ShcA promotes chondrocyte hypertrophic commitment and osteoarthritis in mice through RunX2 nuclear translocation and YAP1 inactivation.

OBJECTIVE: Chondrocyte hypertrophic differentiation, a key process in endochondral ossification, is also a feature of osteoarthritis leading to cartilage destruction. Here we investigated the role of the adaptor protein Src homology and Collagen A (ShcA) in chondrocyte differentiation and osteoarthritis. METHODS: Mice ablated for ShcA in osteochondroprogenitor cells were generated by crossing mice carrying the Twist2-Cre transgene with ShcAflox/flox mice. Their phenotype (n = 5 to 14 mice per group) was characterized using histology, immuno-histology and western-blot. To identify the signaling mechanisms involved, in vitro experiments were conducted on wild type and ShcA deficient chondrocytes (isolated from n = 4 to 7 littermates) and the chondroprogenitor cell line ATDC5 (n = 4 independent experiments) using western-blot, cell fractionation and confocal microscopy. RESULTS: Deletion of ShcA decreases the hypertrophic zone of the growth plate (median between group difference -11.37% [95% confidence interval -17.34 to -8.654]), alters the endochondral ossification process, and leads to dwarfism (3 months old male mice nose-to-anus length -1.48 cm [-1.860 to -1.190]). ShcA promotes ERK1/2 activation, nuclear translocation of RunX2, the master transcription factor for chondrocyte hypertrophy, while maintaining the Runx2 inhibitor, YAP1, in its cytosolic inactive form. This leads to hypertrophic commitment and expression of markers of hypertrophy, such as Collagen X. In addition, loss of ShcA protects from age-related osteoarthritis development in mice (2 years old mice OARSI score -6.67 [-14.25 to -4.000]). CONCLUSION: This study reveals ShcA as a new player in the control of chondrocyte hypertrophic differentiation and its deletion slows down osteoarthritis development.

Anti-Donor HLA Antibody Response After Pancreatic Islet Grafting: Characteristics, Risk Factors, and Impact on Graft Function.

Pancreatic islet grafting restores endogenous insulin production in type 1 diabetic patients, but long-term outcomes remain disappointing as a result of immunological destruction of allogeneic islets. In solid organ transplantation, donor-specific anti-HLA antibodies (DSA) are the first cause of organ failure. This retrospective multicentric study aimed at providing in-depth characterization of DSA response after pancreatic islet grafting, identifying the risk factor for DSA generation and determining the impact of DSA on graft function. Forty-two pancreatic islet graft recipients from the Groupe Rhin-Rhône-Alpes-Genève pour la Greffe d'Ilots de Langerhans consortium were enrolled. Pre- and postgrafting sera were screened for the presence of DSA and their ability to activate complement. Prevalence of DSA was 25% at 3 years postgrafting. The risk of sensitization increased steeply after immunosuppressive drug withdrawal. DSA repertoire diversity correlated with the number of HLA and eplet mismatches. DSA titer was significantly lower from that observed in solid organ transplantation. No detected DSA bound the complement fraction C3d. Finally, in contrast with solid organ transplantation, DSA did not seem to negatively affect pancreatic islet graft survival. This might be due to the low DSA titers, specific features of IgG limiting their ability to activate the complement and/or the lack of allogenic endothelial targets in pancreatic islet grafts.

Sintomas respiratórios e testes espirográficos dos funcionários de uma pedreira do Rio de Janeiro / Respiratory symptoms and spirometric tests of the quarry workers Rio de Janeiro

