Towards Efficient Risky Driving Detection: A Benchmark and a Semi-Supervised Model.

Risky driving is a major factor in traffic incidents, necessitating constant monitoring and prevention through Intelligent Transportation Systems (ITS). Despite recent progress, a lack of suitable data for detecting risky driving in traffic surveillance settings remains a significant challenge. To address this issue, Bayonet-Drivers, a pioneering benchmark for risky driving detection, is proposed. The unique challenge posed by Bayonet-Drivers arises from the nature of the original data obtained from intelligent monitoring and recording systems, rather than in-vehicle cameras. Bayonet-Drivers encompasses a broad spectrum of challenging scenarios, thereby enhancing the resilience and generalizability of algorithms for detecting risky driving. Further, to address the scarcity of labeled data without compromising detection accuracy, a novel semi-supervised network architecture, named DGMB-Net, is proposed. Within DGMB-Net, an enhanced semi-supervised method founded on a teacher-student model is introduced, aiming at bypassing the time-consuming and labor-intensive tasks associated with data labeling. Additionally, DGMB-Net has engineered an Adaptive Perceptual Learning (APL) Module and a Hierarchical Feature Pyramid Network (HFPN) to amplify spatial perception capabilities and amalgamate features at varying scales and levels, thus boosting detection precision. Extensive experiments on widely utilized datasets, including the State Farm dataset and Bayonet-Drivers, demonstrated the remarkable performance of the proposed DGMB-Net.

SvSTL1 in the large subunit family of ribonucleotide reductases plays a major role in chloroplast development of Setaria viridis.

Ribonucleotide reductases (RNRs) are essential enzymes in DNA synthesis. However, little is known about the RNRs in plants. Here, we identified a svstl1 mutant from the self-created ethyl methanesulfonate (EMS) mutant library of Setaria viridis. The mutant leaves exhibited a bleaching phenotype at the heading stage. Paraffin section analysis showed the destruction of the C4 Kranz anatomy. Transmission electron microscopy results further demonstrated the severely disturbed development of some chloroplasts. MutMap analysis revealed that the SvSTL1 gene is the primary candidate, encoding a large subunit of RNRs. Complementation experiments confirmed that SvSTL1 is responsible for the phenotype of svstl1. There are two additional RNR large subunit homologs in S. viridis, SvSTL2 and SvSTL3. To further understand the functions of these three RNR large subunit genes, a series of mutants were generated via CRISPR/Cas9 technology. In striking contrast to the finding that all three SvSTLs interact with the RNR small subunit, the phenotype varied along with the copies of chloroplast genome among different svstl single mutants: the svstl1 mutant exhibited pronounced chloroplast development and significantly fewer copies of the chloroplast genome than the svstl2 or svstl3 single mutants. These results suggested that SvSTL1 plays a major role in the optimal function of RNRs and is essential for chloroplast development. Furthermore, through the analysis of double and triple mutants, the study provides new insights into the finely tuned coordination among SvSTLs to maintain normal chloroplast development in the emerging C4 model plant S. viridis.

Downregulation of long non-coding RNA B-Raf proto-oncogene-activated non-coding RNA reverses cisplatin resistance in laryngeal squamous cell carcinoma.

