Impact of COVID-19 on the mental health of primary schoolchildren during the later phase of the pandemic: A case report of an 18-month longitudinal survey in a Japanese primary school

Background

Drastic changes such as school closures and stay-at-home measures due to the global COVID-19 pandemic, may have long-term negative effects on children's mental health; however, longitudinal studies after 2021 are limited. This study aimed to observe the long-term effects of the COVID-19 pandemic on children's mental health by exploring changes in their mental health over a period of 18 months.

Study design

We conducted a longitudinal study at Chiba Prefecture in Japan, focusing on schoolchildren's mental health changes.

Methods

Data were obtained from the Strengths and Difficulties Questionnaire (SDQ) questionnaire conducted at single primary school three times from October 2021 to March 2023 which and included 183 participants. This study adopted a linear-mixed model to evaluate changes in children's SDQ scores, with sex and grade as the independent variables, and participants as a random effect.

Results

Regarding changes in SDQ scores, there were no significant changes in the total difficulty scores or in each subscale; Emotional Symptoms, Conduct Problems, Hyperactivity/Inattention, Peer Problems, and Prosocial Behavior. There was no statistically significant interaction between changes in SDQ scores and sex.

Conclusions

This report indicates that the impact of the COVID-19 pandemic on the mental health of Japanese primary schoolchildren was negligible in the later phase of the pandemic. However, the impact may differ from country to country owing to factors such as social restrictions during the COVID-19 pandemic.

Association between the Mediterranean Diet Score and Healthy Life Expectancy: A Global Comparative Study

OBJECTIVES

Extending healthy life expectancy (HALE), defined as the average number of years that a person can expect to live in "full health" by taking into account years lived in less than full health due to disease and/or injury, is a common topic worldwide. This study aims to clarify the relationships between the Mediterranean diet score (MDS) and life expectancy (LE) and HALE globally using publicly available international data.

SETTING

Analyses were conducted on 130 countries with populations of 1 million or more for which all data were available. Individual countries were scored from 0 to 9 to indicate adherence to the Mediterranean diet according to the MDS scoring method. The supply of vegetables, legumes, fruits and nuts, cereals, fish, and olive oil per 1,000 kcal per country was calculated based on the Food and Agriculture Organization Corporate Statistical Database, with a score of 1 for above the median and 0 for below. The same method was used to calculate scores of presumed detrimental components (meat and dairy), with consumption below the median given a value of 1, and consumption above the median given a value of 0. For ethanol, a score of 1 was given for 10g to 50 g of consumption. We investigated the cross-sectional associations between the MDS and LE and HALE at birth in 2009, and the longitudinal associations between the MDS in 2009 and LE and HALE between 2009 and 2019, controlling for covariates at baseline using linear mixed models.

RESULTS

In the cross-sectional analysis, the MDS was significantly positively associated with LE (β=0.906 [95% confidence interval, 0.065-1.747], p=0.037) and HALE (β=0.875 [0.207-1.544], p=0.011) after controlling for all covariates. The longitudinal analysis also revealed significantly positive associations between the MDS and LE (0.621 [0.063-1.178], p=0.030) and HALE (0.694 [0.227-1.161], p=0.004) after controlling for all covariates.

CONCLUSION

The present study, based on an analysis using 10 years of international data, showed that countries with a higher MDS showed a positive association with HALE.

Traditional Japanese Diet Score - Association with Obesity, Incidence of Ischemic Heart Disease, and Healthy Life Expectancy in a Global Comparative Study

OBJECTIVES

We created a Traditional Japanese Diet Score (TJDS), and to clarify the relationship between TJDS and obesity, ischemic heart disease (IHD), and healthy life expectancy (HALE).

DESIGN

Ecological study.

SETTING

Food (g/day/capita) and energy (kcal/day/capita) supply was determined using the Food and Agriculture Organization of the United Nations Statistics Division database. The sum of characteristic traditional Japanese foods (beneficial food components in the Japanese diet: rice, fish, soybeans, vegetables, eggs, and seaweeds; food components rarely used in the Japanese diet: wheat, milk, and red meat) was divided as tertiles (beneficial food components: -1, 0, 1; rarely used food components: 1, 0, -1). Obesity rate was determined using the World Health Organization database. Incidence of IHD, HALE and smoking rate were determined using the Global Burden of Diseases, Injuries, and Risk Factors Study 2015 database. Gross domestic product per capita, percentage of population > 65 years old, and health expenditure were determined using the World Bank database. Education years were obtained from the United Nations Educational, Scientific and Cultural Organization Institute for Statistics. Associations between TJDS and obesity, IHD and HALE were examined in 132 countries with a population of 1 million or greater using a general linear model controlled for co-variables.

RESULTS

TJDS was distributed from -6 to 7. TJDS was inversely correlated to obesity (β±SE; -0.70±0.19, p<0.001), IHD (-19.4±4.3, p<0.001), and positively correlated to HALE (0.40±0.14, p<0.01).

CONCLUSIONS

TJDS is a good indicator of a healthy diet, and applies to preventing obesity, IHD and extending HALE.

Effects of alpha-linked galactooligosaccharide on adjuvant-induced arthritis in Wistar rats and type II collagen-induced arthritis in DBA/1J mice

alpha-Linked galactooligosaccharide (alpha-GOS) has been reported to change the composition of enteric microflora. In the present study, the antiarthritic effect of alpha-GOS was evaluated by employing adjuvant-induced arthritis (AIA) in Wistar rats and type II collagen-induced arthritis (CIA) in DBA/1J mice. The animals were given alpha-GOS orally. This substance had beneficial effects on both clinical signs, such as erythema and swelling of the limbs, and histopathological findings in the hind paw joints in a dose-dependent manner. alpha-GOS reduced the plasma nitrite/nitrate (NOx) level in rats with AIA. In the cell culture system employing peritoneal macrophages from rats with AIA, alpha-GOS enhanced interleukin-1 production without lipopolysaccharide stimulation in a dose-dependent manner, suggesting that alpha-GOS stimulates peritoneal macrophages through modulation of enteric microflora. Since alpha-GOS modulates the composition of the enteric microflora, the antiarthritic effects of alpha-GOS could be partly attributable to its immunomodulating activity. Thus, alpha-GOS is a potential functional food for the treatment of human rheumatoid arthritis.

