Essays in Knowledge Transfer

This dissertation advances our understanding of when firms are able to get information from outside agents and the impact of that information on innovation. In chapter one, I set up a theoretical model that illuminates how vertical integration changes the incentives for producers to share information with suppliers. Both transaction costs and bargain ability play major roles in information sharing. One result from chapter one is that producers share less information with vertically integrated suppliers. The second chapter tests this prediction, finding robust evidence that once a supplier vertically integrates, it gains fewer spillovers from competitor producers. Finally, the last chapter looks at how information brought by an external CEO can change the firm’s innovation direction. The third chapter finds that external CEOs tend to shift the direction of innovation less often that internal hires

Fixation of autogenous bone grafts with resorbable screws : histologic study in rabbits

Orientador: Renato MazzonettoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo do presente estudo in vivo foi avaliar histologicamente, de forma comparativa, o emprego de parafusos absorvíveis baseados no polímero poli(L-co-D,L ácido lático) 70:30 sintetizado por um laboratório nacional, para fixação de enxertos ósseos autógenos em tíbias de coelhos. Como controle foram utilizados parafusos à base de liga de titânio (Ti-6Al-4V/Grau V) de mesmas dimensões. Para tanto, foram selecionados 15 coelhos adultos, albinos, da raça Nova Zelândia, machos, com idade aproximada de 6 meses e peso variando entre 3,8 e 4,5 kg no momento do procedimento cirúrgico. De cada animal foram removidos 2 enxertos ósseos em espessura total da calota craniana, sendo um deles fixado à tíbia com parafuso absorvível e o outro com parafuso metálico. Os animais foram divididos em 3 grupos, de acordo com os períodos de sacrifício: 3, 8 e 16 semanas pós-operatórias. Após o processamento histológico, as lâminas foram coradas com hematoxilina e eosina e submetidas à análise histológica descritiva em microscopia óptica. Como resultado encontrou-se que o sistema de fixação baseado em polímero apresentou um comportamento histológico bastante semelhante ao sistema metálico. Em ambos os grupos o enxerto encontrava-se incorporado, ocorrendo neoformação óssea em sua interface com o leito receptor. Em nenhum dos grupos foi evidenciado processo inflamatório indesejável ou reação a corpo estranho. Baseando-se nos achados histológicos para o modelo experimental e metodologia empregada, pode-se concluir que o sistema de fixação baseado no polímero poli(L-co-D,L ácido lático) 70:30 é efetivo para a fixação de enxertos ósseos autógenos, com resultados comparáveis ao materiais à base de liga de titânio.Abstract: The aim of the present in vivo study was to evaluate histologically, by comparative means, the use of resorbable screws based on poli(L-co-D,L lactide) 70:30, manufactured by a brazillian laboratory, used for fixation of autogenous bone grafts in rabbit tibiae. As a control, titanium (Ti-6Al-4V Grade V) screws were used. For this purpose, fifteen white New Zeland male rabbits, with age of 6 months and weight between 3.8 - 4.5 Kg were used. Of each animal, 2 total thickness bone grafts were removed from the cranial vault and one of them was stabilized with resorbable screw while the other was stabilized with the metallic one. Animals were divided in 3 groups, according to the sacrifice period: 3, 8 and 16 week postoperatively. After histological processing, cuts were corated with hematoxilin and eosin and submited to descriptive histological analysis under light microscopy. As a result it was found that the fixation system based on polimer showed a histological behavior similar to the metallic system. For both groups bone graft was incorporated, with the presence of bone neoformation between this and the receptor site. In none of the groups undesirable inflammatory process or foreign body reaction was observed. Based on histological findings and respecting this experimental model it is possible to conclude that that the internal fixation system based on the poli(L-co-D,L lactide) 70:30 polymer is effective for fixation of autogenous bone grafts, offering results that are comparable the titanium fixation systems.DoutoradoCirurgia e Traumatologia Buco-Maxilo-FaciaisDoutor em Clínica Odontológic

A produção do espaço público contemporâneo e as formas de apropriação: o Parque Sólon de Lucena, João Pessoa - PB

