Quiste óseo aneurismático del cóndilo mandibular: reporte de un caso / Aneurysmal bone cyst of the mandibular condyle: a case report

Se reporta el caso de una paciente mujer de 14 años de edad que presentaba una lesión asintomática de apariencia tumoral ubicada en la zona de la articulación témporo mandibular derecha. Durante la apertura bucal había desviación de la mandíbula hacia el mismo lado. El estudio imaginológico mediante radiografía panorámica, tomografía espiral multicorte y angiografía, fue determinante para plantear el diagnóstico de Quiste Óseo Aneurismático. Este es un tipo de pseudoquiste de los maxilares. Se discuten los aspectos clínicos, imaginológicos, anátomo-patológicos y el tratamiento de esta entidad. De la revisión de la literatura se concluye que es una lesión muy rara a nivel del cóndilo, no tiene una apariencia radiográfica patognomónica y puede confundirse con varias otras entidades que ocurren en esta zona anatómica. El estudio imaginológico cuidadoso y la punción aspiración fueron elementos importantes para el diagnóstico y por lo tanto para el correcto tratamiento.

A case of a 14-years-old girl with an asymptomatic tumour like mass located in the area of the right TMJ that produced deviation of the mandible to the same side is presented. The imaging study using panoramic radiograph, axial tomography and angiography were necessary to propose the diagnosis of aneurysmal bone cyst which is considered a type of pseudocyst of the jaw. The clinical aspects, imaging, histopathological studies and treatment regarding this lesion is discussed. By the review of the literature, it is concluded that this lesion very rarely involves the mandibular condyle, does not have pathognomonic radiographic appearance and can be confused with other several lesions affecting this anatomic zone. Careful imaging studies and aspiration puncture were important procedures for the diagnosis and therefore for the correct treatment.

Expression of gremlin, a bone morphogenetic protein antagonist,is associated with vascular calcification in uraemia.

BACKGROUND: Vascular calcification has been widely recognized as a significant contributor to cardiovascular risk in patients with chronic kidney disease. Recent evidence suggests that BMP-7 decreases the vascular calcification observed in uraemic rats, while BMP-2 could also be participating in this process. Gremlin, a bone morphogenetic protein antagonist, has been detected in rat aortic vascular smooth muscle cells (VSMCs), and since the role of the VSMCs into vascular calcification in uraemia is considered critical in this process, we hypothesized that gremlin could be participating in its pathogenesis. With this aim, we studied its expression in aorta from uraemic rats with calcitriol-induced vascular calcification and in 16-vessel biopsies of uraemic patients undergoing kidney transplantation. METHODS: Gremlin was detected by in situ hybridization (ISH) and immunohistochemistry (IMH). BMP-7, BMP-2 and BMP-2 receptor (BMPR2) were detected by IMH. Vascular calcification was assessed by the von Kossa staining method. Sham-operated and 5/6 nephrectomized rats (NFX) (1.2%P) were treated with vehicle or calcitriol (80 ng/kg, intraperitoneally every other day). Rats were killed after 4 weeks of treatment, and abdominal aorta was dissected for assessment of gremlin expression and vascular calcification. Epigastric arteries were obtained from dialysis patients during kidney transplantation procedure. Arteries from kidney donors were also studied. RESULTS: NFX rats developed a mild vascular calcification, whereas NFX-calcitriol rats developed a severe vascular and tissue calcification. A marked overexpression of gremlin was observed in the vascular media of aorta from NFX-calcitriol rats as compared with NFX and sham-calcitriol groups (4.8 +/- 1.3 versus 0.59 +/- 0.17 versus 0.19 +/- 0.07 percentage/mm(2), P < 0.01), and correlated with the BMP-2 and BMPR2 expression. Sham rats showed minimal or null gremlin expression. BMP-7 was not found in sham or calcified arteries. In human studies, we observed strong expression of gremlin mRNA and protein in the media layer of vessels from uraemic patients as compared with those from normal humans (staining score 3.72 +/- 0.95 versus 0.91 +/- 0.08 percentage/mm(2), P < 0.05). CONCLUSION: We observed a marked gremlin overexpression in the media layer of vessels in uraemic rats and patients in association with vascular calcification and BMP-2 expression. We postulate that gremlin may play a role in the vascular calcification process in uraemia, and its interaction with BMP-7 or BMP-2 remains to be elucidated.

