Assessment of mycobacterial interspersed repetitive unit-QUB markers to further discriminate the Beijing genotype in a population-based study of the genetic diversity of Mycobacterium tuberculosis clinical isolates from Okinawa, Ryukyu Islands, Japan

The present investigation focused on genetic diversity and drug resistance of 101 Mycobacterium tuberculosis strains isolated between July 2003 and February 2005 in the Okinawa prefecture, Ryukyu Islands, Japan. A high rate of clustering (87%, eight clusters, 2 to 69 strains/cluster) was observed upon spoligotyping; most of it was due to the lower discriminatory power of this method for the Beijing lineage (n = 72; 71.3% of the isolates). The remaining diversity was limited to seven clusters (two to five isolates/cluster), with the following distribution of major lineages: ill-defined T (n = 13; 12.8%), ancestral East African-Indian (n = 6; 5.9%), Haarlem (n = 4; 4%), Latin American-Mediterranean (n = 2; 2%), X1 (n = 1; 1%), and a total absence of the central Asian clade. Three remaining strains could not be classified on the basis of their spoligotype pattern and were labeled "unknown." Subtyping with mycobacterial interspersed repetitive units (MIRUs) in association with additional QUB minisatellites was performed to discriminate among the Beijing strains. Based on an "in-house" spoligotyping/MIRU database (n = 694 Beijing strains), eight highly discriminative MIRU loci for Beijing strains were selected (loci numbered 10, 16, 23, 26, 27, 31, 39, and 40). The highest discriminatory power (h) observed in our sample (n = 72; M-26, 0.385; M-10, 0.38; M-31, 0.255; M-16, 0.238) was too low, and 73.6% of the Beijing strains from Okinawa remained clustered. Typing of Beijing strains with additional QUB loci (with the exception of "one-copy" QUB-1451) resulted in higher discriminatory powers: QUB-11b, 0.68; QUB-11a, 0.656; QUB-26, 0.644; QUB-18, 0.553; QUB-4156, 0.5; and QUB-1895, 0.453. A definitive algorithm on the use of QUB markers to subtype Beijing isolates in expanded studies would shed light on their hypervariability, which may sometimes blur recognition between epidemiologically linked Beijing isolates. The total absence of multiple drug resistance among Beijing isolates from Okinawa, as well as the relatively older ages of the patients (majority above 60 years), shows that tuberculosis (TB) is a declining disease in Okinawa, and an adequate TB control program has successfully avoided both the emergence and the spread of multidrug-resistant TB in this insular setting.     

Pathologic characteristics of pediatric intracranial pilocytic astrocytomas and their impact on outcome in 3 countries: a multi-institutional study

Pilocytic astrocytoma (PA) is one of the most common glial neoplasms in the pediatric population, and its gross total resection can be curative. Treatment of partially resected or recurrent tumors is challenging, and the factors associated with increased recurrence risk are not well defined. Identification of favorable and unfavorable factors can lead to a better understanding and management of patients with PA. We studied the pathologic characteristics of 116 intracranial PAs from 4 institutions representing 3 distinct geographic regions to identify factors that may be associated with biological behavior. The study included 65 boys and 51 girls with a median age of 6 years. Median follow-up for all patients was 101 months, during which time 38 patients had recurrence. Progression-free and overall survivals were better in patients who underwent gross total resection. We were not able to identify any differences in pathologic and molecular markers among the 4 institutions from 3 different countries. However, progression-free survival varied significantly among institutions. Sox-2 was the most prevalent stem cell marker in PA, and many tumors showed synaptophysin positivity. BRAF immunostaining was not useful in determining BRAF duplication. BRAF duplication was more typical of posterior fossa tumors. There was a strong correlation between BRAF duplication and pERK immunostaining, suggesting that the RAF/MEK/ERK pathway is active in these tumors. This finding has significant implications given its role in oncogen-induced senescence and possible influence on treatment decisions of subtotally resected tumors.     

Longitudinal study of epileptiform EEG patterns in normal children

EEG were recorded in 3,726 children, from 6 to 13 years of age who were neurologically normal and had no history of epileptic seizures. The records were taken during wakefulness, at rest, and during hyperventilation. In 131 cases (3.54%) epileptiform patterns were found. They consisted of 3 count/sec spike and slow waves discharges (4 cases), multiple spike and slow wave complexes (37 cases), midtemporal spikes (50 cases), rolandic or parietal spikes (27 cases), occipital spikes (2 cases), and multifocal spikes (11 cases). Half of the subjects with EEG abnormalities had behavior problems and/or slight psychomotor ability disturbances. Follow-up studies over an 8 to 9 year period were performed. These demonstrated the spontaneous disappearance of the EEG abnormalities, usually within school age or, at the latest, during adolesence. Only seven individuals developed epileptic seizures of the primary generalized type which responded well to anticonvulsant drug treatment. From this study we can deduce that the epileptiform EEG patterns that often are found in children during school age have no clinical relationship to epilepsy in the great majority of cases. The relationship with epilepsy exists probably on a genetic level for the generalized discharges. The spike foci are non-epileptic in nature in all probability, especially if they emerge from a fairly normal background activity and their duration is very similar to that of the constituents of the background activity, as found in the majority of these subjects. On the contrary, it is probable that these alterations express difficulties in affective or motor adaptation during childhood.     

Evaluation of a new binary system of grading oral epithelial dysplasia for prediction of malignant transformation

The aim of this paper is to assess the reproducibility of a novel binary grading system (high/low risk) of oral epithelial dysplasia and to compare it with the WHO classification 2005. The accuracy of the new system for predicting malignant transformation was also assessed. Ninety-six consecutive oral epithelial dysplasia biopsies with known clinical outcomes were retrieved from the Oral Pathology archives. A pilot study was conducted on 28 cases to determine the process of classification. Four observers then reviewed the same set of H&E stained slides of 68 oral dysplastic lesions using the two grading systems blinded to the clinical outcomes. The overall inter-observer unweighted and weighted kappa agreements for the WHO grading system were K_s = 0.22 (95% CI: 0.11–0.35), K_w = 0.63 (95% CI: 0.42–0.78), respectively, versus K = 0.50 (95% CI: 0.35–0.67) for the new binary system. Interestingly, all pathologists showed satisfactory agreement on the distinction of mild dysplasia from severe dysplasia and from carcinoma in situ using the new WHO classification. However, assessment of moderate dysplasia remains problematic. The sensitivity and specificity of the new binary grading system for predicting malignant transformation in oral epithelial dysplasia were 85% and 80%, respectively and the accuracy was 82%. The new binary grading system complemented the WHO Classification 2005 and may have merit in helping clinicians to make critical clinical decisions particularly for the cases of moderate dysplasia. Histological grading of dysplasia using established criteria is a reproducible prognosticator in oral epithelial dysplasia. Furthermore, the present study showed that more consensus scoring on either the degree of dysplasia, assessment of risk or the presence of each morphological characteristic by a panel should be encouraged.