Light sources used in evaluating oral leukoplakia: broadband white light versus narrowband imaging.

This study aimed to investigate the clinical efficacy of using broadband white light (BWL) to observe morphologic appearance, narrow-band imaging (NBI) to observe intraepithelial microvasculature, and both BWL and NBI for the detection of high-grade dysplasia and carcinoma in oral leukoplakia. Among 317 patients (274 males and 43 females; aged 52.4±10.7 years), the odds ratio (95% confidence interval) for detecting high-grade dysplasia and carcinomatous lesions based on morphologic appearances of BWL, and microvasculature patterns of NBI, were 39.12 (9.33-64.10), and 97.16 (38.19-247.21), respectively, which were significantly better than BWL (p<1×10(-15)). The sensitivity, specificity, positive and negative predictive values, and accuracy of use of traditional BWL classification, NBI classification, and combined BWL and NBI classification for detecting high-grade dysplasia and carcinomatous lesions were 96.30, 60.08, 33.12, 98.75, 66.25, 39.92, and 3.70%; 87.04, 93.54, 73.44, 97.23, and 92.43%; and 100.00, 60.08, 33.96, 100.00, and 66.88%, respectively. In conclusion, the diagnostic accuracy by NBI classification of oral leukoplakia based on the intraepithelial microvasculature patterns is significantly better than BWL indicating that NBI is a promising non-invasive tool in detecting high-grade dysplasia and carcinomatous lesions in oral leukoplakia.

Molecular characterization of tetralogy of fallot within Digeorge critical region of the chromosome 22.

The purpose of this study was to determine whether the levels of heterozygosity and microdeletion of specific loci within the DiGeorge critical region (del22q11) are associated with different phenotypes of tetralogy of Fallot (TF). Examinations were conducted on 84 sporadic TF patients and their unaffected parents for del22q11, using the following 9 simple tandem repeat polymorphic microsatellite markers: D22S420, D22S427, D22S941, D22S944, D22S264, D22S311, D22S425, D22S303, D22S257. The microdeletions were confirmed using quantitative PCR with markers TUPLE1, exon 2 of the UFD1L gene, and D22S264; the boundaries of these microdeletions were estimated using genotypic analyses of the unaffected family members. The del22q11 was identified in 14 patients (16.6%). The boundary of the shortest region of deletion overlap (SRO) in these 14 TF patients was identified, proximally using D22S427 and distally using the TUPLE 1 gene. The deletion of exon 2 of the UFD1L gene and TUPLE1 gene was identified in 13 patients (13/14 cases; 93%). The SRO in TF patients with del22q11 was at or close to the ADU breakpoint and centromeric to the UFD1L gene. The level of heterozygosity for the marker D22S944 in TF patients without del22q11 (n = 70) was found to be significantly lower than expected. Overall, this study demonstrated the significantly low level of heterozygosity within DiGeorge critical region in TF patients with or without del22q11. Our results suggest that the genetic factors leading to DiGeorge/velocardiofacial syndrome might also be partly responsible for TF phenotypes.

Monozygotic twins with chromosome 22q11 microdeletion and discordant phenotypes in cardiovascular patterning.

Monozygotic twins with chromosome 22q11 microdeletions offer an ideal situation to observe the association of microdeletion and disrupted cardiovascular patterning. We report monozygotic twins concordant for 22q11.2 microdeletion but discordant for cardiovascular patterning. Both twins showed identical intracardiac defects including tetralogy of Fallot with pulmonary atresia. Nevertheless, their great vessel patternings were variable. These twins show that the mispatterning of the great vessels may not correlate with intracardiac morphogenesis. The discordant development of the great vessels, especially in the pulmonary vascular system, has clinical significance for prognosis. The phenotypic variability of cardiovascular anomalies seen in 22q11 microdeletion cannot be explained on the basis of genotypic difference.

Chromosome 22q11 microdeletion in conotruncal heart defects: clinical presentation, parental origin and de novo mutations.

Using genotype analysis and multiplex quantitative polymerase chain reaction (PCR), chromosome 22q11 deletions were examined in 252 patients with syndromic or isolated conotruncal heart defect. Of these patients, 19 (7.5%) were found to be hemizygous for chromosome 22q11. Parental origin of the deleted chromosome was determined in 16 cases: one patient (6.3%) inherited a deleted chromosome 22 from his mother; all the others (93.7%) consisted of de novo mutations. One-third (5/15) of the de novo 22q11 deletions were of paternal origin and the remainder derived maternally. These results lend further support to our current knowledge of chromosome 22q11 microdeletion syndromes and their implications for the genetic counseling of individuals diagnosed with conotruncal heart defects. Possible mechanisms for gender-biased parental origin are discussed.

Right middle lobe atelectasis associated with endobronchial silicotic lesions.

BACKGROUND: In a period of 18 months, we have encountered 4 cases of right middle lobe atelectasis associated with endobronchial silicotic lesions of right middle lobe bronchi. All patients had occupational exposure to mineral dusts (3 coal miners and 1 sand blaster) for months to decades. METHODS: The nature of the endobronchial silicotic lesions that caused the bronchial obstruction has been confirmed by endobronchial biopsies and energy-dispersive spectrometry of the lesions. Extrinsic compression has been excluded by careful radiographic and computed tomographic image analysis. RESULTS: The endobronchial silicosis does not appear to correlate with the degree of pneumoconiosis of the lung parenchyma. The endobronchial silicosis may cause bronchial obstruction in the absence of radiographic evidence of pulmonary silicosis. CONCLUSION: The endobronchial silicosis and consequent lung atelectasis may be associated with silica exposure.