INTRODUCTION: This study was performed to explore the function of B-Raf proto-oncogene-activated non-coding RNA (BANCR) in laryngeal squamous cell carcinoma (LSCC) and cisplatin resistance. MATERIAL AND METHODS: The relative expression level of long non-coding RNA (lncRNA) BANCR was examined by qRT-PCR in tumor tissues and adjacent tissues, normal laryngeal cells (Het-1A) and laryngeal squamous carcinoma cells (TU686, TU177). Cisplatin-resistant laryngeal squamous carcinoma cell lines (TU686-DDP-R, TU177-DDP-R) were established. Next, we inhibited BANCR expression by transfecting siRNA-BANCR and enhanced BANCR expression by transfecting pcDNA3.1-BANCR into TU686, TU177, TU686-DDP-R and TU177-DDP-R cells. The CCK-8 assay and clone formation assay were performed to detect colony proliferation ability and formation ability of cells. Further, to investigate through which BANCR cell viability/formation is regulated, we detected the expression of MRP1, Bcl-2, p-PKB, and Bax by western blot. RESULTS: BANCR was highly expressed in laryngeal squamous carcinoma tissues and cells. Chemoresistance was generated in TU686-DDP-R and TU177-DDP-R compared with TU686 and TU177 cells after cisplatin treatment. In addition, upregulated lncRNA BANCR reduced or postponed cell sensitivity to cisplatin by enhancing cell proliferation in TU686 and TU177 cells. Meanwhile, the expression of MRP1, Bcl-2, and p-PKB was increased, while Bax was reduced. After cisplatin treatment, down-regulation of BANCR could consequently attenuate TU686-DDP-R and TU177-DDP-R cell proliferation, and the expression of MRP1, Bcl-2, and p-PKB was decreased and Bax was increased. CONCLUSIONS: Down-regulation of BANCR reverses cisplatin resistance of cisplatin-resistant LSCC cell lines.

Dentinal tubule occlusion using Er:YAG Laser: an in vitro study.

OBJECTIVES: We analyzed the effects of the Er:YAG laser used with different parameters on dentinal tubule (DT) occlusion, intrapulpal temperature and pulp tissue morphology in order to determine the optimal parameters for treating dentin hypersensitivity. METHODOLOGY: Dentin specimens prepared from 36 extracted human third molars were randomized into six groups according to the treatment method (n=6 each): control (A); Gluma desensitizer (B); and Er:YAG laser treatment at 0.5 W , 167 J/cm2 (50 mJ, 10 Hz) (C), 1 W , 334 J/cm2 (50 mJ, 20 Hz) (D), 2 W , 668 J/cm2 (100 mJ, 20 Hz) (E), and 4 W and 1336 J/cm2 (200 mJ, 20 Hz) (F). Treatment-induced morphological changes of the dentin surfaces were assessed using scanning electron microscopy (SEM) to find parameters showing optimal dentin tubule occluding efficacy. To further verify the safety of these parameters (0.5 W, 167 J/cm2), intrapulpal temperature changes were recorded during laser irradiation, and morphological alterations of the dental pulp tissue were observed with an upright microscope. RESULTS: Er:YAG laser irradiation at 0.5 W (167 J/cm2) were found to be superior in DT occlusion, with an exposure rate significantly lower than those in the other groups (P<0.05). Intrapulpal temperature changes induced by Er:YAG laser irradiation at 0.5 W (167 J/cm2) with (G) and without (H) water and air cooling were demonstrated to be below the threshold. Also, no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. CONCLUSION: Therefore, 0.5 W (167 J/cm2) is a suitable parameter for Er:YAG laser to occlude DTs, and it is safe to the pulp tissue.

Dentinal tubule occlusion using Er:YAG Laser: an in vitro study

Abstract Objectives We analyzed the effects of the Er:YAG laser used with different parameters on dentinal tubule (DT) occlusion, intrapulpal temperature and pulp tissue morphology in order to determine the optimal parameters for treating dentin hypersensitivity. Methodology Dentin specimens prepared from 36 extracted human third molars were randomized into six groups according to the treatment method (n=6 each): control (A); Gluma desensitizer (B); and Er:YAG laser treatment at 0.5 W , 167 J/cm2 (50 mJ, 10 Hz) (C), 1 W , 334 J/cm2 (50 mJ, 20 Hz) (D), 2 W , 668 J/cm2 (100 mJ, 20 Hz) (E), and 4 W and 1336 J/cm2 (200 mJ, 20 Hz) (F). Treatment-induced morphological changes of the dentin surfaces were assessed using scanning electron microscopy (SEM) to find parameters showing optimal dentin tubule occluding efficacy. To further verify the safety of these parameters (0.5 W, 167 J/cm2), intrapulpal temperature changes were recorded during laser irradiation, and morphological alterations of the dental pulp tissue were observed with an upright microscope. Results Er:YAG laser irradiation at 0.5 W (167 J/cm2) were found to be superior in DT occlusion, with an exposure rate significantly lower than those in the other groups (P<0.05). Intrapulpal temperature changes induced by Er:YAG laser irradiation at 0.5 W (167 J/cm2) with (G) and without (H) water and air cooling were demonstrated to be below the threshold. Also, no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Conclusion Therefore, 0.5 W (167 J/cm2) is a suitable parameter for Er:YAG laser to occlude DTs, and it is safe to the pulp tissue.

