Distribution of 10 periodontal bacterial species in children and adolescents over a 7-year period.

OBJECTIVE: There is scant information available regarding the distribution of periodontal bacterial species in children and adolescents over an extended period. The purpose of this study was to compare bacterial profiles in the same individuals over a period of 7 years. SUBJECT AND METHODS: Twenty-six children and adolescents from whom dental plaque and saliva specimens were obtained during both the first (1999-2000) and second (2006-2007) periods, were analyzed. Bacterial DNA was extracted from each specimen and the presence of 10 periodontal bacterial species was determined using a PCR method, with a focus on the red complex species of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. RESULTS: Subjects with red complex species in saliva specimens obtained during the second collection possessed a significantly higher number of total bacterial species than those without. The detection rate of the red complex species in the second collection period samples was significantly greater in subjects who had two or more species detected in samples taken during the first collection compared with the other subjects. CONCLUSION: Subjects possessing red complex species may be at possible risk for infection with a high number of periodontal bacterial species during adolescent and younger adult years.

Health effects of indoor fluoride pollution from coal burning in China.

The combustion of high fluoride-content coal as an energy resource for heating, cooking, and food drying is a major exhaust emission source of suspended particulate matter and fluoride. High concentrations of these pollutants have been observed in indoor air of coal-burning families in some rural areas in China. Because airborne fluoride has serious toxicological properties, fluoride pollution in indoor air and the prevalence of fluorosis have been analyzed in a fluorosis area and a healthy nonfluorosis area in China and in a rural area in Japan. For human health, fluoride in indoor air has not only been directly inhaled by residents but also has been absorbed in stored food such as corn, chilies, and potatoes. In the fluorosis area in China, concentrations of urinary fluoride in the residents have been much higher than in the nonfluorosis area in China and in the rural area in Japan. In the fluorosis area, almost all elementary and junior high school students 10-15 years of age had dental fluorosis. Osteosclerosis in the skeletal fluorosis patients was very serious. Urinary deoxypyridinoline in rural residents in China was much higher than in rural residents in Japan. Data suggest that bone resorption was extremely stimulated in the residents in China and that fluoride may stimulate both bone resorption and bone formation. Because indoor fluoride from combustion of coal is easily absorbed in stored food and because food consumption is a main source of fluoride exposure, it is necessary to reduce airborne fluoride and food contamination to prevent serious fluorosis in China.

Cortical cells driven by the low-threshold tooth pulpal afferent in cats.

The input pattern and spatial distribution of tooth pulp-driven neurons (TPNs) in the cat cortex were studied by recording the unitary activities of these neurons. Stimulation was applied to the upper and lower canine and molar tooth pulps. It was possible to record activities of TPNs in the deep layers of the areas 3a and 3b of the coronal gyrus of cerebral cortex. TPNs driven by the ipsilateral tooth pulp stimulation were distributed more anteroventrally than those driven by contralateral stimulation. Cells driven by bilateral pulp stimulation were situated between these two neurons. The threshold intensity for TPNs in the area 3a was lower than that for neurons in 3b. The majority of TPNs in the area 3a of the anterior part of the coronal gyrus received inputs from low-threshold masseteric muscular afferents as well as from tooth pulp afferents. The findings suggest that TPNs in the area 3a may have a relation to orofacial motor functions.

Biting suppresses stress-induced expression of corticotropin-releasing factor (CRF) in the rat hypothalamus.

Corticotropin-releasing factor (CRF) expressed in the hypothalamus plays an important role in mediating behavioral responses to stressors. Restraining the body of an animal has been shown to activate and induce an enhanced expression of CRF in paraventricular neurons of the rat hypothalamus. Since aggressive biting behavior is known to suppress stress-induced noradrenaline secretion in the central nervous system and the formation of gastric ulcers, we investigated the effect of biting on restraint-induced CRF expression in the rat hypothalamus. The number of CRF-expressing neurons in the paraventricular nucleus increased significantly after short time restraint (30 or 60 min) followed by a 180-minute post-restraint period. Biting of a wooden stick during the restraint stress significantly suppressed the restraint-induced enhancement of CRF expression in the paraventricular nucleus. These observations suggest a possible anti-stress effect of biting and an important role of para-functional masticatory activity in coping with stressful events.