Angiogenic, hyperpermeability and vasodilator network in utero-placental units along pregnancy in the guinea-pig (Cavia porcellus).

BACKGROUND: The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs. METHODS: Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test. RESULTS: In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy - and replacing the smooth muscle at term - displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy. CONCLUSION: The demonstration of different angiogenic, hyperpermeability and vasodilator factors in the same cellular protagonists of angiogenesis and invasion in the pregnant guinea-pig, supports the presence of a functional network, and strengthens the argument that this species provides an adequate model to understand human pregnancy.

Spatio-temporal expression of MMP-2, MMP-9 and tissue kallikrein in uteroplacental units of the pregnant guinea-pig (Cavia porcellus).

BACKGROUND: In humans trophoblast invasion and vascular remodeling are critical to determine the fate of pregnancy. Since guinea-pigs share with women an extensive migration of the trophoblasts through the decidua and uterine arteries, and a haemomonochorial placenta, this species was used to evaluate the spatio-temporal expression of three enzymes that have been associated to trophoblast invasion, MMP-2, MMP-9 and tissue kallikrein (K1). METHODS: Uteroplacental units were collected from early to term pregnancy. MMP-2, MMP-9 and K1 were analysed by immunohistochemistry and Western blot. The activities of MMP-2 and MMP-9 were assessed by gelatin zymography. RESULTS: Immunoreactive MMP-2, MMP-9 and K1 were detected in the subplacenta, interlobar and labyrinthine placenta, syncytial sprouts and syncytial streamers throughout pregnancy. In late pregnancy, perivascular or intramural trophoblasts expressed the three enzymes. The intensity of the signal in syncytial streamers was increased in mid and late pregnancy for MMP-2, decreased in late pregnancy for MMP-9, and remained stable for K1. Western blots of placental homogenates at days 20, 40 and 60 of pregnancy identified bands with the molecular weights of MMP-2, MMP-9 and K1. MMP-2 expression remained constant throughout gestation. In contrast, MMP-9 and K1 attained their highest expression during midgestation. Placental homogenates of 20, 40 and 60 days yielded bands of gelatinase activity that were compatible with MMP-2 and MMP-9 activities. ProMMP-2 and MMP-9 activities did not vary along pregnancy, while MMP-2 and MMP-9 increased at 40 and 40-60 days respectively. CONCLUSION: The spatio-temporal expression of MMPs and K1 supports a relevant role of these proteins in trophoblast invasion, vascular remodeling and placental angiogenesis, and suggests a functional association between K1 and MMP-9 activation.

Expression and immunolocalization of endothelin peptides and its receptors, ETA and ETB, in the carotid body exposed to chronic intermittent hypoxia.

Increased levels of endothelin-1 (ET-1) in the carotid body (CB) contribute to the enhancement of chemosensory responses to acute hypoxia in cats exposed to chronic intermittent hypoxia (CIH). However, it is not known if the ET receptor types A (ETA-R) and B (ETB-R) are upregulated. Thus, we studied the expression and localization of ETA-R and ETB-R using Western blot and immunohistochemistry (IHC) in CBs from cats exposed to cyclic hypoxic episodes, repeated during 8 hr for 4 days. In addition, we determined if ET-1 is expressed in the chemoreceptor cells using double immunofluorescence for ET-1 and tyrosine hydroxylase (TH). We found that ET-1 expression was ubiquitous in the blood vessels and CB parenchyma, although double ET-1 and TH-positive chemoreceptor cells were mostly found in the parenchyma. ETAR was expressed in most chemoreceptor cells and blood vessels of the CB vascular pole. ETB-R was expressed in chemoreceptor cells, parenchymal capillaries, and blood vessels of the vascular pole. CIH upregulated ETB-R expression by approximately 2.1 (Western blot) and 1.6-fold (IHC) but did not change ETA-R expression. Present results suggest that ET-1,ETA-R, and ETB-R are involved in the enhanced CB chemosensory responses to acute hypoxia induced by CIH.