[Drug consultation for a terminal cancer patient at home care-management of dyspnea and pain by morphine]

We studied on the points of that a management of dyspnea and pain by morphine for a terminal cancer patient at Home care. It was suggested that a necessary on management of symptoms for a terminal cancer patient before home drug therapy, a education to patient and his family by drug consultation before and after home drug therapy, a confirmation of dyspnea and pain for a terminal cancer patient from one drug to the next, and a importance of communication between medical staffs.

[Anti-tuberculosis drug resistance in Japan and in the world]

In 1994, the World Health Organization (WHO) and the International Union against Tuberculosis and Lung Disease (IUATLD) launched a global project on anti-tuberculosis drug resistance surveillance. The results from the first 4 years (1994-1997) and the second 4 years (1996-1999) of the projects were reported in 1998 and 2000, respectively. These surveillance results showed that resistance to anti-tuberculosis drugs is a global problem. The reports also showed that there were several hot spots around the world where prevalence of multidrug resistant tuberculosis (MDR-TB, defined as resistance to at least isoniazid and rifampin) was particularly high and could possibly threaten control programs. The Tuberculosis Research Committee of Japan (Ryoken) has conducted nationwide surveys for drug resistant tuberculosis at 2- or 5-yearly intervals since 1957. The 1997 survey showed that among patients with no prior treatment, resistance to any of the four drugs was found in 10.3%, and the prevalence of primary MDR was 0.8%. The prevalence of drug resistance in the previously treated cases was 42.4% for any of the four drugs and 19.7% for MDR, indicating a high prevalence rate compared with those reported in the global project. Compared with the previous survey in 1992, the current survey shows increased prevalence of drug resistance in both new and re-treatment cases. No significant differences in resistance rates by sex, age group, nationality, district, and/or accompanying diseases were observed in any of the new or re-treatment cases. Other factors associated with the high prevalence in re-treatment cases remain to be determined. A total of 78 hospitals in various districts of Japan participated the cooperative study. Each collaborating laboratory sent all the isolated mycobacterial cultures to the Research Institute of Tuberculosis (RIT). In the local laboratories, the absolute concentration method using 1% Ogawa egg slant, its modified methods using a 48-well plate and a 16-well plate, combination of above 2 or 3 methods, and other method were used for drugsusceptibility testing, and the proportion method using 1% Ogawa egg slant was used in the RIT. The results in the local laboratories were compared with those in the RIT. There was no significant difference in the concordance rates according to the test drugs among methods for drug susceptibility testing used in the local laboratories. Relatively lower concordance rates were seen in the laboratories using the Microtiter method related to high overestimation rates, compared with those in the laboratories using the standard method and Well-pack method. However, relatively lower concordance rates (less than 90%) were seen in the laboratories using any of the three methods, indicating that there are variations among facilities.

Clinical evaluation of anti-tuberculous glycolipid immunoglobulin G antibody assay for rapid serodiagnosis of pulmonary tuberculosis

Previously we reported the development of a highly sensitive enzyme-linked immunosorbent assay specific for anti-tuberculous glycolipid (anti-TBGL) for the rapid serodiagnosis of tuberculosis. In this study, the usefulness of an anti-TBGL antibody assay kit for rapid serodiagnosis was evaluated in a controlled multicenter study. Antibody titers in sera from 318 patients with active pulmonary tuberculosis (216 positive for Mycobacterium tuberculosis in smear and/or culture tests and 102 smear and culture negative and clinically diagnosed), 58 patients with old tuberculosis, 177 patients with other respiratory diseases, 156 patients with nonrespiratory diseases, and 454 healthy subjects were examined. Sera from 256 younger healthy subjects from among the 454 healthy subjects were examined as a control. When the cutoff point of anti-TBGL antibody titer was determined as 2.0 U/ml, the sensitivity for active tuberculosis patients was 81.1% and the specificity was 95.7%. Sensitivity in patients with smear-negative and culture-negative active pulmonary tuberculosis was 73.5%. Even in patients with noncavitary minimally advanced lesions, the positivity rate (60.0%) and the antibody titer (4.6 +/- 9.4 U/ml) were significantly higher than those in the healthy group. These results indicate that this assay using anti-TBGL antibody is useful for the rapid serodiagnosis of active pulmonary tuberculosis.

[Evaluation of the BACTEC MGIT 960 system for drug susceptibility testing of Mycobacterium tuberculosis isolates compared with the proportion method on solid media]

The methods most widely used for susceptibility testing against anti-tuberculosis drug (AST) are the proportion method on Löwenstein-Jensen egg (L-J), Ogawa egg or Middle-brook agar media, and BACTEC TB 460 system. Recently, drug concentrations have been established for AST using the automated BACTEC MGIT 960 system (aMGIT). We have evaluated the BACTEC MGIT 960 SIRE kit for AST of Mycobacterium tuberculosis to isoniazid, rifampin, streptomycin and ethambutol. Also we compared the results with the proportion methods on Middlebrook 7H10 agar (7H10), L-J and Ogawa egg, and the manual MGIT system (mMGIT). Overall concordance rates among aMGIT and the proportion method on 7H10 or Ogawa media were 98.3% and 96.9% for 4 first-line drugs, respectively. Rates were particularly high for isoniazid and rifampin between aMGIT and 7H10 (efficiency of 100%). On the other hand, overall concordance rates among two egg media, L-J and Ogawa were 99.9%. Agreement between aMGIT and mMGIT was high for the AST to isoniazid and rifampin, but lower for the AST to ethambutol (90.9%), which relates to a lower specificity of mMGIT. The mean times to aMGIT and mMGIT results of susceptibility were 7 and 6 days, respectively, contrasted with 3 weeks in 7H10 and 4 weeks in L-J and Ogawa, indicating that both MGIT systems have the potential to consistently meet the turnaround time suggested by Centers for Disease Control and Prevention (CDC) of the United States. These results demonstrate that the fully automated BACTEC MGIT 960 SIRE system for AST is useful for rapid diagnosis of drug resistant tuberculosis.

