[Diffusion-weighted imaging characteristics of uterine leiomyomas with different pathological subtypes at 3.0 T].

OBJECTIVE: To investigate the imaging features of uterine leiomyomas with different pathological subtypes on DWI. METHODS: Clinical records and MR images of pathologically confirmed uterine leiomyomas were retrospectively collected from the Second Affiliated Hospital of Wenzhou Medical University from June 2012 to April 2015. A total of 60 uterine leiomyomas were found and evaluated.All the patients were divided into three groups according to different pathological types, which included 17 cases of cellular leiomyomas, 10 cases of degenerated leiomyomas and 33 cases of ordinary leiomyomas.The DWI signal and ADC values in cellular portion of the lesions and adjacent normal myometrium (the control group) were measured. RESULTS: (1) Most cellular leiomyomas showed hyperintensity on DWI (15/17), while degenerated leiomyomas manifested hypointensity, isointensity or hyperintensity signal on DWI, and most ordinary leiomyomas displayed isointensity signal on DWI (57.6%, 19/33). (2) The ADC values of cellular leiomyomas, degenerated leiomyomas and ordinary leiomyomas were (1.01±0.14)×10(-3) mm(2)/s, (1.73±0.49)×10(-3) mm(2)/s and (1.38±0.22)×10(-3) mm(2)/s respectively.The ADC values of adjacent normal myometrium (the control group) were (1.35±0.16)×10(-3) mm(2)/s.There were no significant statistical differences in the ADC values between ordinary leiomyomas and adjacent normal myometrium (P=0.623). There were significant statistical differences in the ADC values among other groups(all P<0.05). (3)The ROC curve showed that the diagnostic threshold for cellular leiomyomas was 1.11×10(-3) mm(2)/s, the sensitivity and specificity were 88.2%and 93.0% respectively. CONCLUSION: The signal intensity on DWI and the ADC values are different in uterine leiomyomas with different pathological subtypes.Combination of these two parameters in clinical practice may be helpful to reflect the histopathological characteristics of uterine leiomyomas.

Identification and genetic mapping of the putative Thinopyrum intermedium-derived dominant powdery mildew resistance gene PmL962 on wheat chromosome arm 2BS.

KEY MESSAGE: Powdery resistance putatively derived from Thinopyrum intermedium in the wheat line L962 is controlled by a single dominant gene designated PmL962 and mapped to chromosome arm 2BS. Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease affecting the production of wheat (Triticum aestivum). Powdery mildew resistance was putatively transferred from Thinopyrum intermedium to the common wheat line L962, which conferred resistance to multiple Chinese Bgt isolates. Genetic analysis of the powdery mildew response was conducted by crossing the resistant line L962 with the susceptible line L983. Disease assessments of the F1, F2, and F2:3 populations from the cross L983/L962 indicated that resistance was controlled by a single dominant gene. A total of 373 F2:3 lines and 781 pairs of genomic simple sequence repeat (SSR) primers were employed to determine the chromosomal location of the resistance gene. The gene was linked to four publicly available and recently developed wheat genomic SSR markers and seven EST-STS markers. The resistance gene was mapped to chromosome arm 2BS based on the locations of the linked markers. Pedigree, molecular marker and resistance response data indicated that the powdery mildew resistance gene in L962 is novel. It was temporarily designated PmL962. It is flanked by Xwmc314 and BE443737at genetic distances of 2.09 and 3.74 cM, respectively, and located in a 20.77 cM interval that is co-linear with a 269.4 kb genomic region on chromosome 5 in Brachypodium distachyon and a 223.5 kb genomic region on rice (Oryza sativa) chromosome 4. The markers that are closely linked to this gene have potential applications in marker-assisted breeding.

A novel quantitative trait locus for Fusarium head blight resistance in chromosome 7A of wheat.

