Characteristics of culture-negative subclinical pulmonary tuberculosis: a single-center observation.

BACKGROUND: Little is known about culture-negative subclinical pulmonary tuberculosis (TB), and its diagnosis remains challenging. Therefore, this study aimed to identify the characteristics and the extent of disease associated with culture-negative subclinical pulmonary TB. METHODS: This retrospective cohort study was conducted on immunocompetent individuals with subclinical pulmonary TB at a university hospital in Thailand from January 2014 to December 2019. Subclinical pulmonary TB was diagnosed based on the presence of radiographic abnormalities consistent with TB in the absence of TB symptoms. All subjects demonstrated significant improvement or resolution of radiographic abnormalities following the completion of treatment. At least two negative sputum cultures were needed to fulfill the definition of culture-negative pulmonary TB. Data were analyzed using univariate and multiple logistic regression analyses to determine the characteristics of those with culture-negative subclinical pulmonary TB compared to culture-positive ones. RESULTS: Out of the 106 individuals identified with subclinical pulmonary TB, 84 met the criteria for inclusion in the analysis. The study found lower radiographic extent and increasing age were key attributes of culture-negative subclinical pulmonary TB. The odds ratios (95% confidence interval) were 7.18 (1.76 to 29.35) and 1.07 (1.01 to 1.13), respectively. They tend to have lower rates of bilateral involvement in both chest x-ray (8.5% vs. 32.0%, p=0.006) and computed tomography (15.4% vs. 42.9%, p=0.035). However, no other specific radiographic findings were identified. CONCLUSIONS: People with culture-negative subclinical pulmonary TB were likely to have less radiographic -severity, reflecting early disease. Nevertheless, no radiographic patterns, except for unilaterality, were related to culture-negative subclinical pulmonary TB.

Asian Intensive Reader of Pneumoconiosis program: examination for certification during 2008-2020.

This study examined physicians' participation and performance in the examinations administered by the Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) program from 2008 to 2020 and compared radiograph readings of physicians who passed with those who failed the examinations. Demography of the participants, participation trends, pass/fail rates, and proficiency scores were summarized; differences in reading the radiographs for pneumoconiosis of physicians who passed the examinations and those who failed were evaluated. By December 2020, 555 physicians from 20 countries had taken certification examinations; the number of participants increased in recent years. Reported background specialty training and work experience varied widely. Passing rate and mean proficiency score for participants who passed were 83.4% and 77.6 ± 9.4 in certification, and 76.8% and 88.1 ± 4.5 in recertification examinations. Compared with physicians who passed the examinations, physicians who failed tended to classify test radiographs as positive for pneumoconiosis and read a higher profusion; they likely missed large opacities and pleural plaques and had a lower accuracy in recognizing the shape of small opacities. Findings suggest that physicians who failed the examination tend to over-diagnose radiographs as positive for pneumoconiosis with higher profusion and have difficulty in correctly identifying small opacity shape.

Underdiagnosis of silicosis revealed by reinterpretation of chest radiographs in Thai ceramic workers.

Background: In Thailand, epidemiological data on silicosis in the ceramic sector is lacking and the underdiagnosis of silicosis remains an extensive concern. Therefore, this study aimed to determine the prevalence of silicosis and the extent of underdiagnosis among Thai ceramic workers by reinterpreting chest radiographs previously taken by a health check-up unit. Methods: This retrospective cross-sectional study was conducted on ceramic workers undergoing health surveillance using chest radiographs in one ceramic factory in September 2018. All chest radiographs were done retrospectively, then were reinterpreted by professional readers specially trained in using the ILO International Classification of Radiograph of Pneumoconioses (ILO/ICRP). Chest radiographs with a profusion of 1/1 or greater were suggestive of silicosis. Results: Out of the 244 participants undergoing chest radiography, the prevalence of silicosis was 2.9%. Overall, the mean age of the participants was 41 years, and 72.1% were female. Among individuals with silicosis, the median age was 43 years; 71.4% were male; the average employment duration was 26.9 years; while the male sex was the significant variable associated with silicosis with an odds ratio of 7.01 (95% confidence interval 1.31 to 37.4). Regarding the underdiagnosis, the health check-up unit failed to recognize all individuals with silicosis, and could not detect any radiographic chest abnormalities in 57.1% of those with silicosis. Conclusions: Despite the low prevalence of silicosis among Thai ceramic workers, this finding indicates ongoing exposure to silica in the ceramic industry. In addition, a significant proportion of the silicosis cases were underrecognized. Future efforts to prevent underdiagnosis and improve an occupational health surveillance service in Thailand are needed.

