O método em Marx: a determinação ontológica da realidade social / The method in Marx: the ontological determination of social reality

Resumo: O objetivo deste estudo foi discutir o método materialista histórico dialético, apontando elementos essenciais presentes no percurso metodológico. O método em Marx é um movimento dialético que parte da sua concepção ontológica da realidade social, em que o ser social produz suas próprias condições objetivas e subjetivas de existência e, por isso, teoria, método e concreto social constituem uma unidade metodológica.

Abstract: The objective of this study was to discuss the dialectical historical materialist method, pointing out essential elements present in the methodological course. The method in Marx is a dialectical movement that starts from its ontological conception of social reality, in which the social being produces its own objective and subjective conditions of existence and, therefore, theory, method and social concrete constitute a methodological unit.

¿Cómo afrontar un paciente con dependencia a benzodiacepinas en atención primaria? Estrategias para la deshabituación / How to face a patient with benzodiazepine dependence in primary health care? Strategies for withdrawal

Las benzodiacepinas son fármacos ampliamente utilizados en atención primaria de salud. Su uso prolongado se ha convertido en un problema relevante dadas las consecuencias médicas que ocasionan, especialmente en adultos mayores. Entre otras, estas son: dependencia, deterioro cognitivo y riesgo de caídas. Además, los médicos que trabajan en atención primaria cuentan con pocas herramientas para ayudar al paciente en su deshabituación. Se realizó una búsqueda y revisión de la mejor evidencia disponible sobre estrategias prácticas para el médico no especialista en adicciones, para evitar la dependencia al momento de la prescripción inicial y en el paciente con uso prolongado y probablemente dependiente. Se encontraron 10 revisiones sistemáticas relevantes que mostraron evidencia a favor del uso de estrategias multifacéticas en la prescripción, disminución progresiva, cartas y consejería estandarizadas, farmacoterapia y psicoterapia cognitiva conductual. Una estrategia sencilla, eficaz y duradera para prescribir benzodiacepinas es informar al paciente de la necesidad de reducir su consumo, dándole por escrito la pauta de retirada, señalando sus posibles efectos y su solución. Debido a la evidencia disponible, se propone un modelo integrado y escalonado para el manejo del paciente usuario de benzodiacepinas, desde su prescripción hasta su descontinuación.

Benzodiazepines are widely used in primary health care, and their prolonged use is an important problem given the medical consequences particularly in older adults, such as dependence, cognitive impairment, and risk of falls, among others. Primary care doctors generally have few tools to help with managing withdrawal from benzodiazepines. We conducted a review of the best available evidence on practical strategies to avoid dependence at the time of the initial prescription, and to help the patient with prolonged and probably dependent use. We found ten relevant systematic reviews showing evidence in favor of the use of multifaceted prescription strategies, gradual dose reduction, standardized letters, standardized counseling, pharmacotherapy and cognitive behavioral psychotherapy. For benzodiazepine withdrawal, a simple strategy that can be effective and long-lasting is to inform patients of the need to reduce consumption, giving them in writing the withdrawal guideline, indicating the possible effects of withdrawal and its solution. Given the available evidence, an integrated and step-by-step model is proposed for the management of the benzodiazepine user, from prescription to withdrawal.

¿Es la mitomicina C superior al 5-fluorouracilo como antimetabolito en la trabeculectomía para el glaucoma? / Is mytomicyn better than 5-fluorouracil as antimetabolite in trabeculectomy for glaucoma?

INTRODUCCIÓN: La trabeculectomía es considerada la intervención de elección en pacientes con glaucoma con indicación de manejo quirúrgico. Dentro de los factores asociados al fracaso de este tratamiento se encuentra la cicatrización postoperatoria. Para disminuir este factor se han usado distintos antimetabolitos, en particular el 5-fluorouracilo y la mitomicina C. Si bien ambos se consideran efectivos, no está claro si existen diferencias entre ambos en relación al éxito de la trabeculectomía y los efectos adversos. MÉTODOS: Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis, preparamos tablas de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cuatro revisiones sistemáticas que en conjunto incluyen 17 estudios primarios, de los cuales, 12 corresponden a ensayos aleatorizados. Concluimos que el uso de mitomicina C podría lograr una mayor disminución de la presión intraocular e incrementar la tasa de éxito calificado en comparación con el 5-fluorouracilo. Sin embargo, su uso podría asociarse a una mayor incidencia de complicaciones.