A Chinese Spring-Sumai 3 chromosome 7A disomic substitution line (CS-Sumai 3-7ADSL) was reported to have a high level of Fusarium head blight (FHB) resistance for symptom spread within a spike (Type II) and low deoxynivalenol accumulation in infected kernels (Type III), but a quantitative trait locus (QTL) on chromosome 7A has never been identified from this source. To characterize QTL on chromosome 7A, we developed 191 7A chromosome recombinant inbred lines (7ACRIL) from a cross between Chinese Spring and CS-Sumai 3-7ADSL and evaluated both types of resistance in three greenhouse experiments. Two major QTL with Sumai 3 origin, conditioning both Type II and III resistance, were mapped in the short arm of chromosomes 3B (3BS) and near the centromere of chromosome 7A (7AC). The 3BS QTL corresponds to previously reported Fhb1 from Sumai 3, whereas 7AC QTL, designated as Fhb7AC, is a novel QTL identified from CS-Sumai 3-7ADSL in this study. Fhb7AC explains 22% phenotypic variation for Type II and 24% for Type III resistance. Marker Xwmc17 is the closest marker to Fhb7AC for both types of resistance. Fhb1 and Fhb7AC were additive, and together explained 56% variation for Type II and 41% for Type III resistance and resulted in 66% reduction in FHB severity and 84% reduction in deoxynivalenol (DON) content. Haplotype analysis of Sumai 3 parents revealed that Fhb7AC originated from Funo, an Italian cultivar. Fhb7AC has the potential to be used in improving wheat cultivars for both types of resistance.

Quantitative trait loci for Fusarium head blight resistance in a recombinant inbred population of Wangshuibai/Wheaton.

Use of diverse sources of Fusarium head blight (FHB)-resistant germplasm in breeding may significantly improve wheat resistance to FHB. Wangshuibai is an FHB-resistant Chinese landrace unrelated to cv. Sumai 3, the most commonly used FHB-resistant source. In all, 139 F(6) recombinant inbred lines were developed from a cross between Wangshuibai and an FHB-susceptible cultivar, Wheaton, to map quantitative trait loci (QTL) for wheat resistance to initial infection (type I resistance), spread of FHB symptoms within a spike (type II resistance), and deoxynivalenol (DON) accumulation (type III resistance) in infected grain. The experiments were conducted in a greenhouse at Manhattan, KS from 2003 to 2005. More than 1,300 simple-sequence repeat and amplified fragment length polymorphism markers were analyzed in this population. Five QTL for type I resistance were detected on chromosomes 3AS, 3BS, 4B, 5AS, and 5DL after spray inoculation; seven QTL for type II resistance were identified on chromosomes 1A, 3BS, 3DL, 5AS, 5DL, and 7AL after point inoculation; and seven QTL for type III resistance were detected on chromosomes 1A, 1BL, 3BS, 5AS, 5DL, and 7AL with the data from both inoculation methods. These QTL jointly explained up to 31.7, 64, and 52.8% of the phenotypic variation for the three types of FHB resistance, respectively. The narrow-sense heritabilities were low for type I resistance (0.37 to 0.41) but moderately high for type II resistance (0.45 to 0.61) and type III resistance (0.44 to 0.67). The QTL on the distal end of 3BS, 5AS, and 5DL contributed to all three types of resistance. Two QTL, on 7AL and 1A, as well as one QTL near the centromere of 3BS (3BSc), showed effects on both type II and type III resistance. Selection for type II resistance may simultaneously improve type I and type III resistance as well. The QTL for FHB resistance identified in Wangshuibai have potential to be used to pyramid FHB-resistance QTL from different sources.

[Single-strand conformational polymorphism markers associated with a major QTL for fusarium head blight resistance in wheat].