Comparison of the BACTEC MGIT 960 with Löwenstein-Jensen medium for recovery of mycobacteria from clinical specimens.

SETTING: Taiwan Provincial Chronic Disease Control Bureau. OBJECTIVE: To evaluate the rate of recovery and the mean time to detection (TTD) of mycobacteria in clinical specimens with two culture systems, the BACTEC MGIT 960 and Löwenstein-Jensen (LJ) medium. DESIGN: We studied 365 specimens, collected from 166 patients. Specimens were processed with standard N-acetyl-L-cysteine (NALC)-NaOH method, then inoculated onto BACTEC MGIT 960 and onto LJ slants. RESULTS: A total of 124 mycobacterial isolates (114 Mycobacterium tuberculosis and 10 non-tuberculous mycobacteria) were detected. The recovery rates were 94% (117/124) with BACTEC MGIT 960 and 75.8% (94/124) with LJ. The rates of contamination for each of the systems were 5.5% with BACTEC MGIT 960 and 4.1% with LJ. The TTDs for mycobacteria were 10.7 days with BACTEC MGIT 960 and 30.6 days with LJ. Excluding the non-tuberculous mycobacteria, the TTDs for M. tuberculosis were 11.1 days with BACTEC MGIT 960 and 30.7 days with LJ. The difference in TTD between smear-positive and smear-negative specimens for either mycobacteria (10.0 vs 12.6 days; P = 0.06) or M. tuberculosis (10.1 vs 12.7 days; P = 0.06) with BACTEC MGIT 960 was not statistically significant. CONCLUSION: The BACTEC MGIT 960 system can expedite the recovery of mycobacteria in culture. Combined with conventional solid medium, it also increases the overall recovery of mycobacteria in culture.

In vitro activity of rifabutin and rifampin against clinical isolates of Mycobacterium tuberculosis in Taiwan.

BACKGROUND AND PURPOSE: To determine the in vitro activity of rifabutin against Mycobacterium tuberculosis (MTB) and the cross-resistance rate between rifampin and rifabutin. METHODS: A total of 56 clinical isolates of MTB, including 23 multidrug-resistant (MDR) isolates and 33 susceptible isolates, were tested for susceptibility to rifampin and rifabutin using the absolute concentration method. The concentrations of drugs tested were 2.5 and 5 mg/mL for rifampin and 0.1, 0.5, 1, 2.5, 5, and 10 mg/mL for rifabutin. RESULTS: All 33 MTB isolates that were susceptible to rifampin were also susceptible to rifabutin. None of the 23 MDR-MTB isolates were inhibited by rifabutin at a concentration of 0.1 mg/mL. Among these 23 MDR isolates, three were susceptible to rifabutin at concentrations > or = 0.5 mg/mL, six were susceptible to rifabutin at concentrations > or = 5 mg/mL, 18 were susceptible to rifabutin at concentrations > or = 10 mg/mL and five were not inhibited at any of the concentrations tested. The cross-resistance rate between rifampin and rifabutin was 87%. CONCLUSIONS: Our results indicate that the in vitro activity of rifabutin against drug-susceptible MTB isolates is greater than that of rifampin. For MDR-MTB isolates, the cross-resistance is high between rifampin and rifabutin.

Prevalence and parental origin in Tetralogy of Fallot associated with chromosome 22q11 microdeletion.

OBJECTIVE: Tetralogy of Fallot is a common cardiac anomaly that is associated with chromosome 22q11 microdeletion. In this study we examined the mode of transmission as well as the parental origin of microdeletion in patients with tetralogy of Fallot. METHODS: Eighty-four children with sporadic tetralogy of Fallot (40 boys and 44 girls; mean age, 34 months) were analyzed for microdeletion at chromosome 22q11 by genotype analysis, using five microsatellite markers, D22S427, D22S941, D22S944, D22S264 and D22S311, and confirmed by quantitative polymerase chain reaction, using TUPLE1 and D22S264. All parents of these subjects consented to their own participation and their child's participation in the clinical evaluation and molecular study. To provide a molecular characterization of microdeletion, we isolated DNA from the parents and typed their DNA with each of the five polymorphic markers. RESULTS: Sixty-six patients were associated with pulmonary stenosis; and 8 of these cases (12%) had microdeletion. Eighteen patients were associated with pulmonary atresia, and 6 (33%) of these cases had microdeletion. The parental origins of the 14 patients with microdeletion were paternal in 3 cases and maternal in 11 cases. The most common mode of transmission was de novo without parental hemizygosity (93%). Transmission by autosomal dominant heredity was uncommon (7%). CONCLUSIONS: Biased parental origin was consistently found in tetralogy of Fallot patients with chromosomal 22q11 microdeletion. Our results indicated a higher prevalence of microdeletion because of inheritance of maternal microdeletion (78%).

Ethambutol-induced pulmonary infiltrates with fever and skin rash: a case report.

A 55-year-old man presented with the suspicion of pulmonary tuberculosis. He was treated with isoniazid, ethambutol, rifampicin and pyrazinamide. However, he developed high fever, skin rash and pulmonary infiltrates following 10 days of treatment. The above-mentioned conditions subsided promptly after stopping ethambutol therapy and reappeared after rechallenge, marking ethambutol as the offender. To present knowledge, this is the second case of an ethambutol-induced hypersensitivity lung reaction reported in English literature.