[Epidemiological study on association of periodontal disease and total and differential leukocyte counts]

Periodontal disease is defined as inflammation that is caused by bacteria in dental plaque. This disease is liable to be a factor contributing to the high leukocyte count over an extended period. Furthermore, a number of prospective epidemiologic studies have shown that the leukocyte count is a good predictor of ischemic heart disease (IHD). However there have been few epidemiological studies of the relationship between periodontal disease and the leukocyte count. The purpose of this study was to investigate the relationship between the total and differential leukocyte counts and oral conditions of Japanese factory workers who were classified according to their smoking habits. The 1,167 subjects were male factory workers employed with a chemical factory in Osaka, Japan. The oral conditions recorded were periodontal status (Community Periodontal Index of Treatment Needs, CPITN). The relationship between the total and differential leukocyte counts and the CPITN score of subjects who were classified according to their smoking habits was investigated in 1996 and 1997. In both the current smokers and nonsmokers, the subjects with severe periodontal disease, in contrast to the normal subjects, exhibited total leukocyte, neutrophil and monocyte counts that were significantly high for 1 year during follow-up studies. The periodontal disease is shown that causes the total leukocyte and neutrophil counts related to the development of IHD to remain at a high level.

High-resolution cardiac PET in rabbits: imaging and quantitation of myocardial blood flow

A high-resolution PET system for small animals was tested for its applicability to the investigation of regional myocardial blood flow (MBF) in rabbits.

METHODS

Nineteen measurements were performed in 10 closed-chest anesthetized rabbits at baseline and during infusions of adenosine (0.2 mg/kg/min) and propranolol (0.20-1.20 mg slow infusion) to obtain a wide range of MBF. Myocardial blood flow was assessed both by dynamic 13N-ammonia PET and by colored microspheres. Blood was withdrawn directly from the femoral artery, and arterial 13N activity was measured by coincidence type gamma detection system for the input function. Nitrogen-13 myocardial uptake was calculated by dividing the myocardial 13N activity by the integral value of the input function.

RESULTS

Three or four contiguous cross-sectional myocardial images were obtained after 13N-ammonia injection. The left ventricular wall and cardiac cavity were clearly visualized. Moreover, initial passage of the tracer through the heart was obtained with serial 10-sec PET images. Nitrogen-13 myocardial uptake correlated well with flow measured with microspheres (r = 0.88).

CONCLUSION

Our cardiac PET system can be used for in vivo imaging and quantitation of MBF in small animals and may play an important role in the future study of animal models of cardiovascular diseases.

An epidemiological study on the association between the total leukocyte and neutrophil counts, and risk factors of ischemic heart disease by smoking status in Japanese factory workers

Several epidemiologic studies have shown the association between total leukocyte count and the risk of developing myocardial infarction. The purpose of this study was to assess the association between the total leukocyte and neutrophil counts and risk factors of ischemic heart disease in 1,384 Japanese factory workers. Total leukocyte and neutrophil counts were significantly higher in current smokers than in non-smokers. Among current smokers, the total leukocyte and neutrophil counts were positively associated with the number of cigarettes smoked daily and the duration of cigarette smoking and alcohol consumption. Being independent of smoking habit, the total leukocyte and neutrophil counts were also related to several characteristics recorded at the physical examinations. The total leukocyte and neutrophil counts were positively associated with serum total cholesterol, serum triglyceride and hematocrit levels, and inversely associated with the serum HDL-cholesterol level. No significant associations of the total leukocyte or neutrophil counts were found with the red blood cell count and hemoglobin level. These results suggest that the total leukocyte and neutrophil counts may represent the metabolic condition with a high coronary risk among apparently healthy people.

[Epidemiological study on the relationship between hypertension and dental disease in Japanese factory workers]

The purpose of this study was to investigate the relationship between hypertension and oral health in about 2,000 male Japanese factory workers. The results obtained were as follows: in both current smokers and nonsmokers, the results for hypertension patient groups showed a significantly higher CPITN (Community Periodontal Index of Treatment Needs) than healthy control groups. The results of regression analysis indicated that systolic blood pressure was significantly associated with CPITN in the nonsmoking patients without hypertension. The results suggested that there was significant relationship between periodontal disease and the prevalence of hypertension among employees in a company.