Polymorphisms in mitochondrial ribosomal protein S5 (MRPS5) are associated with leprosy risk in Chinese.

Leprosy is an infectious disease caused by Mycobacterium leprae (M. leprae), with about 210,000 new cases per year worldwide. Although numerous risk loci have been uncovered by genome-wide association studies, the effects of common genetic variants are relatively modest. To identify possible new genetic locus involved in susceptibility to leprosy, whole exome sequencing was performed for 28 subjects including 14 patients and 12 unaffected members from 8 leprosy-affected families as well as another case and an unrelated control, and then the follow-up SNP genotyping of the candidate variants was studied in case-control sample sets. A rare missense variant in mitochondrial ribosomal protein S5 (MRPS5), rs200730619 (c. 95108402T>C [p. Tyr137Cys]) was identified and validated in 369 cases and 270 controls of Chinese descent (Padjusted = 0.006, odds ratio [OR] = 2.74) as a contributing factor to leprosy risk. Moreover, the mRNA level of MRPS5 was downregulated in M. leprae sonicate-stimulated peripheral blood mononuclear cells. Our results indicated that MRPS5 may be involved in leprosy pathogenesis. Further studies are needed to determine if defective MRPS5 could lead to impairment of energy metabolism of host immune cells, which could further cause defect in clearing M. leprae and increase susceptibility to infection.

[Design, screening and antimicrobial activity of novel peptides against Streptococcus mutans].

OBJECTIVE: To construct antimicrobial peptides with potent antimicrobial activity, low cytotoxicity and efficient killing rate of Streptococcus mutans for prevention and treatment of dental caries. METHODS: We exploited the existing design strategies to modify reutericin 6 or gassericin A produced by Lactobacillus species in the oral cavity based on their cationicity, amphipathicity and α-helical structure. We examined their antimicrobial activities using bacterial susceptibility assay, their cytotoxicity through cytotoxicity assay and their killing rate of Streptococcus mutans with time-kill assay. We further evaluated the candidate derivatives for their killing rate against Streptococcus mutans, their antimicrobial activity against different oral pathogens and the development of drug resistance. RESULTS: We constructed 6 AT-1 derivatives, among which AT-7 showed an MIC of 3.3 µmol/L against Streptococcus mutans, Porphyromonas gingivalis and Actinomyces viscosus with a killing rate of 88.7% against Streptococcus mutans within 5 min. We did not obtain de novo strains of Streptococcus mutans resistant to AT- 7 after induction for 10 passages. CONCLUSIONS: Hydrophobicity and imperfect amphipathic structure are two key parameters that define the antimicrobial potency of the antimicrobial peptides. The imperfectly amphipathic peptide AT-7 shows the potential for clinical application in dental caries treatment.

Helicobacter pylori inhibited cell proliferation in human periodontal ligament fibroblasts through the Cdc25C/CDK1/cyclinB1 signaling cascade.

PURPOSE: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. METHODS: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. RESULTS: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. CONCLUSIONS: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.

Rational design of peptides with enhanced antimicrobial and anti-biofilm activities against cariogenic bacterium Streptococcus mutans.

