2108. Evaluation of Bezlotoxumab for the Prevention of Recurrent Clostridioides difficile Infection in Patients Living With Cancer at a Large Comprehensive Cancer Center

Background

Bezlotoxumab is a fully human monoclonal antibody that binds and neutralizes Clostridioides difficile toxin B. Administration of bezlotoxumab along with standard of care antibiotic (SoC) treatment of C. difficile infections (CDI) is associated with lower rates of CDI recurrence (rCDI). We aimed to determine the real-world incidence of rCDI in patients with cancer within 12 weeks after receiving bezlotoxumab.

Methods

This is a retrospective, single-center, descriptive study of patients with cancer that received bezlotoxumab from Jan 2018 through Oct 2021 at a large cancer center. rCDI was defined as a clinical illness associated with a positive stool nucleic acid amplification test with or without a confirmatory toxin assay for which CDI SoC was prescribed.

Results

A total of 131 patients were included in the study (median age of 63 years, 47% male, 77% Caucasian, 21% ICU admission), with 31% having one or more CDI episodes ≤ 6 months prior to receiving bezlotoxumab. The most common primary cancer type was leukemia (36%) followed by a solid organ tumor (35%), lymphoma (21%), and myeloma (8%). Cytotoxic chemotherapy or immune checkpoint inhibitors were prescribed within 6 months in 78% of cases and 60% of patients were given antibiotics not related to CDI. Fidaxomicin was most frequently administered as SoC (56%), followed by oral vancomycin (44%) with or without intravenous metronidazole. Within 12 weeks following bezlotoxumab treatment, rCDI occurred in 14 (10.7%, 95% Cl 5.4% to 16.0%) patients. Using univariate analysis, patients with rCDI were more likely to have received levofloxacin before and during bezlotoxumab treatment (86% versus 47%; OR 6.76, 95% CI 1.45 - 31.56, p=0.009).

Conclusion

In this real-world study, the rate of rCDI following use of bezlotoxumab during SoC antibiotics was comparable to that seen in clinical trials. Use of levofloxacin as prophylaxis for prolonged neutropenia in hematologic malignancies was associated with significantly higher rates of rCDI in patients that received bezlotoxumab. Our study suggests that neutropenia and antibiotic induced dysbiosis are risk factors for rCDI despite bezlotoxumab administration.

Disclosures

Pablo C. Okhuysen, MD, AstraZeneca: Stocks/Bonds|Beam Therapeutics: Stocks/Bonds|Biontech: Stocks/Bonds|Deinove: Grant/Research Support|Ferring: Advisor/Consultant|Glaxo Smith Kleine: Stocks/Bonds|Johnson and Johnson: Stocks/Bonds|Melinta: Grant/Research Support|Merck Sharp & Dohme Corp: Grant/Research Support|Moderna: Stocks/Bonds|Napo Pharmaceuticals: Advisor/Consultant|Napo Pharmaceuticals: Grant/Research Support|Novavax: Stocks/Bonds|Pfizer: Stocks/Bonds|Summit: Advisor/Consultant|Summit: Grant/Research Support.

Dual-Layer Spectral-Computed Tomography Enhances the Separability of Calcium-Based Implant Material from Bone: An Ex Vivo Quantitative Imaging Study

Local treatment of bone loss with an injection of a resorbable, calcium-based implant material to replace bone has a long history of clinical use. The in vivo discrimination of changes in bone versus implant is challenging with standard computed tomography (CT). However, spectral-CT techniques enable the separation between tissues of similar densities but different chemical compositions. Dual-layer spectral-CT imaging and postprocessing analysis methods were applied to investigate the separability of AGN1 (a triphasic calcium-based implant) and bone after AGN1 injection in n = 10 male cadaveric femurs ex vivo. Using the area under the curve (AUC) from receiver-operating characteristic (ROC) analyses, the separability of AGN1 from bone was assessed for AGN1 (postoperatively) versus compact and versus femoral neck cancellous bone (both preoperatively). CT techniques included conventional Hounsfield (HU) and density-equivalent units (BMD, mg hydroxyapatite [HA]/cm³ ) and spectral-CT measures of effective atomic number (Zeff) and electron density (ED). The samples had a wide range of femoral neck BMD (55.66 to 241.71 mg HA/cm³ ). At the injection site average BMD, HU, Zeff, and ED increased from 69.5 mg HA/cm³ , 109 HU, 104.38 EDW, and 8.30 Zeff in the preoperative to 1233 mg HA/cm³ , 1741 HU, 181.27 EDW, and 13.55 Zeff in the postoperative CT scan, respectively. For compact bone at the femoral shaft the preoperative values were 1124.15 mg HA/cm³ , 1648 HU, 177 EDW, and 13.06 Zeff and were maintained postoperatively. Zeff showed substantially sharper distributions and significantly greater separability compared to ED, BMD, and HU (all p < 0.002, for both regions) with average AUCs for BMD, HU, ED, and Zeff of 0.670, 0.640, 0.645, and 0.753 for AGN1 versus compact and 0.996, 0.995, 0.994, and 0.998 for AGN1 versus femoral neck cancellous sites, respectively. Spectral-CT permits better discrimination of calcium-based implants like AGN1 from bone ex vivo. Our results warrant application of spectral-CT in patients undergoing procedures with similar implants. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Dose-efficient assessment of trabecular microstructure using ultra-high-resolution photon-counting CT

Photon-counting (PC) detectors for clinical computed tomography (CT) may offer improved imaging capabilities compared to conventional energy-integrating (EI) detectors, e.g. superior spatial resolution and detective efficiency. We here investigate if PCCT can reduce the administered dose in examinations aimed at quantifying trabecular bone microstructure. Five human vertebral bodies were scanned three times in an abdomen phantom (QRM, Germany) using an experimental dual-source CT (Somatom CounT, Siemens Healthineers, Germany) housing an EI detector (0.60 mm pixel size at the iso-center) and a PC detector (0.25 mm pixel size). A tube voltage of 120 kV was used. Tube current-time product for EICT was 355 mAs (23.8 mGy CTDI_{32 cm}). Dose-matched UHR-PCCT (UHRdm, 23.8 mGy) and noise-matched acquisitions (UHRnm, 10.5 mGy) were performed and reconstructed to a voxel size of 0.156 mm using a sharp kernel. Measurements of bone mineral density (BMD) and trabecular separation (Tb.Sp) and Tb.Sp percentiles reflecting the different scales of the trabecular interspacing were performed and compared to a gold-standard measurement using a peripheral CT device (XtremeCT, SCANCO Medical, Switzerland) with an isotropic voxel size of 0.082 mm and 6.6 mGy CTDI_{10 cm}. The image noise was quantified and the relative error with respect to the gold-standard along with the agreement between CT protocols using Lin's concordance correlation coefficient (r_CCC) were calculated. The Mean ± StdDev of the measured image noise levels in EICT was 109.6 ± 3.9 HU. UHRdm acquisitions (same dose as EICT) showed a significantly lower noise level of 78.6 ± 4.6 HU (p = 0.0122). UHRnm (44% dose of EICT) showed a noise level of 115.8 ± 3.7 HU, very similar to EICT at the same spatial resolution. For BMD the overall Mean ± StdDev for EI, UHRdm and UHRnm were 114.8 ± 28.6 mgHA/cm³, 121.6 ± 28.8 mgHA/cm³ and 121.5 ± 28.6 mgHA/cm³, respectively, compared to 123.1 ± 25.5 mgHA/cm³ for XtremeCT. For Tb.Sp these values were 1.86 ± 0.54 mm, 1.80 ± 0.56 mm and 1.84 ± 0.52 mm, respectively, compared to 1.66 ± 0.48 mm for XtremeCT. The ranking of the vertebrae with regard to Tb.Sp data was maintained throughout all Tb.Sp percentiles and among the CT protocols and the gold-standard. The agreement between protocols was very good for all comparisons: UHRnm vs. EICT (BMD r_CCC = 0.97; Tb.Sp r_CCC = 0.998), UHRnm vs. UHRdm (BMD r_CCC = 0.998; Tb.Sp r_CCC = 0.993) and UHRdm vs. EICT (BMD r_CCC = 0.97; Tb.Sp r_CCC = 0.991). Consequently, the relative RMS-errors from linear regressions against the gold-standard for EICT, UHRdm and UHRnm were very similar for BMD (7.1%, 5.2% and 5.4%) and for Tb.Sp (3.3%, 3.3% and 2.9%), with a much lower radiation dose for UHRnm. Short-term reproducibility for BMD measurements was similar and below 0.2% for all protocols, but for Tb.Sp showed better results for UHR (about 1/3 of the level for EICT). In conclusion, CT with UHR-PC detectors demonstrated lower image noise and better reproducibility for assessments of bone microstructure at similar dose levels. For UHRnm, radiation exposure levels could be reduced by 56% without deterioration of performance levels in the assessment of bone mineral density and bone microstructure.