INTRODUCTION: Trabeculectomy is considered the standard for glaucoma surgery. Postoperative scarring is one the factors associated with surgery failure. Different antimetabolites have been used in order to reduce this risk, particularly 5-fluorouracil and mitomycin C. Although both are considered effective, it is not clear if they are different in terms of success of trabeculectomy and adverse effects. METHODS: To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified four systematic reviews including 17 studies overall, of which 12 were randomized trials. We concluded mitomycin C might be more effective in reducing intraocular pressure and increasing qualified success compared to 5-fluorouracil. However, its use might be associated to a higher risk of complications.

¿Es la válvula Ahmed superior al implante Baerveldt como derivación acuosa para el manejo del glaucoma? / Is Ahmed valve superior to Baerveldt implant as an aqueous shunt for the treatment of glaucoma?

Resumen INTRODUCCIÓN: La derivación acuosa ha surgido como una técnica alternativa a la trabeculectomía, considerada la cirugía de elección en pacientes con glaucoma. Actualmente, se considera que la principal indicación de esta técnica es ante el fracaso de la trabeculectomía o en tipos de glaucoma que tienen alto riesgo de fracasar. La válvula Ahmed y el implante Baerveldt son las derivaciones acuosas más utilizadas. Sin embargo, no está claro cuáles son las diferencias entre estas dos alternativas. MÉTODOS: Para responder esta pregunta utilizamos Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud a nivel mundial, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, reanalizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cinco revisiones sistemáticas que en conjunto incluyeron 10 estudios primarios, de los cuales dos son ensayos aleatorizados. Concluimos que la válvula Ahmed probablemente logra una menor disminución de la presión intraocular; podría lograr un menor éxito calificado y probablemente necesita más reintervenciones que el implante Baerveldt. Respecto al perfil de seguridad, la válvula Ahmed no se presenta claramente superior ni inferior al implante Baerveldt.

Abstract INTRODUCTION: Aqueous shunt has emerged as an alternative technique to trabeculectomy, considered the standard for glaucoma surgery. Currently, it is mainly indicated after failure of trabeculectomy or in glaucoma with high risk of failure. The Ahmed valve and the Baerveldt implant are the most commonly used aqueous shunts. However, it is not clear whether there are differences between them. METHODS.: o answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified five systematic reviews including 10 studies overall, of which two were randomized trials. We concluded the Ahmed valve probably achieves a lower decrease in intraocular pressure, might lead to less qualified success and probably needs more reinterventions than the Baerveldt implant. Regarding safety profile, the Ahmed valve is not clearly superior or inferior to the Baerveldt implant.

Derivación acuosa versus trabeculectomía para el manejo del glaucoma / Aqueous shunt versus trabeculectomy for treatment of glaucoma

INTRODUCCIÓN: La derivación acuosa ha surgido como una técnica alternativa a la trabeculectomía, la cual se considera el tratamiento estándar para cirugía de glaucoma. Actualmente, su principal indicación es en el glaucoma con trabeculectomía fallida o en algunos tipos de glaucoma con alto riesgo de fracaso. Sin embargo, aún existe controversia con respecto a su efectividad en comparación con la trabeculectomía. MÉTODOS: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. RESULTADOS Y CONCLUSIONES: Identificamos cinco revisiones sistemáticas que en conjunto incluyeron nueve estudios primarios, de los cuales, cuatro corresponden a ensayos aleatorizados. Concluimos que la derivación acuosa podría aumentar el éxito calificado en comparación con la trabeculectomía, pero que no está claro si tiene algún efecto sobre el resto de los desenlaces críticos para la toma de decisión, porque la certeza de la evidencia es muy baja.