Dialysate pressure isobars in a hollow-fiber dialyzer determined from magnetic resonance imaging and numerical simulation of dialysate flow

A procedure to determine dialysate pressure isobars by comparing the results of magnetic resonance imaging (MRI) and numerical simulation of the dialysate flow was established. The assumption used in the filtration analyses, that the dialysate pressure varies only in the central-axial direction, is supported by the finding that the determined isobars have no steep radial gradient. MRI of the contrast solution permeating the hollow fibers verifies the uniformity of the hollow fiber density in the dialyzer.

Prognostic value of dipyridamole-thallium myocardial scintigraphy in patients with Kawasaki disease

BACKGROUND

Although coronary artery lesions are critical complications of Kawasaki disease, their long-term outcome is still unclear. It is sometimes difficult to monitor progressive changes from aneurysms to stenotic lesions because coronary angiography (CAG) cannot be repeated very often, especially in infants. Our prospective study was designed to evaluate the prognostic value of dipyridamole-thallium single-photon-emission CT (SPECT) in the long-term follow-up of patients with Kawasaki disease.

METHODS AND RESULTS

Of 459 consecutive patients with Kawasaki disease, coronary aneurysms were detected in 90 cases by echocardiography during the acute stage. After paired studies of selective CAG and SPECT were conducted, all patients were followed up and monitored for the occurrence of any cardiac events for > or =8 years. During the follow-up interval, there were 15 cardiac events (1 death, 5 infarctions, 2 coronary artery bypass graft operations, and 7 occurrences of unstable angina). Of patients who had some event, thallium redistribution was found on SPECT in 14 (93%, P<0.001). Of the various clinical and scintigraphic image variables, the presence of thallium redistribution was the best multivariate independent predictor of a late cardiac event (chi2=57.8, P<0.0001). The number of aneurysms detected on CAG added minimal statistical improvement to the model (chi2=1.9, P=0.0009).

CONCLUSIONS

Dipyridamole-thallium SPECT is safely performed and is useful and important for risk stratification in the long-term follow-up of patients with Kawasaki disease.

[Investigation on feasibility of using a gamma camera for the measurement of blood radioactivity]

The present study was undertaken to determine whether gamma cameras can be used to measure radioactivity in samples, e.g. in blood. Aqueous 123I solution with a concentration of 10.3 MBq/ml was infused at a volume of one ml into a blood-sampling vial having an internal diameter of 22.5 mm. Various concentrations of radioactivity were generated by leaving the vial and taking radioactive decay into account. Static images were acquired for five minutes with a gamma camera using a 64 x 64 matrix to measure radioactivity counts, and the regions of interest with 7 x 7 pixels (21 mm x 21 mm) were defined on the image. The results showed that there was a good linear correlation between the radioactivity counts measured with the gamma camera without collimator and those measured with the well-type scintillation counter in the range between 0.032 kBq/ml and 279 kBq/ml. It therefore appears that gamma cameras can be substituted for well-type scintillation counters in the measurement of radioactivities in samples.

Spectral analysis applied to dynamic single photon emission computed tomography studies with N-isopropyl-p-(123I)iodoamphetamine

This study was performed to evaluate the usefulness of spectral analysis (SA) applied to dynamic single photon emission computed tomography studies with N-isopropyl-p-(123I)iodoamphetamine (IMP). The unidirectional clearance of IMP from the blood to the brain tissue (K1) obtained by SA (y (ml/g/min)) agreed well with that obtained from a two-compartment model using the nonlinear least-squares (NLSQ) method (x (ml/g/min)) (y = 0.994x + 0.003, r = 0.999, standard error of the estimate (SEE) = 0.005 ml/g/min). The rate constant for back diffusion of IMP from the brain tissue to the blood (k2) obtained by SA (y (min(-1))) also agreed well with that obtained by the NLSQ method (x (min(-1))) (y = 0.985x + 0.000, r = 0.948, SEE = 0.001 min(-1)). The brain vascular volume (V0) obtained by SA (y (ml/g)) correlated well with that obtained by the NLSQ method (x (ml/g)) (y = 1.138x + 0.000, r = 0.867, SEE = 0.012 ml/g). These results indicate that SA is applicable and useful for quantification of the kinetic parameters of IMP in the human brain, and can be an alternative approach to compartment analysis.