Improved accuracy in the assessment of vertebral cortical thickness by quantitative computed tomography using the Iterative Convolution OptimizatioN (ICON) method

Vertebral whole bone strength is substantially affected by cortical bone properties. Disease and therapy may affect cancellous and cortical bone differently. Unlike Dual X-ray Absorptiometry (DXA), Quantitative Computed Tomography (QCT) permits selective assessment of cortical and cancellous bone, but image quality limits the accuracy. We present an image processing method specifically adopted to thin cortices that substantially improves accuracy. Ten human vertebrae embedded in epoxy resin were imaged using clinical QCT and High-Resolution QCT (HR-QCT) protocols, both acquired on a clinical whole body CT scanner, whereas high resolution peripheral QCT (HR-pQCT) was used as gold standard. Microstructural variables and BMD were calculated using in-house software StructuralInsight for QCT and HR-QCT and the manufacturer's μCT evaluation software for HR-pQCT. An adjusted measure, a deconvolved cortical thickness (dcCt.Th), corrected for partial volume effects, was derived applying the new Iterative Convolution OptimizatioN (ICON) method. Direct measurements of cortical thickness (Ct.Th) showed substantial overestimation with mean ± standard deviation of 1.8 ± 0.5 mm for QCT and 1.5 ± 0.3 mm for HR-QCT compared to 0.37 ± 0.07 mm using HR-pQCT. Correlations of both QCT (r² = 0.05, p > 0.5.) and HR-QCT (r² = 0.38, p = 0.060) with the gold standard HR-pQCT were not significant. Also QCT-based BMD and BMC as well as HR-QCT-based BMD did not show a significant correlation with the gold standard approach. Only HR-QCT-based BMC showed a modest correlation (r² = 0.59, p = 0.01) After applying ICON corrections, dcCt.Th resulted in 0.52 ± 0.09 mm for QCT and 0.43 ± 0.07 mm for HR-QCT, both significantly correlated to HR-pQCT (r² = 0.75, p = 0.0012 and r² = 0.93, p < 0.0001, respectively). The average overestimation bias of Ct.Th was reduced from (402 ± 157)% to (45 ± 17)% for QCT and from (330 ± 69)% to (19 ± 8)% for HR-QCT. Due to inaccurate segmentation uncorrected QCT-based Ct.Th measures as well as BMD and BMC showed no correlation to HR-pQCT and thus such bias cortical data can be misleading. The application of ICON reduced random overestimation bias to about 50 μm and 20 μm for QCT and HR-QCT, respectively, leading to a recovery of a significant correlation with the reference data of HR-pQCT. This reveals the potential for fairly accurate assessment of cortical thickness, allowing to better characterize cortical mechanical competence. These results warrant testing of the performance in vivo.

Assessment of Bone Fragility in Patients With Multiple Myeloma Using QCT-Based Finite Element Modeling

Multiple myeloma (MM) is a malignant plasma cell disease associated with severe bone destruction. Surgical intervention is often required to prevent vertebral body collapse and resulting neurological complications; however, its necessity is determined by measuring lesion size or number, without considering bone biomechanics. Finite element (FE) modeling, which simulates the physiological loading, may improve the prediction of fragility. To test this, we developed a quantitative computed tomography (QCT)-based FE model of the vertebra and applied it to a dataset of MM patients with and without prevalent fracture. FE models were generated from vertebral QCT scans of the T₁₂ (T₁₁ if T₁₂ was fractured) of 104 MM patients, 45 with fracture and 59 without, using a low-dose scan protocol (1.5 mm slice thickness, 4.0 to 6.5 mSv effective dose). A calibration phantom enabled the conversion of the CT Hounsfield units to FE material properties. Compressive loading of the vertebral body was simulated and the stiffness, yield load, and work to yield determined. To compare the parameters between fracture and nonfracture groups, t tests were used, and standardized odds ratios (sOR, normalized to standard deviation) and 95% confidence intervals were calculated. FE parameters were compared to mineral and structural parameters using linear regression. Patients with fracture showed lower vertebral stiffness (-15.2%; p = 0.010; sOR = 1.73; 95% CI, 1.11 to 2.70), yield force (-21.5%; p = 0.002; sOR = 2.09; 95% CI, 1.27 to 3.43), and work to yield (-27.4%; p = 0.001; sOR = 2.28; 95% CI, 1.33 to 3.92) compared to nonfracture patients. All parameters correlated significantly with vBMD (stiffness: R²  = 0.57, yield force: R²  = 0.59, work to yield: R²  = 0.50, p < 0.001), BV/TV (stiffness: R²  = 0.56, yield force: R²  = 0.58, work to yield: R²  = 0.49, p < 0.001), and Tb.Sp (stiffness: R²  = 0.51, yield force: R²  = 0.53, work to yield: R²  = 0.45, p < 0.001). FE modeling identified MM patients with compromised mechanical integrity of the vertebra. Higher sOR values were obtained for the biomechanical compared to structural or mineral measures, suggesting that FE modeling improves fragility assessment in these patients. © 2016 American Society for Bone and Mineral Research.

Off-Clamp Renal Tumourectomy by Retroperitoneoscopy in Posterior Renal Tumours of Medium Complexity (Padua score 8-9)

BACKGROUND

The guidelines recommend partial surgery for T1 renal tumours. Various aspects of this surgery have evolved in recent years, including the clamping method and duration, enucleation, the retroperitoneoscopic approach and the use of 3mm ports. We present our initial series on laparoscopic renal tumourectomy by retroperitoneoscopy (LRTR) and analyse our learning curve and use of 3-mm instrumentation.

MATERIAL AND METHODS

From January 2011 to January 2015, we performed LRTR on 50 patients with posterior or convex T1 renal tumours. After 10 cases, the technique changed to off-clamp, and 11 cases were subsequently performed with 3mm instrumentation.

RESULTS

The mean tumour size was 34.36 mm (14-62), with a mean PADUA score of 8.42 (5-12). The mean operative time was 163.1 minutes (75-300), and the mean warm ischaemia time was 4.21 minutes (0-28). The main renal artery was not clamped in 41 (82%) patients, and no vessel (zero ischaemia) was clamped in 39 (78%) patients. Seven cases had positive margins (6 focal). Eleven LRTRs were performed with 3mm instrumentation, with shorter surgical times, less intraoperative bleeding and shorter hospital stays.

CONCLUSIONS

Retroperitoneoscopy coupled with enucleation enables the extirpation without clamping of posterior renal tumours, with a relatively short learning curve. The 3-mm material enables the technique to be performed, although in our experience it has resulted in a higher rate of positive surgical margins.

