Influence of dosage, age, and co-medication on plasma topiramate concentrations in children and adults with severe epilepsy and preliminary observations on correlations with clinical response

The influence of dosage, age, and co-medication on plasma topiramate (TPM) concentrations at steady state was investigated in 51 patients aged 3 to 30 years. All patients had chronic active epilepsy, and most were receiving concomitant medication with enzyme-inducing anticonvulsants (carbamazepine and phenobarbital). Plasma TPM concentrations were determined by a specific immunoassay in samples obtained before the morning dose. Thirty-five patients could be evaluated prospectively at different dose levels, and the relationship between plasma TPM concentration and dosage was linear over the assessed dose range (1.8 to 10.0 mg/kg) both in adults and in children. The influence of age on pharmacokinetic parameters could be assessed only for the 42 patients co-medicated with enzyme inducers. In these patients dose-normalized plasma TPM concentrations correlated positively with age (r = 0.59, P < 0.0001), where apparent oral clearance values (CL/F) were inversely related to age (r = 0.73, P < 0.0001). In particular, CL/F values in children aged less than 10 years (112 +/- 82 mL/kg/h, mean +/- SD, n = 14) were almost three times as high as those observed in patients aged >15 to 30 years (42 +/- 16 mL/kg/h, n = 17), whereas the CL/F value in children aged 10 to 15 years (66 +/- 22 mL/kg/h, n = 11) was intermediate between those found in the two other age groups. Patients not receiving enzyme-inducing AEDs showed lower CL/F values than did age- and gender-matched patients on enzyme-inducing co-medication. A preliminary evaluation of the relationship between plasma TPM concentration and therapeutic response could be made in 41 patients. No significant difference in drug concentration was detected between patients showing a greater than 50% reduction in seizure frequency compared with baseline (5.9 +/- 2.2 micrograms/mL, n = 30) and those having no clinical improvement (5.2 +/- 2.2 micrograms/mL, n = 11). Likewise, there was no consistent relationship between plasma TPM concentration and appearance of adverse effects. These results indicate that plasma TPM concentrations are linearly related to dosage both in adults and in children and that children aged <10 years require much greater body weight-adjusted dosage to achieve drug levels comparable to those observed in young adults. The marked increase in TPM clearance caused by enzyme-inducing co-medication was confirmed.     

New N6- or N(9)-hydroxyalkyl substituted 8-azaadenines or adenines as effective A1 adenosine receptor ligands

In this paper we describe synthesis and biological assays of some A(1) ligands more water-soluble than the effective, but very lipophilic, 8-azaadenines and adenines discovered in the past and obtained introducing on N(6) or N(9) substituent a hydroxy group. Five of the new N(6)-hydroxyalkyl- and N(6)-hydroxycycloalkyl-2-phenyl-9-benzyl-8-azaadenines showed very high affinity (Ki<40 nM) and selectivity for A(1) adenosine receptors. Among the 2-phenyl-9-(2-hydroxy-3-alkyl)-8-azaadenines or adenines prepared, the compounds with the higher A(1) affinity and selectivity resulted 2-phenyl-9-(2-hydroxy-3-propyl)-N(6)-cyclopentyl- and cyclohexyl-8-azaadenine with Ki 2.2+/-0.2 nM and 2.8+/-0.3 nM respectively. From the point of view of water-solubility, 2-phenyl-9-(2-hydroxy-3-propyl)-8-azaadenine was the most interesting compound, having a CLogP of 1.066991 and a water-solubility of 1.2 mg mL(-1).     

Morphine withdrawal-induced abnormalities in the VTA: confocal laser scanning microscopy

Morphine withdrawal is characterized by functional alterations at the level of the ventrotegmental area. We investigated the effects of chronic morphine administration and withdrawal on the morphological properties of immuno-labelled tyrosine hydroxylase-positive neurons of the rat ventrotegmental area with a confocal laser scanning microscope. Morphological evaluation revealed a reduction in the area and perimeter of tyrosine hydroxylase-positive somata in morphine-withdrawn rats. Conversely, the number of cells per field was found to have increased in the naloxone group. Collectively, the present results indicate that withdrawal from a chronic morphine treatment, and not chronic morphine per se, modifies cellular morphology of tyrosine hydroxylase-positive, presumably dopamine-containing, neurons of the rat VTA. This is consistent with the idea that withdrawal from morphine alters functioning of the mesolimbic dopamine system and provides a direct morphological correlate for the functional abnormalities typical of morphine withdrawal.     