Foram investigados os sintomas e antecedentes respiratórios, bem como os resultados das provas espirográficas, de 72 dos 86 (83,7 por cento) funcionários de uma pedreira de porte médio do Rio de Janeiro. Setenta e um (98,6 por cento) eram homens, e a média das idades foi de 36,2 + ou - 9,3 anos (20 a 65 anos). Quarenta e dois (58,3 por cento) tinham ocupaçöes consideradas muito expostas ao pó de pedra e 30 (44,7 por cento) pouco expostas. Quarenta (55,6 por cento) eram fumantes, 20 (27,8 por cento) näo fumantes e 12 (16,7 por cento) ex-fumantes. Foi utilizado um questionário padronizado baseado em modelos internacionais e adaptados a condiçöes brasileiras. Houve elevada freqüência de sintomas, com exceçäo da dispnéia: 47 (65,3 por cento) referiram um ou mais sintomas, dos quais 31,9 por cento referiram tosse, 41,7 por cento expectoraçäo, 9,7 por cento dispnéia e 33,3 por cento chiado torácico. Os sintomas se associaram principalmente à presença de antecedentes de doenças respiratórias, havendo também associaçäo com o tabagismo. Um ou outro desses fatores explicaram os sintomas. Näo houve associaçäo com a maior exposiçäo ao pó de pedra, qua näo explicou os sintomas. As provas espirográficas foram realizadas com o espirógrafo de campânula de 6 litros, observando-se discreta reduçäo das médias da capacidade vital forçada (CVF) (89,9 + ou - 11,2 por cento do teórico), do volume de expiraçäo forçada do 1§ segundo (VEF1) (90,1 + ou - 12,9 por cento) e do fluxo expiratório forçado entre 25 por cento e 75 por cento da CVF (FEF 25-75) (92,9 + ou - 32,7 por cento) em relaçäo às médias esperadas numa amostra populacional näo selecionada. Contudo, as proporçöes de valores subnormais foram comparáveis às de amostras näo selecionadas da literatura nacional e internacional. Näo houve influência estatisticamente significativa da maior exposiçäo ao pó de pedra, antecedentes respiratórios e tabagismo sobre as médias dos resultados espirográficos. Concluímos que, neste grupo de funcionários de uma pedreira, näo se demonstrou associaçäo entre a maior exposiçäo ao pó de pedra e os sintomas respiratórios, ou influência dessa exposiçäo sobre as médias dos resultados espirográficos. Com relaçäo aos antecedentes respiratórios e tabagismo, houve associaçäo com os sintomas mas näo influência sobre as médias dos resultados espirográficos.

[Respiratory symptoms and spirometric tests of quarry workers in Rio de Janeiro]. / Sintomas respiratórios e testes espirográficos dos funcionários de uma pedreira do Rio de Janeiro.

Respiratory symptoms and past history of chest disease as well as spirometric tests were investigated in 72 of 86 (83.7%) employees of a middle sized quarry in Rio de Janeiro, Brazil. Seventy one were men (98.6%), and the mean age was 36.2 +/- 9.3 years (20-65). Forty two (58.3%) had occupations considered as highly exposed to dust, and 30 (44.7%) were considered as lightly exposed. Forty (55.6%) were smokers, 20 (27.8%) never had been smokers and 12 (16.7%) were former smokers. Symptoms and past history were investigated with a questionnaire based on international models, and adapted for the Brazilian public. A high prevalence of symptoms (except for dyspnea) was noted: 47 (65.3%) had one or more symptoms-there was cough in 31.9%, expectoration in 41.7% dyspnea in 9.7% and wheezing in 33.3%. The symptoms were found to be associated mostly with a past history of chest disease, and also with smoking, factors which explained, in part, the presence of the symptoms. No association with a higher exposure to dust was found. The exposure to dust did not explain the symptoms. The spirometric tests were performed on a 6 liter bell spirometer. The means of the parameters were lower than one would expect in a non selected population sample--89.9 +/- 11.2% of predicted for the Forced Vital Capacity (FVC), 90.1 +/- 12.9% for the Forced Expiratory Volume in 1 second (FEV1) and 92.9 +/- 32.7% for the Forced Expiratory Flow between 25% and 75% of the FVC (FEF25-75). However, the proportions of abnormal results were comparable to the reported ones from unselected samples. There was no statistically significant influence of higher dust exposure, past history or smoking on the means of the results. It is concluded that, in this sample of quarry employees, no association between respiratory symptoms or spirometric results and dust exposure could be demonstrated. There was an association between the symptoms, but not with the spirometric results, and a past history of chest disease, as well as with smoking.

Pulmonary function changes in the acute stage of histoplasmosis, with follow-up. An analysis of eight cases.

We have studied eight patients, six children and two adults, during a microepidemic of soil- and patient-proven histoplasmosis. Pulmonary function tests were performed between the 15th and 23rd days after the onset of symptoms, and repeated between the fifth and sixth, the ninth and tenth and the 15th and 22nd months afterward. Initial abnormalities were mild in seven cases and severe in one. There was a restrictive pattern in three cases and an obstructive pattern in two. The fraction of CO extraction was reduced in five cases and the diffusing capacity for CO was reduced in five of six cases so tested. Hypoxemia was present in three cases. On follow-up, the obstructive defect had disappeared by the sixth month, the restrictive pattern by the tenth month, and the diffusing defect still remained in three cases by the end of follow-up. Hypoxemia remained only in the severe case.

Pulmonary function in paracoccidioidomycosis (South American blastomycosis). An analysis of the obstructive defect.