Effects of parathyroid hormone on cortical porosity, non-enzymatic glycation and bone tissue mechanics in rats with type 2 diabetes mellitus

Type 2 diabetes mellitus increases skeletal fragility; however, the contributing mechanisms and the efficacy of bone-forming agents are unclear. We studied diabetes and parathyroid hormone (PTH) treatment effects on cortical porosity (Ct.Po), non-enzymatic glycation (NEG) and bone mechanics in Zucker diabetic fatty (ZDF) rats. Eleven-week old ZDF diabetic (DB) and non-diabetic (ND) rats were given 75μg/kg PTH (1-84) or vehicle 5days per week over 12weeks. The right femora and L4 vertebrae were excised, micro-CT scanned, and tested in 3-point bending and uniaxial compression, respectively. NEG of the samples was determined using fluorescence. Diabetes increased Ct.Po (vertebra (vert): +40.6%, femur (fem): +15.5% vs. ND group, p<0.05) but had no effect on NEG. PTH therapy reduced vertebral NEG in the ND animals only (-73% vs untreated group, p<0.05), and increased femoral NEG in the DB vs. ND groups (+63%, p<0.05). PTH therapy had no effect on Ct.Po. Diabetes negatively affected bone tissue mechanics where reductions in vertebral maximum strain (-22%) and toughness (-42%) were observed in the DB vs. ND group (p<0.05). PTH improved maximum strain in the vertebra of the ND animals (+21%, p<0.05) but did not have an effect in the DB group. PTH increased femoral maximum strain (+21%) and toughness (+28%) in ND and decreased femoral maximum stress (-13%) and toughness (-27%) in the DB animals (treated vs. untreated, p<0.05). Ct.Po correlated negatively with maximum stress (fem: R=-0.35, p<0.05, vert: R=-0.57, p<0.01), maximum strain (fem: R=-0.35, p<0.05, vert: R=-0.43, p<0.05) and toughness (fem: R=-0.34, p<0.05, vert: R=-0.55, p<0.01), and NEG correlated negatively with toughness at the femur (R=-0.34, p<0.05) and maximum strain at the vertebra (R=-0.49, p<0.05). Diabetes increased cortical porosity and reduced bone mechanics, which were not improved with PTH treatment. PTH therapy alone may worsen diabetic bone mechanics through formation of new bone with high AGEs cross-linking. Optimal treatment regimens must address both improvements of bone mass and glycemic control in order to successfully reduce diabetic bone fragility. This article is part of a Special Issue entitled "Bone and diabetes".

Microsatellites and Alu elements from the human MHC in Valencia (Spain): analysis of genetic relationships and linkage disequilibrium

Two different sets of noncoding markers (microsatellites and Alu elements) from the human chromosome six were analysed in 106 individuals from Valencia (Spain), with the aim of exploring the effect of evolutionary forces on the genetic variability of the major histocompatibility complex (MHC) and assessing the potential usefulness of these genetic loci in phylogenetic studies. Linkage disequilibrium (LD) analyses revealed statistically significant associations among markers located in the MHC class I region, and also between the microsatellite D6S2792 and several genetic loci from MHC class I, II and III regions. Results of the Ewens-Watterson test indicated that only D6S2792 showed significant departure from selective neutrality. Despite the paucity of haplotype data in the literature, results of the phylogenetic analyses at world scale (Alu elements) showed that the genetic relationships of Valencia were mainly determined by the ethnic ancestry of the populations considered, whereas at European scale (microsatellites) population affinities were strongly influenced by geography. Our findings suggest that noncoding markers from the MHC such as Alu and microsatellite loci might have a potential value as lineage (ancestry) markers in investigations into evolutionary, medical and forensic perspectives.

Alterations in myeloid dendritic cell innate immune responses in the Galphai2-deficient mouse model of colitis

BACKGROUND

The G protein alpha subunit type-2 (Galpha(i)2)-deficient mouse develops inflammatory bowel disease (IBD) with increased severity in mice on a 129SvEv (129) background compared to the C57BL/6 (B6) background. Since dendritic cells (DCs) are key cells of innate immunity, we determined whether Galpha(i)2(-/-) DCs have functional defects, influenced by strain background, that predispose to IBD.

METHODS

By breeding these strains to homozygosity for the first time, it became possible to study innate immunity in this animal model with more precision than ever before. Immature DCs were generated using bone marrow monoblasts cultured in the presence of GM-CSF (BMDCs), DC subsets sorted and responses to TLR9 activation were assayed.

RESULTS

In contrast to Galpha(i)2(-/-) B6, Galpha(i)2(-/-) 129 mice display accelerated onset and increased severity of colitis, abnormal mucosal DC distribution, accompanied by preponderance for Th1 and Th17-associated gut cytokine expression. TLR9 activation of BMDCs induces sustained p38 MAPK activation and greater Th1- and Th17-type cytokine secretion in both strains of Galpha(i)2-deficient compared to wildtype BMDCs. However, only B6 Galpha(i)2(-/-) BMDCs concomitantly produces IL-10 while Galpha(i)2(-/-) 129 BMDCs do not.

CONCLUSIONS

Loss of Galpha(i)2 promotes a Th1/Th17 phenotype and relative IL-10 insufficiency in Galpha(i)2(-/-) 129 BMDCs may account for the striking difference in disease.

Cognitive functioning in children with multiple sclerosis

Objective

To examine the cognitive functioning of children with multiple sclerosis (MS).

Methods

Six children with a diagnosis of clinically definite MS were evaluated using a neuropsychological test battery.

Results

The majority of the children showed deficits in at least two of the administered subtests, with IQ scores within the deficient classification.

Conclusions

Verbal and non-verbal skills were equally impaired, and patients who were older at the moment of the onset of the disease had a better cognitive performance. Cognitive deficits should be regarded as a common occurrence in the course of MS in children.

Mitochondrial DNA haplogroup diversity in Basques: a reassessment based on HVI and HVII polymorphisms

This study provides a more complete characterization of the mitochondrial genome variability of the Basques, including data on the hypervariable segment HVII of the D-loop region, which remains relatively unknown. To that end, genomic DNA from 55 healthy men living in the Arratia Valley (Biscay province) and the Goiherri region (Guipúzcoa province) was examined by direct sequencing. Three-generation pedigree charts were compiled to ensure the collection from autochthonous individuals. The most notable findings emerging from the analysis of haplogroup composition are: (i) lack of U8a mitochondrial lineage, a rare subhaplogroup recently identified in Basques and proposed as a Paleolithic marker, (ii) low frequency of haplogroup V, which conflicts with results of earlier analyses describing high frequencies in southwestern Europe, and (iii) high frequency of haplogroup J, especially subhaplogroups J1c1 and J2a. The frequency of haplogroup J does not coincide with previous mtDNA studies in present-day Basques, but is congruent with frequencies found in prehistoric and historic Basque populations. In explaining divergence in haplogroup composition between modern Basque samples, we hypothesized spatial heterogeneity promoted by population fragmentation due to extreme limitation of dispersal opportunities during the Pleistocene glaciations. Similarities between extinct and extant Basque populations as for the high frequency of lineage J, as well as the abundance of this haplogroup in northern Spain endorse a shift in the focus of attention of mtDNA analysts. A refined dissection of haplogroup J might provide more solid evidence about the process of postglacial recolonization of Europe, and thus about the shaping of the European gene pool.

Polymorphic Alu insertions and the genetic structure of Iberian Basques

Eight Alu sequences (ACE, TPA25, PV92, APO, FXIIIB, D1, A25 and B65) were analyzed in two samples from Navarre and Guipúzcoa provinces (Basque Country, Spain). Alu data for other European, Caucasus and North African populations were compiled from the literature for comparison purposes to assess the genetic relationships of the Basques in a broader geographic context. Results of both MDS plot and AMOVA revealed spatial heterogeneity among these three population clusters clearly defined by geography. On the contrary, no substantial genetic heterogeneity was found between the Basque samples, or between Basques and other Europeans (excluding Caucasus populations). Moreover, the genetic information obtained from Alu data conflicts with hypotheses linking the origin of Basques with populations from North Africa (Berbers) or from the Caucasus region (Georgia). In order to explain the reduced genetic heterogeneity detected by Alu insertions among Basque subpopulations, values of the Wright's F(ST )statistic were estimated for both Alu markers and a set of short tandem repeats (STRs) in terms of two geographical scales: (1) the Basque Country, (2) Europe (including Basques). In the Basque area, estimates of Wahlund's effect for both genetic markers showed no statistical difference between Basque subpopulations. However, when this analysis was performed on a European scale, F(ST) values were significantly higher for Alu insertions than for STR alleles. From these results, we suggest that the spatial heterogeneity of the Basque gene pool identified in previous polymorphism studies is relatively recent and probably caused by a differential process of genetic admixture with non-Basque neighboring populations modulated by the effect of a linguistic barrier to random mating.

