Avoidance of ant chemical traces by spider mites and its interpretation.

Spider mites become easy prey for ants when they leave their protective webs; therefore, the ability to avoid traces of ongoing ant activity should confer a selective advantage to mites. We examined avoidance of ant traces by the spider mites Tetranychus kanzawai and Tetranychus urticae. Both mite species avoided host plant leaves with active traces of Pristomyrmex punctatus or Formica japonica ants. Pristomyrmex punctatus trace avoidance by T. kanzawai lasted for more than 1 h, but not more than 3 h. Tetranychus kanzawai also avoided P. punctatus traces on plant stems, along which the mites access leaves. Moreover, T. kanzawai avoided hexane extracts of P. punctatus or F. japonica applied to a filter paper pathway. This study represents the first demonstration of a repellent effect of ant chemical traces on spider mites. Considering the substantial abundance and global distribution of ants in nature, such repellent effects may help to answer the long-standing question of why only a small fraction of available plant resources is used by herbivores. Although spider mites have developed resistance against many synthetic pesticides, natural compounds that simulate ant chemical traces may repel spider mites from agricultural crops.

Oviposition-site shift in phytophagous mites reflects a trade-off between predator avoidance and rainstorm resistance.

Predators can reduce prey population densities by driving them to undertake costly defences. Here, we report on a remarkable example of induced antipredator defence in spider mites that enhances the risk to rainstorms. Spider mites live on the undersides of host plant leaves and usually oviposit on the leaf undersurface. When they are threatened by predatory mites, they oviposit on three-dimensional webs to avoid egg predation, although the cost of ovipositing on webs has not yet been clearly determined. We prepared bean plants harbouring spider mite (Tetranychus kanzawai) eggs on either leaf surfaces or webs and exposed them to rainstorms outdoors. We found that fewer eggs remained on webs than on leaf surfaces. We then examined the synergistic effect of wind and rain by simulating both in the laboratory. We conclude that ovipositing on webs comes at a cost, as eggs are washed off the host plants by wind and rain. This may explain why spider mite populations decrease drastically in the rainy season, although they inhibit leaf undersides where they are not directly exposed to rainfall.

Ant-mediated indirect negative effects of aphids on spider mites living on the same plant.

Some aphid species are known to have mutualistic relationships with tending ants; that is, the aphids supply the ants with honeydew and are protected by the ants. Although spider mites and honeydew-producing aphids often live on the same host plant, it has not previously been determined whether the ants tending these aphids affect spider mite survival. Using replicated microcosms, each containing an artificial ant nest, we compared experimentally the survival of two-spotted spider mites on kidney bean plants with and without cowpea aphids. Our results showed significantly fewer spider mites on plants with aphids, indicating that spider mites were preyed upon by ants tending aphids. On the other hand, there was no detectable plant-mediated indirect effect of aphids on mite performance in the microcosms. Therefore, we conclude that aphids indirectly reduced the survival of spider mites living on the same host plant via their tending ants. Nonetheless, spider mites did not avoid settling on plant leaves infested with aphids.

[THE MINIMUM NUMBER OF SPUTUM SMEAR SAMPLES NEEDED FOR THE DIAGNOSIS OF TUBERCULOSIS].

[Objective] To determine whether three sputum examinations with fluorescent staining are necessary to diag- nose tuberculosis (TB) in our hospital. [Patients] From April 2005 to December 2012, 379 TB patients were admitted and received anti-TB therapy in our hospital. [Methods] A retrospective study was conducted to assess the positivity rates of sputum smears based on three exami- nations. The positivity rate of first sputum smear and the cumulative smear-positive rates in the second and third were determined. Then, we also determined difference of positivity rates in sputum properties, sampling procedures and cavity formation. [Results] Of the 379 patients who met the screening criteria, 300 tested positive based on the first sputum smear (79.2%). The positivity rate of the first sputum smears was higher in the purulent sputum group than in the mucous sputum group (91.2% vs. 72.3%). Cavity formation, and sputum extraction procedures were not related to the positivity rate of the first sputum smears. In the mucous sputum group, the cumulative smear-positive rate in the second test significantly rose, but did not rise in the third test. [Conclusions] Three sputum smear examinations were necessary in patients who submitted mucous sputum samples. It is important to get purulent sputum.