Streptococcus mutans (S. mutans) is known to be a leading cariogenic pathogen in the oral cavity. Antimicrobial peptides possess excellent properties to combat such pathogens. In this study, we compared the antimicrobial activity of novel linear reutericin 6- and/or gassericin A-inspired peptides and identified LR-10 as the leading peptide. Antibacterial assays demonstrate that LR-10 is more active against S. mutans (3.3 µM) than many peptide-based agents without resistance selection, capable of killing many oral pathogens, and tolerant of physiological conditions. LR-10 also presented a faster killing rate than chlorhexidine and erythromycin, and appeared to display selective activity against S. mutans within 10 s. S. mutans is usually encased in plaque biofilms. Biofilm inhibitory assays indicated that LR-10 had excellent inhibitory effect on the biofilm formation of S. mutans and biofilm-encased cells in vitro at low concentrations (6.5 µM). Consistent with most peptides, LR-10 kills S. mutans mainly by disrupting the cell membranes. Notably, both hemolytic activity assays and cytotoxicity tests indicated that LR-10 could keep biocompatible at the effective concentrations. Hence, LR-10 could be a good candidate for clinical treatment of dental caries.

Identification of novel genetic loci GAL3ST4 and CHGB involved in susceptibility to leprosy.

Leprosy has long been thought to have a strong genetic component, and so far, only positional cloning and genomewide association studies have been used to study the genetic susceptibility to leprosy,while whole exome sequencing (WES) approach has not yet been applied. In this study, we used WES approach on four leprosy patients and four healthy control relatives from two leprosy families. We found three new susceptible loci of leprosy, one in GAL3ST4 and two in CHGB. We went on to validate the findings of WES using 151 leprosy cases and 226 healthy controls by Sanger sequencing. Stratified by gender, GAL3ST4 was found to be the susceptible gene only for the female population, and CHGB48 and CHGB23 were susceptibile to leprosy for the male population, respectively). Moreover, the gene expression levels of the three susceptible loci were measured by real-time PCR after the stimulation by M. leprae antigens in the PBMC (peripheral blood mononuclear cells) of 69 healthy people. The results showed that the female subjects with high frequent genotype in GAL3ST4 had a fivefold elevated expression. We suggest the polymorphisms in GAL3ST4 in different population are associated with increased risk of leprosy.

Characterization of Mycobacterium leprae Genotypes in China--Identification of a New Polymorphism C251T in the 16S rRNA Gene.

Leprosy continues to be prevalent in some mountainous regions of China, and genotypes of leprosy strains endemic to the country are not known. Mycobacterium lepromatosis is a new species that was discovered in Mexico in 2008, and it remains unclear whether this species exists in China. Here, we conducted PCR- restriction fragment length polymorphism (RFLP) analysis to classify genotypes of 85 DNA samples collected from patients from 18 different provinces. All 171 DNA samples from skin biopsies of leprosy patients were tested for the presence of Mycobacterium leprae and Mycobacterium lepromatosis by amplifying the 16S rRNA gene using nested PCR, followed by DNA sequencing. The new species M. lepromatosis was not found among the 171 specimens from leprosy patients in 22 provinces in China. However, we found three SNP genotypes among 85 leprosy patients. A mutation at C251T in the 16S rRNA gene was found in 76% of the strains. We also found that the strains that showed the 16S rRNA C251T mutation belonged to SNP type 3, whereas strains without the point mutation belonged to SNP type 1. The SNP type 3 leprosy strains were observed in patients from both the inner and coastal regions of China, but the SNP type 1 strains were focused only in the coastal region. This indicated that the SNP type 3 leprosy strains were more prevalent than the SNP type 1 strains in China. In addition, the 16S rRNA gene sequence mutation at C251T also indicated a difference in the geographical distribution of the strains. To our knowledge, this is the first report of a new polymorphism in 16S rRNA gene in M. leprae in China. Our findings shed light on the prevalent genotypes and provide insight about leprosy transmission that are important for leprosy control in China.

Evaluation of novel tools to facilitate the detection and characterization of leprosy patients in China.