Expression of kallikrein, bradykinin b2 receptor, and endothelial nitric oxide synthase in placenta in normal gestation, preeclampsia, and placenta accreta.

In an effort to define the varied expression of three vasoactive markers in the clinical models of normal placenta/ normal invasion (n = 11), preeclampsia/restricted trophoblast invasion (n = 15), and placenta accreta/exaggerated invasion (n = 6), we performed semiquantitative immunohistochemistry for kallikrein, bradykinin B2 receptor, and endothelial nitric oxide synthase (eNOS). In the floating villi, the syncytiotrophoblast expressed more kallikrein in placenta accreta (p < 0.05), than in normal and preeclamptic placentas, while the bradykinin B2 receptor and eNOS were similarly expressed in all groups; in the fetal endothelium, the bradykinin B2 receptor was enhanced in placenta accreta (p < 0.005), but kallikrein and eNOS were similarly expressed in the other two groups. In the extravillous trophoblast, both kallikrein and eNOS expression were higher in placenta accreta (p < 0.001), while the bradykinin B2 receptor signal was only enhanced in preeclampsia (p < 0.05). The presence and localization of kallikrein, the bradykinin B2 receptor, and eNOS in the fetomaternal interface in the three study conditions supports a local role for interrelated vasodilatory/antiaggregating systems. This first report of the variations observed in kallikrein and eNOS in a condition of exaggerated trophoblast invasion supports the participation of vasodilatation in trophoblast migration.

Effect of ammonium chloride and dietary phosphorus in the azotaemic rat. I. Renal function and biochemical changes.

BACKGROUND: Both dietary phosphorus restriction and the ingestion of ammonium chloride (NH(4)Cl) given to rats on a high-phosphorus diet have been shown to preserve renal function in the azotaemic rat. Parathyroidectomy also has been reported to preserve renal function and, in addition, to prevent kidney hypertrophy in the remnant kidney model. Our goals were (i) to evaluate in azotaemic rats the effect of dietary phosphorus on renal function in a shorter time frame than previously studied and (ii) to determine whether NH(4)Cl administration (a) enhances the renoprotective effect of dietary phosphorus restriction and (b) improves renal function in the absence of parathyroid hormone (PTH). METHODS: High (H; 1.2%), normal (N; 0.6%) and low (L; <0.05%) phosphorus diets (PD) were given for 30 days to 5/6 nephrectomized rats. In each dietary group, one-half of the rats were given NH(4)Cl in the drinking water. The six groups were HPD + NH(4)Cl, HPD, NPD + NH(4)Cl, NPD, LPD + NH(4)Cl and LPD. The effect of NH(4)Cl administration was also evaluated in 5/6 nephrectomized, parathyroidectomized (PTX) rats on NPD. RESULTS: In each of the three dietary phosphorus groups, creatinine and urea clearances were greater (P<0.01) in rats receiving NH(4)Cl. Neither creatinine nor urea clearance was reduced by high dietary phosphorus. Urine calcium excretion was greatest in the LPD group and was increased (P < or = 0.001) in all three groups by NH(4)Cl ingestion. An inverse correlation was present between plasma calcium and phosphorus in the parathyroid intact (r = -0.79, P<0.001) and PTX groups (r = -0.46, P = 0.02). In PTX rats, NH(4)Cl ingestion increased (P < or = 0.01) creatinine and urea clearances and both an increasing plasma calcium concentration (r = 0.67, P<0.001) and urine calcium excretion (r = 0.73, P<0.001) increased urine phosphorus excretion. CONCLUSIONS: At 30 days of renal failure (i) NH(4)Cl ingestion increased creatinine and urea clearances, irrespective of dietary phosphorus; (ii) high urine calcium excretion, induced by dietary phosphorus restriction and NH(4)Cl ingestion, did not adversely affect renal function; (iii) high dietary phosphorus did not decrease renal function; (iv) the absence of PTH did not preserve renal function or prevent NH(4)Cl from improving renal function; and (v) both an increasing plasma calcium concentration and urine calcium excretion resulted in an increase in urine phosphorus excretion in PTX rats.