Studies of fluorescence depolarization at high pressures of dimyristoylphosphatidylcholine liposomes containing poly(gamma-benzyl-L-glutamate).

The behaviors of four kinds of poly(gamma-benzyl-L-glutamate) (PBLG) molecules and their locations in dimyristoyl-phophatidylcholine (DMPC) liposomes were studied by fluorescence techniques at high pressures of up to 981 bar. The fluorescent substances 1,6-diphenyl-1,3,5-hexatriene (DPH), 1-aminonaphthalene-8-sulfonate (ANS) and PBLGs labeled with a dansyl group were used as probes of hydrophobic and hydrophilic spheres and the motions of polypeptides, respectively. The changes in mobilities of the PBLG molecules depended on their concentrations, degrees of polymerization and the lengths of hydrocarbon chains attached to their terminals. The molecular motions of the PBLGs were altered by increase in their contents, caused by squeezing the PBLG molecules out of the membranes. Models of the membranes and the behavior of polypeptides in the membranes at high pressures are discussed.

Health effects of fluoride pollution caused by coal burning.

Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

Evaluation of human tooth structure with the ultrasonic imaging technique.

In recent years, ultrasonic waves have been an interesting subject for studies due to their wide range of applications in medical diagnoses. In this study, the acoustic properties of the structure of human teeth was determined with the ultrasonic imaging technique. This study may offer some fundamental findings related to the clinical application of the ultrasonic imaging technique in the further development of a virtual system for dental education and research. Twenty freshly-extracted permanent human teeth (10 molars and 10 premolars) were used to investigate their acoustic velocity and impedance by the ultrasonic image analyzing system with a high-resolution focusing probe. Additionally, the relationship between the acoustic properties and the hardness of the teeth was evaluated. It was found that the acoustic properties of the human teeth were influenced by factors related to their structure, such as degree of calcification, distribution of dentinal tubules, and volume of the dentin matrix. The acoustic velocity and impedance showed an apparent correspondence to the hardness of tooth. This analyzing system provides visual information related to tooth structure that can easily quantitatively evaluate their acoustic properties. It is expected that this system will have a wide range of applications and be further developed for clinical uses.

Comparison of plastic prostheses and self-expandable metallic stents in the treatment of malignant esophageal stenosis.

OBJECTIVE: We compared the efficacy of plastic prostheses and self-expandable metallic stents in the treatment of malignant esophageal stenosis and/or fistula. SUBJECTS AND METHODS: Subjects were 31 patients with esophageal cancer, 4 with esophagotracheal fistula, and 1 with esophageal stenosis. A plastic prosthesis was inserted in 15 patients (group A) and a self-expandable metallic stent in 21 patients (group B). We evaluated food ingestion improvement, effectiveness, complications, mean survival, food ingestion duration, the percentage of food ingestion capability in total survival time, and inhospital mortality. RESULTS: No differences were seen in food intake improvement or in the effectiveness between groups, whereas fatal complications were higher in Group A. No significant differences were seen in mean survival, food ingestion duration, percentage of food ingestion capability, or inhospital mortality between groups. CONCLUSION: We concluded that a self-expandable metallic stent was safer than a plastic prosthesis because of fewer serious complications such as bleeding, and recommended the use of metallic stents in the treatment of malignant esophageal stenosis and/or fistula.

[Abnormal evoked EMG and blink reflex responses in patients with hemifacial spasm (HFS)].

