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Biomedical subjects

M Castillo

Publications and source records attributed to M Castillo.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Risk factors for psychomotor development among infants born under optimal biological conditions].

OBJECTIVE: The objective of this study is to evaluate the effect of risk factors on infant development, among low socioeconomic children born under optimal biological conditions, and who are exposed to adverse social circumstances. METHOD: Infants of both sexes, in the amount of 788, were studied and controlled prospectively at between 6 and 12 months. Their mental (MDI) and psychomotor (PDI) development was evaluated using the Bayley Scale of Infant Development. Eighteen risk factors were identified and dichotomized (high or low risk). RESULTS: Breast feeding, child temperament, maternal intelligence and home stimulation are consistently associated with lower MDI and PDI. After adjustment for co-variables, home stimulation persisted as a significant factor for explaining the variation of both developmental indexes and child sex also appears as a risk factor for motor skills development. The accumulated effect of 7 or more risk factors is associated with a significant decrease of development scores. The combination of risk categories of child temperament, maternal IQ, paternal role and home stimulation shows higher prediction power for infant development than other combinations analyzed in this study. CONCLUSION: The findings suggest than even for children born under optimal biological conditions their psychomotor development is negatively affected by the presence of simultaneous adverse environmental conditions.

Child Development↗
PubMed1998

Usefulness of proton MR spectroscopy in the evaluation of temporal lobe epilepsy.

OBJECTIVE: The purpose of our study was to compare the ability of MR spectroscopy with that of standard presurgical methods to accurately lateralize the abnormal hippocampus in a group of patients with complex partial seizures. SUBJECTS AND METHODS: Ten healthy volunteers (five male, five female) without a history of seizures, significant head trauma, or other neurologic abnormalities were chosen to participate in the study. Twelve consecutive patients (three male, nine female) having intractable temporal lobe epilepsy and undergoing presurgical evaluation for temporal lobectomy were chosen to participate in the study. The condition of all patients was refractory to medications. All patients underwent presurgical examination with interictal and video ictal electroencephalography, ictal single-photon emission computed tomography, interictal positron emission tomography, MR imaging, and neuropsychologic testing. When noninvasive data were inconclusive, depth or grid recordings were performed. The results of MR spectroscopy were also compared with postsurgical seizure control as defined by the Engel classification. RESULTS: Nine (90%) of 10 control subjects showed no significant difference in N-acetyl aspartate. One control subject showed 16% asymmetry in N-acetyl aspartate between sides. The control group showed no statistically significant differences in ratios of N-acetyl aspartate:creatine, N-acetyl aspartate:choline, or creatine:choline when comparing sides (p < .05). All 12 patients showed clearly lateralizing values identified by the index of asymmetry in N-acetyl aspartate (range, 24-93%), with a mean difference of 51% (SD, 22) (p = .01). Additionally, as a group, statistically significant indexes of asymmetry (p = .01) were seen in ratios of N-acetyl aspartate:choline (mean, 42; SD, 22%), N-acetyl aspartate:creatine (mean, 41; SD, 27), and N-acetyl aspartate:creatine + choline (mean, 42; SD, 22). Using an N-acetyl aspartate index of asymmetry of greater than 15%, which represents the mean index of asymmetry of the control subjects +/- two SDs, as our cutoff level for lateralization, the correct side was identified in all patients. When comparing both hippocampi using an asymmetry index of 15% for N-acetyl aspartate:choline + creatine, 11 (92%) of 12 were correctly lateralized. When comparing the unaffected temporal lobes between patients and control subjects, no statistically significant differences were detected in any metabolites or ratios. CONCLUSION: Our study agrees with others in showing decreased N-acetyl aspartate in the hippocampus of seizure patients when compared with control subjects. Using N-acetyl aspartate, N-acetyl aspartate:creatine, N-acetyl aspartate:choline, and N-acetyl aspartate:creatine + choline as our parameters, patients with mesial temporal lobe epilepsy were correctly lateralized with MR spectroscopy when compared with clinical consensus criteria. We consider MR spectroscopy to be complementary to MR imaging. Both studies can be performed as a single integrated examination.

