Inter- and intra-rater reliability in fibroptic endoscopic evaluation of swallowing.

Fibroptic endoscopic evaluation of swallowing (FEES) is a useful way for dentists to evaluate oropharyngeal dysfunction. However, no study has paid attention to inter- and intra-rater reliability of FEES evaluation about oropharyngeal dysfunction. The purpose of this study is to verify whether dentist who trained and experienced for evaluation of dysphagia could diagnose oropharyngeal function with FEES. Nine dentists independently evaluated FEES images of 10 cases four times each. At first, evaluators performed the first evaluation without consulting the evaluative criteria. Subsequently, evaluators independently re-evaluated at 1-week intervals for three consecutive weeks, consulting the evaluative criteria. And then, inter- and intra-rater reliability was calculated. Cohen's Kappa was used to assess reliability. The results found that overall inter-rater reliability was 0·35±0·04 (first evaluation), 0·45±0·05 (s), 0·44±0·05 (third) and 0·46±0·04 (fourth). Most of inter-rater reliability related to aspiration was moderate to high, but lower for categories that evaluated timing of swallowing and mastication. In contrast, intra-rater reliability was moderate to high for overall categories, at 0·53±0·04 (first vs. second evaluation), 0·55±0·04 (first vs. third), 0·53±0·04 (first vs. fourth), 0·55±0·03 (second vs. third), 0·60±0·03 (second vs. fourth) and 0·78±0·03 (third vs. fourth). FEES is reliable for experienced dentists to diagnose oropharyngeal function. Moreover, repeated evaluation with the aids of evaluative criteria is useful to improve the reliability of FEES.

Host beta-globin gene fragments in crevicular fluid as a biomarker in periodontal health and disease.

BACKGROUND AND OBJECTIVE: Leukocytes and epithelium are the first line of defense in preventing bacterial invasion into periodontium. Some of these cells die in gingival crevicular fluid, whereupon their DNA is spilled out. The present study was designed to investigate the profile of host beta-globin gene fragments in the gingival crevicular fluid of various periodontal conditions. MATERIAL AND METHODS: Gingival crevicular fluid from 40 teeth with chronic periodontitis, 30 with gingivitis and 22 that were clinically healthy were centrifuged (3,000 g, 10 min). The supernatant (cell-free gingival crevicular fluid) was centrifuged again (13,000 g, 10 min), resulting in the pellet and the supernatant as debris and debris-free fractions, respectively. Specific primers for amplifying 110 bp, 536 bp and 2 kb amplicons of human beta-globin gene were used to investigate host DNA by quantitative and qualitative polymerase chain reaction. RESULTS: The periodontitis group showed the largest amount of host beta-globin gene fragments, while the healthy group had the lowest. In the debris and debris-free fractions, the 536 bp and 2 kb amplicons were more often detected in the periodontitis group than in the other groups. Interestingly, the presence of 2 kb amplicon in the debris fraction could be used to discriminate periodontitis from gingivitis and healthy groups because we found it in 85% of periodontitis samples but only in 13% of gingivitis samples, and it was absent in the healthy group. CONCLUSION: This study shows the different DNA profiles of cell-free gingival crevicular fluid in periodontal health and disease. It suggests that the quantity and quality of host DNA are dependent on the disease conditions. Therefore, the beta-globin gene fragments in cell-free gingival crevicular fluid may be a potential biomarker of periodontal disease progression.

Degradation of serine-containing oligopeptides by Peptostreptococcus micros ATCC 33270.

BACKGROUND/AIMS: Microorganisms of Peptostreptococcus micros are asaccharolytic, anaerobic gram-positive cocci that are frequently isolated from human oral sites such as periodontal pockets. Preliminary study showed that several amino acids, including serine, enhanced slightly the growth of P. micros. Therefore, we investigated the degradation of serine and serine-containing oligopeptides. METHODS: Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed. RESULTS: Washed P. micros degraded serine-tripeptides (Ser-Ser-Ser), and produced formate, pyruvate, acetate, and ammonia. They also degraded serinyl-tyrosine (Ser-Tyr) to the same products. Related enzymatic activities, such as serine dehydratase, pyruvate formate-lyase, formate dehydrogenase, pyruvate oxidoreductase, phosphate acetyltransferase, and acetate kinase, were detected in the cell-free extract, indicating that the organisms produced ATP in the serine metabolism. CONCLUSION: P. micros utilized serine-containing oligopeptides as exogenous metabolic substrates rather than serine itself, and degraded Ser-Ser-Ser and Ser-Tyr to formate, pyruvate, acetate, and ammonia with ATP generation.