Abstracts presented at the Fifth International Conference on Geriatric Nephrology and Urology, 4–6 October 1999, Salamanca,Spain (part 4)

Abstract List

Abstracts presented at the Fifth International Conference on Geriatric Nephrology and Urology, 4–6 October 1999, Salamanca, Spain (part 4)     

Expansion of natural killer cells in patients with head and neck cancer: detection of "noninhibitory" (activating) killer Ig-like receptors on circulating natural killer cells

BACKGROUND: In a group of patients with head and neck cancers (H&NC), the expansion of the population of CD3-,CD16+ natural killer (NK) cells in the peripheral blood was studied. METHODS: Cytofluorimetric analysis of the expression of killer Ig-like receptors (KIR, namely p58.1, p58.2, p58.3, p70, and p140) and CD94-NKG2a was performed. Cytolytic activities were studied using 51Cr release assay. T and NK cell cloning was performed using limiting dilution culture conditions. Cytokine production was analyzed using commercial enzyme immunoassays. RESULTS: Phenotypic analysis showed that the expanded populations were heterogeneous. Even in the presence of a large number of circulating NK cells, "nonspecific" cytolytic capacities were heavily reduced, whereas cytolytic capacity related to T cells was virtually normal. Unlike NK cell clones derived from healthy donors, most NK cells derived from H&NC patients expressed surface "activating" NK cell receptors (KAR) for HLA, detected by use of a redirected cytolytic assay. Analysis of the CD4+ subpopulation at the clonal level demonstrated that they had a severe proliferative defect. CONCLUSION: These experimental data indicated that H&NC patients have a polyclonal expansion of functionally deficient NK cells expressing KAR. In addition, the proliferative capacity of patients' "helper" cells was strongly inhibited, thus accounting for a severe impairment of cytolytic activity of the expanded NK cells.     

Diabetes insipidus as first manifestation of acute myeloid leukaemia with EVI‐1‐positive, 3q21q26 syndrome and T cell‐line antigen expression: what is the EVI‐1 gene role?

Two cases of acute myeloid leukaemia (AML) with CD2 and CD7 expression associated with diabetes insipidus (DI) as the initial symptom are presented. Both patients had t(3;3)(q21;q26) associated with monosomy 7 and EVI-1 overexpression. No neurohypophysis infiltration was evident. One patient died during induction chemotherapy, the other did not respond to therapy and died with persistent DI. Our findings further support the existence of a distinct AML entity characterized by the presence of DI, abnormalities of chromosome 3q, dysmegakaryopoiesis and poor outcome, and provide evidence of EVI-1 gene involvement. The possible role of chromosome 3q26 abnormalities in determining this peculiar clinical-biological association is emphasized.     

A rapid method for obtaining mesenchymal stem cells and platelets from bone marrow aspirate

Mesenchymal stem cells (MSCs) and platelet‐rich plasma (PRP) are currently used alone or in combination for therapeutic applications especially for bone repair. We tested whether MSCs can be isolated from bone marrow (BM) aspirate using a commercially available kit commonly used to obtain PRP from peripheral blood (PB). Results revealed that mononuclear cells and platelets from both PB and BM could be efficiently isolated by obtaining a mononuclear and platelet rich fraction (PB‐MPRF and BM‐MPRF, respectively). Starting with comparable volumes, the number of platelets increased 1.5‐fold in BM‐MPRF compared to PB‐MPRF. The number of clonogenic cells in BM‐MPRF samples was significantly higher than whole BM samples as revealed by CFU‐F assay (54.92 ± 8.55 CFU‐F/1.5 x 10⁵ nucleated cells and 32.50 ± 12.43 CFU‐F/1.5 x 10⁵ nucleated cells, respectively). Cells isolated from BM‐MPRF after in vitro expansion fulfilled the definition of MSCs by phenotypic criteria, and differentiated along osteogenic, adipogenic and chondrogenic lineages following induction. Results showed that the kit isolated MSCs and platelets from BM aspirate. Isolated MSCs were further expanded in a laboratory and BM‐MPRF was used clinically following BM withdrawal for rapid intra‐operative cell therapy for the treatment of bone defects. Copyright © 2012 John Wiley & Sons, Ltd.     