Abnormal evoked EMG and blink reflex responses have been observed on the affected side in patients with HFS. These characteristic responses were used as methods of preoperative differential diagnosis, and the disappearance of these abnormal responses during intraoperative monitoring was assessed as confirmation of nerve decompression. The subjects were 30 patients with a diagnosis of HFS. Three responses were evaluated: 1) the orbicularis oris muscle (OR) response to stimulation of the orbicularis oculi muscle branch (OB), OB-->OR; 2) the orbicularis oculi muscle (OC) response to stimulation of the marginal mandibular branch (MB), MB-->OC; and 3) the (OR) response to stimulation of the supraorbital nerve (SO), SO-->OR. The facial nerve in the root exit zone was compressed by a vessel in all 21 patients diagnosed as typical HFS who had abnormal responses, and OB-->OR was always detected. The MB-->OC and SO-->OR detection rates were low (50% and 25%, respectively) when the interval since the onset of HFS was less than 3 years, but increased to 78% and 67%, respectively, when it was 3 to 5 years, and all three abnormal responses were always detected when the interval was more than 5 years. In 17 of the patients these responses began to change and eventually disappeared before decompression of the facial nerve, and in 2 patients they persisted even after decompression. Abnormal responses disappeared at the time of decompression in only 2 patients, and their HFS was completely cured postoperatively. These findings confirmed that disappearance of abnormal responses is not a very useful guide for facial nerve decompression.(ABSTRACT TRUNCATED AT 250 WORDS)

Laser-induced pattern formation in liquid sulfur. An indication of laser-induced phase transition to ordered polymer.

Liquid sulfur is a well-known liquid which exhibits a polymerization transition at T(p)=159 degrees C. Recently, it was found from our experiments that such a transition can be induced below T(p) through laser illumination and that an iridescent pattern appears under strong illumination with a pulsed laser of more than 60 mJ/cm(2) pulse. It is proposed that the visible change in iridescence is due to a macroscopic reconstruction of laser-generated polymers and that a laser-induced phase transition takes place from a freely expanded polymer phase to an ordered polymer phase when increasing the laser illumination. To further examine this possibility, the time variation of the iridescent pattern has been fully investigated using a macro lens, a polarized microscope and an optical microscope. In an analysis of the iridescent pattern, a rapid decrease in the area was observed after an initial slow decrease, suggesting a type of phase transition. Results from the observation of a quenched sulfur sample with a polarized microscope gave evidence that the iridescent region consists of polymers. Through observation of the liquid with a microscope, a striped pattern with micrometer sized spacing was noted in the iridescent pattern. A drastic color change was observed in the pattern from its generation to its disappearance. Sample thickness dependence of the pattern was also observed. These results were well explained by assuming the self-arrangement of laser-generated colloidal polymers.

Detection and serotype distribution of Actinobacillus actinomycetemcomitans in cardiovascular specimens from Japanese patients.

Actinobacillus actinomycetemcomitans, an important pathogen in periodontitis, has also been detected in cardiovascular tissues. Sixty heart valves were collected during valve replacement surgery from 60 patients (one from each), 10 were from patients with infective endocarditis (IE group) and 50 were from patients with other valvular diseases (non-IE group). In addition, 46 samples of aneurysmal tissue were taken from 46 patients with a thoracic or abdominal aneurysm (Aneurysm group, one from each). Dental plaque samples were taken from 54 of the patients, 31 in the IE and non-IE groups and 23 in the aneurysm group. First, the distribution of A. actinomycetemcomitans in all specimens was analysed using a polymerase chain reaction method, which resulted in a positive reaction in 33 (31.1%) of the cardiovascular specimens and 25 (46.3%) of the dental plaque samples. Next, using serotype-specific sets of primers, the serotype distribution of A. actinomycetemcomitans in the cardiovascular specimens and dental plaque samples was found to be significantly different compared to dental plaque samples from Japanese subjects reported previously.

Accidentally induced periodontitis in primary dentition: longitudinal examinations of periodontal bacteria and clinical conditions.