Degradation of arginine by Slackia exigua ATCC 700122 and Cryptobacterium curtum ATCC 700683.

Slackia exigua ATCC 700122(T) and Cryptobacterium curtum ATCC 700683(T) were our isolates from infected root canal and human periodontal pocket, respectively; they are asaccharolytic anaerobic gram-positive rods, which are predominant in the oral cavity. They utilize arginine, so our aim was to investigate the pathway of arginine degradation. Metabolic end products were determined with high-performance liquid chromatography. The related enzymatic activities in cell-free extract were also assayed. Both S. exigua and C. curtum degraded arginine and produced substantial amounts of citrulline, ornithine and ammonia. Arginine and citrulline supported the growth of both strains. As the related enzymatic activities, arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activities were detected in the cell-free extract of S. exigua and C. curtum. Arginase and urease activities were not detected in either organism. These results suggest that arginine was metabolized by the arginine deiminase pathway. Both S. exigua and C. curtum degrade arginine via the arginine deiminase pathway.

Perfusion imaging of meningioma by using continuous arterial spin-labeling: comparison with dynamic susceptibility-weighted contrast-enhanced MR images and histopathologic features.

PURPOSE: The goal of the present study was to determine the utility of continuous arterial spin labeling (CASL) for characterization of meningioma by MR perfusion imaging and to compare these results with those obtained from the T2 dynamic susceptibility contrast (T2DSC) method and from histopathologic examination. METHODS: Twenty-one cases of meningiomas were examined at 1.5T. CASL perfusion imaging was implemented on the basis of multisection single-shot echo-planar imaging with velocity-driven adiabatic spin-inversion preparation. T2DSC perfusion imaging was also performed by using a double-echo spoiled gradient echo sequence in a section containing the tumor. By focusing on the regions of interest, maps of % signal intensity change and cerebral blood flow (CBF) were determined from CASL and cerebral blood volume (CBV). CBF and mean transit time (MTT) were obtained from T2DSC. The microvessel area (MVA) was determined from specimens immunostained with anti-CD31 in 14 cases by measuring the total amount of staining in each histologic section. Linear regression analysis was performed for rCBF values from both perfusion methods and for % signal intensity change and MVA. RESULTS: There was a significant correlation between CBF values determined from both perfusion methods (r(2) = 0.73; P < .001); however, the slope from T2DSC to CASL was less than unity, likely because of the different vascular weighting used for each method. There was also a significant correlation between CASL-% signal intensity change and MVA determined by histopathology (r(2) = 0.91; P < .00001). Perfusion values were the greatest for angiomatous meningioma and lowest for fibrous meningioma when using either perfusion method. CONCLUSIONS: CASL and T2DSC perfusion methods are comparable in the characterization of meningiomas. Further, CASL is of use in assessing tumor microcirculation.

Colonisation on the tongue surface by respiratory pathogens in residents of a nursing home--a pilot study.

OBJECTIVE: The morbidity and mortality of the dependent elderly that result from aspiration pneumonia have been recognised as a major geriatric health problem. The tongue has an extremely large surface area and due to its papillary structure can retain considerable quantities of food, and thus can support and harbour a large bacterial population. The purpose of this study was to gain more information on the microflora of the tongue surface and to assess the existence of oral infectious pathogens potentially causing respiratory disease in nursing home residents. SUBJECTS AND METHODS: The tongue bacterial flora of 69 nursing home residents were examined to identify microorganisms by the culture method. RESULTS: Thirteen species of microorganisms were detected from the tongue in this study. In 41 of 69 subjects (59%), potential respiratory pathogens, had colonised the tongue surface. CONCLUSION: The results of the present study revealed that bacteria that commonly cause respiratory infection colonised the tongue of nursing home residents, suggesting that it may function as a reservoir of potential respiratory pathogens to facilitate colonisation on the oropharynx.

Degradation of arginine and other amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods in periodontal pockets.

The use of 20 amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods (AAGPRs) in periodontal pockets, i.e. Eubacterium minutum, Filifactor alocis, E. infirmum, E. sulci and E. saphenum, was studied. E. minutum used only arginine and lysine, and produced substantial amounts of butyrate and ammonia as the main metabolic products from arginine, and acetate, butyrate and ammonia from lysine. Fi. alocis used arginine alone and produced butyrate and ammonia. E. infirmum, E. sulci and E. saphenum used lysine alone and produced acetate, butyrate and ammonia. The growth of these bacterial species was supported and enhanced by arginine and/or lysine enriched to culture media, but not by the other amino acids. Arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activity were detected in the cell-free extract of E. minutum, suggesting that arginine was metabolised to citrulline initially, and subsequently to ornithine and carbamoyl phosphate. Ornithine and carbamoyl phosphate were further converted to butyrate, and carbon dioxide and ammonia, respectively. Enzymatic activity of arginine deiminase and ornithine carbamoyltransferase was not detected in Fi. alocis, indicating that Fi. alocis converted arginine to ornithine directly, not via citrulline, and further to butyrate.

