Surface activity, lipid profiles and their implications in cervical cancer.

BACKGROUND: The profiles of lipids in normal and cancerous tissues may differ revealing information about cancer development and progression. Lipids being surface active, changes in lipid profiles can manifest as altered surface activity profiles. Langmuir monolayers offer a convenient model for evaluating surface activity of biological membranes. AIMS: The aims of this study were to quantify phospholipids and their effects on surface activity of normal and cancerous human cervical tissues as well as to evaluate the role of phosphatidylcholine (PC) and sphingomyelin (SM) in cervical cancer using Langmuir monolayers. METHODS AND MATERIALS: Lipid quantification was done using thin layer chromatography and phosphorus assay. Surface activity was evaluated using Langmuir monolayers. Monolayers were formed on the surface of deionized water by spreading tissue organic phase corresponding to 1 mg of tissue and studying their surface pressure-area isotherms at body temperature. The PC and SM contents of cancerous human cervical tissues were higher than those of the normal human cervical tissues. Role of PC and SM were evaluated by adding varying amounts of these lipids to normal cervical pooled organic phase. Statistical analysis: Student's t-test (p < 0.05) and one-way analysis of variance (ANOVA) was used. RESULTS: Our results reveals that the phosphatidylglycerol level in cancerous cervical tissue was nearly five folds higher than that in normal cervical tissue. Also PC and sphingomyelin SM were found to be the major phospholipid components in cancerous and normal cervical tissues respectively. The addition of either 1.5 microg DPPC or 0.5 microg SM /mg of tissue to the normal organic phase changed its surface activity profile to that of the cancerous tissues. Statistically significant surface activity parameters showed that PC and SM have remarkable roles in shifting the normal cervical lipophilic surface activity towards that of cancerous lipophilic component. CONCLUSION: The Langmuir monolayer technique was sensitive to detect changes in tensiometric profiles of cervical cancers and these could be modulated by alterations in phosphatidylcholine and sphingomyelin levels. Therapeutic strategies may be designed to modulate these tensiometric profiles and lipid constituents of cancerous tissues.

Lues maligna in an HIV-infected patient

Descrevemos um caso de sífilis maligna em um paciente de 42 anos com infecção pelo HIV e pelo vírus da hepatite B. O paciente, com lesões cutâneas clássicas de lues maligna e VDRL positivo no soro e no líquor, teve uma resposta excelente ao tratamento com penicilina cristalina. O VDRL sérico, que no diagnóstico era de 1:64, aumentou três meses depois para 1:2.048 e diminuiu para 1:8 após 15 meses.

Column chromatographic fractionation of soybean phospholipid and chemical analysis of isolated phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid and cerebroside

Phospholipid mixtures were isolated from crude soybean oil and laboratory prepared soy lecithin were fractionated on two silicic acid columns with subsequent thin layer chromatography identification of isolated fractions. The percentages of the isolated four eluted fractions from each of the two columns were calculated. Phosphatidylcholine, phosphatidylethanolamine phosphatidylinositol, phosphatidic acid and cerebroside were isolated. Fatty acid composition and total phosphorus of the isolated phospholipids were determined

Comparison of effects of cholecystokinin and erythromycin on bile chemistry and gallstone formation in aged guinea pigs.

BACKGROUND: There has been considerable interest in gall bladder motility in recent years. We compared the effects of cholecystokinin (CCK) and erythromycin on bile chemistry and gallstone formation in aged guinea pigs. METHODS: Two groups of guinea pigs (1-mo and 3-y old; n=40 each) were studied. Each group was divided into four subgroups of 10 animals each; one subgroup received lithogenic diet, one each received CCK or erythromycin daily in addition to lithogenic diet for 4 weeks, and one received normal diet. After 4 weeks, the presence of gallstones or sludge was recorded and bile composition including concentrations of bile acid, cholesterol, lecithin and protein concentrations was studied. RESULTS: No gallstones were observed in the 1-mo-old animals. In the 3-year-old animals, 9 of 10 guinea pigs on lithogenic diet and 4 of 10 in each treatment subgroup and the normal diet subgroup developed gallstones. CCK and erythromycin had similar effects on bile chemistry and stone formation. CONCLUSIONS: Aging increases the formation of gallstones in guinea pigs. Erythromycin is as effective as CCK in reducing gallstone formation by improving gall bladder motility.

Histamine induced decrease of lecithin levels in broncho-alveolar lavage fluid of rats is mediated by H2 receptor.