[A study on resistance of Mycobacterium tuberculosis to four first-line anti-tuberculosis drugs in Japan: comparison of results in the local facilities and in the reference laboratory, in 1997]

Five years after the last survey of drug-resistant tuberculosis in Japan, a nationwide survey was conducted by the Tuberculosis Research Committee (Ryoken). A total of 78 hospitals in various districts of Japan participated in this cooperative study. Each collaborating laboratory sent all the isolated mycobacterial cultures during June 1 to November 30, 1997 to the Research Institute of Tuberculosis (RIT), which is one of the Supranational Reference Laboratories of the WHO/IUATLD Global Project on Anti-tuberculosis Drug Resistance Surveillance. At RIT identification and drug susceptibility of Mycobacterium tuberculosis isolates were reexamined. The RIT received a total of 2,167 cultures. Among them, 523 cultures were excluded from further examinations because of various reasons, such as growth of mycobacteria other than tubercle bacilli (MOTT, 453), mixed cultures of M. tuberculosis and MOTT (16), and contamination or non-viability (54). Thus drug susceptibility test results were available for 1,644 cultures, including 47 from foreign-born people. In the local laboratories, the absolute concentration method using 1% Ogawa egg slant (standard method, 26 hospitals), its modified methods using a 48-well plate (Microtiter method, 29 hospitals) and a 16-well plate (Well-pack method, 7 hospitals), combination of above 2 or 3 methods (13 hospitals), and other method (3 hospitals) were used for drug susceptibility testing, and the proportion method using 1% Ogawa egg slant was used in the RIT. The results in the local laboratories were compared with those in the RIT. A high concordance rate (over 90%) was seen in the testing for 1 microgram/ml of isoniazid (INH), rifampin (RFP) and streptomycin (SM), but the rate was lower (under 90%) in the testing for 0.1 microgram/ml of INH and ethambutol (EMB). However, there was no significant difference in the concordance rates according to the test drugs among methods for drug susceptibility testing used in the local laboratories. Median concordance rates between the results with the standard method, Microtiter method and Well-pack method in the local laboratories, and those in the RIT were 95.9%, 93.2% and 96.4% respectively. Relatively lower concordance rates were seen in the laboratories using the Microtiter method related to high overestimation rates (median overestimation rate of 5.3%), compared with 1.2% and 2.3% in the laboratories using the standard method and Well-pack method, respectively. However, relatively lower concordance rates (less than 90%) were seen in the laboratories using any of the three methods, indicating that there are variations among facilities. Part of the results concerning the resistance patterns to four first-line anti-tuberculosis drugs were reported elsewhere.

Interleukin-1 or tumor necrosis factor-alpha augmented the cytotoxic effect of mycobacteria on human fibroblasts: application to evaluation of pathogenesis of clinical isolates of Mycobacterium tuberculosis and M. avium complex

Mycobacteria-induced in vitro events reflecting human tuberculosis can contribute to the evaluation of the pathogenesis of Mycobacterium tuberculosis (MTB). In this study, we propose such an in vitro method based on live mycobacteria-induced cytotoxicity to human cell lines. When human lung-derived normal fibroblast cell line MRC-5 was infected with various strains of mycobacteria (M. tuberculosis H(37)Rv and H(37) Ra, Mycobacterium avium 427S and 2151SmO, and Mycobacterium bovis BCG Pasteur and Tokyo), the fibroblasts were killed by mycobacteria according to the degree of virulence. Other human originated macrophage (U-937, THP-1), myeloid (HL-60), and epithelial carcinoma (A549) cell lines exhibited a similar cytotoxic response to virulent mycobacteria. MRC-5 was most susceptible to virulent mycobacteria among various human cell lines examined. The cytotoxicity was enhanced by the proinflammatory cytokines, interleukin-1 (IL-1) and tumor necrosis factor-a (TNF-alpha), which in the absence of mycobacteria stimulate the growth of normal human fibroblasts. This in vitro evaluation system was applied to clinical isolates of drug-sensitive MTB (DS-MTB), drug-resistant MTB (DR-MTB) including multidrug-resistant (MDR-MTB), and M. avium complex (MAC). MTB strains (n = 24) exhibited strong cytotoxic activity, but MAC strains (n = 5) had only weak activity. Furthermore, there was no significant difference in cytotoxicity between DS-MTB (n = 11) and DR-MTB (n = 13). Collectively, these results suggest that this new in vitro system is useful for evaluating the pathogenesis of mycobacteria and that there was no difference in the pathogenesis between drug-susceptible and drug-resistant clinical isolates.

Prevalence of drug-resistant tuberculosis in an HIV endemic area in northern Thailand

SETTING

Chiang Rai Province in Northern Thailand, where human immunodeficiency virus (HIV) infection has been prevalent since the 1990s.

OBJECTIVE

To observe the prevalence of drug-resistant tuberculosis (TB) and investigate the factors related to the level of drug resistance in an HIV endemic area.

DESIGN

Population-based surveillance study covering the whole province.

METHOD

Drug susceptibility testing was performed at the Thai Ministry of Public Health laboratory for all sputum smear-positive TB patients diagnosed in hospitals in Chiang Rai Province over a 25-month period in 1996-1998. Patient characteristics were obtained through interview by trained personnel. HIV testing was performed with informed consent.

RESULTS

Among the 1077 incident patients without previous history of treatment, the proportion of patients with resistance to isoniazid was 13.2%, 10.8% to rifampicin, 15.6% to streptomycin, and 5.8% to ethambutol. Multidrug resistance (MDR), i.e., resistance to at least both isoniazid and rifampicin, was observed in 6.3%. Factors associated with primary MDR-TB were HIV positivity (OR 2.2, 95%CI 1.3-3.9), age <50 years (OR 2.0), and treatment in the provincial hospital (OR 2.3), compared to patients treated in the community and private hospitals. Stratified analysis shows a significantly high prevalence of primary MDR-TB among HIV-positive patients treated in the provincial hospital against HIV-negative patients or HIV-positive patients in other hospitals.

CONCLUSION

The prevalence of primary MDR-TB in this area was high. It is necessary to strengthen TB control activities in order to reduce the burden of MDR-TB.