Inter-observer agreement and accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking AIR Pneumo certification examination.

This study examined inter-observer agreement and diagnostic accuracy in classifying radiographs for pneumoconiosis among Asian physicians taking the AIR Pneumo examination. We compared agreement and diagnostic accuracy for parenchymal and pleural lesions across residing countries, specialty training, and work experience using data on 93 physicians. Physicians demonstrated fair to good agreement with kappa values 0.30 (95% CI: 0.20-0.40), 0.29 (95% CI: 0.23-0.36), 0.59 (95% CI: 0.52-0.67), and 0.65 (95% CI: 0.55-0.74) in classifying pleural plaques, small opacity shapes, small opacity profusion, and large opacities, respectively. Kappa values among Asian countries ranging from 0.25 to 0.55 (pleural plaques), 0.47 to 0.73 (small opacity profusion), and 0.55 to 0.69 (large opacity size). The median Youden's J index (interquartile range) for classifying pleural plaque, small opacity, and large opacity was 61.1 (25.5), 76.8 (29.3), and 88.9 (23.3), respectively. Radiologists and recent graduates showed superior performance than other groups regarding agreement and accuracy in classifying all types of lesions. In conclusion, Asian physicians taking the AIR Pneumo examination were better at classifying parenchymal lesions than pleural plaques using the ILO classification. The degree of agreement and accuracy was different among countries and was associated with background specialty training.

Assessment of physicians' proficiency in reading chest radiographs for pneumoconiosis, based on a 60-film examination set with two factors constituting eight indices.

Two hundred and thirty-three individuals read chest x-ray images (CXR) in the Asian Intensive Reader of Pneumoconiosis (AIR Pneumo) workshop. Their proficiency in reading CXR for pneumoconiosis was calculated using eight indices (X1-X8), as follows: sensitivity (X1) and specificity (X2) for pneumoconiosis; sensitivity (X3) and specificity (X4) for large opacities; sensitivity (X5) and specificity (X6) for pleural plaques; profusion increment consistency (X7); and consistency for shape differentiation (X8). For these eight indices, one-way analysis of variance (ANOVA) and Scheffe's multiple comparison were conducted on six groups, based on the participants' specialty: radiology, respiratory medicine, industrial medicine, public health, general internal medicine, and miscellaneous physicians. Our analysis revealed that radiologists had a significant difference in the mean scores of X3, X5, and X8, compared with those of all groups, excluding radiologists. In the factor analysis, X1, X3, X5, X7, and X8 constituted Factor 1, and X2, X4, and X6 constituted Factor 2. With regard to the factor scores of the six participant groups, the mean scores of Factor 1 of the radiologists were significantly higher than those of all groups, excluding radiologists. The two factors and the eight indices may be used to appropriately assess specialists' proficiency in reading CXR.

Radiographic progression of silicosis among Japanese tunnel workers in Kochi.

OBJECTIVE: The aim of our study was to investigate the natural course of silicosis in terms of radiographic progression among Japanese tunnel workers. METHODS: Tunnel workers with silicosis were included in our study between January 2008 and June 2011. We retrospectively assessed workers' radiographs from their first through last visits to see whether there was progression. All films were interpreted by two physicians, who had been specially trained in using the ILO (2000) International Classification of Radiographs of Pneumoconioses (ILO/ICRP). We classified the radiographic findings according to the ILO/ICRP. Survival analysis was performed and then presented as time to progression. Subgroup analysis among the progressed group was performed to demonstrate duration of progression. RESULTS: A total of 65 patients, who were no longer exposed to silica for the duration of the study, were included. The mean age at the first visit was 58.60 ± 7.10 years. The incidence rate of progression was 42 per 1,000 person-years with a median time to progression of 17 years. Progression was demonstrated among 33 cases (51%). The mean durations of progression from category 1 to category 4 and category 2 to category 4 were 14.55 and 10.65 years, respectively. Most patients (86%) had radiographic change from category 1 or 2 directly to category 4. CONCLUSION: Silicosis progressed at a relatively high rate among tunnel workers without further silica exposure. The high probability of progression directly from category 1 to category 4 may lead to further investigation for the improvement of disease prevention.

Serum selenium and selenoprotein P in patients with silicosis.