Periodontitis is very rare in the primary dentition although it can be accidentally induced in young children. The purpose of this study was to describe a case of periodontitis in a 4-year-old child, which was accidentally induced by insertion of small plastic tubes into the dental cervix of the primary incisors during play, and to discuss the clinical, radiographic, and microbiological findings. Removal of the plastic tubes resulted in resolution of the periodontal condition. Prevotella nigrescens and Campylobacter rectus were detected in subgingival plaque samples from the affected teeth at every examination, whereas Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, and Bacteroides forsythus were never found during the two-year observation period. The clinical and microbiological results suggest that the type of periodontitis caused by such an incidence is not progressive, unlike other periodontal diseases such as prepubertal and juvenile periodontitis.

Breathing out into water during subtotal immersion: a therapy for chronic pulmonary emphysema.

OBJECTIVE: To determine the importance of a breathing out into water exercise during subtotal immersion for emphysematous patients. DESIGN: Results of a respiratory function test and arterial blood gas analysis were examined to compare the programs of breathing exercise with and without the breathing out into water exercise. The breathing exercises in a pool filled with 38 degrees C water were performed 30 min/day, 5 days/wk, for 2 mo in 17 patients with stable chronic emphysema. Patients were randomly assigned to breathing exercise programs including subtotal water immersion with the nose and mouth either immersed (9 patients) or out of the water (8 patients) during exhalation. RESULTS: The ratio of %forced expired volume in 1 sec to forced vital capacity and %forced vital capacity at rest were significantly increased in the program with the breathing out into water exercise, but they did not change in the program without the breathing out into water exercise. A significant increase in peak flow was observed in the former program, although it did not change in the latter program. The maximal expiratory flow at 25% did not change in either program. Pao2 was significantly increased and Paco2 was significantly decreased in the former program, although a trend for a decrease in Paco2 was observed in the latter program. CONCLUSIONS: These results suggest that the breathing out into water exercise enhances the effects of a breathing exercise during immersion and is useful in rehabilitation for chronic pulmonary emphysema.

Do low-power lasers change phase transition temperature of dipalmitoyl phosphatidylcholine (DPPC) membrane?

This study was designed to investigate the effects of the He-Ne laser (632.8 nm of wavelength, 8.5 mW in power, Senko Med. Co. Ltd., Tokyo, Japan) on the phase transition temperature of dipalmitoyl phosphatidylcholine (DPPC) membranes. Liposomal bilayers of DPPC (12.5 mM) were obtained with ultrasonification for 45 min at 40 degrees C and refrigerated for 2-3 days at 5 degrees C. The bilayers vesicle solution was divided into 3-ml working aliquots, which were assigned to three groups. The aliquots in Group 1 were used as controls without irradiation and the aliquots in Groups 2 and 3 were irradiated in 37 degrees C baths for 15 to 30 min, respectively. To determine phase transition temperature, optical density (%T; percent of permittance) of each aliquot was measured spectrophotomechanically at a wavelength of 440 nm while increasing its temperature at a rate of 0.5 degrees C every minute. Main phase transition temperatures in Groups 1, 2, and 3 were 41.54 +/- 0.23 degrees C (n = 10), 41.50 +/- 0.27 degrees C (n = 10), and 41.30 +/- 0.36 degrees C (n = 10), respectively. No significant difference between the nonirradiation and irradiation groups was established. These results suggest that irradiations of low-power He-Ne lasers up to 30 min do not change important physical characteristics of artificial DPPC membranes.

A fragile X female with Down syndrome.

Clinical and cytogenetic aspects of a female infant with trisomy 21 and the fragile X [fra(X)] chromosome are reported. Most of the facial characteristics of the patient are those observed in Down syndrome, but some features such as long face with prominent forehead and lower jaw, and large ears are related to the fra(X) syndrome. The origin of an additional chromosome 21 may be ascribed to maternal first meiotic nondisjunction in our case. It has been suspected that female carriers of the fra(X) chromosome may be predisposed to meiotic nondisjunctional events. However, there is probably no relationship between the two chromosomal abnormalities in our case because of the maternal age at the delivery.

Experimental studies of a hybrid artificial esophagus combined with autologous mucosal cells.