INTRODUCTION: Aqueous shunt has emerged as an alternative technique to trabeculectomy, which is considered the standard treatment for glaucoma surgery. Currently, it is mainly indicated after failure of trabeculectomy or in some types of glaucoma with high risk of failure. However, there is still controversy regarding its effectiveness compared to trabeculectomy. METHODS: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified five systematic reviews including nine studies overall, of which four were randomized trials. We concluded that aqueous shunt might increase the qualified success compared to trabeculectomy, but it is not clear whether it has any effect on the rest of the critical outcomes for decision-making because the certainty of the evidence is very low.

Reproducibility of heart rate variability parameters measured in healthy subjects at rest and after a postural change maneuver

Heart rate variability (HRV) provides important information about cardiac autonomic modulation. Since it is a noninvasive and inexpensive method, HRV has been used to evaluate several parameters of cardiovascular health. However, the internal reproducibility of this method has been challenged in some studies. Our aim was to determine the intra-individual reproducibility of HRV parameters in short-term recordings obtained in supine and orthostatic positions. Electrocardiographic (ECG) recordings were obtained from 30 healthy subjects (20-49 years, 14 men) using a digital apparatus (sampling ratio = 250 Hz). ECG was recorded for 10 min in the supine position and for 10 min in the orthostatic position. The procedure was repeated 2-3 h later. Time and frequency domain analyses were performed. Frequency domain included low (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.4 Hz) bands. Power spectral analysis was performed by the autoregressive method and model order was set at 16. Intra-subject agreement was assessed by linear regression analysis, test of difference in variances and limits of agreement. Most HRV measures (pNN50, RMSSD, LF, HF, and LF/HF ratio) were reproducible independent of body position. Better correlation indexes (r > 0.6) were obtained in the orthostatic position. Bland-Altman plots revealed that most values were inside the agreement limits, indicating concordance between measures. Only SDNN and NNv in the supine position were not reproducible. Our results showed reproducibility of HRV parameters when recorded in the same individual with a short time between two exams. The increased sympathetic activity occurring in the orthostatic position probably facilitates reproducibility of the HRV indexes.

Effects of chronic treadmill training on body mass gain and visceral fat accumulation in overfed rats

This study evaluated the effects of chronic treadmill training on body mass gain and visceral fat accumulation in overfed rats. Overfeeding was induced by reducing the litter size to 3 male pups per mother during the suckling period. The litter size of control rats was adjusted to 10 male pups per mother. Seven weeks after birth overfed and normally fed rats were selected and assigned to a sedentary protocol or to a low-intensity treadmill training protocol (60 min, 5 times/week, for 9 weeks). Four groups (overfed sedentary, N = 23; normally fed sedentary, N = 32; overfed exercised, N = 18, and normally fed exercised, N = 18) were evaluated at 18 weeks. Data are reported as means ± SEM. Initial body weight was similar in control and overfed rats [8.0 ± 0.2 g (N = 42) vs 8.0 ± 0.1 g (N = 50); P > 0.05] and body weight gain during the suckling period was higher in the overfed rats (30.6 ± 0.9 vs 23.1 ± 0.3 g; P < 0.05). Exercise attenuated the body weight gain of overfed compared to sedentary rats (505 ± 14 vs 537 ± 12 g; P < 0.05). The sedentary overfed rats showed higher visceral fat weight compared to normally fed animals (31.22 ± 2.08 vs 21.94 ± 1.76 g; P < 0.05). Exercise reduced visceral fat by 36.5 percent in normally fed rats and by 35.7 percent in overfed rats. Exercise attenuated obesity in overfed rats and induced an important reduction of visceral fat.