Resistance of Mycobacterium tuberculosis to four first-line anti-tuberculosis drugs in Japan, 1997

SETTING

Five years after the last survey of drug-resistant tuberculosis in Japan, a nationwide survey was conducted by the Tuberculosis Research Committee.

OBJECTIVE

To determine the prevalence of and risk factors for resistance to four first-line anti-tuberculosis drugs.

DESIGN

Cultures were obtained from patients hospitalized at 78 hospitals in different districts of Japan throughout a 6-month period, 1 June-30 November 1997. Drug susceptibility testing was carried out at the Research Institute of Tuberculosis, Tokyo, one of the supranational reference laboratories of the WHO/IUATLD global project.

RESULTS AND CONCLUSION

Among patients with no prior treatment, resistance to any of the four drugs was found in 10.3%, and the prevalence of primary multidrug resistance (MDR) was 0.8%. The prevalence of acquired resistance was 42.4% for any of the four drugs and 19.7% for MDR, indicating a high prevalence rate compared with those reported in the WHO/IUATLD global project. About 73% of resistant isolates from new cases were resistant to one drug, while 64.3% of resistant isolates from the re-treatment cases were resistant to two or more drugs (P < 0.0001). No significant differences in resistance rates by sex, age group, nationality, district, and/or accompanying diseases were observed in any of the new or re-treatment cases. Other factors associated with the high prevalence in re-treatment cases remain to be determined.

[Home drug therapy for a patient who rejected use of morphine--management of dyspnea and pain by codeine phosphate]

We encountered a terminal lung cancer patient with severe back pain and dyspnea who refused the use of morphine, and succeeded in home palliative care with the use of an original prescription (CA), the main ingredient of which was codeine phosphate.

[Molecular genetic approaches to Mycobacterium tuberculosis]

Recent progress of molecular genetics has been providing tools for new approaches to disease treatment and diagnosis of Mycobacterium tuberculosis. In 1998, Cole et al. reported the complete genome sequence of Mycobacterium tuberculosis. The new information will provide us the knowledge and understanding of the biology of Mycobacterium tuberculosis. Further, it will provide us new conception of diagnosis and treatment of the disease. Four topics were selected in this symposium. Dr. Iinuma reviewed and prospected the clinical utility of nucleic acid amplification methods of Mycobacterium tuberculosis. Dr. Suzuki reviewed the molecular mechanism of acquired resistance to anti-TB drugs and reported the early detection of genetic mutation by new designed DNA tip method. Dr. Takahashi reviewed the method of molecular epidemiology and genetic elements as a tool for strain differentiation of tuberculosis. Dr. Mizuguchi interpreted the essential feature of mycobacterial genome maps, and genes and their biological activity. He also reviewed the importance and the utility of the complete genome sequence of tuberculosis in association with pathogenecity. These topics were summarized in this report, based on the symposium of "Molecular genetic approaches to Mycobacterium tuberculosis" in the 75th annual meeting of the Japanese Society for Tuberculosis.

Suppression of type II collagen-induced arthritis by a new isocoumarin, NM-3

The anti-arthritic effect of NM-3, a new isocoumarin, was examined using a type II collagen-induced arthritis model for human rheumatoid arthritis in DBA/1J mice. NM-3 by oral administration suppressed dose-dependently (2-20 mg/kg/day) not only macroscopic changes such as erythema and swelling of limbs but also histopathologic changes and radiographic changes such as bone lesions. The efficacy of NM-3 was greater than those of disease-modifying anti-rheumatoid drugs (DMARDs), auranofin (40 mg/kg/day) and bucillamine (10 mg/kg/day). NM-3 failed to suppress carageenan-induced edema and to inhibit the activities of inflammation-related enzymes including cyclooxygenase-1 and -2, 5-lipoxygenase and phospholipase A2, suggesting that the mode of anti-arthritic action of NM-3 may be different from those of non-steroidal anti-inflammatory agents (NSAIDs). Since NM-3 inhibits angiogenesis in a mouse dorsal air-sac model, the observed anti-arthritic effect of NM-3 might be partly attributed to the antiangiogenic activity. Thus, NM-3 is a potential orally active therapeutic agent for the treatment of human rheumatoid arthritis.

[Detection of rifampin-resistant Mycobacterium tuberculosis by line probe assay (LiPA)]

A recently described reverse hybridization-based line probe assay is used for the rapid detection of the mutations in the rpoB genes of rifampin-resistant Mycobacterium tuberculosis and for the identification of the M. tuberculosis complex. A multicenter study that included 5 laboratories was performed to evaluate the line probe assay in comparison with the in vitro susceptibility test. A total of 406 mycobacteria isolates which were composed of 103 rifampin-resistant and 230 rifampin-susceptible M. tuberculosis isolates, and 73 mycobacteria other than tubercle bacilli (MOTT), were subjected to this study. All 333 M. tuberculosis isolates were discriminated correctly from MOTT bacilli by a line probe assay. Concordance rates with sequencing results for five wild-type probes (S probes) and four specific mutations (R probes) for detecting the mutations in the rpoB genes were both 100%. The overall concordance rate with the in vitro susceptibility testing results was 98.5% (328 of 333 isolates). These results indicate that a line probe assay kit may be useful for the rapid diagnosis of rifampin-resistant tuberculosis.

[Role of pharmacists in the medical team--attempting palliative care]

The Pharmacy Department at our hospital is attempting to develop methods for palliative care, for example of cancer pain or smelly tumors. The participation of pharmacists on the medical team for home care is necessary, because the supply of proper drugs for patients' individual conditions is indispensable in palliative care. Communication between not only patients, but also between their families and us, as well as the maintenance of close contact with the medical team, are important in home care.