A major quantitative trait locus (QTL) associated with resistance to Fusarium head blight (FHB) was identified on chromosome 3BS between simple sequence repeat (SSR) markers Xgwm389 and Xgwm493 in wheat 'Ning 7840', a derivative from 'Sumai 3'. However, the marker density of SSR in the QTL region was much lower than that required for marker-assisted selection (MAS) and map-based cloning. The objective of this study was to exploit new markers to increase marker density in this QTL region by using single-strand conformational polymorphism (SSCP) markers developed from wheat expressed sequence tags (ESTs) on 3BS bin 8-0.78-1.0. Sixty-nine out of 85 SSCP primer pairs amplified PCR (polymerase chain reaction) products from the genomic DNA of 'Chinese Spring'. Thirty-four primer pairs amplified PCR products that could form clear ssDNA (single strand DNA) bands through denaturation treatment. Ten SSCP markers had polymorphisms between 'Ning 7840' and 'Clark'. Five of the ten polymorphic SSCP markers were located on chromosome 3B by nulli-tetrasomic analysis. Three SSCP markers (Xsscp6, Xsscp20, and Xsscp21) were mapped into the region between Xgwm493 and Xgwm533, and possessed higher coefficient of determination (R2) than Xgwm493 and Xgwm533. The SSCP markers, Xsscp6, Xsscp20, and Xsscp21, can be used for map-based cloning of the QTL and for marker-assisted selection in FHB resistance breeding.

Trend of anti-tuberculosis drug resistance in Korea, 1994-2004.

SETTING: The 245 health centres through which the National Tuberculosis Programme (NTP) is implemented in Korea and the TB Laboratory Network of the Korean National Tuberculosis Association. OBJECTIVE: To observe the trend of anti-tuberculosis drug resistance in Korea from 1994 to 2004 and possible related factors. DESIGN: All tuberculosis (TB) patients registered for treatment at the health centres for a given period were assessed. RESULTS: Of 2636 new smear-positive patients from the 2004 survey, 338 cases (12.8%, 95% confidence interval [CI] 11.5-14.1) showed resistance to any of the first-line drugs: 261 with isoniazid (INH) resistance (9.9%, 95%CI 8.8-11.0) and 71 with multidrug resistance (MDR) (2.7%, 95%CI 2.1-3.3). Compared with previous surveys, a statistically significant increase in MDR (P=0.00675), any drug resistance (P=0.03779), any INH resistance (P=0.00313) and any rifampicin resistance (P = 0.00176) has been observed among new cases since 1994. Any resistance to second-line drugs ranged from 0.1% (capreomycin) to 1.1% (para-aminosalicylic acid) among new cases and from 1.1% to 3.6% among retreatment cases. Resistance to kanamycin and ofloxacin was found in 1.4% and 2.6%, respectively, of new and previously treated MDR-TB cases. CONCLUSION: A statistically significant increase in drug resistance was noticed among new cases.

An Internet-based surveillance system for tuberculosis in Korea.

SETTING: The Korea Tuberculosis Surveillance (KTBS) network includes 248 health centres throughout the country, as well as other public and private health institutions. OBJECTIVE: To develop a web-based surveillance system for tuberculosis (TB) and to monitor implementation of the National TB Control Programme (NTP) on an ongoing basis. DESIGN: A TB notification form was developed with new case definitions, and standardised to obtain uniform essential information of the cases with ease and speed. Data collection, compilation, analysis and feedback were made available at every level of the health authority via the Internet without restrictions of time and space. RESULTS: The Internet-based surveillance system was successfully implemented across the country, providing real-time national figures of TB using different variables-patient, time, area, site and type of disease--and facilitating on-line evaluation of NTP implementation. CONCLUSION: The web-based surveillance system has been well established within the existing health infrastructure, providing real-time figures on the TB burden. However, it requires continued improvement of the quality of information and of case reporting activities.

Main effects, epistasis, and environmental interactions of quantitative trait Loci for fusarium head blight resistance in a recombinant inbred population.