[[CASE OF TUBERCULOSIS COMPLICATIONS DURING PREGNANCY LEADING TO AN INFECTION OUTBREAK].]

A 31-year-old woman developed a constant cough during the 8th week of pregnancy and was diagnosed with bronchial asthma. She was prescribed prednisolone and inhaled corticosteroids. At 28 weeks of pregnancy, she showed worsening weight loss, fever, night sweats, hoarseness, and coughs. At 31 weeks of pregnancy, a scatter shadow and cavitary lesions were detected on the chest radiograph. Acid- fast bacilli smear test and tuberculosis (TB) polymerase chain reaction tests yielded positive results (G-8), and she was diagnosed with TB. Contact tracing and screening indicated 3 patients with TB onset and 18 patients with latent TB infec- tion attributed to the initial patient, who infected a total of 36 people. In the present case, physicians were reluctant to order a chest radiograph for fear of harming the fetus and did not order sputum or interferon gamma release (IGRA) assay tests either. The diagnosis was delayed by 152 days, which was considered as a factor that caused the outbreak. The diag- nosis of TB in a pregnant patient may be very challenging because symptoms may initially be ascribed to the pregnan- cy, and delayed diagnosis and treatment of military TB can lead to the death of the mother and fetus. Consequently, to ensure early diagnosis and treatment, chest radiography and sputum and IGRA tests are recommended for pregnant women who have TB symptoms or are at high risk for TB.

[AN OUTBREAK OF PULMONARY TUBERCULOSIS DUE TO DEFINITE EXOGENOUS REINFECTION AMONG ELDERLY INDIVIDUALS IN WELFARE FACILITIES].

PURPOSE: We report an outbreak of 64 cases of tuberculosis (TB) that spread in a welfare facility for elderly individuals. OBJECTIVE AND METHODS: First, 64 TB patients who had contact with the source patient were screened at our hospital. We examined the time course up to the discovery of symptoms and analyzed the results for variable numbers of tandem repeats (VNTR) and the drug susceptibility tests. Second, we performed chest computed tomography to examine lesions due to a previous TB infection. RESULT: The source patient had recurrent aspiration pneumonia. The delay in doctor consultation was considered day 0, and the delay of diagnosis was 267 days. On examining the contacts, we found that 29 patients had TB while 35 had a latent TB infection. Results of the VNTR and the drug susceptibility tests showed that all the patients who developed TB had the same pattern as that of the source patient. Chest computed tomography showed lesions due to a previous TB infection in 8 patients. CONCLUSION: Based on the results of the VNTR and drug susceptibility tests, we concluded that the outbreak was due to an exogenous infection from the same source. All 8 patients who showed lesions due to a previous TB infection were aged > 81 years, and TB in these patients was found to be due to exogenous re-infection.

Predation risk increases dispersal distance in prey.

Understanding the ecological factors that affect dispersal distances allows us to predict the consequences of dispersal. Although predator avoidance is an important cause of prey dispersal, its effects on dispersal distance have not been investigated. We used simple experimental setups to test dispersal distances of the ambulatory dispersing spider mite (Tetranychus kanzawai) in the presence or absence of a predator (Neoseiulus womersleyi). In the absence of predators, most spider mites settled in adjacent patches, whereas the majority of those dispersing in the presence of predators passed through adjacent patches and settled in distant ones. This is the first study to experimentally demonstrate that predators induce greater dispersal distance in prey.

Phase II trial of S-1 as third-line or further chemotherapy in patients with advanced non-small-cell lung cancer.

OBJECTIVES: This study was conducted to evaluate the efficacy and safety of S-1 in patients with advanced non-small-cell lung cancer (NSCLC), receiving two or more prior chemotherapy regimens. METHODS: S-1 was administered orally for 14 consecutive days, followed by a 7-day rest period. This treatment course was repeated until disease progression or intolerable toxicity occurred. RESULTS: From 2010 to 2012, 45 patients were enrolled in this study. Of the 45 patients, 4 patients [8.9 %, 95 % confidence interval (CI) 0.6-17.2 %] exhibited a partial response and 24 patients (53.3 %) exhibited stable disease. The disease control rate was 62.2 % (95 % CI 48.1-76.4 %). Median progression-free survival was 71 days, and median survival time was 205 days. Four patients had grade 3 hematological toxicities, but toxicities of grade 4 were not observed in this study. CONCLUSION: Although S-1 monotherapy as third-line treatment or beyond was well tolerated, the response rate for this regimen did not demonstrate sufficient activity for patients with advanced NSCLC.