Preliminary results, obtained using an artificial esophagus combined with autologous mucosal cells in dogs, are reported. The authors' prosthesis is a silicone tube coated with freeze dried collagen sponge. Cells infiltrate this collagen layer and synthesize new tissue, which will become the neoesophagus. The silicone tube imparts rigidity to the prosthesis and prevents infection, leakage, and dislocation of the prosthesis at the anastomotic site. After formation of the epithelized neoesophageal lumen, the silicone tube drops into the stomach as the result of peristalsis in response to food. Eventually, no artificial prosthesis remains in place, and the defect is replaced by ingrowing tissue. This process was shortened by mucosal cell seeding. Before replacement, the authors harvested oral mucosal (OM) cells, cultured them for 10 days, and seeded them in the collagen layer of the prosthesis just after anastomosis. The neo-esophageal lumen was formed 1 week after the operation without any local complications, infection, leakage, or stenosis, and 2 weeks later the firm, epithelized neoesophagus was completed. OM cell seeding accelerated not only epithelization, but also regeneration of mesenchymal tissue. Parallel with this, transmission electron microscopy showed that most of the cells in the neoesophagus exhibited large nuclei and prominent rough endoplasmic reticulum, indicative of active collagen production.

In vivo evaluation of 2-cyanoacrylates as surgical adhesives.

To evaluate 2-cyanoacrylates as surgical adhesives, the bond strength in vivo as well as the tissue reaction was investigated using methyl-, ethyl-, isobutyl-, and ethoxyethyl-2-cyanoacrylate. In addition, their set time and spreading on blood were studied. When the 2-cyanoacrylates were applied to an incised site of rabbit skin, they could maintain the skin closure without suturing during the first week and the bond strength increased during the second week. Significant inflammatory response was observed around the subcutaneous tissue glued with methyl- and ethoxyethyl-2-cyanoacrylate and persisted for approximately one week. All the 2-cyanoacrylate polymers were absorbed and the tissues treated were healed two weeks after the operation. There was a mild inflammatory reaction in the tissue treated with ethyl- and isobutyl-2-cyanoacrylate, and their polymers still remained at the wound site at the second week postoperatively. The disappearance rate of the 2-cyanoacrylate polymers was roughly in proportion to the inflammatory tissue response. Ethoxyethyl-2-cyanoacrylate spread more broadly on tissues than the other 2-cyanoacrylates, while its set time was shorter than that of methyl- and ethyl-2-cyanoacrylates.

Hypercoagulable state induced by thrombocytapheresis.

The influence of the continuous-flow automated blood cell separator. Fenwal CS-3000, on blood coagulation and the fibrinolytic system in blood donors was studied. Blood samples were taken from the collection line of donors undergoing extracorporeal circulation, before and after platelet pheresis. Of the molecular markers, prothrombin fragment-F1 + 2 (PF1 + 2) markedly increased from 0.8 +/- 0.3 to 2.9 +/- 2.0 nM/ml (P < .004), thrombin antithrombin III complex (TAT) also markedly increased from 2.6 +/- 1.3 to 56.0 +/- 24.0 micrograms/L (P < .001), fibrinopeptide A (FPA) increased slightly from 0.8 +/- 0.9 to 3.8 +/- 4.2 micrograms/L (P < .05), and alpha 2-plasmin inhibitor (alpha 2-PI) decreased slightly from 95 +/- 8 to 91 +/- 9% (P < .05). In one donor with the highest level of PF1 + 2, TAT, FPA, and plasmin inhibitor complex after platelet pheresis, protein C, protein S, C4b-binding protein, ATIII, plasminogen, alpha 2-PI, and coagulation factors were decreased. In blood donors undergoing platelet pheresis using the continuous-flow automated blood cell separator, Fenwal CS-3000, a hypercoagulable state was observed. Changing the materials of the plastic disposables to a more thromboresistant material may prevent the hypercoagulable state in donors induced by platelet pheresis using the blood cell separator.