ABSTRACT Chinese Spring Sumai 3 chromosome 7A disomic substitution line (CS-SM3-7ADS) is highly resistant to Fusarium head blight (FHB), and an F(7) population of recombinant inbred lines derived from the cross CS-SM3-7ADS x Annong 8455 was evaluated for resistance to FHB to investigate main effects, epistasis, and environmental interactions of quantitative trait loci (QTLs) for FHB resistance. A molecular linkage map consists of 501 simple sequence repeat and amplified fragment length polymorphism markers. A total of 10 QTLs were identified with significant main effects on the FHB resistance using MapQTL and QTLMapper software. Among them, CS-SM3-7ADS carries FHB-resistance alleles at five QTLs on chromosomes 2D, 3B, 4D, and 6A. One QTL on 3BS had the largest effect and explained 30.2% of the phenotypic variance. Susceptible QTLs were detected on chromosomes 1A, 1D, 4A, and 4B. A QTL for enhanced FHB resistance was not detected on chromosome 7A of CS-SM3-7ADS; therefore, the increased FHB resistance in CS-SM3-7ADS was not due to any major FHB-resistance QTL on 7A of Sumai 3, but more likely was due to removal of susceptible alleles of QTLs on 7A of Chinese Spring. QTLMapper detected nine pairs of additive-additive interactions at 17 loci that explained 26% phenotypic variance. QTL-environment interactions explained 49% of phenotypic variation, indicating that the environments significantly affected the expression of the QTLs, especially these epistasis QTLs. Adding FHB-enhancing QTLs or removal of susceptible QTLs both may significantly enhance the degree of wheat resistance to FHB in a wheat cultivar.

Molecular characterization of a powdery mildew resistance gene in wheat cultivar suwon 92.

ABSTRACT Powdery mildew, caused by Blumeria graminis f. sp tritici, is an important foliar disease of wheat worldwide. Pyramiding race-specific genes into a single cultivar and combining race-specific resistance genes with durable resistance genes are the preferred strategies to improve the durability of powdery mildew resistance. The objectives of this study were to characterize a powdery mildew resistance gene in Suwon 92 and identify gene-specific or tightly linked molecular markers for marker-assisted selection (MAS). A population of recombinant inbred lines (RILs) was derived by single seed descent from a cross between Suwon 92 and a susceptible cultivar, CI 13227. The RILs were screened for adult-plant infection type of powdery mildew and characterized with amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. The linked markers explained 41.3 to 69.2% of the phenotypic variances measured in 2 years. A morphological marker, hairy glume, was also associated with powdery mildew resistance in Suwon 92, and explained 43 to 51% of the phenotypic variance. The powdery mildew resistance gene in Suwon 92 was located on the short arm of chromosome 1A where Pm3 was located. Two gene-specific markers were developed based on the sequence of the cloned Pm3b gene. These two markers, which were mapped at the same locus in the peak region of the LOD score for the RIL population, explained most of the phenotypic variance for powdery mildew resistance in the RIL population. The powdery mildew resistance in Suwon 92 is most likely conditioned by the Pm3 locus. The gene markers developed herein can be directly used for MAS of some of the Pm3 alleles in breeding programs.

Prevention of encephalomyocarditis virus-induced diabetes by live recombinant Mycobacterium bovis bacillus Calmette-Guérin in susceptible mice.

The D variant of encephalomyocarditis (EMC-D) virus causes diabetes in susceptible mice by direct cytolysis of pancreatic beta-cells. cDNA covering the major outer capsid protein (VP1) of the EMC-D virus was cloned into Mycobacterium bovis bacillus Calmette-Guerin (BCG). None of the SJL/J mice immunized with live recombinant BCG-VP1 (rBCG-VP1) became diabetic when challenged with the highly diabetogenic EMC-D virus, but the control mice inoculated with normal BCG developed diabetes during the same challenge. VP1-specific antibodies (including neutralizing antibodies) were markedly increased over time and reached the maximum titer at week 10 after a single immunization. The plateau of the titer lasted longer than 4 weeks. Mice and guinea pigs immunized with live rBCG-VP1 showed strong delayed-type hypersensitivity to the VP1 of the EMC-D virus. The preventive immunity still worked effectively 10 months after the primary immunization. At that time, the VP1-specific antibody was almost undetectable in the bloodstream, but a large number of VP1-specific lymphocytes was found in the spleen of the immunized mice. Our results show that live rBCG-VP1 elicits effective humoral and long-lasting cellular immune responses against EMC-D virus infection that results in the prevention of virus-induced diabetes in susceptible mice.