Potential lethal and non-lethal effects of predators on dispersal of spider mites.

Predators can affect prey dispersal lethally by direct consumption or non-lethally by making prey hesitate to disperse. These lethal and non-lethal effects are detectable only in systems where prey can disperse between multiple patches. However, most studies have drawn their conclusions concerning the ability of predatory mites to suppress spider mites based on observations of their interactions on a single patch or on heavily infested host plants where spider mites could hardly disperse toward intact patches. In these systems, specialist predatory mites that penetrate protective webs produced by spider mites quickly suppress the spider mites, whereas generalist predators that cannot penetrate the webs were ineffective. By using a connected patch system, we revealed that a generalist ant, Pristomyrmex punctatus Mayr (Hymenoptera: Formicidae), effectively prevented dispersal of spider mites, Tetranychus kanzawai Kishida (Acari: Tetranychidae), by directly consuming dispersing individuals. We also revealed that a generalist predatory mite, Euseius sojaensis Ehara (Acari: Phytoseiidae), prevented between-patch dispersal of T. kanzawai by making them hesitate to disperse. In contrast, a specialist phytoseiid predatory mite, Neoseiulus womersleyi Schicha, allowed spider mites to escape an initial patch, increasing the number of colonized patches within the system. Our results suggest that ants and generalist predatory mites can effectively suppress Tetranychus species under some conditions, and should receive more attention as agents for conservation biological control in agroecosystems.

Chemical investigation of aggregation behaviour in the two-spotted spider mite Tetranychus urticae.

The silk produced by the group-living mite Tetranychus urticae provides group protection and is used as an informative material during habitat settlement, egg laying, mating, and dispersal events. In this context, cues contained in the silk and other materials produced by mites [eggs, black faeces (BF) and white faeces + silk (WFS)] were investigated. Chemical compounds were extracted by hexane or methanol, and choice tests were used to determine the individual attractiveness of each extract. For both solvents, individuals did not respond to the extract from eggs and WFS. BF extracts were attractive for both solvents. After separating the BF methanol extract into four different chemical components using thin layer chromatography, no component was determined to be responsible for mite attraction. This work supports the evidence that the faeces of T. urticae do contain substances that promote behavioural changes. Not particular chemical compounds but combinations of them seem to induce the mites' preference. Moreover, the response of mites to chemicals seemed to be context dependent as mites belonging to populations with different densities differed in their attraction to BF extracts.

Factors determining species displacement of related predatory mite species (Acari: Phytoseiidae).

Neoseiulus womersleyi (Acari: Phytoseiidae) used to be the dominant species in fruit-tree orchards throughout Japan, but starting in the 1990s, N. womersleyi began to be displaced by Neoseiulus californicus in central and southwestern Japan. The present study was conducted to examine factors explaining the displacement of N. womersleyi by N. californicus. First, we confirmed under laboratory conditions that N. californicus could exclude N. womersleyi if they initially coexisted in a 1:1 ratio. During a 2-h continuous observation period, none of the heterospecific pairs had copulated and after 5 days together with heterospecific males, none of the females had laid eggs. When these females were placed with conspecific males, normal numbers of offspring were produced. Moreover, conspecific matings were not substantially disturbed in the presence of heterospecific males or females. Total fecundity was significantly lower in N. womersleyi than in N. californicus, but their r m values did not differ from each other. On the other hand, the frequency of intraguild predation by N. californicus on N. womersleyi was significantly higher than vice versa. From these results, we concluded that not reproductive interference nor differential female fecundity but asymmetrical intraguild predation seemed to explain the competitive exclusion of N. womersleyi by N. californicus.

Spider mites avoid caterpillar traces to prevent intraguild predation.