Adult↗
PubMed1998

Imaging of Bezold's abscess.

OBJECTIVE: Our purpose was to describe the CT findings in patients with Bezold's abscesses. CONCLUSION: Bezold's abscesses are rare complications of mastoiditis. In our series most were seen in adults and were associated with a history of cholesteatoma and mastoidectomy. CT of the neck and temporal bone can help the surgeon determine appropriate treatment.

Abscess↗
PubMed1998

Proton MR spectroscopy in neoplastic and non-neoplastic brain disorders.

The basic principles of proton MR spectroscopy as well as newer and more advanced related techniques are reviewed. Spectroscopy is capable of differentiating normal from pathologic brain and provides tissue specificity greater than that of imaging in many instances. Spectroscopic mapping allows for the visualization of the concentration of different metabolites and their distribution within a lesion. This article emphasizes the utility of proton MR spectroscopy in the diagnosis of brain tumors, postradiation therapy changes, infections, degenerative brain disorders, hepatic encephalopathy, ischemia, and demyelination.

Brain↗
PubMed1998

MR spectroscopy in the evaluation of epilepsy.

MR spectroscopy may be a helpful, reliable, noninvasive test with which to lateralize the seizure focus in patients with partial complex seizures. MR spectroscopy is complementary to other studies, especially MR imaging, and both may be performed in a single integrated examination and result in improved surgical management and outcome.

Brain↗
PubMed1998

Normal cross-sectional anatomy of the nasopharynx, oropharynx, and oral cavity.

The anatomy of the extracranial head and neck is complex and difficult to understand. In contrast to other regions, the majority of lesions involving the upper aerodigestive tract (pharynx and oral cavity) are either visible on endoscopy or palpable on clinical examination. This article describes the normal cross-sectional computed tomography and magnetic resonance imaging anatomy of the upper aerodigestive tract.

Humans↗
PubMed1998

Usefulness of contrast material in MR of patients with neurofibromatosis type 1.

PURPOSE: Our objective was to determine the usefulness of routine administration of contrast material in brain MR imaging for the evaluation of areas of probable myelin vacuolization and neoplasms in patients with neurofibromatosis type 1 (NF-1). METHODS: We retrospectively reviewed 112 consecutive contrast-enhanced brain MR studies obtained over a period of 7 years in 109 symptomatic and asymptomatic patients compiled from two institutional NF-1 data bases. MR studies were analyzed for areas of probable myelin vacuolization, with attention to degree of enhancement and its impact on lesion detection and characterization. Usefulness of contrast material was graded as 0 = not useful, 1+ = somewhat useful, and 2+ = useful. RESULTS: Of 112 studies, 45% (n = 49) were normal. In the remaining 63 studies, 88 regions of probable myelin vacuolization and 52 tumors were identified. Enhancement was not observed in any regions of probable myelin vacuolization. Enhancement was present in 31% of tumors, and, of these, was found to be useful in 44%, somewhat useful in 12%, and not useful in 44%. For enhancing tumors, contrast agent was useful for lesion detection in 19% and for lesion characterization in 25%. CONCLUSION: Contrast administration is useful in baseline MR studies to maximize tumor detection and characterization, to add confidence to the diagnosis of benign probable myelin vacuolization, and to document stability of neoplasms on follow-up examinations.

Adolescent↗
PubMed1998

Spinal intradural cerebellar ectopia.

An ectopic cerebellum, as in Chiari malformations and ectopic cerebellar dysplastic tissue, is a common finding; however, the presence of an organized ectopic cerebellum is exceedingly rare. We describe the MR imaging, surgical, and histologic appearance of an intraspinal ectopic cerebellum in an infant.

Cerebellum↗
PubMed1998

Proton MR spectroscopy of common brain tumors.