Simple and rapid identification of the Mycobacterium tuberculosis complex by immunochromatographic assay using anti-MPB64 monoclonal antibodies

A newly developed immunochromatographic assay (MPB64-ICA) for identification of the Mycobacterium tuberculosis complex was evaluated with 20 reference strains of mycobacterial species and 111 clinical isolates. MPB64-ICA displayed a very strong reaction band with organisms belonging to the M. tuberculosis complex but not with mycobacteria other than M. tuberculosis (MOTT bacilli), except for one of four M. marinum strains tested and one M. flavescens strain, both of which gave very weak signals. The effectiveness of MPB64-ICA in combination with two liquid culture systems (MB-REDOX and MGIT) was tested. A total of 108 of 362 sputum specimens processed were positive for acid-fast bacilli. Samples taken from the cultures on the same days when either of the two culture systems became positive for mycobacteria were assayed with MPB64-ICA. Of 108 cultures with mycobacteria, 51 showed a positive signal with the test, in which the presence of the M. tuberculosis complex was demonstrated later by the Accuprobe for M. tuberculosis complex. In addition, MPB64-ICA could correctly detect the M. tuberculosis complex in mixed cultures of the M. tuberculosis complex and MOTT bacilli. These results indicate that MPB64-ICA can be easily used for rapid identification of the M. tuberculosis complex in combination with culture systems based on liquid media without any technical complexity in clinical laboratories.

[Comparison of the newly developed MB redox system with mycobacteria growth indicator tube (MGIT) and 2% Ogawa egg media for recovery of mycobacteria in clinical specimens]

The rate of recovery and the mean time to detection of mycobacteria in clinical specimens were determined in a newly-developed MB Redox system based on liquid medium, and the results were compared with those of MGIT and 2% Ogawa egg media. From 587 sputum specimens processed, totally 203 mycobacterial isolates were detected, of which 177 (87.2%) with MB Redox, 185 (91.1%) with MGIT and 133 (65.6%) with 2% Ogawa medium. The difference in the percentages of positive cultures between either of the two liquid media and 2% Ogawa medium was significant (p < 0.0001). The mean time to detection of the Mycobacterium tuberculosis complex was 17.5 days with MB Redox, 18.7 days with MGIT, and 26.2 days with 2% Ogawa medium. The contamination rates were 1.5, 1.7, and 4.1% for MB Redox, MGIT, and 2% Ogawa medium, respectively. In conclusion, both MB Redox and MGIT systems, based on liquid medium, are more efficient than 2% Ogawa medium for the recovery of mycobacteria in clinical specimens.

Effects of ER-34122, a novel dual 5-lipoxygenase/cyclooxygenase inhibitor, on indices of early articular lesion in MRL/MpJ-lpr/lpr mice

OBJECTIVE AND DESIGN

To investigate effects of ER-34122, a novel dual 5-lipoxygenase (LOX)/cyclooxygenase (COX) inhibitor, and indomethacin on progression of articular lesions in MRL/MpJ-lpr/lpr (MRL/1) mice.

MATERIAL

100 male MRL/l mice.

TREATMENT

ER-34122 (1-100 mg/kg) and indomethacin (1 mg/kg) were orally administered once a day to MRL/l mice from 6 to 10 or 16 weeks old.

METHODS

Articular lesions were analyzed histopathologically in the early (10 weeks old) or late (16 weeks old) stages of MRL/l mice arthritis. Serum levels of rheumatoid factor were measured by using enzyme-linked immunosorbent assay.

RESULTS

Articular lesions in the late stage of MRL/l mice arthritis were characterized by cartilage degeneration and pannus formation which were severer than those in the early stage. Polymorphonuclear leukocyte (PMN) infiltration and subsynovial soft tissue edema were observed as characteristic lesions in the early stage. ER-34122 suppressed progression of PMN infiltration, subsynovial soft tissue edema and multiplication of synovial lining cells in the early stage of the arthritis, even though it had no significant effect on other indices of articular lesion, enlargement of lymph nodes and serum levels of rheumatoid factors. On indices of late articular lesion, ER-34122 had no significant beneficial effects. Neither in the early nor late stage, indomethacin, a COX inhibitor, had significant effect on the arthritis at the examined dose.

CONCLUSIONS

These results disclosed that ER-34122, a dual LOX/COX inhibitor, has anti-inflammatory activity in the early stage of the spontaneous arthritis.

Mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis strains isolated mostly in Asian countries and their rapid detection by line probe assay

Mutations in the rpoB gene of 90 rifampin-resistant Mycobacterium tuberculosis isolates mostly from Asian countries were analyzed. Ten distinct single-nucleotide substitutions were found among the isolates by automated sequencing. A 3-nucleotide insertion was found in two isolates, and no mutation was found in five isolates (5.6%). A reverse hybridization-based line probe assay (INNO-LiPA Rif TB) for rapid detection of the mutations was evaluated with these isolates. Concordance rates with sequencing results for five wild-type probes (S probes) and four probes for specific mutations (R probes) were 96.7 and 100%, respectively. The overall concordance rate with the in vitro susceptibility testing results was 92.2% (83 of 90 isolates). These results indicate that a commercial line probe assay kit may be useful for rapid diagnosis of rifampin-resistant tuberculosis.

[Recent advance in the isolation of mycobacteria]

Two systems, the newly developed Mycobacteria Growth Indicator Tube (MGIT) and biphasic Septi-Chek AFB based on liquid media, proved to be significantly better than the egg-based solid media for the isolation of mycobacteria from clinical specimens. The isolation of Mycobacterium tuberculosis by MGIT occurred 8 days previous to the isolation by the conventional Ogawa method. These results indicate that the MGIT system is efficient for the recovery of mycobacteria.

[Drug consultation for patients who present with symptoms like dementia]

It is a lowering of compliance in taking drugs of patients who present with symptoms like dementia that being impairment in a therapy for disease. We started drug consultation to that one at home care, because of improvement of non-compliance in taking drugs. Improvement of consciousness in taking drugs for patients and consciousness in necessity of taking drugs for their family that be brought about by our drug consultation could be made progress of compliance in taking drugs.

Anti-inflammatory effects of mao-bushi-saishin-to in mice and rats

Effects of Mao-Bushi-Saishin-to (MBS) on anti-inflammatory activities were examined in mice and rats. MBS significantly inhibited the increase in vascular permeability induced by acetic acid, the ear edema induced by arachidonic acid and phorbol ester, and the cutaneous extravasation induced by bradykinin and histamine. MBS, however, was not effective against the serotonin-induced cutaneous permeability increase in mice. MBS significantly inhibited carrageenin-induced hind foot edema and cotton pellet-induced granulation tissue growth in rats. These results show that MBS may exert anti-inflammatory effects through the underlying mechanism(s) of preventing mediator release from mast cells and macrophages.