The phytophagous spider mites Tetranychus kanzawai and Tetranychus urticae can be as small as < 0.5 mm; thus, they are often incidentally consumed along with food plant leaves by voracious lepidopteran larvae (hereafter, 'caterpillars'). Therefore, the ability to avoid such intraguild predation should confer a selective advantage to mites. We experimentally demonstrated that adult females of both mite species avoided settling on food plant leaves with traces of all tested caterpillar species (Bombyx mori, Papilio xuthus, Spodoptera litura and Theretra oldenlandiae). We examined additional interactions using B. mori and T. kanzawai and found that B. mori trace avoidance by T. kanzawai lasted for more than 48 h. Tetranychus kanzawai also avoided B. mori traces on plant stems, along which mites access leaves. Moreover, T. kanzawai avoided acetone extracts of B. mori traces applied to filter paper, indicating that chemical substances of caterpillar traces are responsible for the avoidance. This study is the first demonstration of a repellent effect of herbivore trace chemicals on heterospecific herbivores. Although spider mites have developed resistance against many synthetic pesticides, these results predict that natural compounds simulating caterpillar traces may repel spider mites from agricultural crops.

Tuberculous hilar lymphadenopathy progressing after isoniazid administration.

Right hilar lymphadenopathy was the only radiologic finding in an immunocompetent 19-year-old man with a positive whole blood interferon-γ enzyme-linked immunosorbent test (QuantiFERON-TB-2G). Because his initial treating physician did not notice the lung lesion on chest radiography, isoniazid (INH) monotherapy was begun with subsequent progression of the lymphadenopathy. We must take into consideration even hilar lymphadenopathy in patients with tuberculosis (TB) disease without detectable Mycobacterium (M.) tuberculosis organisms, because INH monotherapy may result in progression of the TB lesion.

Coincidental intraguild predation by caterpillars on spider mites.

Intraguild predation (IGP) is defined as the killing and eating of prey species by a predator that also can utilize the resources of the prey. It is mainly reported among carnivores that share common herbivorous prey. However, a large chewing herbivore could prey upon sedentary and/or micro herbivores in addition to utilizing a host plant. To investigate such coincidental IGP, we observed the behavioral responses of the polyphagous mite Tetranychus kanzawai Kishida (Acari: Tetranychidae) when its host plant Cayratia japonica (Thunb.) Gagnep. (Vitaceae) was attacked by hornworms, Theretra japonica Boisduval (Sphingidae) and T. oldenlandiae Fabricius (Sphingidae). We also examined an interaction between the oligophagous mite Panonychus citri McGregor (Acari: Tetranychidae) and caterpillars of the swallowtail Papilio xuthus L. (Papilionidae) that share citrus plants as their main food source. Although all T. kanzawai and some active stage P. citri tried to escape from the coincidental IGP, some were consumed together with eggs, quiescent mites, and host plant leaves, suggesting that coincidental IGP occurs on spider mites in the wild. Moreover, neither hornworms nor swallowtail caterpillars distinguished between spider mite-infested and uninfested leaves, suggesting that the mite-infested leaves do not discourage caterpillar feeding. The reasons that the mites have no effective defense against coincidental IGP other than escaping are discussed.

[Clinical analysis of non-tuberculous mycobacteriosis cases complicated with pulmonary aspergillosis].

OBJECTIVES: To clarify the clinical features of nontuberculous mycobacteriosis (NTM) complicated with chronic pulmonary aspergillosis (CPA), we analyzed 257 cases diagnosed with newly developed NTM during the last 12 years in our hospital. RESULTS: Fifty-six per cent of the patients were females. Ten cases (3.9%) of them were complicated with CPA in their clinical course. Mean age at the diagnosis of CPA was 65.5 years, and 8 of 10 cases were males. The average period from the diagnosis of NTM to CPA was almost 7 years. Six NTM cases were classified as the cavitary type and 4 as the nodular-bronchiectasis type. At the time of the diagnosis of CPA, NTM bacilli were isolated in 5 cases, but in the other 5 bacilli were not detected. Radiologically it was found that in many cases the infiltrative shadow had increased and the cavity wall had thickened. Antifungal drug administration was effective in 67% of the cases. In particular, in cases with progressive infiltrative shadows, the antifungal drug was effective in 83% of patients. DISCUSSION: For the clinical management of NTM, careful attention to the complication of CPA is required.

[Pulmonary tuberculosis with atypical radiological findings in a patient with chronic obstructive pulmonary disease].

A 77-year-old-man who had been treated for chronic obstructive pulmonary disease (COPD) was referred to our hospital for further examination of a chest X-ray abnormality. The chest X-ray showed consolidation in the right upper and middle lung field. Chest computed tomography showed an airspace consolidation extending subpleurally and nonsegmentally without nodular lesions. The tentative diagnosis was cryptogenic organizing pneumonia. However, bronchoalveolar lavage fluid was positive for acid-fast bacilli on smear and also positive for tuberculosis PCR, leading to a diagnosis of tuberculous pneumonia. Tuberculous pneumonia in COPD patients can be non-segmental and mimic organizing pneumonia.