Lecithin, a major surface active substance of the surfactant system of the lung, was estimated in broncho-alveolar lavage (BAL) fluid in four groups of healthy adult male albino rats. Rats from group I were not administered any drug and acted as controls. Group II were administered histamine diphosphate. Group III were given H1 blocker (pyrilamine maleate) followed by histamine diphosphate. Group IV received H2 blocker (ranitidine hydrochloride) followed by histamine diphosphate. Lecithin content of BAL fluid in the control group was compared with that in the other three groups. A significant decrease in lecithin content was observed in the rats that received either histamine diphosphate or H1 blocker followed by histamine diphosphate. However, compared to control rats no significant difference in lecithin content was seen in rats that received H2 blocker followed by histamine diphosphate. The results clearly indicate that the decrease in surface active lecithin content in BAL fluid following administration of histamine diphosphate was unaffected by prior administration of H1 blocker, but was blocked by prior administration of H2 blocker. It was concluded that histamine induced decrease in lecithin content of BAL fluid is mediated through H2 receptors. Since the predominant source of intra-alveolar lecithin are Type II cells of the alveolar epithelium, It is possible that Type II cells have H2 receptors, stimulation of which resulted in decreased intraalveolar lecithin.

Lipids shed into the culture medium by trypomastigotes of Trypanosoma cruzi

Trypomastigote forms of Trypanosoma cruzi were metabolically labeled with [14C]-ethanolamine and [3H]-palmitic acid. Lipids shed to the culture medium were analyzed and compared with the parasite components. Phosphatidylcholine and lysophosphatidylcholine accounted for 53 per cent of the total incorporated precursor. Interestingly, phosphatidylethanolamine and its lyso derivative lysophosphatidylethanolamine, although present in significant amounts in the parasites, could not be detected in the shed material. Shed lipids were highly enriched in the desaturated fatty acids C16:1 and C18:1 when compared to the total fatty acid pool isolated from the parasites.

Quantitative determination of phosphatidylcholine by high performance liquid chromatography using silica column

A fosfatidilcolina é um fosfolipídeo muito utilizado na obtençäo de lipossomas, o que requer alto grau de pureza. Neste trabalho, foi desenvolvido um método qualitativo e quantitativo de CLAE para a determinaçäo da lecitina de ovo e de soja. O método envolveu coluna de sílica, fase móvel de n-hexano/n-propanol/água e detecçäo por UV em 206 nm. O método apresentou reprodutibilidade apropriada e permitiu a quantificaçäo rápida e segura da fosfatidilcolina.

Avaliação da maturidade pulmonar fetal em gestaçöes de alto risco / Prenatal diagnosis of fetal lung maturity in high-risk pregnancies

Trata-se de um estudo prospectivo para a avaliaçao da maturidade fetal em 121 gestaçoes de alto risco realizado no Hospital Sao Paulo - Universidade Federal de Sao Paulo, entre janeiro de 1990 e janeiro de 1995. Em todos os casos, o parto foi realizado em até 3 dias após a obtençao de líquido amniótico por amniocentese. O objetivo principal foi o de analisar a acurácia do teste de Clements (TC), da relaçao lecitina/esfingomielina (L/E), da presença de fosfatidilglicerol (PG) e do perfil pulmonar (relaçao L/E>1,7 e PG presente) para antecipar a ocorrência ou nao de síndrome de desconforto respiratório neonatal (SDR). Foram calculados a sensibilidade, a especificidade e os valores preditivos positivo (VPP) e negativo (VPN) de todos os testes. O grupo de estudo foi composto por 48 geraçoes complicadas por diabetes mellitus, 41 por síndromes hipertensivas, 14 por isoimunizaçao Rh e 18 por diversas patologias. O perfil pulmonar apresentou sensibilidade de 100 por cento em todos os casos. O teste de Clements também nao apresentou resultados falso-positivos em gestantes hipertensas apurando-se, contudo, de 20 por cento a 50 por cento de falso-negativos em todos os outros testes. Os quatro testes apresentaram baixos VPP (23 por cento no TC, 51 por cento na relaçao L/E, 63 por cento na presença de PG, 61 por cento no perfil pulmonar) e elevados VPN (92 por cento no TC, 88 por cento na relaçao L/E, 89 por cento na presença de PG, 100 por cento no perfil pulmonar). Este estudo demonstrou que a presença de PG e relaçao L/E>1,7 simultâneos no líquido amniótico comprovam a maturidade pulmonar com muito baixo risco de Dr ao nascimento. Concluiu-se também que o teste de Clements deve constituir o rastreamento inicial para predizer a ausência de SDR, particularmente em gestaçoes complicadas por síndromes hipertensivas.