OBJECTIVES: Selenoprotein P (SeP) is a selenium (Se) supply protein, which is an antioxidant micronutrient considered to be vital for human health. The aim of this study was to assess the serum selenium status in patients with silicosis. METHODS: We conducted a retrospective case-control study where serum samples from a total of 78 patients (males with a median age of 73.5 years old) with silicosis and 20 healthy controls (males with a median age of 72.5 years old) were assayed for Se and SeP. They underwent medical and job history taking, lung function testing, and chest radiography examinations. Levels of serum Se were measured using electrothermal atomic absorption spectrophotomerty, while levels of SeP were assessed with sandwich Enzyme Immunoassay. Spearman's rank correlation test was carried out to evaluate the relationship between Se and SeP. The Mann-Whitney test was used to evaluate differences in serum Se and SeP between study groups. RESULTS: The median serum Se and SeP concentrations were significantly lower in cases (74.0 µg/l and 4.2mg/l, respectively) compared with controls (116.0 µg/l and 5.8 mg/l, respectively). In both cases and controls, serum Se was positively correlated with serum SeP (rho=0.781, p<0.001 and rho=0.768, p<0.001, respectively). Serum Se and SeP levels were significantly lower in patients classified in category four compared with those who were classified in category two or three. CONCLUSIONS: Serum Se and SeP concentrations were found to be at inadequate levels in patients with silicosis, and decreased significantly with the severity of the disease.

Mini Nutritional Assessment and functional capacity in community-dwelling elderly in rural Luozi, Democratic Republic of Congo.

AIM: Good nutrition is beneficial both for the health and the functional capacity of the elderly. However, malnutrition is a serious health problem among the elderly, particularly the elderly living in rural areas in many developing countries. The aim of the present study was to carry out a cross-sectional study of the elderly in the city of Luozi, Democratic Republic of Congo, through the use of the long and the short forms of the Mini Nutritional Assessment (MNA) scale. METHODS: We carried out a cross-sectional study in the city of Luozi, a city facing serious socioeconomic problems as a result of wartime conditions in the country. The study included 370 volunteer community-dwelling elderly people aged 65-88 years, both male and female. Investigations took into account the MNA, the activities of daily living, and the instrumental activities of daily living, falls, current diseases and lifestyle. RESULTS: Approximately 57.8% of the participants were at risk of malnutrition, whereas 28.4% were malnourished according to the MNA scale. MNA scores were significantly lower (Student's t-test, P=0.03) in those with a fall history (MNA score 18.3±4.0) compared with those who did not (MNA score, 21.0±2.7). All the participants with malnutrition suffered from at least one chronic disease. The percentage of participants with dependency was significantly higher in the malnourished participants (87.6%) than in well-nourished participants (50.9%). CONCLUSION: These findings provide information that malnutrition is a serious health concern among elderly people in the city of Luozi, and shows the need for adequate nutrition and social programs for the elderly.

Asbestos-related diseases in Thailand and review literature.

Asbestos is a harmful substance that can cause both malignancy and non-malignancy in humans. Although it has been used in Thailand for several years, few cases of asbestos-related diseases were reported. Concerning about high consumption and long exposure of asbestos in the country, the incurable but preventable diseases caused by asbestos will be the health problem in the near future. The authors presented 2 cases with asbestos-related diseases, one diagnosed as malignant mesothelioma and the other as asbestosis.

Limonene inhalation reduces allergic airway inflammation in Dermatophagoides farinae-treated mice.

Limonene is one of the main flavonoids which is reported to inhibit the inflammatory response by suppressing the production of reactive oxygen species. The aim of this study was to evaluate whether limonene can inhibit Dermatophagoides farinae-induced airway hyperresponsiveness (AHR), eosinophilic infiltration and other histological changes in the lung, T helper (Th) 2 cytokine production and airway remodeling in a mice model of asthma. Treatment with limonene significantly reduced the levels of IL-5, IL-13, eotaxin, MCP-1, and TGF-ß1 in bronchoalveolar lavage fluid. The goblet cell metaplasia, thickness of airway smooth muscle, and airway fibrosis were markedly decreased in limonene-treated mice. Furthermore, AHR to acetylcholine was significantly abrogated in limonene-treated mice. These results indicate that limonene has a potential to reduce airway remodeling and AHR in asthma model.

Proficiency in reading pneumoconiosis radiographs examined by the 60-film set with 4-factor structuring 8-index.