[Multidrug-resistant tuberculosis. 1. Drug susceptibility testing and its standardization]

Drug susceptibility testing is one of the most difficult procedures to standardize in mycobacteriology laboratories. International standardization of the test is needed for comparative evaluation of controlled chemotherapeutic trials, for epidemiological surveys on the prevalence of drug resistance, and for guidance in the treatment of tuberculosis patients. In 1996, a new procedure for drug susceptibility testing was proposed by an ad hoc committee of the Japanese Society for Tuberculosis. The proposal is for a test with the proportion method using an Ogawa egg medium similar to those recommended by the WHO. Resistance is expressed as the percentage of colonies that grow on critical concentrations of the drugs, i.e. 0.2 microgram/ml for isoniazid, 40 micrograms/ml for rifampicin, 10 micrograms/ml for streptomycin and 2.5 micrograms/ml for ethambutol. Strains of tubercle bacilli which are grown on drug-containing media represents more than 1% of the number of colonies that develop on drug-free media are considered to be clinically resistant to that agent. The results are recorded as susceptible (S) or resistant (R) on the laboratory forms. The proportion method using agar- and liquid-based media is used worldwide. In the near future a test with agar- or liquid-based media will be discussed for standardization of the test in Japan, as described by the National Committee for Clinical Laboratory Standards of the United States.

Mutation in pncA is a major mechanism of pyrazinamide resistance in Mycobacterium tuberculosis

OBJECTIVE

To characterize the correlation of the mutations in the pncA gene encoding pyrazinamidase (PZase) of Mycobacterium tuberculosis to a loss of PZase activity and development of pyrazinamide (PZA) resistance.

DESIGN

The association of PZase activity, minimum inhibitory concentrations (MICs), and mutations in the pncA gene of M. tuberculosis isolated in mostly Asian countries was investigated.

RESULTS

One hundred thirty-five out of 168 isolates were PZase positive, and 33 were negative. The MICs of PZA at pH 6.0 were over 400 micrograms/ml for all 33 PZase-negative isolates, while those of PZase-positive isolates were equal to or less than 200 micrograms/ml. Among 33 PZase-negative isolates sequenced, 32 (97%) had mutations within the pncA gene. A mutation was seen in various regions throughout the pncA gene. It was surprising that all three strains of in vitro selected PZA resistant mutants were PZase-positive and showed no change in the pncA gene. These results indicate that additional mechanisms may be involved in PZA resistance. No mutations were observed in all of 135 PZase-positive M. tuberculosis isolates tested, indicating that mutations in the pncA gene could be involved in the loss of PZase activity.

CONCLUSIONS

Sequencing analysis of the pncA gene should provide rapid diagnosis of PZA resistant clinical isolates of M. tuberculosis.

Detection of kanamycin-resistant Mycobacterium tuberculosis by identifying mutations in the 16S rRNA gene

In Mycobacterium smegmatis and a limited number of Mycobacterium tuberculosis strains, the involvement of alterations of the 16S rRNA gene (rrs) in resistance to kanamycin has been shown. To investigate the extent to which mutations in a specific region of the rrs gene and the kanamycin-resistant phenotype in clinically isolated M. tuberculosis strains were correlated, 43 kanamycin-resistant strains (MICs, > or =200 microg/ml), 71 kanamycin-susceptible strains, and 4 type strains were examined. The 300-bp DNA fragments carrying the rrs gene and the intervening sequence between the rrs gene and 23S rRNA (rrl) gene fragments were amplified by PCR and were subjected to PCR-based direct sequencing. By comparing the nucleotide sequences, substitutions were found in 29 of 43 (67.4%) kanamycin-resistant clinical isolates at positions 1400, 1401, and 1483 but in none of the 71 sensitive isolates or the 4 type strains. The most frequent substitution, from A to G, occurred at position 1400. A substitution from C to T at position 1401 was found once. Two clinical isolates carried the double mutation from C to A at position 1401 and from G to T at position 1483. In addition, we found that these mutants can be distinguished from wild-type strains by digestion with the restriction endonucleases TaiI and Tsp45I. Furthermore, we found that the genotypes of kanamycin-resistant strains can be discriminated from each other by digestion with a restriction endonuclease, BstUI or DdeI.

[Reinfection tuberculosis at a day-laborers' facility equipped with a sauna]

Restriction-fragment-length polymorphism (RFLP) analysis was used to study one outbreak of reinfection pulmonary tuberculosis at a day-laborers' facility equipped with a sauna. The results were interpreted in conjunction with clinical and epidemiologic data. The DNA prove was derived from the insertion sequence IS 6110. A 63-year-old man who stayed at a day-laborers' facility for eight months was found to have advanced cavitary lung disease with sputum smears strongly positive for acid-fast bacilli. One year later a 46-year-old man staying at the same facility for 24 months was also found to have sputum-positive tuberculosis. The 46-year-old man had undergone treatment for tuberculosis 16 years previously and showed radiographic evidence of previous lung damage from tuberculosis. The second man had no tubercule bacilli in sputum when the 63-year-old man was found to have sputum-positive tuberculosis. The organisms isolated from these two men were both drug sensitive and had a similar RFLP pattern which suggests that 63-year-old man was the source of this outbreak and that pulmonary tuberculosis in the 46-year-old man was caused by exogenous reinfection. We conclude that exogenous reinfection may have been one pattern of tuberculosis transmission in this high-risk environment.

[Drug consultation and at home care--the present situation and the point at issue in our hospital]

We began drug consultation in our hospital and at home care about one year ago, because of progress in the quality of medical care. As the method for drug consultation, we tried to educate patients using our own pamphlets. It was assumed that the education was important not only for the patients but also for their family. Again, it was assumed that the usefulness of a conference with doctors, nurses, MSW and us made for better compliance in taking drugs, assured early detection of side effects and better management of the disease. With home care, it is supposed that the drug consultation will be carried out by clinical pharmacists will make for progress in the quality of medical care.