Effect of ammonium chloride and dietary phosphorus in the azotaemic rat. Part II--Kidney hypertrophy and calcium deposition.

BACKGROUND: Kidney hypertrophy is stimulated by both partial nephrectomy and NH(4)Cl administration. Also, parathyroidectomy (PTX) has been reported to prevent kidney hypertrophy induced by a high protein diet. Our goal was to determine in the azotaemic rat: (i) the combined effects of NH(4)Cl administration and dietary phosphorus on the development of kidney hypertrophy and calcium deposition in the kidney and (ii) whether the absence of parathyroid hormone (PTH) affected the development of kidney hypertrophy and calcium deposition. METHODS: High (HPD, 1.2%), normal (NPD, 0.6%) or low (LPD, <0.05%) phosphorus diets were given to 5/6 nephrectomized rats for 30 days. In each dietary group, one-half of the rats were given NH(4)Cl in the drinking water. The six groups of rats were: (i) HPD + NH(4)Cl; (ii) HPD; (iii) NPD + NH(4)Cl; (iv) NPD; (v) LPD + NH(4)Cl and (vi) LPD. In a separate study, PTX was performed to determine whether PTH affected renal hypertrophy in 5/6 nephrectomized rats given NH(4)Cl. RESULTS: Both with and without NH(4)Cl (+/-NH(4)Cl), kidney weight was greatest (P<0.05) in the HPD groups. In each dietary phosphorus group, kidney weight was greater (P<0.05) in the NH(4)Cl group. In both the +/-NH(4)Cl groups, kidney calcium content was greatest (P<0.05) in the HPD group, but was less (P<0.05) in the NPD and HPD groups given NH(4)Cl. An inverse correlation was present between creatinine clearance and kidney calcium content (r = -0.51, P<0.001). When factored for kidney weight, creatinine clearance was less (P<0.05) in the HPD group in both the +/-NH(4)Cl groups, but was greater in the HPD + NH(4)Cl than in the HPD group. In PTX rats, kidney weight was greater (P<0.05) and kidney calcium deposition was less (P<0.05) in rats given NH(4)Cl. CONCLUSIONS: In azotaemic rats studied for 30 days, NH(4)Cl administration induced kidney hypertrophy. A HPD also induced kidney hypertrophy. The effects on kidney calcium deposition were divergent for which NH(4)Cl administration decreased and a HPD increased calcium deposition. The inverse correlation between kidney calcium content and creatinine clearance suggests that kidney calcium deposition is harmful to renal function. When factored for kidney weight, the lower creatinine clearance in the high phosphorus group suggests that kidney hypertrophy does not completely compensate for the harmful effects of a HPD. This result also suggests that a longer study would probably result in more rapid deterioration in the high phosphorus group. In PTX rats, the absence of PTH did not prevent NH(4)Cl from inducing kidney hypertrophy and reducing kidney calcium deposition. In conclusion, NH(4)Cl and dietary phosphorus each independently affect kidney growth and calcium deposition in the growing rat with renal failure.

Hyperphosphatemia modestly retards parathyroid hormone suppression during calcitriol-induced hypercalcemia in normal and azotemic rats.