This research analyzes the production of urban public spaces and the forms of use and appropriation of the population, having as object of analysis the Sólon de Lucena Park. This public space is the second oldest urban park in the city of João Pessoa, capital of Paraíba. It is located in the city´s perimeter of state´s heritage protection. It is one of the places of greatest attraction and movement of people and has symbolic relevance for the locals. Between 2014 and 2016, it underwent a process of requalification whose transformations were the reason for this work to develop. In the light of urban ethnography, we seek to uncover the connections and dissociations of the proposed, perceived and practiced uses, as well as to connect the reality of the object of study with the theories of Lefebvre, Serpa and Certeau, among others, on the production and appropriation of public spaces. From this theoretical - methodological matrix, the corpus of research analyzed revealed that the requalification strategies undertaken in the space called "Lagoa" promoted, on one hand, an image as a postcard, of the Park and even more geared towards the tourist and cultural character and, on the other, through the new equipment and activities, expanded the use and the diversified appropriation by the population. This process happens amid contradictions and daily conflicts typical of the public / private relation of contemporary urban space.NenhumaEsta pesquisa tem por objetivo analisar a produção de espaços públicos urbanos e as formas de uso e apropriação da população, tendo como objeto de análise o Parque Sólon de Lucena. Este espaço livre público é o segundo parque urbano mais antigo da cidade de João Pessoa, capital da Paraíba. Está situado no perímetro da poligonal de tombamento estadual da cidade, é um dos locais de maior atração e circulação de pessoas e possui relevância simbólica para os moradores locais. Entre os anos de 2014 e 2016, passou por um processo de requalificação cujas transformações foram o mote para que este trabalho se desenvolvesse. À luz da etnografia urbana, procura-se descortinar as conexões e dissociações dos usos propostos, percebidos e praticados, bem como conectar a realidade do objeto de estudo com as teorias de Lefebvre, Serpa e Certeau, entre outros, sobre a produção e apropriação dos espaços públicos. A partir desta matriz teórico - metodológica, o corpus de pesquisa analisado revelou que as estratégias de requalificação empreendidas no espaço dito “Lagoa”, promoveram por um lado, uma imagem do Parque ainda mais voltada para o caráter turístico e cultural, enquanto cartão postal da cidade e, por outro, através dos novos equipamentos e atividades, ampliaram o uso e a apropriação diversificada por parte da população. Esse processo acontece em meio a contradições e conflitos cotidianos próprios da relação público/privado do espaço urbano contemporâneo

Possible function of the protein bound to nuclear complementary RNA

It was demonstrated that individual renal endothelial dilatory function of the healthy rat predicts susceptibility to subsequent renal damage induced by 5/6 nephrectomy. In addition, it is reported that myocardial infarction (MI) that was performed upon unilateral nephrectomy (UNx) induced highly variable renal damage. Therefore, whether the variability in renal damage after MI could be explained by the variation in individual renal endothelial function before the induction of injury was studied. Endothelium-dependent relaxation to acetylcholine was investigated in vitro in small arteries that were isolated from the extirpated kidney at UNx. MI was induced 1 wk after UNx by ligation of the left coronary artery. Proteinuria and systolic BP were evaluated weekly for 16 wk thereafter using metabolic cages and the tail-cuff method, respectively. Upon termination of the study, focal glomerulosclerosis was evaluated by histology as an additional marker of renal damage. After MI, nephrectomized male Wistar rats (n = 15) gradually developed variable proteinuria, ranging from 20 to 507 mg/24 h at week 16, with an average systolic BP of 131 +/- 7 mmHg. The individual renal endothelial function of the healthy rats predicted the extent of renal damage in terms of proteinuria (r = -0.62, P = 0.008) and focal glomerulosclerosis (r = -0.70, P = 0.003). The individual level of renal endothelial function in the healthy rat is able to predict the severity of renal damage that is induced by MI. Further exploration of the underlying mechanisms may lead to discovery of preventive renoprotective therapies

The Realm and Frontiers of Mycosis Fungoides

Objectives Chronic renal failure (CRF) is associated with altered systemic arterial tone and hypertension. Myogenic constriction and endothelium-derived hyperpolarizing factor (EDHF)-dependent relaxation represent major vasoregulatory mechanisms in small systemic arteries. Elevated myogenic response and impaired EDHF might participate in the development of essential hypertension; however, their role in CRF-related hypertension is unknown. We investigated whether myogenic response and EDHF are altered in subtotally nephrectornized (sNX) rats and whether these changes are modifiable by chronic treatment with angiotensin-converting enzyme (ACE) inhibitor. Methods In a pressure arteriograph, myogenic constriction and EDHF-mediated relaxation were evaluated in small mesenteric arteries isolated from male Wistar rats 15 weeks after either sham operation (n = 7) (SHAM), sNX (n = 12) or sNX followed by 9 weeks of treatment with lisinopril (sNX + LIS, 2.5 mg/kg, n = 13). Results Surprisingly, myogenic response was reduced in hypertensive CRF rats (maximal myogenic tone: 37 +/- 2 and 18 +/- 4%, P <0.01; peak myogenic index: -0.80 +/- 0.08 and -0.40 +/- 0.12%/mmHg, P <0.05 in SHAM and sNX respectively). At the same time EDHF-mediated relaxation was also impaired (maximal response: 92 +/- 2 and 77 +/- 5%, P <0.01; pD(2): 6.5 +/- 0.1 and 5.9 +/- 0.1, P <0.05). Both myogenic response and EDHF were inversely related to the severity of renal failure and restored by treatment with lisinopril to levels found in SHAM animals. Conclusion Major constrictive (myogenic) and dilatory (EDHF) mechanisms of small systemic arteries are impaired in hypertensive CRF rats. These alterations do not seem to participate in the development of hypertension, being rather directly related to the severity of renal impairment. Both systemic vascular changes might be restored by renoprotective treatment with ACE inhibitor

