Endocrine disrupting properties of organochlorine(chlorinated hydrocarbon) insecticides are reviewed. Physicochemical properties such as water solubility and partition coefficient of the ...organochlorine insecticides greatly influence their environmental fates. Insolubility in water and high partition coefficient usually enhance the environmental persistence of the compounds. On the endocrine disrupting properties, an important metabolite of p,p'-DDT, p,p'-DDE, is known to exhibit weak anti-androgenic properties. An isomer o,p'-DDT is estrogenic. Metabolites of methoxychlor, mono-demethylated and di-demethylated methoxychlor derivatives, are weakly estrogenic. Their dehydochlorinated product also exhibits estrogenicity. HCH isomers are environmentally persistent compounds, but there is few reports on their endocrine disrupting properties. Some other organochlorine pesticides such as cyclodienes and chlordecone is reported to be estrogenic.
Neutrophils from asthmatic patients seem to be in an activated state. This study demonstrated that superoxide radical (O2–) production was enhanced in asthmatic patients compared with healthy control ...subjects. Production of (O2–) also increased with progression of disease and with disease duration. In addition, (O2–) release was inversely correlated with FEV1 and midflows and was greater in neutrophils from patients with exacerbated disease than in those from patients with stable disease. These findings suggest that oxygen metabolites may play a direct or indirect role in the modulation of airway inflammation.
Dimethylsulfoxide (DMSO) reductase was purified to electrophoretic homogeneity from the periplasmic fraction of a photodenitrifier, Rhodopseudomonas sphaeroides f.s. denitrificans. The enzyme had a ...molecular weight of 82,000 and had no subunit. It contained 1 mol of molybdenum per mol of enzyme, but iron and acid-labile sulfur were not present. The UV-visible spectrum showed only one absorption maximum at 280 nm. Denaturation of the enzyme released a molybdopterin cofactor, the fluorescence spectra of which were almost the same as those of a form B derivative of molybdopterin found in formate dehydrogenase. The Km value for DMSO was 15 μM, which was much lower than that for trimethylamin-N-oxide (TMAO), whereas Vmax with TMAO was larger than that with DMSO.
The first 920 MHz high-resolution NMR (nuclear magnetic resonance) magnet was successfully installed at the Tsukuba Magnet Laboratory of the National Institute for Materials Science. A persistent ...operation at 21.6 T has continued since April 2002 without any problems. Excellent field stability of 0.31 Hz/h was observed from December 2002 to January 2003. Since July 2002, the magnet was used as an essential part of the only 920 MHz high-resolution NMR spectrometer in the world. The signal-to-noise ratio of 0.1% ethylbenzene using a proton-selective probe was as high as 2981. An HCN triple-resonance probe is now attached to the spectrometer to contribute to the National Project on Protein Structural and Functional Analysis in Japan. The completion of the second 920 MHz-class NMR spectrometer is scheduled for spring 2004.
Summary
Background
Endoscopic classifications were reported to reflect the pathophysiology of gastric mucosa. However, relationship between gastric lesions and classifications has not been examined ...well.
Aim
To investigate the relationship between endoscopic classifications and cancers or ulcers.
Methods
In this study, 487 patients undergoing upper gastrointestinal endoscopy in Takahashi Clinic and 257 patients with early gastric cancer in Keio University Hospital were enrolled.
Results
Incidence of reflux oesophagitis was higher in Helicobacter pylori‐negative patients. K‐form was better in the H. pylori‐positive patients. Most cancers in the patients with the closed‐type or reflux oesophagitis were of undifferentiated types. Incidences of ulcers were highest in C‐2 and C‐3 in which the borders of atrophy cross the medial oblique muscle bundle, the border circular muscle bundle or both, and 94% of ulcers in C‐2 and C‐3 stomach were located along the lesser curvature.
Conclusion
The predominant existence of undifferentiated types in patients with reflux oesophagitis or closed‐type stomach can be useful information for early diagnosis of cancers. The relationship between the Kimura–Takemoto classification and ulcer location may explain why H. pylori infection is related to ulcer formation along the lesser curvature.
We have used conductive scanning probe microscope (SPM) in high vacuum and operated at
173
K
in order to investigate the electronic properties of self-organized InGaAs quantum dots (QDs) grown on ...GaAs
(3
1
1)
B
and
(0
0
1)
substrates. Ordered InGaAs quantum dot arrays on GaAs
(3
1
1)
B
surface were fabricated by atomic-H assisted molecular beam epitaxy (H-MBE), and Si SPM tips coated with Au which warrants electrical conductivity were used to measure simultaneously both the topographic and current images of QDs surface. From the current–voltage (
I–
V) curves, unique and different plateau features were observed for QDs formed on GaAs
(3
1
1)
B
and
(0
0
1)
substrates. The results suggested that a high degree of symmetry of InGaAs QDs on
(3
1
1)
B
was responsible for the observed degeneracy of electronic states and artificial atom-like states. We demonstrate that this conductive SPM technique becomes a powerful tool in studies of single electron charging of individual dots.
Recent studies have suggested that infectious organisms play a role in vascular diseases. In this study, to explore a possible link between oral infection and Buerger disease, we investigated whether ...oral (periodontal) bacteria were present in occluded arteries removed from patients with characteristic Buerger disease.
Fourteen male patients with a smoking history who had developed characteristics of Buerger disease before the age of 50 years were included in this study. Occluded arteries, including superficial femoral (n = 4), popliteal (n = 2), anterior tibial (n = 4), and posterior tibial (n = 4) arteries, were removed and studied. A periodontist performed a periodontal examination on each patient and collected dental plaque and saliva samples from them at the same time. The polymerase chain reaction method was applied to detect whether seven species of periodontal bacteria—Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Campylobacter rectus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Prevotella nigrescens—were present in the occluded arteries and oral samples. In addition, arterial specimens from seven control patients were examined by polymerase chain reaction analysis.
DNA of oral bacteria was detected in 13 of 14 arterial samples and all oral samples of patients with Buerger disease. Treponema denticola was found in 12 arterial and all oral samples. Campylobacter rectus, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Prevotella nigrescens were found in 14% to 43% of the arterial samples and 71% to 100% of the oral samples. A pathologic examination revealed that arterial specimens showed the characteristics of an intermediate-chronic-stage or chronic-stage lesion of Buerger disease. All 14 patients with Buerger disease had moderate to severe periodontitis. None of the control arterial samples was positive for periodontal bacteria.
This is the first study to identify oral microorganisms in the lesions of Buerger disease. Our findings suggest a possible etiologic link between Buerger disease and chronic infections such as oral bacterial infections.
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