Cuantificación de lecitina en líquido amniótico mediante el efecto lítico de la lisolecitina / Quantification of lecithin in amniotic fluid by the litic effect of lysolecithin

Se describe un método para determinar lecitina en líquido amniótico, el cual se basa en la acción de la fosfolipasa A2 sobre la lecitina originando lisolecitina, que en presencia de una suspensión de eritrocitos, produce ruptura de la membrana de los mismos. La concentración de lecitina se obtiene espectrofotométricamente a 500 nm, determinando la disminución de absorbancia que se produce entre los 20 y 100 segundos. El método es relativamente sencillo, rápido, económico, preciso, exacto y requiere solamente 100 µL de muestra. El análisis comparativo con un método enzimático mostró un coeficiente de correlación r = 0,943 y una ecuación de regresión lineal y = 0,975x + 0,486. El método presenta coeficientes de variación día a día de 3,5 y 4,7 por ciento para concentraciones de lecitina de 14,0 y 5,3 mg/dL, respectivamente. El intervalo analítico es de 15,0 mg/dL. La sangre, meconio y hemoglobina producen interferencia negativa

Effect of histamine on lecithin content in broncho-alveolar lavage fluid of rat.

Deficiency of surfactant in alveoli leads to increased resistance to breathing. Histamine is a mediator in allergic respiratory diseases. Though the bronchoconstrictor effect of histamine is well recognised, histamine may have additional actions that contribute to pathogenesis in these diseases. The present study aimed to observe the effect of histamine on lecithin, a major component of alveolar surfactant. Lecithin content in broncho-alveolar lavage (BAL) fluid of healthy adult male rats was estimated by enzymatic method using Boehringer-Mannheim kits. Lecithin content in these control animals was compared with that in three groups of healthy adult male rats following subcutaneous administration of 0.06 mg of histamine diphosphate at 10 minutes, 30 minutes and 60 minutes intervals, respectively. A significant reduction in lecithin levels in BAL fluid was observed up to one hour after administration of histamine. The results indicate a possible additional action of histamine in the pathogenesis of allergic respiratory diseases.

The relationship of sonographic placental grading, biochemical pulmonary maturity and neonatal outcome in pregnancy-induced hypertension.

In a prospective study, the accuracy of placental grade in predicting pulmonary maturity was evaluated in 50 cases of pregnancy-induced hypertension (PIH) between 28 and 41 weeks of gestation. Pulmonary maturity was measured by lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol (PG) in amniotic fluid and by clinical development of respiratory distress syndrome (RDS) in the neonates. Fifty normotensive healthy primigravidae, who were matched for age and period of gestation, served as control. No difference (p > 0.05) in the placental grading was observed between normotensive and hypertensive pregnancies. The advancement of placental grade was found to be associated with an increase in L/S ratio and PG level in amniotic fluid. A mature placental grade (grade III) identified by real-time sonography corresponded to foetal lung maturity (L/S > or = 2.0, PG > or = 0.36 mg/dl) and absence of RDS in all cases. Hence, in PIH a grade III placenta appeared to be a reliable predictor of foetal lung maturity in the population examined.

Clinical and histopathological features of secondary syphilis.

Fifty-four patients with secondary syphilis were studied in regard to the clinical manifestations, response to treatment and histopathology of the skin lesions. The correlation between the skin lesions and histopathology, between the duration of skin lesions and VDRL titer, between type of skin lesions and VDRL titer were also determined. The clinical manifestations varied from macular, maculopapular, papular, papulosquamous and urticarial lesions. The hair loss usually occurred on the scalp, but the eyebrows or even total body hair loss could occur. The response to treatment was good, only one patient relapsed. The histopathology was related to the clinical manifestations, there was sparse inflammatory cell infiltration in the dermis in macular lesions, but more dense infiltration as well as more epidermal change in papular and papulosquamous lesions. There were significant correlation between the duration of skin lesions and VDRL titer, but no correlation between types of skin lesions and VDRL titer.

Avaliaçäo da maturidade pulmonar através da análise comparativa do teste de Clements, relaçäo lecitina/esfingomielina e fosfatidilglicerol no líquido amniótico / Evaluation of fetal lung maturity by comparative amniotic fluid analysis of the Clement's test lecithin/sphimgomyelin and phosphatidilglycerol