BACKGROUND/AIMS: In in vitro studies, a high phosphate concentration has been shown to directly stimulate parathyroid hormone (PTH) secretion in a normal calcium concentration and to reduce PTH suppression in a high calcium concentration. In hemodialysis patients during dialysis-induced hypercalcemia, the effect of hyperphosphatemia on PTH secretion was less than in vitro studies. Our goal was to determine whether hyperphosphatemia retards PTH suppression during calcitriol-induced hypercalcemia in azotemic rats with hyperparathyroidism. METHODS: Rats underwent a two-stage 5/6 nephrectomy or sham operations. After surgery, rats received a high phosphate diet (P 1.2%, Ca 0.6%) for 4 weeks to induce hyperparathyroidism and then were placed on a normal diet (P 0.6%, Ca 0.6%) for two additional weeks to normalize serum calcium values in azotemic rats. At week 7, rats were divided into five groups and before sacrifice received at 24-hour intervals, three doses of calcitriol (CTR) or its vehicle. The five groups and dietary phosphate content were: group 1--normal renal function (NRF) + 0.6% P + vehicle; group 2--NRF + 0.6% P + CTR; group 3--renal failure (RF) + 0.6% P + vehicle; group 4--RF + 1.2% P + CTR; and group 5--RF + 0.6% P + CTR. RESULTS: In the two CTR-treated groups with marked hypercalcemia (groups 2 and 5), 15.52 +/- 0.26 and 15.12 +/- 0.13 mg/dl, respectively, stepwise regression showed that hyperphosphatemia retarded PTH suppression. When the two azotemic groups treated with CTR (groups 4 and 5) were combined to expand the range of serum calcium values, stepwise regression showed that hypercalcemia suppressed and hyperphosphatemia modestly retarded PTH suppression. Similarly, in groups 4 and 5 combined, correlations were present between PTH and both serum calcium (r = -0.70, p < 0.001) and serum phosphate (r = 0.64, p = 0.001). CONCLUSIONS: Hypercalcemia and high doses of calcitriol markedly reduced PTH secretion in azotemic rats despite severe hyperphosphatemia. Even though hyperphosphatemia did retard PTH suppression during hypercalcemia, its effect was small.

How dietary phosphate, renal failure and calcitriol administration affect the serum calcium-phosphate relationship in the rat.

BACKGROUND: The effect of hyperphosphataemia on serum calcium regulation in renal failure has not been well studied in a setting in which hypercalcaemia is not parathyroid hormone (PTH) mediated. In azotemic rats with a normal serum calcium concentration, an increased dietary phosphate burden affects serum calcium regulation because of its effects on skeletal resistance to PTH, calcitriol production, and possibly intestinal calcium absorption. Our goal was to determine how hyperphosphataemia affected the development of hypercalcaemia during calcitriol-induced hypercalcaemia and PTH suppression in azotemic rats with established hyperparathyroidism. METHODS: Rats underwent a two-stage 5/6 nephrectomy or corresponding sham operations. After surgery, rats were given a high phosphate diet (P 1.2%) for 4 weeks to exacerbate hyperparathyroidism and were then changed to a normal diet (P 0.6%) for 2 weeks to normalize serum calcium values in the azotemic rats. At week 7, rats were divided into five groups and sacrificed after receiving three intraperitoneal doses of calcitriol (CTR, 500 pmol/100 g) or vehicle at 24 h intervals. The five groups and dietary phosphate content were: group 1, normal renal function (NRF)+0.6% P+vehicle; group 2, NRF+0.6% P+CTR; group 3, renal failure (RF)+0.6% P+vehicle; group 4, RF+1.2% P+CTR; and group 5, RF+0.6% P+CTR. Both the 0.6% and 1.2% phosphate diets contained 0.6% calcium. RESULTS: Serum creatinine values were increased (P<0.05) in 5/6 nephrectomized rats (groups 3, 4 and 5), as were serum calcium values (P<0.05) in CTR-treated rats (groups 2, 4 and 5) and serum phosphate values (P<0.05) in CTR-treated azotemic rats (groups 4 and 5). Serum PTH values were suppressed (P<0.05) in CTR-treated hypercalcemic rats (groups 2, 4 and 5) and increased (P<0.05) in azotemic rats not given CTR (group 3). In the azotemic groups (groups 3, 4 and 5), an inverse correlation was present between serum calcium and phosphate in each group, despite a wide variation in serum calcium values. The slope of the inverse relationship between serum calcium and phosphate was steeper in CTR-treated azotemic rats on a 1.2% phosphate (group 4) diet than on a 0.6% phosphate (group 5) diet (P=0.02). Thus, for a similar increase in the serum phosphate concentration, serum calcium values decreased more in group 4 than in group 5. The independent effect of dietary phosphate on serum calcium values was also confirmed by analysis of covariance. Finally, the serum calcium concentration was shown to be greater for any given serum phosphate value in CTR-treated rats than in those not on CTR. CONCLUSIONS: In azotemic rats with calcitriol-induced hypercalcaemia, the magnitude of hypercalcaemia is affected by: (i) the serum phosphate concentration; and (ii) differences in dietary phosphate content. Calcitriol administration also acts to shift upwards the relationship between serum calcium and phosphate so that a higher serum calcium concentration can be maintained for any given serum phosphate value.