Genetic position of Valencia (Spain) in the Mediterranean basin according toAlu insertions

In this work, eight human-specific Alu insertion polymorphisms (ACE, TPA25, PV92, APO, FXIIIB, D1, A25, and B65) were typed in 106 unrelated healthy individuals born in the province of Valencia (Spain), with the aim of analyzing the genetic relationships between this region of the Iberian Peninsula and other Mediterranean populations. To that end, Alu data on Eastern European, Western European, and North African populations were compiled from previous studies. The genetic information was stressed by means of genetic distances (R matrix method), nonmetric multidimensional scaling (MDS) and analyses of molecular variance (AMOVA). In Valencia, the most common Alu insertion was APO (0.940), and the least frequent was A25 (0.104). The average gene diversity (GD) computed for the sample examined was comparatively high (0.382). The insertion frequencies estimated for the eight Alu markers were very similar to the mean frequencies calculated for the whole set of populations included in the study, suggesting the hybrid nature of the Valencia's gene pool. MDS and AMOVA results generated from Alu data reveal that the Mediterranean has acted as a strong genetic boundary between the north (Europe) and the south (Northern Africa), resulting in significant gene diversity between the populations of the two regions. Restricted exclusively to the European scope, we suggest the possibility that the Mediterranean could have also acted as a migratory passageway, propitiating the dissemination of cultures and genes between the east and west of Europe and giving rise to some homogenization of gene frequencies among coastal dwelling populations.

[Current evidence about atomoxetine. A therapeutic alternative for the treatment of attention deficit hyperactivity disorder]

AIMS

To conduct an updated review of the mechanisms of action, pharmacokinetics, clinical effectiveness and safety of atomoxetine in the treatment of the symptoms of ADHD.

DEVELOPMENT

Atomoxetine is the first of the group of non-stimulant drugs to be approved by the US Food and Drug Administration to treat this disorder in children, adolescents and adults. Atomoxetine has a direct effect on noradrenalin and dopamine concentrations by exerting a strong and highly selective inhibiting action on the pre-synaptic noradrenalin transporter, with a minimum affinity for other transporters and receptors. After adjustment of the dosage for body weight, the pharmacokinetic parameters are similar across all age and gender groups. Maximal plasma concentration is reached one to two hours after oral administration. Data concerning the effectiveness and safety from the clinical trials and studies reported in the literature are discussed.

CONCLUSIONS

Atomoxetine is an effective and well-tolerated drug when used for the pharmacological treatment of ADHD symptoms. Despite being a drug that has only recently been developed, evidence from the large number of comparative studies that have been carried out endorse its widespread use in the treatment of this syndrome.

Allelic frequencies of 13 STR loci in autochthonous Basques from the province of Vizcaya (Spain)

Allelic frequencies of 13 STR loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D16S539, TH01, TPOX, CSF1PO, and D7S820) were estimated from a sample of 73 unrelated healthy donors natives of the Spanish Basque province of Vizcaya. These STR loci constitute the core of polymerase chain reaction (PCR)-based DNA genetic markers in the US Combined DNA Index System (CODIS). All STR loci analysed met Hardy-Weinberg expectations. Based upon the allelic frequencies, forensically important parameters including gene diversity (GD), polymorphism information content (PIC) and power of discrimination (PD) were calculated.

Genetic polymorphism and linkage disequilibrium of the HLA-DP region in Basques from Navarre (Spain)

In this work, a sample of 116 individuals from an autochthonous Basque population (northern Navarre, Spain) was typed at the DNA level for HLA-DPA1 and HLA-DPB1 loci, with the aim of analysing the genetic polymorphism and the linkage disequilibrium (LD) of the HLA-DP region. In this Basque subpopulation, the most frequent alleles were *0103 (0.767) and *0201 (0.185) for DPA1 locus, whereas for DPB1 locus the *0401 allele was predominant (0.307). Accordingly, the most frequent haplotype was DPA1*0103-DPB1*0401 (0.300), which showed a significant LD. However, the haplotypes that most differentiated the sample of Navarre from other worldwide populations already analysed were DPA1*0105-DPB1*1901 (0.011) and DPA1*0201-DPB1*7601 (0.021), both of which showed a strong LD. Analysis of the relationships between populations based on data provided by HLA-DPA1 and HLA-DPB1 loci revealed a high genetic affinity between the Basque samples (North Navarre and Guipúzcoa), which, in turn, tend to plot separately from the remaining European populations. Gene frequency clines for DPB1*01, DPB1*04 and DPB1*11 alleles among European populations are reported for the first time. These alleles showed maximum values of F(ST) (0.033, 0.034 and 0.025, respectively). Various evolutionary forces were considered in discussing the origin of the spatial structuring of the gene frequencies: (i) gene flow, argued from the hypotheses of Post-glacial recolonization from southern Europe or the demic diffusion of farmers from the Near East into Europe, and (ii) the existence of selective pressures that could have generated genetic microdifferentiation.

Genotypic and phenotypic studies of murine intestinal lactobacilli: species differences in mice with and without colitis

Lactobacilli represent components of the commensal mammalian gastrointestinal microbiota and are useful as probiotics, functional foods, and dairy products. This study includes systematic polyphasic analyses of murine intestinal Lactobacillus isolates and correlation of taxonomic findings with data from cytokine production assays. Lactobacilli were recovered from mice with microbiota-dependent colitis (interleukin-10 [IL-10]-deficient C57BL/6 mice) and from mice without colitis (Swiss Webster and inducible nitric oxide synthetase-deficient C57BL/6 mice). Polyphasic analyses were performed to elucidate taxonomic relationships among 88 reference and murine gastrointestinal lactobacilli. Genotypic tests included single-locus analyses (16S ribosomal DNA sequencing and 16S-23S rRNA intergenic spacer region PCR) and genomic DNA profiling (repetitive DNA element-based PCR), and phenotypic analyses encompassed more than 50 tests for carbohydrate utilization, enzyme production, and antimicrobial resistance. From 20 mice without colitis, six Lactobacillus species were recovered; the majority of the mice were colonized with L. reuteri or L. murinus (72% of isolates). In contrast, only, L. johnsonii was isolated from 14 IL-10-deficient mice. Using an in vitro assay, we screened murine isolates for their ability to inhibit tumor necrosis factor alpha (TNF-alpha) secretion by lipopolysaccharide-activated macrophages. Interestingly, a subpopulation of lactobacilli recovered from mice without colitis displayed TNF-alpha inhibitory properties, whereas none of the L. johnsonii isolates from IL-10-deficient mice exhibited this effect. We propose that differences among intestinal Lactobacillus populations in mammals, combined with host genetic susceptibilities, may account partly for variations in host mucosal responses.

[Characterization of neuronal ceroid lipofuscinosis in Venezuelan children]

INTRODUCTION

Neuronal ceroid lipofuscinosis (NCL), represents a group of inherited neurodegenerative disorders. Based on the age of the patient at onset, clinical course and ultrastructural morphology it has been identified three clinical types for the pediatric group: 1) Infantile NCL (INCL); 2) Late infantile NCL (LINCL); and 3) Juvenile NCL (JNCL). Other variants or atypical forms represent around 20% of the NCL in different populations. Genetic advances have made possible a better characterization, diagnostic and classification of these disorders.

CASE REPORTS

We present the clinical, neurophysiological, neuroradiological, and morphological data from 6 patients with NCL, who were assessed at the pediatric neurology department of the Hospital Universitario de Maracaibo during a ten years period (1993 2003). All 6 cases corresponded with the late infantile form. Age of onset ranged form 2 to 5 years. For most of the patients initial symptoms included seizures, psychomotor delay, accompanied by macular degeneration and optic atrophy. The EEG was characterized by high voltage spikes elicited by low frequency photic stimulation, in 5 cases. Neuroimaging findings were characteristic of the late infantile form of the NCL. In three patients a decreased intensity of signal was seen in the thalami and putamen on T2-weighted images. The ultrastructural examination of the samples obtained through a biopsy showed curvilinear bodies in all patients.