Kinetics of cardiac and vascular remodeling by spontaneously hypertensive rats after discontinuation of long-term captopril treatment

Angiotensin-converting enzyme inhibitors reduce blood pressure and attenuate cardiac and vascular remodeling in hypertension. However, the kinetics of remodeling after discontinuation of the long-term use of these drugs are unknown. Our objective was to investigate the temporal changes occurring in blood pressure and vascular structure of spontaneously hypertensive rats (SHR). Captopril treatment was started in the pre-hypertensive state. Rats (4 weeks) were assigned to three groups: SHR-Cap (N = 51) treated with captopril (1 g/L) in drinking water from the 4th to the 14th week; SHR-C (N = 48) untreated SHR; Wistar (N = 47) control rats. Subgroups of animals were studied at 2, 4, and 8 weeks after discontinuation of captopril. Direct blood pressure was recorded in freely moving animals after femoral artery catheterism. The animals were then killed to determine left ventricular hypertrophy (LVH) and the aorta fixed at the same pressure measured in vivo. Captopril prevented hypertension (105 ± 3 vs 136 ± 5 mmHg), LVH (2.17 ± 0.05 vs 2.97 ± 0.14 mg/g body weight) and the increase in cross-sectional area to luminal area ratio of the aorta (0.21 ± 0.01 vs 0.26 ± 0.02 ìm²) (SHR-Cap vs SHR-C). However, these parameters increased progressively after discontinuation of captopril (22nd week: 141 ± 2 mmHg, 2.50 ± 0.06 mg/g, 0.27 ± 0.02 ìm²). Prevention of the development of hypertension in SHR by using captopril during the prehypertensive period prevents the development of cardiac and vascular remodeling. Recovery of these processes follows the kinetic of hypertension development after discontinuation of captopril.

Glycosaminoglycan loss from cartilage after anterior cruciate ligament rupture: influence of time since rupture and chondral injury

OBJECTIVE: To quantify the concentration of sulfated glycosaminoglycans (GAGs) concentration in the synovial fluid (SF) of knees with chronic anterior cruciate ligament (ACL) rupture and to identify possible associations between GAG concentration in SF and the time elapsed since rupture and degree of chondral injury. METHOD: Fourteen adult male subjects with total unilateral ACL rupture, which had occurred between 5 and 144 months earlier, were assessed. All subjects underwent joint aspiration; it was possible to collect SF from ten individuals. The samples were quantified to determine the GAG concentration using dimethylmethylene blue (DMMB) staining. The degree of chondral injury was macroscopically evaluated using the modified Mankin histological scale. Spearman correlation test (< 0.05) was used to evaluate the association between GAG concentration and chondral injury, and Pearson correlation test (< 0.05) was used to evaluate the association between GAG concentration and the time elapsed since rupture. RESULTS: The GAG concentration in SF showed a mean variation of 73.84 ± 40.75 µg/ml, with a mean time of 40.4 ± 40.3 months since the rupture. There was no correlation between GAG concentration and time since the rupture (r= -0.09, p= 0.81). The chondral injury grades found were 0, 1, 4 and 5. There was no correlation between chondral injury grade and GAG concentration in SF (r= -0.41, p= 0.24). CONCLUSION: After at least 5 months, the GAG concentration in SF from knees with ACL rupture is independent of the time elapsed since rupture and/or the severity of chondral injury.