Blood volume of gliomas determined by double-echo dynamic perfusion-weighted MR imaging: a preliminary study.

BACKGROUND AND PURPOSE: After bolus injection, gadopentetate dimeglumine causes a T2* rate change in permeable tissue that is contaminated by the T1 shortening effect due to the leakage of contrast agent. Therefore, tumor vascularity as reported in previous single-echo perfusion-weighted MR imaging studies has been underestimated. Our aim was to quantitatively and qualitatively evaluate the degree of blood volume of glioblastoma multiformes (GBMs) underestimated by this T1 shortening effect. METHODS: We used double-echo dynamic MR imaging after a bolus injection of gadopentetate dimeglumine (double-echo perfusion-weighted MR imaging) to simultaneously determine tumor blood volume without (V(T1U)) and with (V(T1C)) T1 shortening correction. MR imaging was performed in five consecutive patients with GBMs. The ratios of V(T1U) and V(T1C) were calculated and compared by means of quantitative analysis. The degree of tumor blood volume as determined by V(T1U) and V(T1C) maps were qualitatively compared using a three-point scale. RESULTS: All GBMs showed contrast enhancement on postcontrast T1-weighted images. In all subjects, the values of V(T1U) were significantly lower than those of V(T1C) (mean +/- SD, 2.05 +/- 1.01 vs. 3.62 +/- 1.40, respectively [P <.05]), indicating that tumor blood volume obtained by double-echo perfusion-weighted MR imaging was significantly higher than that by single-echo imaging. In the qualitative analysis, tumor blood volume on the V(T1U) map was less conspicuous than that on the V(T1C) map. CONCLUSION: Careful attention should be paid to the underestimation of tumor blood volume resulting from T1 shortening effects when using single-echo perfusion-weighted MR imaging. Double-echo imaging may be more suitable for the analysis of blood volume in GBMs.

Pulmonary MR angiography with contrast agent at 4 Tesla: a preliminary result.

In this study, pulmonary MR angiography (MRA) using a tailored coil at 4 Tesla in conjunction with an intravenous injection of contrast agent is described. Three-dimensional gradient-echo images were obtained during the intravenous injection of 0.05, 0.1, and 0.2 mmol/kg body weight of gadodiamide to investigate the signal enhancement effect of the contrast agent in pulmonary arteries qualitatively and quantitatively. In the qualitative analysis, the subsegmental branches were visualized on every dose. In the quantitative analysis, the average contrast-to-noise ratios (CNRs) of the main pulmonary arteries increased in a dose-dependent manner. However, the CNRs of segmental arteries did not increase as the dose of contrast agent increased, as observed at 1.5 Tesla MRI. These observations demonstrate the feasibility of delineating the pulmonary vasculature using a contrast agent; however, our results also suggest possible high-field-related disabilities that need to be overcome before high-field (> or =4 Tesla) MRI can be used to full advantage.

Time course of arterial hyperintensity with fast fluid-attenuated inversion-recovery imaging in acute and subacute middle cerebral arterial infarction.

The purpose of this study was to evaluate the time course of arterial hyperintensity (AH) in acute and subacute cerebral infarctions of the middle cerebral artery (MCA) distribution by using fast fluid-attenuated inversion-recovery (FLAIR) imaging. A total of 40 FLAIR MR examinations were performed in 27 patients with MCA infarction within 13 days after ictus. Thirteen patients underwent two MR examinations during this period. Thrombotic or embolic infarctions were included in this study, but lacunar infarctions were excluded. The presence or absence of AH and the location of AH were analyzed. Overall, AH was found in 24 (60%) of 40 FLAIR examinations within 13 days after onset. AH was seen in 17 (100%) examinations less than 24 hours old, four (40%) of 10 examinations 1-4 days old, two (18%) of 11 examinations 5-9 days old, and one (50%) of two examinations 10-13 days old. AH was most frequently found at the sylvian fissure (87%), followed by the sulci (54%), and the horizontal segment of MCA (29%) in the affected MCA distribution. Although AH could be seen even at 13 days after ictus, the presence of AH declined over time. AH represented an early sign of acute embolic or thrombotic infarction. J. Magn. Reson. Imaging 2001;13:987-990.