CONCLUSION

There is not epidemiological data of the NCL in Venezuela; it is presumed the presence of clinical forms and variants in the pediatric group. This first study could contribute to the knowledge and a better research of this group of disorders in our population.

[Epidemiological data about attention deficit hyperactivity disorder in a sample of Marabino children]

AIMS

This study reports the findings of a research project aimed at determining the rate of prevalence of attention deficit hyperactivity disorder (ADHD) in school aged children.

PATIENTS AND METHODS

Different behavioural and cognitive measures were administered to a sample of children between 3 and 13 years of age obtained by means of a multistage sampling procedure that was stratified by socioeconomic and educational level. The sample was made up of 394 children; 33.25% (n = 131) were females and the remaining 66.75% (n = 263) males. The mean age of the sample was 7.64 years old (SD: 2.33). The assessment battery included the Conners Rating Scales adapted for parents and teachers, the abbreviated version of the Wechsler Intelligence Scale for Children (WISC III) and for Preschool children Revised (WPPSI R), several academic achievement scales, development history and DISC IV.

RESULTS

The estimated prevalence of ADHD was 10.15%, and a figure of 2.03% was obtained for the hyperactive type, 0.51% for the inattentive subtype, and 7.61% for the combined subtype. Prevalence was higher for males, the ratio being 3:1. Subjects performance in the cognitive and academic measures was within the average interval.

CONCLUSIONS

The prevalence of ADHD in our population oscillates around the average figures reported in other countries. This study confirms the prevalence of ADHD in the population of Venezuela, with a distribution of subtypes and in terms of gender similar to those reported in the literature.

HLA-DQA1 polymorphism in autochthonous Basques from Navarre (Spain): genetic position within European and Mediterranean scopes

In this work, a sample of 112 individuals from an autochthonous Basque population (Northern Navarre, Spain) were typed at the DNA level for the HLA-DQA1 locus, with the aim of characterizing its polymorphism and analyzing the genetic relationships of Basque Navarrese with other Caucasian populations. Northern Navarre is a neighboring area with Guipúzcoa, a province located in the core of the Basque territory having the highest proportion of Basque-speakers. In Navarrese population, the most frequent alleles were DQA1*01 (0.375) and DQA1*02 (0.259). Frequency clines for both DQA1*0103 allele and DQA1*04* allele cluster (including DQA1*0401, DQA1*0501 and DQA1*0601) among the European and Mediterranean populations considered are reported for the first time. Furthermore, a spatial structuring previously described for DQA1*02 allele is corroborated. The information provided by the highly polymorphic HLA-DQA1 locus was stressed by using genetic distances and non-metrical multidimensional scaling (MDS). The analysis of genetic relationships among populations showed a high genetic affinity between the Basque subpopulations of Northern Navarre and Guipúzcoa, which in turn tended to plot separately from the remaining European and Mediterranean populations. In the same way, the Basques showed no clear relationship to North African populations, as postulated in several previous HLA studies. The observed genetic heterogeneity seems to be conditioned by the high frequencies of the DQA1*02 allele in Basques from Guipúzcoa and North Navarre. These two subpopulations seem to show low levels of admixture with other non-Basque neighboring populations, probably because of their deeply rooted ethnicity and the existence of a linguistic barrier to random mating.

Allele variation of DYS19 and Y-Alu insertion (YAP) polymorphisms in Basques: an insight into the peopling of Europe and the Mediterranean region

Two Y-chromosome DNA polymorphisms, the DYS19 microsatellite and the YAP (at locus DYS287), were tested in males from two autochthonous Basque populations from France and northern Navarre (Spain). The results are compared to those obtained for the same genetic markers in 32 populations from Europe, northern Africa, and western Asia. The high predominance of the DYS19*11 (190-base-pair) allele in Basques indicates that their genetic diversity for microsatellite DYS19 is around half that observed in Europeans, North Africans, and western Asians. The Y-Alu insertion (YAP+) was not detected in the Basque samples. This study attempts to throw some light on the importance of historically recent migratory movements, the main corridors of gene flow, and demographic sizes and their variations in shaping gene frequency patterns in contemporary human populations, particularly in the Mediterranean region. Historical processes may have had more significant effects on the genetic make-up of current human populations than those of prehistoric times.

[The attention deficit hyperactivity disorder myth or reality?]

INTRODUCTION

The attention deficit hyperactivity disorder (ADHD) has been defined as a disorder of self control characterized clinically by a short attention span, excessive motor activity and poor impulse control.

OBJECTIVE

The main objective is to describe how methodological difficulties related to the design of epidemiological studies make an important contribution to the group of heterogeneous data which might lead to doubts regarding the validity of ADHD in children. In recent decades the psychiatric definition of this disorder has varied. This has affected the number and combination of clinical signs necessary for diagnosis of ADHD. The variation in the prevalence rates of the disorder reported in different studies is largely due to these changes. Other factors involved are related to the assessment methods, the type of sample (clinical or community), the source of information (parents, teachers and/or children) and sociocultural characteristics.

CONCLUSIONS

ADHD is a valid disorder. It cannot be considered to be a myth since there is considerable evidence of its existence and clinical characteristics in children in different countries.

[Estimations of the prevalence of attention deficit hyperactivity disorder in Marabino children]

AIMS

This study reports the findings of research aimed at determining the rate of prevalence of attention deficit hyperactivity disorder (ADHD) in children of school age.

SUBJECTS AND METHOD

The epidemiological study was conducted using a community sample extracted by means of multi stage stratified sampling according to socio economic level and schooling and consisted in 1,141 children of both sexes of school age from the city of Maracaibo. The revised Conners scales were used to collect data.

RESULTS

The estimated prevalence of ADHD was 7.19% and we also obtained 0.35% for the hyperactive type, 1.14% for the disattentional subtype, and 5.70% for the combined type. Contrary to what was expected, prevalence was higher for females. It was found that 7.45% of the general sample scored higher on the academic problems scales, whereas for the sample identified as having ADHD, academic problems were 50% and the comorbidity between ADHD and academic problems was confirmed.

CONCLUSIONS

The estimates for prevalence found in this study are consistent with those reported in the literature, which suggests that ADHD is a valid diagnosis for Marabino children.

Inbreeding and demographic transition in the Orozco Valley (Basque Country, Spain)

Inbreeding in the Orozco Valley (Basque Country, Spain) between the 18th and 20th centuries was investigated on the basis of ecclesiastical dispensations and surname lists. The variations over time are very similar to those observed elsewhere in Europe, with a major increase in the coefficient of inbreeding in the late 19th and early 20th centuries. This is due mainly to an increase in marriages between first cousins. A highly marked decrease in inbreeding is observed during the 20th century. The secular trends described by the coefficient calculated on the basis of dispensations and by that calculated on isonymy are very similar. The nonrandom component of isonymy reveals a selective search for a related spouse during the period of maximum inbreeding. These results are associated with the process of demographic transition which affected European populations as a whole in the 19th century, resulting in a greater availability of kin among potential mates and thus enabling inbreeding to increase to levels far higher than those observed for earlier centuries.

[A pilot study of methylphenidate and parent training in the treatment of children with attention-deficit hiperactivity disorder]

OBJECTIVE

This study gives information about a parent training program and a clinical trial with a stimulant drug (methylphenidate) to reduce the symptoms of attention deficit hiperactivity disorder (ADHD) in a group of children in Venezuela.

PATIENTS AND METHODS

24 children, aged between 6 and 10 years and diagnosed as having ADHD, identified in ADHD screening days, were randomly assigned to two groups of treatment: parent training and a stimulant drug (methylphenidate).

