acid. The protein inducing compounds included cell wall hydrolysates of Erythrina caffra, the marine alga Ecklonia maxima Osbeck (Papenfuss) as well as Lycopersicon esculentum Mill which induced the, synthesis of proteinase inhibitors suggested to be involved in the defense mechanism of plants. None of the substances used, increased the t-PA inhibitor content of excised leaves or in vitro cultures of Erythrina caffra. It is suggested that the t-PA inhibitor is probably not involved in a defense mechanism of Erythrina caffra. A callus and suspension culture derived from shoot tissue was developed to determine the occurrence of the t-PA inhibitor in vitro. The optimal nutrient medium for the growth of callus was the salts and vitamins of MURASHIGE and SKOOG (1962). The medium was supplemented with 3 % sucrose, 0. 1 gramme per litre meso - inositol, 10 micromoles per litre benzyl adenine and 5 micromoles per litre 2,4- dichlorophenoxyacetic acid . Different auxins and cytokinins had a similar growth stimulatory effect on the growth of callus derived from a number of organs of Erythrina caffra. The callus from different organs did however, grow at different rates on the same nutrient medium. Callus derived from leaf, shoot, and cotyledonary tissue grew at similar rates on the nutrient media of MURASHIGE and SKOOG (1962), SCHENK and HILDEBRANDT (1972) and B5 (GAMBORG, MILLER and OJIMA, 1968) despite large differences in the concentration of the nutrients in the three nutri.ent media. The source of nitrogen and ratio of nitrate to ammonium was critical to the growth of callus cultures . The optimal concentration of nitrate and ammonium was 30 millimoles per litre . The growth of callus from different organs was significantly affected by the concentration of sucrose in the nutrient medium. A concentration of 3% was optimal for callus growth. Temperature had a significant effect on the growth of callus. The optimal temperature for callus growth was 25 °C. A shoot cell suspension culture was established and maintained at the same temperature and on the same medium as the callus cultures but with a ten times lower concentration of growth regulators. A low shake speed was essential for the growth of the suspension culture. Maximum growth was obtained at a shake speed of 60 rpm. Relatively low quantities of t-PA inhibitor, in the order of 1 to 5 microgrammes per gramme protein, was detected in the suspension cultures. An attempt was made to increase the t-PA inhibitor content of the suspension cultures with the pro te in i nduc i ng compounds used on excised leaves, but without success. However, the t-PA inhibitor content of the suspension culture was significantly increased with a ten times increase in the sulphate content of the nutrient medium. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1990.