Recovery rate of NTM from AFB smear-positive sputum specimens at a medical centre in South Korea.

OBJECTIVE: To investigate the recovery rate of non-tuberculous mycobacteria (NTM) from acid-fast bacilli (AFB) smear-positive sputum specimens at a tertiary care medical centre in South Korea with a high pulmonary tuberculosis (PTB) burden. DESIGN: Retrospective analysis of data from AFB smear- and culture-positive sputum specimens collected between January 1998 and December 2001. RESULTS: Over 4 years, 1328 sputum specimens collected from 616 patients were AFB smear- and culture-positive. NTM were recovered from 9.1% (121/1328) of the smear-positive sputum specimens, and from 8.1% (50/616) of patients with smear-positive sputum. NTM were isolated at least twice in 94% (47/50) of the patients from whom NTM was recovered. The most common organism found was Mycobacterium avium complex, followed by M. abscessus. CONCLUSION: These results suggest that a substantial proportion of patients at a tertiary care medical centre in South Korea with AFB smear-positive sputum specimens may have NTM lung disease rather than PTB.

Drug-resistant tuberculosis in Korea, 1994.

SETTING: Sample survey based on pulmonary tuberculosis (TB) patients registered in 264 health centres in Korea, compared with data obtained from nationwide TB prevalence surveys conducted since 1965. OBJECTIVE: To determine the level of antituberculosis drug resistance (DR) and to assess its impact on treatment outcome and its relationship with cure rates in the National TB Programme (NTP). DESIGN: Mycobacterium tuberculosis isolates from 2,486 new patients and 189 previously treated patients were subjected to susceptibility testing against 10 antituberculosis drugs. Treatment outcome was assessed. The DR levels were compared with those observed in the national TB prevalence surveys, and the trend was correlated with the cure rate of patients treated in the NTP. RESULTS: Resistance to any drug was 11.3% in new cases and 54.0% in previously treated cases. Initial resistance to isoniazid (INH) or rifampicin (RMP) was 7.7% or 2.2%, and to INH and RMP (+/- other drugs) 1.6%. Compared with previous data, initial drug resistance (IDR) has decreased significantly and is inversely related to improvement of cure rates in the NTP. The treatment outcome of patients with single drug resistance was satisfactory. CONCLUSION: Drug-resistant TB has decreased remarkably during the last decades in Korea as a result of improved efficiency in the treatment programme of the NTP.

3'UTR polymorphisms in the NRAMP1 gene are associated with susceptibility to tuberculosis in Koreans.

SETTING: Korea University and the Korean Institute of Tuberculosis, Seoul, Korea. OBJECTIVE: To determine whether polymorphisms in the 3' untranslated region (UTR) of the NRAMP1 gene are associated with susceptibility to tuberculosis in Koreans. DESIGN: A case-control study design was used to compare the frequency of 3'UTR of NRAMP1 among 192 tuberculosis patients and 192 healthy individuals. All of the samples were diagnosed by X-ray, smear and culture tests between 1998 and 1999 in the Cross of Lorraine Clinic at the Korean Institute of Tuberculosis. RESULTS: A significant association was found between the Korean tuberculosis patients and polymorphisms in the 3'UTR of the NRAMP1 gene (odds ratio [OR] 1.845; 95% confidence interval [CI] 1.097-3.104; chi2 = 5.424; P = 0.020). CONCLUSION: This study showed that genetic variations in the human NRAMP1 gene are associated with susceptibility to smear-positive tuberculosis in Korean patients. The 3'UTR variant allele associated with susceptibility to tuberculosis is very uncommon in Caucasians, but is present in Koreans and West Africans. These observations may explain in part why African Americans and Koreans have greater susceptibility to tuberculosis than Caucasians.