[Rapid diagnosis of tuberculosis]

Two systems, the newly developed Mycobacteria Growth Indicator Tube (MGIT) and biphasic Septi-Chek AFB based on liquid media, proved to be significantly better than the egg-based solid media for the isolation of mycobacteria from clinical specimens. The difference in the rates of isolation of bacteria between the two groups of media was more remarkable with smear-negative specimens. The isolation of the Mycobacterium tuberculosis complex by MGIT occurred 8 days previous to the isolation by the conventional Ogawa method. The mean time for detecting M. tuberculosis complex by Septi-Chek AFB was similar to those of the Ogawa method. A greater difference in isolation time was observed for mycobacteria other than M. tuberculosis (MOTT) isolates. These results indicate that the MGIT and Septi-Chek AFB systems based on liquid media are efficient for the recovery of mycobacteria. PCR and other nucleic acid amplification methods are widely used for the detection of M. tuberculosis in clinical specimens. Although the sensitivities of the Gen-Probe Amplified Mycobacteria Direct Test (MTD) and Amplicor Mycobacteria for the detection of the M. tuberculosis complex appear to be similar to the sensitivity of the culture method using the Septi-Chek AFB, the two methods should be quite useful for rapid detection of M. tuberculosis infections. On the other hand, two cooperative blind studies conducted between 6 to 9 laboratories to estimate the reliability and reproducibility of these two commercially available kits revealed the necessity of good laboratory practice and development of reference reagents to monitor the performance of the whole assay, including pretreatment of clinical specimens. Considerable progress has been made in recent years toward understanding the molecular basis of the resistance to antituberculosis drugs, isoniazid (katG, inhA, ahpC), rifampin (rpoB), pyrazinamide (pncA), streptomycin (rpsL, rrs), ethambutol (embB), and fluoroquinolones (gyrA). Most cases of resistance are related usually to simple nucleotide substitutions rather than to acquisition of new genetic elements. Multidrug-resistant isolates of M. tuberculosis arise as a consequence of sequential accumulation of mutations conferring resistance to single therapeutic agents. The basis of resistance is not able to be explained yet in a substantial percentage of strains (> 90%) for other antituberculosis drugs than rifampin. Further studies are required to fully understand the molecular mechanisms of resistance.

Characterization of the rpsL and rrs genes of streptomycin-resistant clinical isolates of Mycobacterium tuberculosis in Japan

Mutations in the rpsL and rrs genes associated with streptomycin resistance in Mycobacterium tuberculosis clinically isolated in Japan were characterized. The rpsL genes of 172 clinical isolates were amplified by PCR and classified into two groups on the basis of MboII restriction digestion. Thirty-three out of 54 (61.1%) streptomycin-highly resistant isolates (MIC > 200 micrograms ml-1) were not digested by MboII. By contrast, the remaining 21 of 54 (38.9%) streptomycin-highly resistant isolates, all of 41 isolates with streptomycin resistance at a lower level (20 micrograms ml-1 < MIC < or = 200 micrograms ml-1), and all of 77 streptomycin-sensitive isolates, were restricted. Thus, all isolates resistant for MboII digestion showed a high level of resistance to streptomycin. Subsequently, the sequence for the rpsL and rrs genes from the 46 isolates were analysed. Eighteen out of 19 (94.7%) streptomycin-highly resistant isolates carried a mutation in any rpsL gene at position 43 or 88, or the rrs gene; 10 out of 17 (58.8%) streptomycin-resistant isolates at a lower level were confirmed to exhibit the mutation of either the mutated rpsL gene at position 88, or the rrs gene. In the total 36 streptomycin-resistant isolates, the mutation of the rpsL or rrs gene was observed in 28 streptomycin-resistant isolates, corresponding to 77.8%, whereas none of the streptomycin-sensitive isolates had mutations in either the rpsL or rrs gene.

Molecular analysis of kanamycin and viomycin resistance in Mycobacterium smegmatis by use of the conjugation system

We examined the molecular mechanisms of resistance to kanamycin and viomycin in Mycobacterium smegmatis. All of the M. smegmatis strains with high-level kanamycin resistance had a nucleotide substitution from A to G at position 1389 of the 16S rRNA gene (rrs). This position is equivalent to position 1408 of Escherichia coli, and mutation at this position is known to cause aminoglycoside resistance. Mutations from G to A or G to T at position 1473 of the M. smegmatis rrs gene were found in viomycin-resistant mutants which had been designated vicB mutants in our earlier studies. Using the M. smegmatis conjugation system, we confirmed that these mutations indeed contributed to kanamycin and viomycin resistance, and kanamycin susceptibility was dominant over resistance in a heterogenomic strain. Additional experiments showed that three of four Mycobacterium tuberculosis strains with high-level kanamycin resistance had a mutation from A to G at position 1400, which was equivalent to position 1389 of M. smegmatis.

A dtsR gene-disrupted mutant of Brevibacterium lactofermentum requires fatty acids for growth and efficiently produces L-glutamate in the presence of an excess of biotin

A dtsR gene encoding a homolog of the beta subunit of some biotin-containing enzymes suppresses a detergent-sensitive mutation of Brevibacterium lactofermentum (E. Kimura et al., 1996, Biosci. Biotech. Biochem. 60, 1565-1570), which has been used for the fermentative production of L-glutamate. When the dtsR gene was disrupted, the organism exhibited strict fatty acid auxotrophy; oleate or oleate ester, but not palmitate ester or stearate ester, supported the growth of the delta dtsR mutant. Immunoblotting with an anti-DtsR antibody revealed that no intact DtsR was present in the cytosol of the delta dtsR mutant. In the presence of an excess of biotin, the wild type strain did not produce L-glutamate whereas the delta dtsR mutant efficiently produced it. The mechanism underlying the efficient production of L-glutamate by the delta dtsR mutant is discussed as to the possible role of dtsR in fatty acid metabolism.