Com o objetivo de avaliar o método mais fidedigno de avaliatpo da maturidade pulmonar do concepto foram realizados em 119 amostras de líquido aminiotico (LA) obtidas através da amniocentese transabdominal de 94 gestantes de risco elevado, o teste de Clements (TC), a determinaçäo da relaçäo lecitina/esfingomielina (L/S) e do fosfatidilglicerol (PG). O teste da "espuma" foi realizado segundo Clements (1972) e a relaçäo L/S e o PG determinados pela técnica de cromatografia de papel em camada fina (Gluck & col, 1971). O teste de Clements quando revelador de maturidade pulmonar correlacionou-se com a relaçäo L/S também reveladora de maturidade em 90 por cento dos casos. Assinale-se, todavia, que na vigência do TC indicativo de imaturidade, a relaçäo L/S indicativa de maturidade pulmonar ocorreu em 45 por cento dos casos. A correlaçäo da relaçäo L/S e PG foi realizada em 105 amostra de LA. A relaçäo L/S revelando maturidade (36 casos) mostrou presenta de fosfatidilglicerol em 31 casos (86 por cento). Sumarizando, nossos dados revelam que o teste de Clements näo apresenta praticamente resultados falsos-positivos, contudo, a alta incidência de falsos-negativos impöe, nestes casos, a determinaçäo da relaçäo lecitina/esfingomielina e do fosfatidilglicerol.

Estudio histoquímico ultraestructural con lecitinas del cáncer gástrico y mucosa adyacente / Lectins in gastric cancer. A histochemical and ultraestructural study

Hemos realizado un estudio ultraestructural con 5 tipows de lecitinas (UEA-1, PNA, WGA, SBA and DBA) en 25 piezas de gastrecromía con adenocarcinoma, con el objeto de establecer diferencias entre la composición del moco secretado por la mucosa aparentemente normal y la neoplásica. Todas las muestras fueron incluidas en resina Sprurr y LR White, con diferentes condiciones de fijación y deshidratación; además, las lecitinas fueron incubadas siguiendo dos métodos diferentes: directo e indirecto. Los mejores resultados fueron obtenidoscon el método indirecto en el tejido incluido en LR White. Nuestros resultados muestran una gran hetereogenicidad en la composición azucarada, especialmente en la secreción de la mucoso neoplásica. La reacción con WGA fue negativa en el moco extracelular secretado en normalidad, mientras que resultó positiva en el secretado por las células neoplásicas. En marcaje con SBA sobre el aparato de Golgi sugiere que el inicio de la glicosilación sucede a nivel de la cara cis, aunque no podemos excluir que en ocaciones se realice en el retículo endoplásmatico rugoso. La intensidad en el marcaje con lecitinas aumentó con la diferenciación tumoral. La presencia de reacción con WGA en el moco extracelular en los carcinomas, así como la distribución azarosa de la reacción sobre el aparato de Golgi, podría estar relacionadas con glicosilaciones aberrantes y/o elongaciones anormales de la cadena de carbohidratos.

Determinación de madurez pulmonar fetal en líquido amniótico obtenido por vagina / Determination of pulmonary fetal maturity in amniotic fluid obtained via vagina

Con el objeto de evaluar la utilidad de la spruebas de madurez pulmonar fetal en líquido amniótico obtenido por vagina en embarazos complicados con ruptura prematura de membranas; se analizan la relación lecitina/esfingomielina, la deteminación de tromboplastina en líquido amniótico en 50 pacientes con embarazos entre 28 y 40 semanas correlacinándose con el estado de madurez pulmonar fetal al nacimiento. El análisis de dichos casos comprueba la alta correlación entre la determinación de fosfatidilglicerol y el tiempo de aceleración de tromboplastina en líquido amniótico y el estado de madurez pulmonar al nacimiento; la baja especificidad y sensibilidad de la relación lecitina/esfingomielina que parece modificarse por los contaminantes vaginales. Se concluye en la utilidad del procedimiento para la toma de decisiones dentro del manejo del embarazo pretérmino complicado con ruptura prematura de membranas

Estudio de la proporción de lecitina-esfingomielina en el líquido amniótico de gestantes diabéticas / Study of lecithin-sphingomyelin ratio in amniotic fluid of diabetic pregnant women

Se realiza el estudio de 80 gestantes diabéticas ingresadas en el Servicio de Obstetricia a las cuales se les tomó muestra del líquido amniótico para determinar la relación de lecitina esfingomielina (L/E). Se agrupan los estudios por semanas de embarazo de la 33 a la 40 y de acuerdo con la clasificación de Priscilla White. Se comparan los valores obtenidos de éstas gestantes con la curva de gestantes normales en los valores de L/E. Se expresa que el objetivo fue evaluar el pronóstico que estableció la evolución respiratoria del recién nacido, de acuerdo con los valores del índice L/E determinados por la técnica de Gluck modificada. Se comparan los resultados en cada grupo de pacientes y los valores encontrados en fetos con anomalías congénitas