Jaw osteonecrosis after dental implants associated with oral bisphosphonates – case report of resection of mandible

Osteonecrosis of the jaw is associated with defects in vascularization and with the use of oral bisphosphonates. Osseous exposition and infection may occur. Recommended treatment is variable, from antibiotic medication, bony decortication to resections of the mandible in severe cases. Reconstruction of mandible, in cases of resections is essential for maintaining esthetic profile and adequate form and function. Objective: To report a case about the dangers oforal bisphosphonates in association with invasive procedures such as dental implants Case report: Female patient, 64 years-old, with osteonecrosis of the jaw caused by use of oral bisphosphonates after rehabilitation with dental implants. She had an edentulous and atrophic mandible and poor healthy. After diagnosis, partial resection of the jaw was performed together with the reconstruction with titanium plate, with no success. Then, iliac bone graft fixed by plates and screws was attempted, again with no success. Conclusion: Despiteof the small number of cases of osteonecrosis associated with oral bisphosphonate reported in the literature, a simple implant surgery could result in adverse consequences if the use of this medication were overlooked in the anamnesis.Osteonecrosis of the jaw is associated with defects in vascularization and with the use of oral bisphosphonates. Osseous exposition and infection may occur. Recommended treatment is variable, from antibiotic medication, bony decortication to resections of the mandible in severe cases. Reconstruction of mandible, in cases of resections is essential for maintaining esthetic profile and adequate form and function. Objective: To report a case about the dangers oforal bisphosphonates in association with invasive procedures such as dental implants Case report: Female patient, 64 years-old, with osteonecrosis of the jaw caused by use of oral bisphosphonates after rehabilitation with dental implants. She had an edentulous and atrophic mandible and poor healthy. After diagnosis, partial resection of the jaw was performed together with the reconstruction with titanium plate, with no success. Then, iliac bone graft fixed by plates and screws was attempted, again with no success. Conclusion: Despiteof the small number of cases of osteonecrosis associated with oral bisphosphonate reported in the literature, a simple implant surgery could result in adverse consequences if the use of this medication were overlooked in the anamnesis

A method for accurate measurement of GFR in conscious, spontaneously voiding rats

A method for accurate measurement of GFR in conscious, spontaneously voiding rats. Renal function measurement by clearance methods relies on accurately timed urine collection. In small experimental animals, renal function measurement is usually performed under anesthesia and/or with the application of bladder catheters to ensure accurate urine collection. To avoid both anesthesia and the need for bladder catheters we developed a method to measure glomerular filtration rate (GFR) in spontaneously voiding conscious rats. GFR was measured as the urinary clearance of constantly infused 125I-iothalamate. To correct for incomplete bladder emptying, urinary clearance of 125I-iothalamate was multiplied by the ratio of plasma and urinary clearance of simultaneously infused 131I-hippuran, a correction method that has been previously validated in humans. Reproducibility of the technique was evaluated by analysis of the results of four consecutive clearance periods during the day (intra-assay variation) in a group of 17 rats and of two consecutive clearance periods on two or three separate days in a group of 20 rats (inter-assay variation), all with normal renal function. Application of the correction method reduced the intra-assay coefficient of variation (mean ± SD) from 37.4 ± 14.3 to 5.4 ± 2.3% (P < 0.05). The mean inter-assay coefficient of variation fell slightly from 23.4 ± 10.3 to 11.0 ± 7.2% (P < 0.10). In rats with moderately impaired renal function (N = 8) the intra-assay variation fell from 27.9 ± 20.7 to 2.7 ± 1.6% (P < 0.05). Our data show that this correction method is a useful technique to assess renal function in conscious, spontaneously voiding rats