[Estimation of integral value of input function for the quantification of cerebral blood flow with 123I-IMP using one-point arterial blood sampling]

Cerebral blood flow (CBF) has been measured using a microsphere model with octanol-extracted radioactivity counts (integral value of input function). We developed a new method estimating the integral value of input function. First, we fitted the whole brain time-activity curves early after intravenous injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) by the least-squares method. Second, we differentiated this equation. Third, we calibrated it using octanol-extracted radioactivity counts of the arterial blood sampled at 5 min. Finally, we integrated it. A significant correlation was found between the integral values obtained using a new method and those obtained using the continuous arterial blood sampling data (y = 1.048x-1206, r = 0.984). The errors between the CBF values obtained using a new method and those obtained using the 5-min continuous arterial blood sampling was 6.88 +/- 4.78%. Measurement of integral values of the input function using a new method with one-point arterial blood sampling is less invasive and convenient, and is not influenced by cardiopulmonary disease or smoking. Therefore, it would be useful for the routine measurement of CBF.

[Simplified method to quantitate regional cerebral blood flow by 123I-IMP microsphere model: validity of input counts by using the whole brain time-activity curve and one point arterial blood sampling]

We developed a new microsphere method using 123I-IMP in which arterial blood is collected at one time point early after 123I-IMP injection instead of conventional continuous arterial blood sampling, and the input count is estimated using a whole brain time-activity curve until that time point. The differential curve dCb(t)/dt of the brain time-activity curve Cb(t) early after 123I-IMP injection (when the microsphere model is established) approximates the arterial time-activity curve Ca(t) as an input function. The input count as the integral value of Ca(t) at 0-5 min was estimated using the 50 min whole brain activity Cb(5 min) and the differential value dCb(5 min/dt and the 5-min octanol-extracted count of arterial samples obtained at one time point Ca(5 min). The input counts calculated by this method were very closely correlated with measurement values obtained by continuous arterial sampling. This method is more convenient and less invasive than the continuous arterial sampling method.

Quantitative analysis of myocardial ischemia by technetium-99m sestamibi exercise scintigraphy: a new method for change rate mapping

In order to quantitatively assess the extent and severity of myocardial ischemia by Tc-99m sestamibi exercise myocardial scintigraphy, we developed a new method of change rate (CR) mapping and examined its efficiency. CR was calculated to divide the counts per pixel in the stress polar map by that in the rest polar map at each corresponding pixel. The CR map showed the CR values at each pixel. To correct the differences between the stress and rest images for the dose of Tc-99m sestamibi administered, the mean counts per pixel in the stress polar map and the rest map were adjusted to the same level. Regarding the regions in which the CR value was less than 1 as ischemia, we compared the abilities of the CR map and the polar map to detect coronary artery stenosis in 5 patients with angina pectoris. The sensitivity for coronary artery stenosis was 80% in the CR map, and 40% in the polar map. The specificity for both was 75%. We concluded that the CR map was effective in assessing the extent and severity of myocardial ischemia in Tc-99m sestamibi exercise myocardial scintigraphy.

Spectral analysis applied to hepatobiliary dynamic scintigraphy with 99Tcm-N-pyridoxyl-5-methyltryptophan

This study was performed to evaluate the application of spectral analysis (SA) to hepatobiliary dynamic scintigraphy with 99Tcm-N-pyridoxyl-5-methyltryptophan (99Tcm-PMT) in 82 patients with a wide range of liver function, and to compare it with compartment analysis (CA) and deconvolution analysis (DA). The rate of uptake of PMT by the liver from the blood (k1) obtained by SA (y, min-1) agreed well with the k1 value obtained using CA (x, min-1) (y = 1.079x + 0.000, r = 0.993, standard error of the estimate (S.E.E.) = 0.042 min-1). The mean residence time (MRT) of PMT in the liver obtained by SA (y, min) also agreed well with the MRT value obtained by DA (x, min) (y = 1.036x - 0.759, r = 0.967, S.E.E.-1.014 min) and that obtained by CA (x, min) (y = 0.859x + 1.006, r = 0.931, S.E.E. = 1.428 min). The fraction of the measured blood activity superimposed on the true liver activity (f) obtained by SA (y) correlated well with the f value obtained by CA (x) (y = 1.168x - 0.004, r = 0.924, S.E.E. = 0.043). We conclude that the application of SA to hepatobiliary dynamic scintigraphy with PMT appears to be useful in evaluating the functional status of the liver, since it facilitates the interpretation of the kinetic behaviour of PMT in the liver and allows us to extract quantitative parameters corresponding to those obtained by CA or DA.