Does an asthma education program improve quality of life? A two-year randomized trial.

Asthma education programs result in clinical improvement. However, most studies involved programs of up to 1 year of follow-up, and their efficacy in improving quality of life (QoL) is still controversial. The aim of this study was to evaluate the effectiveness of a program of patient education in asthmatics over 2 years. Thirty-seven asthmatic patients were randomly allocated to group A (usual treatment) and 32 to group B (usual treatment plus patient education program). The effectiveness of the education program was evaluated by comparing morbidity outcomes at baseline and 12 and 24 months afterwards. At baseline, no intergroup difference emerged in age, sex, smoking, asthma severity, atopy, FEV1, symptom-free days, use of rescue salbutamol, and QoL. One year later, group B subjects had an improvement in the overall QoL (from 5.8 +/- 0.8 to 6.1 +/- 0.7, p < 0.005), and in "Activities" (from 5.3 +/- 0.9 to 5.7 +/- 0.8, p < 0.05) and "Environment" (from 6.4 +/- 1.0 to 6.8 +/- 0.4, p < 0.05) domains. Two years later the "Activities" domain score increased in group B (from 5.3 +/- 0.9 to 5.7 +/- 1.1, p < 0.05). QoL did not vary in group A. The education program was ineffective in all other parameters at both follow-up time-points. In group A, a significant increase in medication expenses and a significant decrease in rescue salbutamol use was found 1 and 2 years after baseline, respectively. In conclusion, this education program improved QoL for 1 year, but the improvement was not sustained in the 2nd year.     

Blood pressure and cardiovascular involvement in children with neurofibromatosis type1

We evaluated blood pressure in a sample of patients with neurofibromatosis type 1 (NF1), using ambulatory blood pressure monitoring (ABPM), to determine whether ABPM, when compared with casual BP recordings, allowed the detection of a higher risk for hypertension. We also evaluated the correlation between BP and vascular abnormalities. We studied 69 NF1 patients (36 males and 33 females) with a mean age of 11±4 years, divided into group A, with 24-h mean systolic blood pressure (SBP) or diastolic blood pressure (DBP) <95th percentile, and group B, with mean SBP or DBP >95th percentile. Standard electrocardiography and M-mode, two-dimensional echocardiography were performed and all patients were in sinus rhythm. ABPM identified 11 hypertensive patients (16%); 5 had a mean SBP >95th percentile, 3 mean SBP–DBP >95th percentile, and 3 a mean DBP >95th percentile. Laboratory and other investigations to exclude secondary hypertension were normal. Cardiac abnormalities were found in 13 of the 69 patients (18.8%) with NF1. There were no significant clinical and cardiac differences between the normotensive and hypertensive group. Our data emphasize the importance of periodic ABPM in NF1 patients to diagnose hypertension early and avoid target organ damage and increased mortality.     

Presence and distribution of ghrelin-immunopositive cells in the chicken gastrointestinal tract

The presence and distribution patterns of ghrelin, a gastric acylated peptide, were studied in the entire gastrointestinal tract of the chicken (Gallus domesticus) using the peroxidase-antiperoxidase immunohistochemical method, western blot analysis and a specific antibody against the C-terminal region of rat ghrelin. Ghrelin-immunopositive cells were observed in the mucosal layer of all segments examined. The largest numbers of ghrelin-positive cells were located at the base of lobuli of the proventriculus gland, along villi of the intestines and in crypts of the duodenum. Lower numbers of ghrelin-immunostained cells were located in crypts of jejunum and ileum and only few ghrelin-immunostained cells were detected at the base of crypts of the large intestine. Closed and open types of cells were observed in all segments. Western blot analysis confirmed the presence of ghrelin-like protein in the entire chicken gastrointestinal tract. The anatomical distribution patterns and the morphological characteristics of chicken ghrelin-positive cells suggest that they are endocrine cells. Furthermore, it is concluded that ghrelin shows a high degree of preservation during evolution from non-mammalian vertebrates to mammals.