Papers by Julian Rodriguez
Clinical Pharmacokinetics, 1991
The various components required for individualising clinical drug dosage regimens are reviewed, i... more The various components required for individualising clinical drug dosage regimens are reviewed, including a study of 3 types of fitting procedures, 2 types of gentamicin pharmacokinetic model and the utility of D-optimal times for obtaining serum gentamicin concentrations. The combination of the current Bayesian fitting procedure, the kslope pharmacokinetic model [in which the elimination rate constant (kel) can change from dose to dose with changing creatinine clearance] and the explicit measurement of the assay error pattern yielded predictions of future serum gentamicin concentrations which were (a) slightly better than those found using weighted nonlinear least squares; (b) somewhat better than those found with Bayesian fitting and a fixed-kel model; (c) better than those found using the traditional linear regression fitting procedure and a fixed kel model. D-Optimally timed pairs of concentrations also predicted future concentrations at least as well, and more cost effectively.
Pediatric Nephrology, 2007
Rapamycin is a potent immunosuppressant with antitumoral properties widely used in the field of r... more Rapamycin is a potent immunosuppressant with antitumoral properties widely used in the field of renal transplantation. To test the hypothesis that the antiproliferative and antiangiogenic activity of rapamycin interferes with the normal structure and function of growth plate and impairs longitudinal growth, 4-week-old male rats (n = 10/group) receiving 2 mg/kg per day of intraperitoneal rapamycin (RAPA) or vehicle (C) for 14 days were compared. Rapamycin markedly decreased bone longitudinal growth rate (94 ± 3 vs. 182 ± 3 μm/day), body weight gain (60.2 ± 1.4 vs. 113.6 ± 1.9 g), food intake (227.8 ± 2.6 vs. 287.5 ± 3.4 g), and food efficiency (0.26 ± 0.00 vs. 0.40 ± 0.01 g/g). Signs of altered cartilage formation such as reduced chondrocyte proliferation (bromodeoxiuridine-labeled cells 32.9 ± 1.4 vs. 45.2 ± 1.1%), disturbed maturation and hypertrophy (height of terminal chondrocytes 26 ± 0 vs. 29 ± 0 μm), and decreased cartilage resorption (18.7 ± 0.5 vs. 31.0 ± 0.8 tartrate-resistant phosphatase alkaline reactive cells per 100 terminal chondrocytes), together with morphological evidence of altered vascular invasion, were seen in the growth plate of RAPA animals. This study indicates that rapamycin can severely impair body growth in fast-growing rats and distort growth-plate structure and dynamics. These undesirable effects must be kept in mind when rapamycin is administered to children.
Kidney International, 2004
Kidney International, 2004
A new mutation (intron 9 +1 G>T) in the SLC12A3 gene is linked to Gitelman syndrome in Gypsies.
Acta Neuropathologica, 1994
We report a case of spinal cord neurocytoma in a 67-year-old man who had experienced a progressiv... more We report a case of spinal cord neurocytoma in a 67-year-old man who had experienced a progressive numbness of the left foot during the previous 4 years. Magnetic resonance imaging showed a well-defined intramedullary tumor located at the T10-Tll level. The pathological examination revealed histological characteristics described in neurocytomas. The tumor cells showed a uniform small nucleus and clear or slightly eosinophilic cytoplasm with frequent perinuclear halos, resembling the picture of oligodendroglioma. Some tumor cells exhibited mature ganglion cell appearance. Electron microscopy showed cells with microtubules and dense-core vesicles in their cytoplasm and cytoplasmic process. Immunohistochemically, the majority of tumor cells expressed synaptophysin and neuronspecific enolase. We conclude that this tumor is an exceptional case of neurocytoma located in the spinal cord, and consider that the term neurocytoma can be applied to tumors with neuronal differentiation intermediate between neuroblastoma and ganglioneuroma, even if arising in CNS outside of the intracranial ventricular system. Key words Neurocytoma 9 Spinal cord differentiation. It was first described by Hassoun et al. . Since then about 100 other cases have been reported ], very few of which were shown to be located in parts of the brain other than in the ventricular system . Only four cases have been described in the cervical cord . In this report we present a spinal cord tumor in a 67-year-old man, with the histological, immunohistochemical and ultrastructural characteristics of a central neurocytoma.
Kidney International, 1997
Parathyroid hormone prevents 1,25 (OH)2D3 induced down-regulation of the vitamin D receptor in gr... more Parathyroid hormone prevents 1,25 (OH)2D3 induced down-regulation of the vitamin D receptor in growth plate chondrocytes in vitro. I,25(OH)2D1 has an antiproliferative effect on growth plate chondrocytes when given in high doses, whereas low doses stimulate chondrocyte proliferation. In the present in vitro study we investigated the effects of parathyroid hormone (PTI-l) when given concomitantly with 1,25(OH)2D3 on cell proliferation and vitamin D receptor (VDR) regulation. Freshly isolated rat tibial chondrocytes were grown in monolayer cultures or in agarose stabilized suspension cultures (10% charcoal-treated FCS). VDR expression was determined by RT-PCR generating a 297 hp fragment and by binding assays (Scatchard analysis) with [3H]-1,25(OH)2D3. Cell proliferation was measured by [3H]-thymidinc incorporation, growth curves in monolayer cultures and by colony formation in agarose-stabilized suspension cultures. Optimal concentration of 1,25(OH)2D3 (10_12 M) and of PTH fragments [hPTI-I(1-34) or hPTH(28-48), lO° M] showed additive effects on DNA synthesis of and colony formation by growth plate chondrocytes. This may be explained in part by an up-regulation of VDR by PTH: PTH increased both mRNA expression of VDR and binding capacity. 1,25(OH)2D3 (10-12 M)
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Papers by Julian Rodriguez