Synthesis and characterization of lanthanum phosphate nanoparticles as carriers for (223)Ra and (225)Ra for targeted alpha therapy.

INTRODUCTION: Targeted alpha therapy (TAT) has the potential for killing micro-metastases with minimum collateral damage to surrounding healthy tissue. In-vivo generator radionuclides, such as(223)Ra, (225)Ra, and (225)Ac, are of special interest for radiotherapeutic applications as they emit multiple α-particles during their decay. Utilizing appropriate carriers capable of retaining both the parent radioisotope as well as daughter products is important for the effective delivery of the radioisotope to the tumor site while mitigating global in vivo radiotoxicity. In this work, LaPO4 core and core+2 shells nanoparticles (NPs) (NPs with 2 layers of cold LaPO4 deposited on the core surfaces) were synthesized containing either (223)Ra or(225)Ra/(225)Ac, and the retention of the parents and daughters within the NPs in vitro was investigated. METHODS: Core LaPO4 NPs were synthesized in aqueous solution by reacting 1 equivalent of La(NO3)3, along with few microcuries of either (223)Ra or (225)Ra/(225)Ac, with 1 equivalent of sodium tripolyphosphate (TPP) under moderate heating and purified by membrane dialysis. Core-shell NPs were also synthesized with one (core+1 shell) and two (core+2 shells) cold LaPO4 layers deposited onto the radioactive cores. The NPs were then characterized by transmission electron microscopy (TEM) and powder x-ray diffraction (XRD). Identification and quantification of radioactive parents and daughters released from the NPs in vitro were investigated using gamma-ray spectroscopy. RESULTS: XRD and TEM analysis revealed that the NPs crystallized in the rhabdophane phase with mean diameters of 3.4 and 6.3nm for core and core+2 shells, respectively. The core LaPO4 NPs retained up to 88% of (223)Ra over 35days. However, in the core+2 shells NPs, the retention of (223)Ra and its daughter, (211)Pb, was improved to >99.9% over 27days. Additionally, the retention of (225)Ra/(225)Ac parents was >99.98% and ~80% for the (221)Fr and (213)Bi daughters over 35days for the core+2 shells NPs. CONCLUSIONS: The in vitro retention of both parents and daughters results suggests that LaPO4 NPs are potentially effective carriers of radium isotopes.

[Cleidocranial dysostosis. Presentation of a case]. / Disostosis cleidocraneal. Presentación de un caso.

INTRODUCTION: Cleidocranial dysostosis is a syndrome defined by three characteristic findings: clavicular aplasia, retarded cranial ossification, and autosomic dominant hereditary transmission, with completed penetrance and full expression. However, the diagnosis cannot only be made based on those finding, because the polymorphism and extension of the lesions of this disease is important. Therefore, in this disease we can see upset in the second teething, short stature or dwarf, persistence of the biconvex appearance of vertebral body, bone hypoplastic iliac, retarded pubis branch ossification, wedge shape distal phalanges or with brachymesophalangia of the forefinger and fifth finger. CLINICAL CASE: We describe a 20 years old man, with cleidocranial dysostosis, without familiar antecedent (probable mutation), that come to our center for treatment of denture pathology with disabled eating, because anomalous distribution and eruption. He had clavicle agenesis, cranial ossification upset with wormian bones, vertebral bodies biconvex, superior maxillary hypoplastic, and dental packed in the superior maxillary and jawbone. CONCLUSIONS: Cleidocranial dysostosis is a hereditary disease, which can be of spontaneous apparition (mutation), has a grand polymorphism, affect the osseous development, predominate in the middle line membranous bone and is an entity of radiologic diagnosis.

[Intraventricular meningiomas]. / Meningiomas intraventriculares.

Eight cases of surgically intervened intraventricular meningiomas are presented. The patients were six males and 2 females with a mean age of 41.7 years (11-70). The length of symptoms was of several months in 6 (75%) of the cases. The most frequent symptoms observed were cephalea and alterations of the upper functions which were presented in six and four cases, respectively. Papilloedema and involvement of long pathways were the most usual findings observed in neurological examination. Diagnosis was made by computerized tomography and angiography in all the cases. Surgery using a transtemporal approach was carried out in six patients and in the other two a parietal-occipital route was used. Two patients were dead and other two presented bilateral amaurosis. The other patients had good postsurgery.

[Decrease in the incidence of epidural hematomas surgically treated during coma after a lucid interval. Is this an index of quality of care?]. / Disminución de la incidencia de hematomas epidurales intervenidos en coma después de un intervalo lúcido. Es un índice de la calidad asistencial?

The level of consciousness prior to surgery has been analyzed in a series of 64 patients suffering epidural hematoma (EDH) who underwent surgery during the period from July 1987 to June 1989. The percentage of cases which underwent surgery in coma after a lucid interval have been compared in different periods of time (1978-80, 1981-82, 1983-84 and July 1987 to June 1989). During the period from July 1987 to June 1989 surgery was performed on: 15 patients (23.5%) in coma from the moment of accident, 8 patients (12.5%) underwent surgery in coma but after a lucid interval and 41 patients (64.1%) were conscious. During the different periods of time the number of patients undergoing surgery in coma after a lucid interval were the following: 1979-80, 9 cases (26.5%); 1981-82, 17 cases (43.6%); 1983-84, 8 cases (20%) and during the last period, 1987-89, 7 cases (15.2%). The difference between the percentage of patients intervened in coma after a lucid interval in the previously referred periods of time was statistically significant (p 0.05).

[Symptomatic chronic subdural hematoma. Analysis of 68 cases treated surgically with small craniotomy and placement of a closed drainage system]. / Hematoma subdural crónico sintomático. Análisis de 68 casos tratados quirúrgicamente con pequeña craneostomía y colocación de sistema de drenaje cerrado.

Sixty eight cases of chronic subdural hematoma (CSDH) surgically treated (December 1984-December 1988) with twist drill craniostomy (3-4 mm) and application of a closed drainage system (CDS) are reviewed. The patients were distributed in four groups depending on the density of the hematoma: hypodense (36 cases), isodense (6 cases), of mixed density (22 cases) and hyperdense (4 cases). In about one third of patients (25 cases) the duration of symptoms was shorter than one week, in 21 cases it was between one week and one month, and in 22 patients it was longer than one month. 77.95% of cases had a preceding head injury. Headache and motor deficits were the leading symptoms, being present in 43 (63.2%) and 42 (61.7%) cases, respectively. Twelve patients (17.6%) were comatose on admission. Twelve patients required reoperation. Six patients died (8.8%). The preoperative neurological status and associated systemic diseases influenced the outcome. We think that limited craniostomy with CDS is the therapy of choice for symptomatic CSDH.