Leprosy is the disabling outcome of chronic infection with Mycobacterium leprae. The disease often evades early detection, particularly now that fewer clinicians are able to confidently diagnose the disease following the integration of leprosy control measures within general health services in many countries. Although leprosy is officially eliminated in China, endemic regions remain in some difficult-to-reach, underdeveloped areas in Southwest China. In order to better understand the extent of M. leprae infection and identify new leprosy cases in a timely manner, simple tools that can detect infection and the early disease are required. In this report we evaluated the performance of antigen-specific ELISA, the NDO-LID rapid diagnostic test, and antigen-specific whole blood assays (WBA) as potential diagnostic tools. Our data support the use of antibody detection tests and WBA to facilitate the diagnosis of multibacillary and paucibacillary leprosy, respectively. These tools could be invaluable for increased, but simplified, monitoring of individuals in order to provide referrals for clinical exam and early leprosy diagnosis.

Application of RLEP real-time PCR for detection of M. leprae DNA in paraffin-embedded skin biopsy specimens for diagnosis of paucibacillary leprosy.

The TaqMan real-time polymerase chain reaction (PCR) assay was evaluated systematically with respect to the standard curve, linear range, and used for detecting Mycobacterium leprae DNA in paraffin-embedded skin biopsy specimens from 60 confirmed leprosy patients and three healthy individuals and 29 other dermatoses and bacterial DNA from 21 different species. The test was further evaluated with 51 paucibacillary (PB) patients. The results showed that the test had good sensitivity (8 fg) and good specificity with no cross-reactivity with 21 other bacterial species and the control specimens, except one with Xanthomatosis. The real-time PCR detection rate for the 51 PB specimens was 74.5% (38 of 51). We conclude that the real-time PCR test is a useful adjunct test for diagnosing early stage or PB leprosy cases.

Whole-blood nested-PCR amplification of M. leprae-specific DNA for early diagnosis of leprosy.

We evaluated the sensitivity and specificity of a nested-polymerase chain reaction (PCR) method for detection of Mycobacterium leprae DNA from whole blood. Whole-blood specimens were subjected to nested-PCR amplification of M. leprae repeat DNA sequences in 49 multibacillary (MB) and 30 paucibacillary (PB) leprosy patients, 96 household contacts (HHCs), 18 tuberculosis (TB) patients, and 35 normal healthy individuals. M. leprae DNA was detected in 95.92% (47/49) of MB, 70% (21/30) of PB, and 6.25% (6/96) of HHC, but it was not detected in 18 TB or 35 normal controls. The sensitivities of the anti-bovine serum albumin (ND-O-BSA) immunoglobulin M (IgM) and antifusion protein of ML0405-ML2331 IgG for MB were 97.96% and 89.8%, and these values for PB were 70% and 53.33%. However, the ND-O-BSA enzyme-linked immunosorbent assay (ELISA) had lower specificity, with relatively high false-positive results for TB patients (16.67%) and normal healthy controls (10%). Based on these promising findings, we propose the use of nested PCR of whole-blood samples along with ELISA test for early detection of leprosy cases.

[Study on the factors influencing steady transmission of leprosy in Qiubei county, China].

OBJECTIVE: To explore the factors influencing the steady transmission of leprosy as indicated by new case detection rate in Qiubei county, Yunnan province, China despite the implementation of MDT for the last 25 years. METHODS: Information related to case-finding was collected. ELISA and PCR were applied to detect anti-PGL-1 antibody in sera and Mycobacterium leprae in nasal secretions respectively, in leprosy patients, their household contacts and the general population. M. leprae by PCR was also detected from water in the highly endemic villages. VNTR typing was performed to explore the mode and chain of transmission of M. leprae. RESULTS: Prior to 2001, the proportion of new cases detected from the examination of household contacts of leprosy patients was low (number, compared to), while the proportion of patients whose identification was delayed by more than 2 years, was high (number, compared to). Qualities of these two indicators has been improved, along with the improvement of leprosy control program since 2001, but the detection rates has been steady at 4-5/100 000 during 1986 - 2010. The PGL-1 seropositivity rate was 20% - 30% in general population, with the peak rate (30%) detected in the teenage population in the endemic villages. In addition to the fact that M. leprae was detected in nasal secretion from patients, their contacts and from water, the M. leprae VNTR genotypes were found to be highly similar between skin biopsy and nasal secretion in untreated cases. Families with multi-cases were clustered and located in the Northern part of the County, and the genotypes of M. leprae were identical within those families. The percentage of clusters was considerably higher in Northern rather than Southern parts of the County. CONCLUSION: Results from this molecular study demonstrated evidence that transmission of leprosy within the families and in the endemic-villages was severe. M. leprae were detected in waters from the endemic villages and others areas which might have a relation to the continued transmission of leprosy.