The predatory mite Neoseiulus womersleyi (Acari: Phytoseiidae) follows extracts of trails left by the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae).

As it walks, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) spins a trail of silk threads, that is followed by the predatory mite, Neoseiulus womersleyi Schicha (Acari: Phytoseiidae). Starved adult female N. womersleyi followed T. urticae trails laid down by five T. urticae females but did not follow a trail of one T. urticae female, suggesting that the amount of spun threads and their chemical components should correlate positively with the number of T. urticae individuals. To examine whether chemical components of T. urticae trails are responsible for the predatory mite's trail following, we collected separate T. urticae threads from the exuviae and eggs, and then washed the threads with methanol to separate chemical components from physical attributes of the threads. Female N. womersleyi did not follow T. urticae trails that had been washed with methanol but contained physical residues, but they did follow the direction to which the methanol extracts of the T. urticae trails was applied. These results suggest that the predatory mite follows chemical, not physical, attributes of T. urticae trails.

[The changes of hospitalization in our tuberculous ward after new discharge criteria].

PURPOSE: After new criteria for discharge from a tuberculosis ward were introduced, we studied changes in the length of hospitalization before and after adoption of these criteria. METHODS: We evaluated monthly data on hospitalization in our tuberculosis ward between April 2003 and September 2008. RESULTS: Although the number of complicated patients increased, hospitalization decreased after the change in discharge criteria. CONCLUSION: After adoption of the new discharge crite-ria, the length of hospitalization in our tuberculosis ward decreased.

[A case of multidrug-resistant tuberculosis who acquired additional resistance to ethambutol before the result of the initial drug sensitivity test was reported].

On December 6, 2008, a 52-year-old man presented to a clinic with chronic cough, sputum, and chest discomfort, which had lasted since mid-November. Since the chest radiograph showed a small cavity with small nodules and granular shadows, he was referred to another hospital. On TB-PCR, the gastric juice was positive. Therefore, on December 16, 2008, treatment for pulmonary tuberculosis was initiated with isoniazid, rifampicin, ethambutol, and pyrazinamide. However, on February 4, 2009, a drug susceptibility test revealed that the bacilli were resistant to isoniazid and rifampicin. Therefore, he was referred to our hospital. At that time, he had no symptoms and his sputum smear was negative. We performed a right upper lobectomy. The smear result of the surgical specimen was heavily positive (equivalent to Gaffky 6), and the drug susceptibility test showed resistance to ethambutol in addition to isoniazid and rifampicin. After surgery, we treated him with pyrazinamide, streptomycin, para-aminosalicylate, ethionamide, and levofloxacin. We report this case of multidrug-resistant tuberculosis without past treatment who acquired additional resistance to ethambutol during the first 2 months of chemotherapy. When treating multidrug-resistant tuberculosis, very careful consideration of susceptibility to other drugs is warranted.

[A case of miliary tuberculosis and esophageal perforation secondary to tuberculous mediastinal lymphadenitis].

An 80-year-old woman was admitted to a local hospital following transient disturbance of consciousness after a fall. High intermittent fever developed after hospitalization and she was diagnosed as having mediastinal abscess with esophageal perforation. She underwent mediastinal drainage and surgical repair of the esophagus. Acid-fast bacilli were detected in her sputum. Chest CT scanning showed a diffuse granular shadow. Then she was diagnosed as having miliary tuberculosis and treated with combination of INH, RFP, EB, and PZA. However, five days after treatment was initiated, fever and skin eruption appeared and treatment has to be stopped after one month. Then she was referred to our hospital. We gradually increased the dosages of INH and RFP, which resulted in pyrexia. Therefore, we changed EB to SM. Fever subsided and we were able to administer the full dose of drugs from the beginning of January 2007. Thereafter, the patient improved gradually. However, she died in February 2007. At autopsy, we identified tuberculous mediastinal lymphadenitis, inflammatory granuloma under the esophageal mucosa and miliary tuberculosis. We report this case as a rare case of miliary tuberculosis and esophageal perforation secondary to tuberculous mediastinal lymphadenitis.