Comparison of the mean results of routine pulmonary function studies of 17 patients with diffuse pulmonary paracoccidioidomycosis (PM) and manifestations of chronic obstructive pulmonary disease (COPD) to those of 17 matched patients with pure COPD showed no significant differences. These findings were interpreted as fresh evidence suggesting that expiratory obstruction in PM may be secondary to underlying COPD. Other evidence to that effect is discussed.

Pulmonary localization of paracoccidioidomycosis: lung function studies before and after treatment.

Vinte doentes com lesoes pulmonares, difusas causadas pelo Paracoccidioides brasiliensis foram submetidos a provas de funcao pulmonar basicas antes e depois do inicio de tratamento especifico. Apos 1 ou 2 meses de tratamento, a capacidade vital ou a capacidade vital forcada haviam aumentado em mais de 10% em 7 de 19 doentes (36,8%), e a diferenca para o grupo todo foi significativa (P < 0,05). Apos 4 a 10 meses, 5 de 6 doentes apresentaram aumentos superiores a 10% nesse parametro. A evolucao do volume expiratorio forcado em 1 segundo, ou de sua relacao com a capacidade vital, e a da pressao parcial do oxigenio no sangue foi variavel. Estes resultados evidenciam que as provas de funcao pulmonar nao representam meio adequado para o controle do tratamento dessa condicao morbita. Por outro lado, sugerem que os infiltrados pulmonares causados pelo P.brasiliensis tem pouca influencia sobre o componente obstrutivo, que e frequentemente o principal elemento do disturbio funcional na forma pulmonar difusa da paracoccidioidose, mas parece ser causado pela doenca pulmonar obstrutiva cronica frequentemente subjacente

Quadro espirografico na fase assintomatica da asma bronquica. / Spirometric study in asymptomatic period of bronchial asthma

O estudo espirografico de 67 asmaticos totalmente assintomaticos e com o exame fisico normal, atendidos consecutivamente e sem carater de selecao, a nao ser exclusao de doencas concomitantes, mostrou que a obstrucao persistia em 76,1%. Dos l3 com espirograma normal, 9 revelaram resposta significativa apos broncodilatacao. Reforca-se, assim, a impressao de que ha na asma um exame do tonus broncomotor independente de fatores desencadeantes. Em 49,2% a obstrucao esteve presente ao longo de toda a expiracao e em apenas 26,8% so na parte final. A reducao da capacidade vital ocorreu em apenas 11,9%, sempre aliada a obstrucao. A prova broncodialtadora revelou melhora da obstrucao em 68,6% dos casos, e, no grupo todo, o aumento foi significativo em todos os parametros estudados (p < 0,05). No nivel de significancia de 5%, nao houve diferenca entre asmaticos nao-fumantes e asmaticos fumantes ou exfumantes, quer nos resultados pre-broncodilatacao, quer na resposta broncodilatadora, a excecao unica da capacidade vital forcada, em que houve aumento significativamente maior entre fumantes e ex-fumantes (p < 0,05)

The defect in pulmonary gas transfer in patients with sickle cell disease.

Nine patients with sickle cell disease and without concomitant cardiopulmonary illness or acute problems were studied with lung function tests. Besides arterial hemoglobin unsaturation, found in all cases so studied, a slight decrease in PaO2 was also present. The pulmonary gas transfer defect was studied and found to be due mostly to increased right to left shunting, although uneven ventilation/perfusion relationships seem to have been a factor in a few cases. Our data clearly show that the diffusion was not implicated in the gas transfer defect. The clinical implications of this little studied and less mentioned respiratory defect are discussed. Since the defect may enhance the risk of sickling crises, it should be measured in each individual patient, for appropriate prophylactic measures. After accidents, pre and post-operatively and during acute respiratory illness, the defect should be again reevaluated. In all probability many patients will be discovered who represent a respiratory risk, and may require special immunizations, prophylactic antibiotics, professional relocation and, during emergencies, intensive respiratory care.

Cardiopulmonary disease in Manson's schistosomiasis.

Five patients with cardiopulmonary manifestations of Manson's schistosomiasis are described. Two patients had pulmonary hypertension, two had cyanosis and one had the very rare combination of both. The results of routine pulmonary function tests--not sufficiently studied in this form of schistosomiasis--are discussed in detail. Aside from a tendency to hyperventilate, found in all cases, the only significant abnormality encountered was hypoxemia due to increased right-to-left shunt in the cyanotic patients. Although more studies are needed, the results suggest that the pulmonary lesions are mainly vascular in nature. The pathogenesis of cyanosis in this disease is briefly discussed.