RESULTS

Both groups showed an improvement in their symptoms, to different degrees, after treatment. The differences were statistically significant, as evaluated by their parents, regarding the symptoms of inattention, hyperactivity and impulsivity. The teachers observed a significant improvement for the medication group with respect to the symptoms of hyperactivity and impulsivity, but no change in the inattention, whilst in the parent training group there was only significant difference in the ADHD index. There was no difference in the effectiveness of the two types of treatment.

CONCLUSIONS

When the two programs of treatment were compared it was observed that both parent training and psychostimulant medication were effective in reducing the symptoms of ADHD. Although there was no difference in the effectiveness of the two programs, there was a tendency for medication to be more effective

Molecular evidence of Helicobacter cinaedi organisms in human gastric biopsy specimens

One hundred twenty-six urease-negative gastric biopsy specimens were evaluated for the presence of Helicobacter genus-specific 16S ribosomal DNA (rDNA) and H. pylori-specific glmM DNA sequences by PCR. The species specificity of the glmM PCR assay was demonstrated, as H. pylori was the only Helicobacter species that yielded the expected glmM amplicon. Most urease-negative specimens (118 of 126 specimens) lacked Helicobacter DNA. However, 8 of 126 urease-negative specimens contained Helicobacter 16S rDNA. In order to identify the Helicobacter species present in urease-negative gastric biopsy specimens, 16S rDNA amplicons were cloned and sequenced. Sequence comparisons were performed by analyses of the sequences in public sequence databases. Two samples contained 16S rDNA that was identified as H. cinaedi with 100% identity and that spanned approximately 400 bp (398 and 398 bp, respectively). In contrast, multiple differences (97% identity; 390 of 398 bp) were observed with H. pylori 16S rDNA in this region. This finding was verified by sequencing an overlapping 537-bp fragment within the 5' portion of 16S rDNA. Although the clinical findings were consistent with H. pylori infection (e.g., duodenal ulcer disease), rapid urease testing and DNA sequence analyses suggested the presence of H. cinaedi organisms and the absence of H. pylori in two human antral biopsy specimens. This study represents the first report of an enteric urease-negative helicobacter in the human stomach. Although these organisms were previously associated with extragastric infections, the roles of these organisms in the pathogenesis of chronic gastritis or peptic ulcer disease remain unclear.

Microsatellite DNA markers from HLA region (D6S105, D6S265 and TNFa) in autochthonous Basques from Northern Navarre (Spain)

BACKGROUND

The extent of the genetic polymorphism of the HLA complex is becoming well characterized in Basque population and their subpopulations. This level of knowledge mainly concerns HLA class I loci. However, Basque population surveys dealing with HLA class II genes and/or microsatellites in the HLA region are still very scarce.

AIM

The population genetics of three highly polymorphic short tandem repeat (STR) loci, D6S105, D6S265 and TNFa, from HLA region has been analysed in autochthonous (indigenous) Basques from Northern Navarre (Spain). The same blood samples have been typed for HLA class II genes from DQ/DR/DP regions and some findings from that information can be found therein.

SUBJECTS AND METHODS

Blood samples were taken from 107 unrelated autochthonous Basques from Northern Navarre. The criterion used to define Northern Navarrese identity was that of three generations of Basque surnames and birthplaces.

RESULTS

The main features observed in Navarrese Basques were the rather high frequencies of alleles D6S105*4 and D6S265*7. A novel allele has been detected at the D6S265 locus (13: 145 bp). The most frequent haplotype was D6S105*8-D6S265*4 with a highly significant linkage disequilibrium being presented. The high frequency of allele TNFa*1 in Basques is noteworthy and this characteristic is not shared by other European populations, where TNFa*1 is absent or shows negligible values. The multidimensional scaling analysis (MDS) for TNFa allele frequencies has shown a high variability among populations and that alleles TNFa*1 (F(ST) = 0.0615) and TNFa*12 (F(ST) = 0.0424) seem to have significant influence over the spatial population configuration. TNFa*2 showed the lowest FST value (0.0077) because of its conspicuous homogeneous distribution all over the European populations.

CONCLUSIONS

Findings shown here on HLA microsatellites and their relationships with other HLA class I and class II genes in Basques can be helpful for those studies mainly addressed at detecting associations between HLA genes and diseases in the Basque area as a whole, and particularly in its autochthonous population, settled there since remote times.

[Disseminated acute encephalomyelitis in children]

INTRODUCTION

Disseminated acute encephalomyelitis (DAE) is an autoimmune inflammatory condition, usually monophasic with gradual resolution, polysymptomatic, usually in relation to a virus, bacteria or immunizations but may also occur in the absence of any obvious infection.

OBJECTIVE

To describe DAE, its aetiology, clinical features, diagnosis and treatment. Also to analyze these aspects with regard to a series of 13 children with DAE.

RESULTS

The clinical condition started with fever in 61% of the patients. The commonest neurological findings were sensory deterioration, convulsions and motor disorders (paresias). The cerebrospinal fluid was abnormal in four patients. MR showed hyperintense lesions of multifocal distribution, predominantly in the subcortical white matter. All patients were treated with intravenous methylprednisolone at a dose of 20 30 mg/kg. Clinical follow up showed complete recovery in 11/13 patients and mild sequelae in two cases.

CONCLUSIONS

Diagnosis of DAE is based on suggestive clinical data and MR findings. MR is very sensitive in detecting demyelinating lesions and is the method of choice for confirmation of the diagnosis. DAE is characterized by a satisfactory clinical course with simultaneous resolution of the demyelinating lesions.

An insight into recent consanguinity within the Basque area in Spain. Effects of autochthony, industrialization and demographic changes

BACKGROUND

The importance of studying the genetic kinship of those human groups characterized by a deeply rooted ethnicity has traditionally been and still is an interesting goal of anthropological and population genetic studies. However, only a few surveys have aimed to learn about the impact of industrial development on the consanguinity of these populations and even those have concentrated on industrialized regions. This approach is worth analysing in Spain, where industrialization was late in relation to other western European countries.

AIM

In this work we analyse the characteristics of inbreeding in Guipúzcoa from 1951 to 1995. This Basque province underwent industrial and tourist development earlier than other Spanish regions. It has the highest density of Basque speakers and has always occupied a central position within the map of distribution of the Basque language. Guipúzcoa is geographically placed in the core of the Basque area. SUDJECTS AND METHODS: Data on consanguineous marriages recorded in the province of Guipúzcoa between 1951 and 1995 were taken from Roman Catholic dispensations stored in the Diocesan Archives of San Sebastián, the province's capital city. Over the whole time period, a total of 1152 consanguineous marriages were registered.

RESULTS

The high frequencies of first cousin (M22) (F = 1/16) and uncle-niece, aunt-nephew (M12) (F = 1/8) consanguineous marriages distinguish Guipúzcoa from the rest of Iberian populations. The M22/M33 ratio (with M33 being second cousins) has never dropped below 0.67, which represents a significant deviation from the expectation value of 0.25. When consanguineous marriages are classified according to marriage partner birthplaces interesting results emerge. Provincial endogamy shows the highest consanguinity rates (57%) and the proportion of M22/M33 is also rather high (0.63). However, a major contribution to the consanguinity levels and mean inbreeding coefficient recorded in Guipúzcoa over recent decades has been made by immigrant relative groups coming from other geographical areas of Spain. In this segment of population the observed M22/M33 rates are 1.44.

CONCLUSIONS

This study shows again how important preferentiality (or avoidance) is in human consanguinity, and also how human groups, in spite of being spatially settled in the same territory, present differential attitudes for given consanguinity patterns.

Serial MRI findings in the Costa Rican variant of neuronal ceroid-lipofuscinosis

Widespread cerebral atrophy and basal ganglia involvement are highly suggestive imaging features of the variants of late infantile type neuronal ceroid-lipofuscinosis. In the presence of clinical findings indicative of neuronal ceroid-lipofuscinosis, neuroimaging procedures are highly recommended to differentiate the variants from classic late infantile neuronal ceroid-lipofuscinosis. The clinical features and follow-up magnetic resonance imaging studies in a patient with the Costa Rican variant of late infantile neuronal ceroid-lipofuscinosis is presented. These procedures were of the utmost importance to observe the progression of the neurologic ailment and the extent of the cerebral and cerebellar abnormalities.