Tuberculin PPD RT23: has it lost some of its potency?

PPD RT23 is a tuberculin that is used worldwide. Korea has been using 1TU RT23 for its nationwide tuberculosis prevalence surveys at five-yearly intervals since 1965, and found a drop in its potency after the 1975 survey. This finding draws attention to the interpretation of tuberculin survey data observed with RT23 at different time periods.

Incidence of pulmonary tuberculosis in Korean civil servants: second study, 1992-1994.

SETTING: A survey based on biennial medical examinations for civil servants, including school teachers. OBJECTIVE: To estimate the incidence of pulmonary tuberculosis (PTB) for the general population from a sample survey, and to compare it with the previous results from 1988-1990. DESIGN: A retrospective follow-up study which started in April 1996 and ended in December 1997. Development of PTB among all South Korean civil servants who were tuberculosis-free in the 1992 biennial medical examination was followed up to the 1994 medical examination. The survey was based on newly-developed cases by 1) the findings of the biennial medical examination, 2) scrutiny of the medical records of all those claiming health insurance for tuberculosis, and 3) checking of the TB registers in all health centres during the period. Civil servants constituted 2.6% of the Korean population aged 20 to 64. RESULTS: Of 958137 subjects who were found to be TB-free in the 1992 medical examination, 957216 were eligible for the study. Radiologically active PTB was found in 4146 cases over the 2-year period of the study. Bacteriological examinations were performed in 3306 patients: there were 1551 bacteriologically proven cases (46.9%), including 1049 smear-positives (31.7%) and 502 smear-negative culture-positives (15.2%). The age-sex adjusted incidence rate for the general population was 202/100000 in radiologically active PTB, 81/100000 in bacteriologically proven PTB, and 54/100000 in smear-positive PTB. Overall PTB incidence rates were higher in males (240/100000) than in females (163/100000), and in the age group 20-24 years (280/ 100 000) than in the other age groups. CONCLUSION: Comparing the 1992-1994 PTB incidence with that observed in the 1988-1990 survey, the highest incidence was observed among young adults in both surveys, and it had not changed over time.

The treatment of tuberculosis in South Korea.

South Korea's complex system of tuberculosis control has never been fully described. The prevalence of tuberculosis has dropped dramatically since 1965, partly because of farsighted governmental policy that provided low-cost, accessible tuberculosis treatment to the entire population. Within the tuberculosis control system, public and private sector entities provide a wide variety of treatment options. The National Tuberculosis Program focuses on improving cure rates for new cases, while the private sector has taken more of a role in the treatment of drug-resistant tuberculosis and other types of complicated cases. There has been a decrease in drug-resistant tuberculosis since 1980 for multiple reasons, including increased cure rates from the introduction of rifampin-based regimens, improved nutrition and living standards, and the treatment of drug-resistant cases in the private sector. Multidrug-resistant tuberculosis, however, still poses a significant threat to public health. The limited outcomes data that exist in South Korea for multidrug-resistant tuberculosis treatment suggest that cure rates are low and failure and abandonment rates are high. New public health measures are needed to improve the control of multidrug-resistant tuberculosis.

Exclusive mutations related to isoniazid and ethionamide resistance among Mycobacterium tuberculosis isolates from Korea.