29 physicians (A1-Group) and 24 physicians (A2-Group) attending the 1st and 2nd "Asian Intensive Reader of Pneumoconiosis" (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attending the Brazilian training course took the examination of reading the 60-film set. The objective of the study was firstly to investigate the factor structure of physicians' proficiency of reading pneumoconiosis chest X-ray, and secondly to examine differences in factor scores between groups. Reading results in terms of the 8-index of all examinees (Examinee Group) were subjected to the exploratory factor analysis. A 4-factor was analyzed to structure the 8-index: the specificity for pneumoconiosis, specificity for large opacities, specificity for pleural plaque and shape differentiation for small opacities loaded on the Factor 1; the sensitivity for pneumoconiosis and sensitivity for large opacities loaded on the Factor 2; the sensitivity for pleural plaque loaded on the Factor 3; the profusion increment consistency loaded on the Factor 4. 4-Factor scores were compared between each other of the three groups. The Factor 2 scores in A1 and A2 groups were significantly higher than in B-Group. Four factors could reflect four aspects of reading proficiency of pneumoconiosis X-ray, and it was suggested that 4-factor scores could also assess the attained skills appropriately.

Anti-inflammatory effects of sacran, a novel polysaccharide from Aphanothece sacrum, on 2,4,6-trinitrochlorobenzene-induced allergic dermatitis in vivo.

BACKGROUND: Sacran is a newly discovered sulfated polysaccharide extracted from an algae, Aphanothece sacrum, grown in a river of the Kyushu region in Japan. OBJECTIVE: To evaluate sacran's inhibitory effect in 2,4,6-trinitrochlorobenzene (TNCB)-induced allergic dermatitis in NC/Nga mice. METHODS: Sacran was extracted by acid and alkaline treatment of A sacrum cyanobacterial biomaterials. To sensitize mice, 150 µL of 5% TNCB was applied epicutaneously on the abdomen of each mouse on day 1 and challenged with 15 µL of 1% TNCB applied on the ear skin of mice on day 8 and then every other day to induce skin lesions. Serum levels of inflammatory markers were measured and histopathologic examination of ear skin specimens performed. On the other hand, sacran's transepidermal water loss was evaluated in 11 volunteer women with dry skin. RESULTS: Epicutaneous application of sacran in mice has significantly inhibited the development of allergic dermatitis skin lesions and reduced the number of scratching behavior episodes (P < .01). In addition, sacran efficiently inhibited IgE (P < .001), tumor necrosis factor α (P = .02), interleukin 4, interleukin 5, and interferon γ (P < .01; vs buffer in the TNCB group) production and eosinophilic infiltration in the chemical allergen-exposed ear skin. In addition, sacran-treated body regions of human volunteers with dry skin significantly reduced transepidermal water loss levels compared with exogenous hyaluronic acid (P < .01), which is known to improve skin moisture and exert skin barrier repair activity. CONCLUSIONS: This study suggests that sacran exerts anti-inflammatory effects by improving skin barrier function and reducing T(H)2 cytokine production.

The 60-film set with 8-index for examining physicians' proficiency in reading pneumoconiosis chest X-rays.

The 60-film set was developed by experts (Expert Group) for examining 8 indices: sensitivity (X(1)) and specificity (X(2)) for pneumoconiosis, sensitivity(X(3)) and specificity for (X(4)) large opacities, sensitivity (X(5)) and specificity (X(6)) for pleural plaque, profusion increment consistency for small opacities (X(7)), and shape differentiation for small opacities (X(8)) of physicians' reading skills on pneumoconiosis X-ray according to ILO 2000 Classification. The aim of this study was to assess the appropriateness of the exam film set for evaluating physicians' reading skills. 29 physicians (A1-Group) and 24 physicians (A2-Group) attended the 1st and 2nd "Asian Intensive Reader of Pneumoconioses" (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attended Brazilian training course. After training, they took examination of reading 60-film exam set. The examinees' reading results in terms of 8 indices were compared between the examinee groups and the Expert Group by parametric unpaired t-test. The Examinee Group consisting of A1-Group, A2-Group and B-Group was inferior to the Expert Group in all indices. There was no significant difference for X(7) of A1-Group, X(7) and X(8) of A2-Group (p>0.05) compared with the Expert Group. There was a significant difference in X(8) at p<0.05 between A1-Group and A2-Group, in X(3) at p<0.05 between A1-Group and B-Group, in both X(1) and in X(3) at p<0.05 between A2-Group and B-Group. Accordingly, the 60-film set providing 8 indices designed might be a good method for evaluation of the physicians' reading proficiency at different training settings.