[Epidemiological investigation of welder's pneumoconiosis in two container manufacturing industries in Guangdong province].

OBJECTIVE: To investigate the incidence of welder's pneumoconiosis in container manufacturing industries in Guangdong province and present some preventive and curative strategy. METHODS: Occupational epidemiology study methods were used to study the incidence of welder's pneumoconiosis in two container manufacturing enterprises (enterprise A and enterprise B). RESULTS: Before 2004, the rate of up-to-standard of weld fume concentration in the workplaces was relatively low (< or = 40%), and the maximum value of time weighted average (TWA) was 26.7 mg/m(3). After 2004, with the system of dust control, the rate of up-to-standard was 85% in the enterprise A. Of the 813 weld workers examined, 19 were diagnosed as welder's pneumoconiosis (stage I was 15, while I (+) was 4 ) and the incidence was 2.34% (19/813). The age of electric welders suffering from welder's pneumoconiosis and the duration of dust exposure were (33.45 + 4.64) and (8.04 + 1.97) years respectively. Chest radiographic examination showed mainly small round opacities "p". The value of MVV, FEF25%, FEF50% and FEF75% in lung function tests were significantly lower than those of the control group (P < 0.05 or P < 0.01). CONCLUSION: The main features of welder's pneumoconiosis in container manufacturing industries are the short duration of dust exposure, and small round opacities "p" in the chest radiographs. Therefore, it should be the key point of the prevention and treatment of occupational diseases in this industry to control the harmful weld fume.

[Study on genotyping of Mycobacterium leprae and families with multi-cases].

OBJECTIVE: Multiple locus variable number-tandem repeat (VNTR) analysis (MLVA) had been proposed as a means of strain typing for tracking of source and studying the transmission chain of pathogens. However, empirical data for a defined population from scale and duration were lacking for studying the transmission chain of leprosy. METHODS: MLVA on 7 VNTR loci was applied to the strain typing on prevalent Mycobacterium leprae isolates collected from Qiubei county, Yunnan province during 2002-2006 in the study on the relationship between geographic distribution and genotypes of M. leprae. The strain typing, combined with conventional epidemiological investigation was performed to trace the transmission chain. RESULTS: (1) Phylogenetic analyses through application of PAUP 4.0, The M. leprae were grouped into A, B, C, D and E strains according to the allelic range 9, 11-13, 15-26 and > 26 on the GTA9 locus. The strains with 9 copies on GTA9 locus, was named A. (2) Genotypes of strains from the five multi-case families located at North and North-West parts were similar and belonged to A strains. VNTR patterns of intra-family were identical or similar but not identical inter-family. (3) Not only A cluster appeared higher proportion in total isolates but also distributes cluster, indicating ongoing transmission from recent findings. CONCLUSION: VNTR strain typing was suitable to trace the short chain of transmission in both small area and intra-families. Multi-case families might constitute epidemic foci and source of M. leprae in villages, causing the predominant strain or cluster which tends to be those identified in multi-case families and resulted in the spreading of leprosy. A long-term study was underway to reveal whether A strain was predominant strain and to observe the evolution of M. leprae in this spatially and temporally defined endemic population.

Identification and distribution of Mycobacterium leprae genotypes in a region of high leprosy prevalence in China: a 3-year molecular epidemiological study.

Multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) has been proposed as a means of strain typing for tracking the transmission of leprosy. However, empirical data for a defined population are lacking. To this end, a study was initiated to assess the diversity and distribution of prevalent Mycobacterium leprae strains in Qiubei County, Yunnan Province, People's Republic of China, where the annual detection rate of leprosy is 10-fold higher than the national average rate. Sixty-eight newly diagnosed leprosy patients were included in the study. MLVA at eight M. leprae loci was applied using DNA extracts from skin biopsies. The number of alleles per locus ranged from 4 to 24, providing adequate strain discrimination. MLVA strain typing identified several clusters of patients whose M. leprae specimens shared similar VNTR profiles. Two of these clusters were comprised of patients who resided predominantly in the north and northwest parts of Qiubei County. Furthermore, it was found that multicase families are common in this county: 23 of the 68 patients were from 11 families. Intrafamilial VNTR profiles closely matched within six families, although they were different between the families. Moreover, VNTR patterns related to those found in some multicase families were also detected in patients in the same or adjacent townships, indicating the utility of VNTR strain typing to identify and detect short-range transmission events. Social contact through village markets is proposed as a means of transmission.

[Preliminary study on the genotyping of Mycobacterium leprae on 50 isolates from China].

OBJECTIVE: To understand the genotypic mapping of Mycobacterium leprae identified in China and to compare with those from other countries to select suitable alleles for epidemiological investigation in the transmission chain of leprosy. METHODS: Various number of tandem repeat(VNTR) in genomic DNA of Mycobacterium leprae was used in the present genotyping study. 33 skin biopsies from Wenshan prefecture,Yunnan province and 17 from other parts of China were studied. DNA extracted from skin biopsies of leprosy patients was subjected to PCR followed by agarose gel analysis and DNA sequencing to determine the number of repeats. RESULTS: Loci GGT-5,12-5,21-3 and 23-3 were as highly homogenous as 100%; The homogeneity of loci AC-8, 18-8, 27-5 and rpoT were 97%, 94%, 97% and 85% respectively. Loci GTA-9, AC-9 and 6-7 showed significant allelic diversity in isolates and the diversity of GTA-9 in Mycobacterium leprae isolated from China was also different from those identified other countries. We had subjected loci GTA-9 and the ten loci to phylogenetic tree analysis respectively. CONCLUSION: The present study revealed that the genotype of Mycobacterium leprae identified from China was close to the strains from the Philippines and India although a few loci were somehow differentiate. Locus 12-5 manifested as only 3 copies in China whereas 4-5 copies predominating in other countries. 12-5 locus might serve as a useful marker to diffrentiate Chinese strains from those in other countries. However, further study on the diversity of GTA-9 was needed in China. The molecular typing of Mycobacterium leprae from different geographic areas might be useful in studying the transmission of leprosy.

[Studies on the microwave leakage of the interphone].

OBJECTIVE: To assay and study the microwave leakage of 4 types of interphones. METHODS: The radiation intensities of four types of 199 interphones were determined by the microwave leakage measure instrument of model ML-91 made in China. RESULTS: The average intensities of microwave leakage at a distance of 5 cm from aerial part and other parts of interphones during launching [(1 316.0 +/- 144.3), (971.0 +/- 131.6) microW/cm(2) respectively] were significantly higher than during waiting [(14.4 +/- 5.3), (13.2 +/- 4.9) microW/cm(2) respectively] (P < 0.01). The average intensities of microwave leakage at a distance of 50 cm from different parts were (357.3 +/- 27.8) microW/cm(2). The daily average intensity of microwave leakage to which the head, chest and abdomen exposed was (945.5 +/- 447.1) microW.h/cm(2) in total, that exceeded the hygienic standard of microwave in China (400 microW.h/cm(2)), during the normal communication by interphones. CONCLUSION: The microwave leakage was higher during launching than during waiting, and was the highest at the aerial part of the interphones. The microwave radiation of most interphones was higher than the current national standard. It may lead to potential effects on the owner of interphone, so protection against it should be made.