Molecular resistance testing of Helicobacter pylori in gastric biopsies

OBJECTIVE

To evaluate simultaneous diagnosis of infection and molecular resistance testing of Helicobacter pylori.

METHODS

Gastric biopsies were obtained from 26 rapid urease-positive and 51 rapid urease-negative test kits used to diagnose H pylori infection. Following glass bead-assisted DNA isolation, amplification of H pylori 16S ribosomal DNA (rDNA), glmM, and 23S rDNA target genes was performed.

RESULTS

Helicobacter pylori DNA was successfully amplified from 100% (26/26) of urease-positive and 3.9% (2/51) of urease-negative gastric biopsies. Subsequent restriction enzyme-mediated digestion of 23S rDNA amplification products revealed that 17% (4/24) of urease-positive and H pylori DNA-positive biopsy specimens contained point mutations (A2142G or A2143G) associated with clarithromycin resistance. Helicobacter pylori DNA from gastric biopsies was successfully amplified 8 weeks following rapid urease testing.

CONCLUSION

Helicobacter pylori genotyping may be used to detect macrolide-resistant H pylori in individuals prior to initiation of therapy or in patients refractory to anti-H pylori therapy. Two urease-negative specimens yielded Helicobacter DNA distinct from that of H pylori and indicated the need for further investigations of Helicobacter species present in the human stomach.

[Discrepancy between parents and teachers in the evaluation of behavior and educational problems in children and adolescents]

INTRODUCTION

The process of psychological evaluation in children ought to include detailed information as to the behavior and ability of children in different environments (home, school, recreation). The differences in the information from each source may be interpreted as reflecting the differences in behavior caused by the different context or interactions between the child and those reporting on him.

OBJECTIVE

To determine the relation between evaluation of the parents of their children s behavior and the evaluation of these same children by their teachers.

PATIENTS AND METHODS

We studied a group of 855 children distributed as follows: 325 in the group of 9 to 11 years (146 girls, 179 boys); 243 in the group 12 to 14 years (126 girls, 117 boys) and 287 in the group 15 to 17 years (145 girls, 142 boys). The parents and teachers of these children responded to the long version of the Conners Scale, revised for parents and teachers respectively.

RESULTS AND CONCLUSIONS

There was no uniformity in the evaluation of the academic and behavior problems of the children. The evaluations depended on the age of the child and the aspect described (hyperactivity, academic problems, anxiety). There was closer agreement between parents and teachers for academic and hyperactivity problems. This relation was firmer in the adolescent group.

Frameshift mutations in rdxA and metronidazole resistance in North American Helicobacter pylori isolates

In Helicobacter pylori, the oxygen-insensitive nitroreductase RdxA is likely to activate metronidazole (Mtz) by reduction and formation of cytotoxic intermediates. Mutations in rdxA have been associated with Mtz resistance in H. pylori. In vitro Mtz susceptibilities of 17 randomly selected H. pylori isolates were determined by the agar dilution method. DNA sequence analysis of rdxA alleles of eight susceptible isolates (MIC range: 0.25-1.0 mg/L) and nine resistant isolates (MIC range: 16-256 mg/L) showed that six of nine Mtz-resistant H. pylori isolates contained insertion or deletion mutations ('indel' mutations). One isolate contained a substitution mutation at codon position 148 that resulted in the introduction of a premature stop codon. Creation of stop codons within the rdxA coding sequence by either frameshift or substitution mutations resulted in premature translation termination and expression of putatively truncated RdxA polypeptides.

[Neurological aspects of ceroid-lipofuscinoses]

OBJECTIVE

We discuss the historical, epidemiological, clinical, complementary tests and neuropathological details of ceroid-lipofuscinoses in children.

DEVELOPMENT

Initially, we review the basic concepts and historical details of the disorders, and the frequency and distribution of the different clinical forms. Subsequently, we review the subtypes and variants most commonly found in children, together with the elements necessary for diagnosis. Finally we analyze the neuropathological studies and their clinical correlation.

CONCLUSIONS

The clinical diagnosis of ceroid-lipofuscinoses should be based on a clinical history showing disorders of vision, convulsions and regression of psychomotor functions. Neuroimaging findings, neurophysiological changes and ultrastructural studies confirm the diagnosis.

The genetic position of the autochthonous subpopulation of Northern Navarre (Spain) in relation to other basque subpopulations. A study based on GM and KM immunoglobulin allotypes

GM and KM immunoglobulin (Ig) allotypes were tested in 118 autochthonous Basques from northern Navarre. The results are compared to those obtained for the same genetic markers in 6 other Basque subpopulations, 3 from Spain (Guipúzcoa, Vizcaya, and Alava) and 3 from France: Macaye, Saint-Jean Pied de Port, and Mauleon. The northern Navarrese appear genetically closer to the Alava and Saint-Jean Pied de Port subpopulations. The Basques present 3 GM haplotypes that are uncommon in Caucasian populations, suggesting that they have not been completely isolated either from Asian or African populations. The GM*1,17 23' 10,11,13,15,16 north Asian haplotype was probably the first to be introduced into the Basque area. The GM*1,17 23' 5* haplotype, considered an African genetic marker although also detected in Central Asia, would have reached the Iberian Peninsula through consecutive historic migrations from North Africa. The rare haplotype GM*1,17 23 21,28 results probably from a genetic recombination or crossing-over between the 2 common haplotypes GM*1, 17 23' 21,28 and GM*3 23 5*. It is also found with a low frequency in other neighboring regions and countries; but the possibility of its having been introduced through the main passage connecting western France and Spain during the Roman Empire and Middle Ages cannot be ruled out.

[The classical clinical and neuroimaging features of meningiomas are mimicked by other intracranial, supratentorial expansive lesions]

OBJECTIVE

To analyze the surgical neurology cases in which both the clinical and neuroimaging features suggested supratentorial meningioma, and resulted in different entities from the neuropathological point of view.

PATIENTS AND METHODS

The clinical histories of patients harboring intracranial, supratentorial mass lesions diagnosed as meningioma operated in different hospitals of Maracaibo, Venezuela, during the period 1993-1997 were reviewed.

RESULTS

Our analysis revealed 15 cases with different neuropathological diagnosis. They were distributed as follows: three cases of hemangiopericytoma, two cases each of anaplastic ependymoma, metastatic carcinoma, and solitary intracranial plasmacytoma, and one case each of plasma cell granuloma, pleomorphic xanthoastrocytoma, chondroma, actinomycetoma, meningeal fibroma and chronic inflammation not otherwise specified.

CONCLUSION

A heterogeneous group of intracranial, supratentorial expansive mass lesions can masquerade as meningiomas both from the clinical and neuroimaging points of view.

GM, KM immunoglobulin allotypes and other serum genetic markers (HP, GC, PI, and TF) among South American populations living at different altitudes (Jujuy Province, Argentina): admixture estimates

A total of 154 individuals belonging to three populations located at different altitude levels in northwest Argentina (San Salvador de Jujuy, 1,200 m; Tilcara, 2,500 m; Abra Pampa, 3,500 m) were studied for the GM, KM, HP, GC, PI and TF genetic systems. Individuals were selected on the basis of ethnocultural affiliation. Gene frequency values were found to be comparable to those reported for other South American populations. The populations studied showed a close genetic identity and an absence of interpopulation heterogeneity. Distribution of the GM phenotypes and haplotypes corresponds to historical data on human settlements in Jujuy Province. The presence of some alleles and the anthropological significance of the allele distribution are discussed, as are the effects of the admixture with Africans and Spaniards. The genetic pattern appears to be the result of a varying admixture due to the genetic isolation in populations located at various altitude levels.

[Cortical dysplasias and epilepsy]

Cortical dysplasias are a spectrum of malformations of the cerebral cortex that arise during development and are associated with epilepsy and mental retardation. New neuroimaging techniques have helped an in vivo" diagnosis of these conditions and the definition of specific clinical syndromes. This article reviews the etiology of these disorders, and briefly discusses the clinical and neuroimaging findings, and the prognosis of the epilepsy secondary to these malformations.