CIRURGIA CORRETIVA DE FRATURA DE ARCO ZIGOMÁTICO COM A TÉCNICA DE GILLIES: RELATO DE CASO CLÍNICO

O arco zigomático é um componente estrutural do complexo zigomático formado pela junção do processo zigomático do temporal com o processo temporal do zigomático. Em função de sua estrutura frágil e sua posição, traumas de baixa intensidade perpendiculares a ele podem levar a fraturas. As fraturas do arco zigomático compreendem quase 10% dos casos de fraturas do complexo e resultam em uma deformidade angular típica. Estas podem ser classificadas em classe I (fratura em “V”), classe II (fratura com fragmento intermediário), classe III (fratura combinada do osso malar e do arco zigomático) no intuito de orientar o cirurgião no planejamento bem como no tratamento. Os pacientes podem apresentar sinais e sintomas como depressão ou abaulamento na topografia do arco e limitação da abertura bucal. Diversos tratamentos já estão bem estabelecidos na literatura, cada qual com sua indicação específica, sendo o método de Gillies um dos mais usados para redução de tais fraturas. O presente estudo relata um caso clínico de fratura de arco zigomático utilizando o acesso de Gillies, expondo o pré, o trans e o pós operatório

UTILIZAÇÃO DO RAMO E PROCESSO CORONÓIDE DA MANDÍBULA PARA A RECONSTRUÇÃO TOTAL DE MAXILA ATRÓFICA

A reabilitação implanto-suportada dos maxilares atróficos requer reconstrução prévia do volume ósseo a fim de permitir a instalação de implantes dentários em ótima posição tridimensional e assim proporcionar uma reabilitação protética ideal funcionalmente e esteticamente.  A escolha do sítio doador do enxerto ósseo a ser utilizado deve considerar características e intensidade da atrofia óssea. Diversas fontes doadoras de enxerto ósseo estão disponíveis para reconstruções maxilares, diferenciando-se quanto as características embriológicas (ossificação endocondral x intramembranosa), tipo de osso (cortical x medular), características físicas e morfológicas, volume de osso disponível, morbidade associada à remoção e taxa de reabsorção do enxerto. O presente trabalho visa demonstrar um caso clínico de reconstrução total de maxila atrófica com enxerto ósseo removido dos ramos e processos coronóides da mandíbula. Tal enxerto, além de evitar a remoção de enxertos ósseos de fontes extra-orais e consequentemente a morbidade associada a tal remoção, cumpriu os requisitos ideais dos enxertos ósseos, tais como baixa morbidade do sítio doador, mínima reabsorção, facilidade de remoção, alto componente cortical e principalmente promoção de volume ósseo suficiente para a instalação de implantes dentários após incorporação do osso transplantado

Author index for volume 286

Susceptibility to renal injury varies among individuals. Previously, we found that individual endothelial function of healthy renal arteries in vitro predicted severity of renal damage after 5/6 nephrectomy. Here we hypothesized that individual differences in endothelial function in vitro and renal perfusion in vivo predict the severity of renal damage in a model of adriamycin-induced nephropathy. In three separate studies, the following baseline parameters were measured in healthy male Wistar rats: (1) acetylcholine (ACh)-induced relaxation in small renal arteries in vitro (n = 16) and the contribution of prostaglandins, nitric oxide (NO) and endothelium-dependent hyperpolarizing factor (EDHF) to the relaxation; (2) glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) in spontaneously voiding rats in vivo (n = 16) and (3) the acute effect of the NO-synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME, n = 12) on renal blood flow (RBF) as compared to vehicle infusion (n = 9). Following these measurements, adriamycin (1.75 mg/kg i.v.) was injected and subsequent renal damage after 6 weeks was related to the baseline parameters. Total ACh-induced (r = 0.51, P <0.05) and EDHF-mediated relaxation (r = 0.68, P <0.05), as well as ERPF (r = 0.66, P <0.01), positively correlated with the severity of proteinuria 6 weeks after injection. In contrast, pronounced baseline NO-mediated dilation was associated with lower proteinuria (r = 0.71, P <0.01). Nevertheless, an acute L-NAME infusion, strongly reducing RBF by 22 +/- 8%, during adriamycin administration provided protection against the development of proteinuria. Individual animals with pronounced baseline endothelial dilatory ability measured in vitro and high ERPF in vivo are vulnerable to renal damage after the adriamycin injection. Acute inhibition of NO during adriamycin administration, resulting in a decrease of RBF, protects against renal injury, probably by limiting the delivery of the drug to the kidney. Therefore, interindividual variability in renal haemodynamics might be crucially involved in susceptibility to nephrotoxic renal damag