La glomérulonefritis aguda en el niño / Acute glomerulonephritis in children

Se analiza una serie de 45 niños de 2 a 15 años, promedio 7,7 años con cuadro clínico e histológico de GNA, que fueron seguidos hasta por treinta meses. Se realizó en ellos dos estudios histológicos (ML, ME, IN) en biopsias practicadas al comienzo de la enfermedad (promedio 20 días) y la segunda a los 194 ó 590 días en promedio. En el estudio clínico se destaca la normalización del edema a los 8,8 días y la hipertensión a los 4,3 días. Sólo se obtuvo estreptococo betahemolítico en cuatro enfermos, lo que puede relacionarse con el tratamiento antibiótico recibido previamente por estos niños. En el examen de orina un alto porcentaje no presentó hematuria (44%) o proteinuria (49%) en el examen de ingreso y sólo 29,9% tuvo cilindruria. La albuminemia tuvo valores bajo lo normal en el 35,6% de los niños, alfa 2 globulina y gamaglobulina con valores normales en todos. El complemento C3 fue en promedio 41,3m% y sólo 3 enfermos tenían valores sobre 100mg%. Se describen las curvas de antiestreptolisina O (ASO) y STZ en estos niños y se destaca la necesidad de determinaciones seriadas tanto de C3 como ASO y STZ. En el análisis de 194 contactos se obtuvo sólo 5 frotis faríngeos y 10 cutáneos positivos a estreptococo betahemolítico e estafilococo. En el estudio histológico se encontró buena correlación entre la intensidad de las lesiones en microscopía de luz (ML) y microscopía electrónica (ME). En esta última se destaca en la primera biopsia que todos tenían depósitos inmunes intramembranosos segmentarios y 84% con depósitos en joroba. La segunda biopsia mostró una disminución apreciable de la intensidad de las lesiones a los 6 meses y en las realizadas en promedio a los 590 días se encontró ya tres casos que pueden considerarse normales desde el punto de vista histológico. Otros tres con lesiones...

Excreción de calicreína urinaria en niños sanos a distintas edades / Urinary kallikrein excretion in healthy children at different ages

La calicreína es una proteína que genera, luego de varias transformaciones, bradicina, una sustancia con potente acción vasodilatadora. En 53 niños de ambos sexos, sanos y normotensos, cuyas edades fluctuaron entre 12 días y 15 años, se midió calicreína urinaria, expresándola en su valor absoluto y en relación a la masa renal. La calicreína urinaria es francamente inferior en el grupo de menores de 6 meses. (0.30 + ou - 0.29 uU 24 hrs.) con respecto a los valores obtenidos en los lactantes y niños mayores (9.46 + ou _ 2.7 y 16.1 + ou - 3,7 uU 24 hrs.). Concluimos que la excreción urinaria de calicreína es significativamente menor en los menores de 6 meses, lo que puede estar relacionada con la maduración renal