OBJETIVO: Quantificar a concentração de glicosaminoglicanas sulfatadas (GAGs) no líquido sinovial (LS) de joelhos com ruptura crônica do ligamento cruzado anterior (LCA) e identificar uma possível correlação entre a concentração de GAGs no LS e o tempo pós-ruptura e grau de lesão condral. MÉTODOS: Foram avaliados 14 indivíduos adultos do sexo masculino com ruptura total unilateral do LCA, ocorrida entre cinco a 144 meses. Todos os sujeitos foram puncionados, sendo possível a coleta de LS em dez indivíduos. As amostras foram quantificadas para determinar a concentração de GAGs usando a coloração azul de dimetilmetileno, método descrito por Farndale21. O grau de lesão condral foi macroscopicamente avaliado pela escala histológica de Mankin modificada por Messner14. As correlações entre concentração de GAGs e lesão condral foram feitas pelo teste de correlação de Sperman (p< 0,05) e a concentração de GAGs e tempo pós-ruptura pelo teste de correlação de Pearson (p< 0,05). RESULTADOS: Concentração de GAGs no LS apresentou variação média de 73,84 ± 40,75µg/mL, sendo o tempo médio pós-ruptura de 40,4 + 40,3 meses. Não houve correlação entre concentração de GAGs e o tempo pós-ruptura (r= -0,09, p= 0,81). Os graus de lesão condral encontrados foram de 0, 1, 4 e 5. Não houve correlação entre grau de lesão condral e a concentração de GAGs no LS (r= -0,41, p= 0,24). CONCLUSÕES: Após no mínimo cinco meses, a concentração de GAGs no LS de joelhos com ruptura do LCA independe do tempo pós-ruptura e/ou do grau de lesão condral.

Eye pigments of the blood-sucking insect, Triatoma infestans klug (Hemiptera, Reduviidae)

A pigmentação de olhos pretos (forma selvagem) e vermelhos (forma mutante) de Triatoma infestans foi estudada por espectrofotometria e comparada à de olhos vermelhos (selvagem) e brancos (mutante) de Drosophila melanogaster. Os perfis do espectro de absorção dos pigmentos de olho preto e vermelho de T. infestans foram semelhantes entre si e ao dos olhos de tipo selvagem de D. melanogaster. A similaridade com a forma selvagem de D. melanogaster indicou que ambos os tipos de olho de T. infestans continham omocromos do tipo xantomatina, o que foi confirmado por cromatografia ascendente em papel. Não foram detectadas pteridinas, melaninas e ominas como pigmentos de olho em T. infestans. A diferença na cor de olho em T. infestans foi considerada uma função da concentração de xantomatina, sendo menor o conteúdo de omocromo nos olhos vermelhos, embora isso provavelmente não afete a acuidade visual do inseto. Esses resultados estão de acordo com dados de outros autores quanto a semelhanças envolvendo outras características entre espécimes de olho preto e vermelho de T. infestans.

Distribution of small proteoglycans and glycosaminoglycans in humerus-related articular cartilage of chickens

The expression of components present in the cartilaginous extracellular matrix is related to development, gender, and genotype, as well as to the biomechanical properties of each type of cartilage. In the present study, we analyzed small proteoglycans and glycosaminoglycans present in different cartilages of the chicken wing after extraction with guanidine hydrochloride or papain. Quantitative analysis of glycosaminoglycans showed a larger amount in humeral cartilage (around 200 mg/g tissue) than in articular cartilage of the radius and ulna, with 138 and 80 mg/g tissue, respectively. Non-collagenous proteins isolated were predominantly from cartilage in the proximal regions of the humerus and radius. D4 fractions obtained by ultracentrifugation were separated by DEAE-Sephacel and Octyl-Sepharose chromatography and analyzed by SDS-PAGE. Two bands of 57 and 70-90 kDa were observed for all samples treated with ß-mercaptoethanol. Immunoblotting of these proteins was positive for the small proteoglycans fibromodulin and decorin, respectively. Apparently, the 57-kDa protein is present in macromolecular complexes of 160 and 200 kDa. Chondroitin sulfate was detected in all regions. HPLC analysis of the products formed by chondroitinase AC and ABC digestion mainly revealed ß-D-glucuronic acid and N-acetyl ß-D-galactosamine residues. The 4-sulfation/6-sulfation ratio was close to 3, except for the proximal cartilage of the radius (2.5). These results suggest functional differences between the scapula-humerus, humerus-ulna, and humerus-radius joints of the chicken wing. This study contributes to the understanding of the physiology of cartilage and joints of birds under different types of mechanical stress.