Proton MR spectroscopy allows differentiation of normal tissues from pathologic ones. There is now evidence that this technique may be able to distinguish different histological grades of tumors. The proton MR spectroscopic changes due to treatment of brain tumors is discussed in this article.

Brain Neoplasms↗
PubMed1998

Proton MR spectroscopy in psychiatric and neurodevelopmental childhood disorders: early experience.

Variations in brain morphology are increasingly being found in patients with psychiatric disorders. There is early evidence that some metabolic abnormalities may also be present in these patients. In many patients with psychiatric disorders, the diagnosis is not straight forward and may be confounded by co-morbid processes. Establishing the correct diagnosis is important as it leads to institution of appropriate therapies. Descriptions of the authors early experience using proton MR spectroscopy in the evaluation of children with bipolar affective disorder, attention deficit hyperactivity disorder, neurodevelopmental abnormalities in patients with neurofibromatosis type 1, and the effects of certain types of treatment used for these disorders are discussed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1997

Regulation of mevalonate 5-pyrophosphate decarboxylase in HeLa cells. Inhibition of enzymatic protein synthesis by serum lipoproteins.

Mevalonate 5-pyrophosphate decarboxylase (EC 4.1.1.33) has been considered as a secondary site of regulation of cholesterogenesis. Because of this, we have studied the regulation of decarboxylase in HeLa cells by serum lipoproteins in the cell culture medium. A first group of experiments was performed with cells grown in Eagle's medium with 10% foetal calf serum. The specific activity of decarboxylase was increased when whole foetal calf serum was replaced with lipoprotein-poor serum. This increase was clearly reduced in the presence of cycloheximide. Addition of serum lipoproteins to a medium containing lipoprotein-poor serum led to a clear decrease in the decarboxylase activity. An identical decrease was observed after the addition of lipoproteins alone or in combination with cycloheximide. These results suggest for the first time that the effect of serum lipoproteins on decarboxylase activity should be a decrease in the rate of enzymatic protein synthesis, and corroborate the important role of reactions other than those catalysed by 3-hydroxy-3-methylglutaryl-CoA reductase in the regulation of cholesterogenesis.

Blood Proteins↗
PubMed1997

Enhancement of paclitaxel activity against hormone-refractory prostate cancer cells in vitro and in vivo by quinacrine.

Cytoplasmic phospholipase A2 (PLA2) is known to be phosphorylated and activated by MAP kinase (Lin et al 1993, Cell 72: 269-278), an important downstream component of signal transduction, whereas paclitaxel has been shown to inhibit isoprenylation of ras proteins (Danesi et al 1995, Mol Pharmacol 47: 1106-1111). Given that quinacrine (Q), a PLA2 inhibitor, and paclitaxel (P) might act at different sites in the cell signalling pathway, our aim was to test whether they were synergistic in combination against prostate cancer cells. Cell viability of PC-3, PC-3M and DU145 cells in 96 - well plates was assessed 96 h after drugs were added concurrently. Using Chou analysis, we demonstrated synergy for the combination against all three cell lines. Further, synergy was present under both conservative (mutually non-exclusive) and non-conservative (mutually exclusive) models. Studies in the nude mouse xenograft model support the finding of synergy in vitro. In DU145-bearing mice, Q (50 mg kg(-1)) and P (0.5 mg kg(-1)) given daily for 12 consecutive days, either concurrently or sequentially, was more effective than either drug alone, at twice the dose intensity. In an enzyme-linked immunosorbent (ELISA) apoptosis assay, arachidonic acid was able to partially reverse Q- and P-induced apoptosis, suggesting PLA2 pathway involvement. Finally, the combination of lovastatin, another inhibitor of ras isoprenylation, and quinacrine had synergistic inhibitory effects on the growth of PC-3 cells in vitro, suggesting that the combination of these two classes of compounds might serve as an attractive therapeutic approach for prostate cancer.

Animals↗