[Reliability of Amplicor Mycobacteria test for detection of Mycobacterium tuberculosis complex. M. avium and M. intracellulare: a cooperative study among 9 laboratories]

The Amplicor Mycobacteria, a PCR-based assay, is a rapid test for the detection of Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium intracellulare in clinical samples. To estimate the reliability and reproducibility of the method, a cooperative blind study was conducted among 9 laboratories. Materials used for testing consisted of 105 sputum and 30 water samples containing known numbers of M. bovis BCG, M. avium, M. intracellulare, and samples without bacteria. Only 2 out of the 9 laboratories correctly identified the presence or absence of mycobacterial DNA in all 135 samples. In sputum samples, 6 out of the 9 laboratories detected mycobacterial DNA in all positive samples, and 4 out of the 9 laboratories correctly reported the absence of DNA in the negative samples, indicating the need for good laboratory practice and development of reference reagents to monitor the performance of the whole study, including pretreatment of clinical samples. The main problem was lack of specificity rather than lack of sensitivity. From about half of the laboratories, false-positive results were reported, however, the ratio was below 6%; 1% (1/106 sputum samples) in 3 laboratories, 1.9% (2/105) in 2 laboratories, and 5.7% (6/105) in one laboratory, respectively. These results indicate that the Amplicor Mycobacteria is quite useful for a rapid diagnosis of tuberculosis.

[Serodiagnosis with trehalose-6,6'-dimycolate of pulmonary tuberculosis]

Enzyme-linked immunosorbent assay (ELISA) was used to examine serum antibody levels of mycobacterial antigen in 92 patients with active tuberculosis, 36 with cured tuberculosis, 45 with nontuberculous mycobacteriosis, and as 31 with other diseases. Glycolipid fraction containing mainly cord factor (trehalose-6,6'-mycolate) from Mycobacterium tuberculosis H37Rv were used as ELISA antigen. Overall positive rates of the ELISA tests in the patients with active pulmonary tuberculosis, those with nontuberculous mycobacteriosis, and those with other diseases were 67.4%, 75.6%, and 6.5%, respectively. Patients with tuberculosis and those with nontuberculous mycobacteriosis differed from the control group (p < 0.0001). Higher positive rates were correlated with bacterial loads (smear-positive vs smear-negative, p < 0.01) and with chest roenrgenographic findings (far advanced or other cavitary vs noncavitary, p < 0.01). Because 18 of 36 smear-negative patients (50%) had positive results, we believe that the ELISA test with this antigen can be useful for diagnosis of M. tuberculosis, especially in patients with smear-negative.

Studies of polymorphic DNA fingerprinting and lipid pattern of Mycobacterium tuberculosis patient isolates in Japan

Strain differentiation by DNA restriction fragment length polymorphism (RFLP) has been used mainly for the epidemiological purpose of Mycobacterium tuberculosis infection. In this study, we tried to connect the molecular and phenotypic characteristics of M. tuberculosis patient isolates by comparing the DNA fingerprints obtained by RFLP using IS6110 and lipid patterns using two-dimensional thin-layer chromatography (2-D TLC) with silica gel, since M. tuberculosis has a lipid-rich cell envelope which contributes to the virulence and immunomodulatory properties. We found that 66 isolates of M. tuberculosis from tuberculosis patients showed that the occurrence of IS6110 varied from 1 to 24 copies. The IS6110 patterns were highly variable among isolates. Fifty different RFLP patterns were observed, and 12 RFLP patterns were shared by two or more strains. By computerized analysis of the RFLP patterns of M. tuberculosis patient isolates, we found that 95% of the isolates fell into seven clusters, from A to G, with at least two isolates in each (> 30% similarity). Among the cellular lipids, the phospholipid composition did not differ by strain, whereas the glycolipid pattern differed markedly. Especially, the relative concentration of cord factor and sulfolipid, both of which were known as virulent factors, varied by strain. The fingerprints of some strains showed an association between the DNA and glycolipid patterns, even though some of the same DNA fingerprint strains showed differences in lipid patterns. Among the patient isolates, M. tuberculosis strain 249 possessed a specific glycolipid with 2-O-methyl-L-rhamnose and L-rhamnose, which is rarely found in other strains. This glycolipid showed serological activity against the sera of tuberculosis patients, even if the reactivity was not as strong as trehalose dimycolate. It also showed the inhibition of phagosome-lysosome fusion in macrophages, suggesting involvement with virulence. These results suggest that RFLP analysis using IS6110 is useful for clustering the human isolates of M. tuberculosis, however, for further strain differentiation on virulence, a lipid analysis provides more information.

Molecular cloning of the Corynebacterium glutamicum ('Brevibacterium lactofermentum' AJ12036) odhA gene encoding a novel type of 2-oxoglutarate dehydrogenase

The Corynebacterium glutamicum ('Brevibacterium lactofermentum' AJ12036) odhA gene, encoding 2-oxoglutarate dehydrogenase (E1o subunit of the 2-oxoglutarate dehydrogenase complex), has been isolated and identified as an homologous counterpart of the Escherichia coll sucA and Bacillus subtilis odhA genes. The nucleotide sequence of a 4394 bp chromosomal fragment containing the C. glutamicum odhA gene was determined. The odhA gene comprised 3771 bp (1257 codons, including the initiation codon) and a molecular mass of 138656 Da was predicted for the OdhA polypeptide. Northern blot analysis revealed a 3.9 kb transcript. The size of the transcript, together with the presence of a rho-independent terminator-like structure, suggests that C. glutamicum odhA is monocistronic. Cells harbouring plasmids carrying C. glutamicum odhA showed a threefold increase in specific 2-oxoglutarate dehydrogenase complex activity and expression of a protein with an apparent molecular mass of 136 kDa, in good agreement with the predicted size of the OdhA polypeptide. The C-terminal region of the C. glutamicum OdhA protein shows strong sequence similarity to E1os from other organisms. C. glutamicum OdhA has an N-terminal extension not found in previously reported E1os. The amino acid sequence of this extension shows similarity to that of the C-terminal region of dihydrolipoamide S-succinyltransferase (E2o) subunits of 2-oxoglutarate dehydrogenase complexes and dihydrolipoamide S-acetyltransferase (E2p) subunits of pyruvate dehydrogenase complexes. It suggests that the C. glutamicum odhA gene might encode a novel bifunctional protein with E1o and E2o activities.