Estudo anatomotopográfico das vias biliares extrahepáticas e do trígono cistohepático / Anatomotopographic study of the extrahepatic biliary system and the cystichepatic trigonum

OBJETIVO: Estudar a morfologia do sistema biliar extra-hepático e do trígono cistohepático (triângulo de Calot) analisando a sua disposiçäo, variaçöes ou malformaçöes MÉTODOS: foram investigados 50 cadáveres adultos. RESULTADOS: em 47 casos (94 por cento) a junçäo hepato-cística se dava próxima ao hilo hepático. Em 3 casos (6 por cento), a junçäo entre esses ductos se dava distalmente, ao nível da ampola hepato-pancreática (ampola de Vater). O ângulo formado pela junçäo hepato-cística foi menor que 30 graus em 72,3 por cento dos casos; em 23,4 por cento , ficou entre 30 e 45 graus; em 2,1 por cento variou entre 45 e 60 graus e em 2,1 por cento foi maior do que 60 graus. A junçäo hepato-cística se fez, na maior parte dos casos, pela direita (59,6 por cento), seguida pela anterior (17 por cento), posterior (12,8 por cento) e esquerda (10,6 por cento). Em relaçäo aos componentes do trígono cistohepático, a artéria cística esteve presente em 56 por cento dos casos; a veia porta em 36 por cento; a artéria hepática direita em 34 por cento; a artéria hepática esquerda em 2 por cento e a artéria hepática própria em 2 por cento dos casos. O comprimento e o diâmetro do ducto cístico foi 2,53ñ 1,19cm e 0,29ñ 0,12cm, respectivamente. A prega espiral do ducto cístico ( válvula de Heister) foi observada em 80 por cento dos casos. O infundíbulo da vesícula biliar (bolsa de Hartmann) esteve presente em 74 por cento dos casos. Esses conhecimentos säo importantes, principalmente para os cirurgiöes que atuam nesta regiäo, através de videolaparoscopia. CONCLUSAO: No trígono cistohepático a artéria cística foi encontrada com mais freqüência.

Is there a relationship between the state of aggregation os small proteoglycans and the biomechanical properties of tissues?

The small proteoglycans fibromodulin and decorin may play an important role in regulating collagen fibrillogenesis and interactions with growth factors. Here, we describe the presence of these proteoglycans in cartilage submitted to different biomechanical forces. Fibromodulin from chicken and bovine articular cartilage was shown to self-associate. The different states of fibromodulin aggregation due to disulfide bonding demonstrable in different regions of the same joint suggest that the presence of different biomechanical forces results in the differential expression of small proteoglycans. A 250-kDa complex found in chicken tibiotarsal cartilage, which migrates as a 59-kDa component in SDS-PAGE under reducing conditions, and which was recognized by anti-fibromodulin antibodies, was not demonstrable in tarsometatarsal cartilage where a different fibromodulin complex has been recently demonstrated. Biglycan and decorin were not expressed in the same way in different regions of the bovine knee joint, suggesting that there is a relationship between the expression of small proteoglycans and the different biomechanical properties of a tissue.

Detection of a small proteoglycan present in xiphoid cartilage regions submitted to different biomechanical forces

1. The effect of biomechanical forces on larges proteglycans and collagen of cartilage has deserved intensive study, enhacing the importance of these molecules to support a better distribution of compressive forces especially in articular cartilage. In the present study, other extracellular matrix components, non-collagenous proteins and small proteglycans, have been evaluated in terms of biomechanical tension. 2. Different parts of chicken xiphoid cartilage, lateral (R and L) and central (C) portions, which bear different biomechanical tensions, were analyzed. DEAE-cellulose chromatography profiles were similar for R and L portions. SDS-PAGE analyses revealed proteins of 29, 60 and 70 KDa for R and L. The 20-and 70-KDa proteins were not detected in the C portion while the 60-KDaprotein was presented at a high level. 3. The differences found between lateral (R and L) and central portions of the xiphoid cartilage may be related to the struycture of the cartilage which bears higher tension forces than the lateral parts