Adsorption Mechanisms of Pentafluoropropanol (5FP) onto Activated Carbons Produced by Tetraethoxysilane Sol-Gel Method

2,2,3,3,3-Pentafluoro-1-propanol (5FP) has been considered a viable CFC replacement compound. However, 5FP must be recovered in order to decrease the environmental impact and save energy. Activated carbons have been used for the recovery and removal of organic solvents. From the point of view of "zero emission," 5FP and activated carbon must be completely recycled. The purpose of this study is to recycle the activated carbons and to increase the recovery efficiency of 5FP using the activated carbons (ST-ACs) which were coated with tetraethoxysilane by the sol-gel method. The amount of 5FP adsorbed onto the ST-ACs and the degree of 5FP decomposition by the ST-ACs were measured in order to estimate the relationship between the ST-AC surface and 5FP. The amount of 5FP adsorbed and the degree of 5FP decomposition indicated that the recovery of 5FP is suitable for the use with the ST-ACs. Copyright 1997 Academic Press. Copyright 1997Academic Press

Diffuse cystic change of a term placenta with a normal newborn

We recently encountered a case of term placenta with a diffuse cystic lesion of the villi. A 19-year-old primipara at 36 weeks of gestation underwent cesarean section due to breech presentation with premature rupture of the membranes; she delivered a mature male baby of 2,502 g with an Apgar score of 9/9. The placenta was 940 g in weight and 29 x 20 x 3 cm in size, and macroscopically had multiple cystic lesions (3-8 mm in diameter) that resembled hydatidiform moles. However, histopathological examination revealed that the severe hydropic change was localized in the stem villi but not remarkable in the terminal chorionic villi. Moreover, abnormal proliferation of the trophoblast was not observed. However, the hypertrophic change was observed in the vascular wall of stem villi, in which hyperplasia of smooth muscle-like cells was present. The urinary hCG levels at 1 month and 2 months after delivery were less than 50 IU/l. These findings indicate that the multiple cystic lesions of the placenta in this case are essentially different from those of a trophoblastic disease, and that the diffuse cystic lesion of the villi might have been secondary to changes in the local circulation.

Adsorbability of 1,1,1,2-Tetrafluoromethane (HFC134a) onto Plasma-Treated Activated Carbon in CF4 and CCl4

The adsorbability of 1,1,1,2-tetrafluoroethane (HFC134a), which has been the CFC12 replacement, onto tetrafluoromethane and tetrachloromethane plasma-treated activated carbon (FT-ACs and CT-ACs) was investigated. It is proved that the fluorine and the chlorine, which were produced by plasma treatment, were introduced into the pores having radii greater 7.5 A and with less than 7.5 A by plasma treatment, respectively. The adsorption site of HFC134a onto activated carbon may change with the quantities of fluorine or chlorine on the surface of the activated carbon. The amount of HFC134a adsorbed per unit specific surface area of FT-ACs and CT-ACs slightly increased a little compared to the untreated activated carbon (U-AC). The amount of fluoride ion eluted before the adsorption of HFC134a from the FT-ACs increased with the increasing plasma treatment time. That after the adsorption of HFC134a from only the activated carbon with the shortest plasma treatment time decreased. The amount of chloride ion eluted before the adsorption of HFC134a from the CT-ACs increased after 15 min of plasma treatment, but decreased with 30 min of plasma treatment. The chloride ion amount from the CT-ACs decreased after the adsorption of HCF134a. These results could be explained by the Langmuir constants a and Ws, which represent the adsorption equilibrium constant and the saturated amount of HFC134a adsorbed, respectively. The ratio of fluorine and chlorine species, the adsorption type, the layer interstitial type, and the covalent type, is different based on the plasma treatment time. It is concluded that the amount of HFC134a adsorbed onto the FT-ACs and CT-ACs did not depend upon the change of pore structure by the fluorine and chlorine.