SETTING: The single base change at the 94th codon of inhA has been referred to as the event that confers resistance on the drugs isoniazid (INH) and ethionamide (ETH) in Mycobacterium smegmatis and M. bovis. From this observation, it has been anticipated that some of the INH-resistant clinical isolates of M. tuberculosis would carry missense mutations in the same region of the gene. However, few polymorphisms have been identified in this region among INH-resistant isolates. OBJECTIVE: To understand the molecular basis for M. tuberculosis resistance to INH and ETH. DESIGN: The sequence polymorphism at the 94th codon of inhA among M. tuberculosis isolates from Korea was analyzed by polymerase chain reaction (PCR) cloning and sequence analysis. RESULTS: No nucleotide change at the 94th codon of inhA was detected in any of the 24 INH-resistant isolates analyzed in this study. On the other hand, a point mutation was found exclusively at the regulatory region flanking a putative ribosome-binding site of the inhA locus in 14 isolates. Interestingly, all the mutations were of the same kind, which substitutes C to T. Among 14 isolates, 12 were resistant to INH as well as to ETH, while two were resistant to INH only. DISCUSSION: It seems that mutations previously found at the 94th codon of inhA have no particular relationship with the mechanism involved in the resistance of M. tuberculosis to INH and/or ETH. On the other hand, the resistance mechanism of M. tuberculosis to INH/ETH may involve an altered level of InhA, an expression which may have been influenced by the sequence change in the regulatory region of the inhA locus.

Transmission of Mycobacterium tuberculosis among high school students in Korea.

SETTING: Screening of pulmonary tuberculosis (PTB) patients from high school students by chest radiography and sputum examination. OBJECTIVE: To investigate transmission of Mycobacterium tuberculosis among high school students. DESIGN: The restriction fragment length polymorphism (RFLP) profiles of M. tuberculosis isolated from PTB patients of high school students were analysed. RESULTS: Clustering cases were found in PTB patients screened among high school students. During this study, a single strain with a particular RFLP profile was found most frequently. This particular strain was also the one that was found to be most prevalent among Korean clinical isolates of M. tuberculosis during a nationwide TB prevalence survey previously done in 1995. This strain seems to be the most widely distributed one in Korea, and has thus been designated K1. In addition, by close examination of the RFLP profiles, it was also found that there existed 34 isolates that had RFLP profiles that were similar to the K1 strain. Therefore, K1 and K1-related strains (18.4% of strains, designated as the K family) seem to comprise the most dominant M. tuberculosis strains present in Korea. CONCLUSION: Clustering cases were found in PTB patients screened among high school students in Korea. The K family was found to be most prevalent among the clinical isolates of M. tuberculosis found.

Cross-resistance between rifampicin and KRM-1648 is associated with specific rpoB alleles in Mycobacterium tuberculosis.

KRM-1648 resistant Mycobacterium tuberculosis strains were identified from a collection of rifampicin-resistant strains. Several strains had novel rpoB gene mutations in codons 512, 529 and 533 of the rpoB gene. The strains with mutations in codons 526 or 531, major mutation sites in rifampicin-resistant M. tuberculosis, were resistant to KRM-1648. Also, the strains with other mutations in the rpoB gene that were initially susceptible to KRM-1648 were prone to developing KRM-1648 resistance after further mutation. Thus, KRM-1648 is unlikely to be useful for the treatment of rifampicin-resistant tuberculosis.

Mycobacterium tuberculosis infection in an orangutan (Pongo pygmaeus).

A respiratory disorder was noted in a 5-year-old female orangutan kept in the Yongin Farmland. Radiographically, multiple radiodense foci ranging from 2 to 6 mm diameter were seen throughout the lung lobes. Grossly, the thoracic cavity revealed a firm texture and grayish-pink discoloration of the left apical lung lobe. Histopathologically, multifocal areas of granulomatous pneumonia present the right and left apical lung lobes. Both primers from IS1081 and IS6110 targeting 196 bp and 245 bp respectively were used in polymerase chain reaction, Mycobacterium tuberculosis was isolated from liver and confirmed by polymerase chain reaction.