Hallervorden-Spatz disease: two new early childhood onset cases

Hallervorden-Spatz disease is a rare, autosomal-recessive hereditary condition characterized by early onset of progressive movement alterations such as dystonia, rigidity, and choreoathetosis, which is usually associated with pyramidal signs and mental deterioration. The authors report two cases for which diagnosis of Hallervorden-Spatz disease was based on clinical manifestations that appeared during the first year of life, illness progression, and late-stage magnetic resonance imaging findings. The possibility that these two cases, along with other previously described rare instances with similar clinical features, be considered as a variant of subtype of the early-onset type of Hallervorden-Spatz disease is suggested. The need to differentiate these cases from cases of static encephalopathy with mental retardation and motor impairment is also stressed.

[Venezuelan equine encephalitis. 1995 outbreak: clinical profile of the case with neurologic involvement]

INTRODUCTION

Venezuelan equine encephalitis virus has caused periodic epidemics and epizootics in the American continent since the 1920s. Such events have been profusely documented from the epidemiologic point of view, however, reports concerning the clinical features of this disease are rather scarce.

OBJECTIVE

To analyze the clinical characteristics evidenced by Venezuelan equine encephalitis patients from Zulia state (western Venezuela) studied during the outbreak that occurred in Colombia and Venezuela in 1995. These cases, classified as complicated, were hospitalized at the Hospital Universitario de Maracaibo, state of Zulia, Venezuela.

PATIENTS AND METHODS

The clinical charts of 313 Venezuelan equine encephalitis patients hospitalized during the period January 1st 1995-March 31st 1996 were reviewed. These cases accounted for 2.82% of 11,072 patients that were medically assisted during the outbreak. The following variables were analyzed: age, gender, signs and symptoms, contact history, complications and evolution.

RESULTS

Intracranial hypertension signs became eloquent in 55.9% of these patients. Neurologic complications were represented by two cases of cerebellitis, two cases of meningoencephalitis and one case of encephalomyelitis. The mortality rate was 1.7%.

CONCLUSION

Our results corroborate the benign evolutionary profile that is typical of this entity.

[Prognosis of bacterial meningitis]

OBJECTIVES

To review the literature on the risk factors for bacterial meningitis (BM) and evaluate these factors in children diagnosed as having BM in the Paediatric Department of the University Hospital of Maracaibo between 1996 and 1998.

PATIENTS AND METHODS

We made a retrospective study of children diagnosed as having BM in the University of Maracaibo. We evaluated different factors related to BM.

RESULTS

From 1 January 1996 to 31 December 1998 a total of 152 children were diagnosed as having bacterial meningitis; 69.7% were boys and 30.3% were girls. The commonest causal germ was Haemophilus influenzae. Disorders of sensation (42.7%) and signs of meningism (32.8%) were the most frequent neurological alterations. The main laboratory findings were leucocytosis (51.3%), thrombocytosis (49.3%), pleocytosis (70.3%), cerebrospinal fluid protein (49.3%) and low cerebrospinal fluid glucose (72.8%). Twelve patients (7.5%) died. Of this group, 10 were under one year of age and had septic shock.

CONCLUSIONS

BM represents a major group of hospital admissions in everyday paediatric practice. Although the mortality has decreased, an increased risk of sequelas must be borne in mind. Clinico-neurological examination on admission and simultaneous analysis of laboratory investigations allows identification of prognostic indicators of morbidity and mortality.

Genetic population structure of two African-Ecuadorian communities of Esmeraldas

The genetic structure of two African-Ecuadorian communities, Rio Cayapas and Viche (Esmeraldas province, northwest Ecuador), was studied on the basis of ACP1, ADA, AK1, CA2, ESD, GLO1, G6PD, PGD, and PGM1 subtypes and thermostability, PGM2, HBbeta, F13A, F13B, ORM1, AHSG, C6, C7, and APOC2 gene frequency, and migration data on 255 individuals. The fixation index of Wright (F(ST)), correspondence, and genetic distance analysis were applied to compare the genetic relationships between these communities and other American populations of African ancestry. F(ST) values from the migration data and surname origins suggest that Rio Cayapas is genetically more isolated and shows less mobility and admixture than does Viche. The genetic admixture estimates indicate a large contribution of African genes to the gene pool of both communities (74.3% to 58.4%), whereas the proportion of the Amerindian component differs significantly (14.5% in Rio Cayapas to 27.6% in Viche).

Immunoglobulin allotypes (GM and KM) in Basques from Spain: approach to the origin of the Basque population

GM and KM immunoglobulin (Ig) allotypes have been tested in 310 autochthonous Basques from the three subpopulations of Vizcaya, Guipúzcoa, and Alava, Spain. They are compared with allotypes occurring in autochthonous French Basques, some Pyrenean subpopulations in France, and European populations. The analysis suggests that the Basque subpopulations show noticeable genetic distances between them and with other European populations. The genetic similarity between Basques and European populations is greater in the Basques from France than in the Basques from Spain. The genetic distances between Basque subpopulations in Spain fit well with the different historical levels of the spatial implantation of the Basque language. Guipúzcoa, the Basque province with the highest number of Basque-speaking people, shows the most genetic distinctiveness. The main underlying cause of this spatial genetic pattern seems to be admixture with surrounding populations. Our results do not support the hypothesis that Basques are a relict population of ancient Europeans. They might be a consequence of the colonization of the Basque area by a long-distance migrating group, probably a small Neolithic North Caucasian population that introduced agriculture in the region. They experienced early, rapid demographic growth, and they did not breed with the few hunter-gatherers wandering throughout the area. The North Caucasian migrants could have admixed with North Asian groups dating from many centuries before. Furthermore, Basques present polymorphic frequencies of a common African haplotype, suggesting that they have not been completely isolated from populations of Africa. However, another focus of the African haplotype has been detected in Central Asia, and the Basque frequencies alternatively might be due to North Asian groups.

Multiple kinship in two Spanish regions: new model relating multiple and simple consanguinity

The structure of the different categories of multiple consanguineous marriages (MCMs) and their historical variation patterns are analyzed in the Spanish dioceses of Alava (Basque Country) and Sigüenza-Guadalajara (Castile). Consanguineous marriages, up to third cousins, were taken from ecclesiastical dispensations, and the periods studied were 1831-1980 for Alava and 1861-1980 for Sigüenza-Guadalajara. Significant differences exist in the MCM rates in the two Spanish areas. In this study a model is proposed to prove that in a general population there may be dependence between MCM rates for specific relationships and the frequencies of those types of relationships in the form of simple consanguineous marriages (SCMs). The effects of avoidance and preferentiality and of underreporting are discussed to explain the deviations between observed and expected consanguineous marriage frequencies. A limit to the weight of remote consanguinity on the population inbreeding coefficient F is determined. The relationship between FT/FS and ms values from our two Spanish populations are fitted to curvilinear regressions. FT is the total population inbreeding coefficient, FS is the contribution to FT from SCMs, and ms is the relative observed frequency of SCMs in the general population.

[Influence of renal and hepatic function in the serum concentration of prostate specific antigen]

The influence of renal and hepatic functioning on serum levels of prostate specific antigen has been studied by examining its behaviour in a control group (CG) of 178 healthy male, a group of 48 patients with end-stage renal failure (ESRF) 22 of which had pre- and post-dialysis PSA measurements and a group of 48 patients with chronic liver failure (CLF). Mean PSA level in CHF, 0.64 ng/ml, was lower (p < 0.001) than the level seen either in CG, 1.37 ng/ml, and ESRF, 1.33 ng/ml, the last two exhibiting no statistical difference. Also, no significant differences were seen between pre- and post-dialysis PSA levels, 1.52 and 1.33 ng/ml respectively. The authors conclude that renal functioning has little relevance in the regulation of PSA serum levels and that, in spite of levels being lower in liver failure, this does not seem to be meaningful in the clinical practice.