[Study on the relationship between lifestyles and maximal oxygen uptake in healthy adults]

In this study, to determine the influence of different lifestyles on maximal oxygen uptake, we carried out a survey on the effects of age, smoking, physical exercise, clinical examination values and dietary habits of 899 male factory workers on their maximal oxygen uptake. The results of the study were as follows: Maximal oxygen uptake significantly decreased with age. In the male factory workers, there were significant correlations between maximal oxygen uptake and frequency of physical exercise, a greasy diet and seasoning of the diet. Multiple regression analysis showed that the variables which correlated best with the maximal oxygen uptake were serum total cholesterol and HDL cholesterol. These results indicated that good nutrition and physical activity are important for maintaining physical fitness.

Ozone Degradation by Fluoride onto Plasma-Treated Activated Carbon in CF4

The ozone degradation of fluorine was investigated using the tetrafluoromethane plasma-treated activated carbon (PT-AC). The ozone in the stratosphere has been degraded by the chloride and bromide radicals which are produced from chlorofluorocarbons and bromofluorocarbons, respectively. However, we believe that fluorine also was related to the ozone degradation. The fluoride was introduced onto the activated carbon surface by tetrafluoromethane plasma treatment. The breakthrough curve of ozone onto PT-AC was measured to elucidate the relationship between the ozone and the fluoride. The amount of ozone adsorbed/degraded onto the PT-AC was larger than the amount that was adsorbed/degraded onto the untreated activated carbon. The amount of fluoride ion eluted from the PT-AC before the adsorption/degradation of ozone was larger than that which eluted after the adsorption/degradation of ozone. These results indicated that the ozone was degraded by the fluoride on the PT-AC surface.

[Compton-scatter correction using the triple energy window (TEW) method in conventional single photon emission computed tomography without TEW acquisition hardware]

We devised a method which allowed the triple energy window (TEW) method to be applied for Compton-scatter correction in conventional single photon emission computed tomography (SPECT) systems without any hardware for TEW acquisition. In this method, the data within two subwindows located at both sides of the main window were acquired together. The effectiveness of this method was investigated by phantom experiments. The integral and differential uniformities measured using a flood phantom filled with 123I were minimized when the energy width of subwindows was 5 keV (5.8% and 4.2%, respectively). When this method was applied to a brain phantom filled with 123I in which the relative activities in white and gray matter were assigned as 1: 4.3, the ratio of SPECT values between them was more accurate (1:4.26) than that obtained without this method (1:208). This method appears to be useful for Compton-scatter correction in SPECT, because it can be applied to conventional SPECT systems without any hardware for TEW acquisition and is available for routine clinical use for its simplicity.

Relation between smoking and periodontal disease by oral hygiene status in Japanese factory workers

The relation between smoking and periodontal disease as classified by the Community Periodontal Index of Treatment Needs (CPITN) code was investigated in 1,611 Japanese male factory workers in Osaka, 20-59 years of age. The Simplified Debris Index (DI-S) according to the Simplified Oral Hygiene Index was employed as an index for the quantity of dental plaque. For the items related to smoking, a self-reporting form on smoking, the number of years of smoking, and the number of cigarettes smoked was distributed prior to the oral examination. Our results indicated the following: in the group with a poor state of oral hygiene, the negative effects of smoking were evident, resulting in unhealthy periodontal tissue. We believe that this result further confirms the contention that the removal of dental plaque is most important as a prophylaxis for periodontal diseases, and public education about this negative consequence of smoking will further strengthen prophylactic measures.

Inclusion of Volatile Organic Compounds into Natural Cyclodextrins and Their Branched Cyclodextrins in the Gaseous Phase

The adsorption isotherms of water, the differential heat of adsorption, and the entropy of adsorbed water were investigated to elucidate the structure of stability of cyclodextrins (CyD) and branched CyD's. The amount adsorbed on branched CyD's increased with increasing relative humidity. The steep rise in the amount adsorbed at higher relative humidities indicated that the structure of branched CyD's was affected by the water molecules at these higher relative humidities. The bonding force between alpha-CyD's and water molecules was stronger than that between their branched CyD's and water, while that between beta-CyD's and water was weaker than that between their branched CyD's and water. We have used activated carbons for the recovery of organic solvents. There are polar groups on the activated carbon surface. Therefore, the recovered organic solvents were degraded by these groups. However, such polar groups are not expected for the hydroxyl groups of the CyD's. The amounts of 1,1,1-trichloroethane, benzene, and toluene included in natural CyD's and their branched CyD's were measured. The amounts of organic solvents included in the CyD's depended upon the cavity radii and the glucosyl and maltosyl functional groups of the CyD's and the radii of the organic solvent molecules.