Key factors for the dynamic ETEM observation of single atoms.

We present further modifications to aberration-corrected environmental transmission electron microscopy (AC-ETEM) for the dynamic HRTEM observation of single atoms. Additional pumping levels that include three additional turbomolecular pumps (TMPs) enable a base pressure of 3.5 × 10(-5) Pa in the sample chamber. The effect of these additional TMPs on image resolution was measured in reciprocal space using information limit (Young's fringes) on a standard cross grating sample and also with platinum (Pt) single atoms on an amorphous carbon film (Pt/a-carbon). The Pt/a-carbon was used for measuring the effect of gas pressure on single-atom imaging in addition to the evaluation of vibrations of TMPs, samples, magnetic lenses and a microscope column of the AC-ETEM. TMPs did not affect the ETEM imaging performance when an anti-vibration table was used, and 0.10-nm resolution was achieved. Dynamic ETEM observation of Pt single atoms was achieved in 4.0 × 10(-2) Pa of air, using a modified AC-ETEM system and a high-speed CCD camera with a time resolution of 0.05 s.

Comparison of bronchoalveolar lavage cell findings in complete-resolution pneumonia and delayed-resolution pneumonia.

BACKGROUND: In some patients with bacterial pneumonia, the resolution of chest radiograph shadows are delayed. There have been many clinical and pathological studies on delayed-resolution pneumonia (DR). However, there are no reports concerning inflammatory cell findings of bronchoalveolar lavage (BAL) fluid in patients with DR. We compared the BAL fluid cell findings in patients with DR with those in patients with complete-resolution pneumonia (CR). METHODS: The subjects included six patients whose chest radiograph shadows were completely resolved within 2 weeks after an appropriate antibiotic administration (CR), and nine patients whose chest radiograph shadows were unresolved more than 2 weeks after the treatment (DR). BAL was done 2-3 weeks after the antibiotic treatment in both groups. We compared differential counts and lymphocyte subsets in BAL fluid among patients with CR, patients with DR, and asymptomatic subjects. RESULTS: There were no significant differences in BAL fluid cell findings between CR groups and asymptomatic groups. On the other hand, the percentages of lymphocytes, neutrophils and eosinophils in DR group were significantly increased compared with those in CR and normal groups. There was no significant difference in the CD4+/CD8+ ratio of BAL lymphocytes among the three groups. CONCLUSIONS: It is suggested that infiltration of inflammatory cells in the lung exists in DR, despite the disappearance of inflammatory reaction in the peripheral blood.

Cough receptor sensitivity to capsaicin and tartaric acid in patients with Mycoplasma pneumonia.

There has been no detailed study of cough sensitivity during acute lower respiratory infection. The aim of this study was to clarify cough sensitivity in Mycoplasma pneumonia, which is a well known acute lower respiratory infection with persistent nonproductive cough. We examined cough sensitivity to inhaled capsaicin and tartaric acid in both the acute and the convalescent phases of Mycoplasma pneumonia, cell differentials in bronchoalveolar lavage fluid, and pathologic findings of transbronchoscopic bronchial biopsy specimens. Although dry cough was observed in all patients during Mycoplasma pneumonia, cough sensitivity in the acute phase [capsaicin: 19.8 (GSEM, 0.214) microM, tartaric acid: 0.26 (GSEM, 0.356) M] were not enhanced compared with those in both control subjects [capsaicin: 27.9 (GSEM, 1.24) microM, tartaric acid: 0.316 (GSEM, 0.079) M] and patients in the convalescent phase [capsaicin: 15.7 (GSEM, 0.219) microM, tartaric acid: 0.50 (GSEM, 0.326) M] when all symptoms including cough had disappeared. The percentage of lymphocytes and neutrophils in bronchoalveolar lavage fluid BALF was significantly greater than in the control subjects, and lymphocyte-dominant bronchitis was observed in biopsied specimens. We conclude that cough threshold to inhaled capsaicin or tartaric acid was not enhanced during acute Mycoplasma pneumonia with lymphocyte-predominant bronchitis. This is the first report examining cough sensitivity in patients with acute lower respiratory infection with pneumonia.

The artificial restoration of a dental root.

Periodontal ligament (PDL) cells, osteoblasts (OB), and gingival (GIN) cells originating from human periodontium were co-cultured indirectly with human peripheral blood lymphocytes (PBL). The formation of osteoclasts (OC) from each the co-cultured PBL was compared with a standard PBL culture. A marked suppression of OC formation was observed in PBL co-cultured with PDL cells, and an enhanced OC formation was observed in PBL co-cultured with OB and GIN cells, when compared with the standard PBL culture. The suppressing activity of PDL cells and the enhancing activity of OB and GIN cells on the formation of OC derived from PBL were also found, when the co-culture fluids of PDL/PBL, OB/PBL, and GIN/PBL were added to PBL, and the numbers of OC were counted after 7 days' incubation. Furthermore, the alkaline phosphatase (ALPase) activity of PDL cells was stimulated by co-culturing them with PBL, and the ALPase activity of OB and GIN cells was inhibited by co-culturing them with PBL. When PDL cells were seeded on the surfaces of titanium discs and incubated at 37 degrees C in a 5% CO2 incubator, PDL cells could adhere faster onto titanium surfaces that were coated with a cell-and-tissue-adhesive substance than onto non-coated titanium surfaces. These cultures formed a confluent monolayer on the surfaces of titanium discs by means of an autologous serum containing alpha MEM. These results clearly suggest that the periodontal ligament is a specifically differentiated tissue whose function is to protect alveolar bone from bone resorption due to biting force.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of pyridoxine-deficiency on degradation of cytosolic aspartate aminotransferase in rat liver lysosomes.

Highly purified lysosomes were isolated from the livers of control and pyridoxine-deficient rats. The calculation of the lysosomal protein contents indicated that the livers of both groups of rats contain virtually the same amounts of the lysosomal proteins (12.0 and 13.0 mg lysosomal proteins/g liver proteins for the control and pyridoxine-deficient rats, respectively). The immunoblotting of the lysosomal proteins with anti-cytosolic aspartate aminotransferase (cAspAT) showed 46 kDa band, corresponding to the subunit molecular weight of cAspAT, as well as the bands representing degradative intermediates of cAspAT. The relative amounts of the immuno-reactive substances were estimated by scanning the immuno-stained bands and measuring the densitometric tracings. It was found that the lysosomes in the pyridoxine-deficient rat liver contain almost twice as much cAspAT and its degradative intermediates as those in the control rat liver. On the basis of these observations, it was concluded that the increased rate of degradation of cAspAT in the liver of the pyridoxine-deficient rats is brought about by the increased rate of sequestration of cAspAT into lysosomes.

Isolation and classification of anaerobic bacteria from pulp cavities of nonvital teeth in man.

The anaerobic microflora of infected pulp cavities and chronic periapical abscesses was studied. A total of 19 infected nonvital teeth were subjected to this study. The coronal surface was swabbed with 70% ethanol to remove debris and to disinfect. Material in root canal chamber was obtained by sterilized paper points and suspended in reduced transport fluid. The samples were dispersed, diluted, and inoculated on blood agar plates. Isolates were identified by colony characteristics and cellular morphology, fermentation, indole production, nitrate reduction, gelatin digestion, urease production, ability to grow aerobically, API 20A System, and API ZYM System. Anaerobic bacteria were found in 14 pulp cavities. Anaerobic gram-negative rods, Actinomyces species, and Propionibacterium species were predominant in the root canals. Mixed infection with anaerobes and facultative anaerobes were demonstrated in most of the pulpal cavities of nonvital teeth.