123I-BMIPP, a Radiopharmaceutical for Myocardial Fatty Acid Metabolism Scintigraphy, Could Be Utilized in Bacterial Infection Imaging

In this study, we evaluated the use of 15-(4-123I-iodophenyl)-3(R,S)-methylpentadecanoic acid (123I-BMIPP) to visualize fatty acid metabolism in bacteria for bacterial infection imaging. We found that 123I-BMIPP, which is used for fatty acid metabolism scintigraphy in Japan, accumulated markedly in Escherichia coli EC-14 similar to 18F-FDG, which has previously been studied for bacterial imaging. To elucidate the underlying mechanism, we evaluated changes in 123I-BMIPP accumulation under low-temperature conditions and in the presence of a CD36 inhibitor. The uptake of 123I-BMIPP by EC-14 was mediated via the CD36-like fatty-acid-transporting membrane protein and accumulated by fatty acid metabolism. In model mice infected with EC-14, the biological distribution and whole-body imaging were assessed using 123I-BMIPP and 18F-FDG. The 123I-BMIPP biodistribution study showed that, 8 h after infection, the ratio of 123I-BMIPP accumulated in infected muscle to that in control muscle was 1.31 at 60 min after 123I-BMIPP injection. In whole-body imaging 1.5 h after 123I-BMIPP administration and 9.5 h after infection, infected muscle exhibited a 1.33-times higher contrast than non-infected muscle. Thus, 123I-BMIPP shows potential for visualizing fatty acid metabolism of bacteria for imaging bacterial infections.

Comparison of L- and D-Amino Acids for Bacterial Imaging in Lung Infection Mouse Model

The effectiveness of L- and D-amino acids for detecting the early stage of infection in bacterial imaging was compared. We evaluated the accumulation of ³H-L-methionine (Met), ³H-D-Met, ³H-L-alanine (Ala), and ³H-D-Ala in E. coli EC-14 and HaCaT cells. Biological distribution was assessed in control and lung-infection-model mice with EC-14 using ³H-L- and D-Met, and ¹⁸F-FDG. A maximum accumulation of ³H-L- and D-Met, and ³H-L- and D-Ala occurred in the growth phase of EC-14 in vitro. The accumulation of ³H-L-Met and L-Ala was greater than that of ³H-D-Met and D-Ala in both EC-14 and HaCaT cells. For all radiotracers, the accumulation was greater in EC-14 than in HaCaT cells at early time points. The accumulation was identified at 5 min after injection in EC-14, whereas the accumulation gradually increased in HaCaT cells over time. There was little difference in biodistribution between ³H-L-and D-Met except in the brain. ³H-L- and D-Met were sensitive for detecting areas of infection after the spread of bacteria throughout the body, whereas ¹⁸F-FDG mainly detected primary infection areas. Therefore, ¹¹C-L- and D-Met, radioisotopes that differ only in terms of ³H labeling, could be superior to ¹⁸F-FDG for detecting bacterial infection in lung-infection-model mice.

Novel Hyaluronate Lyase Involved in Pathogenicity of Streptococcus dysgalactiae subsp. equisimilis

Streptococcus dysgalactiae subsp. equisimilis (SDSE) causes cellulitis, bacteremia, and invasive diseases, such as streptococcal toxic shock syndrome. Although SDSE infection is more prevalent among elderly individuals and those with diabetes mellitus than infections with Streptococcus pyogenes (Group A streptococci; GAS) and Streptococcus agalactiae (Group B streptococci; GBS), the mechanisms underlying the pathogenicity of SDSE remain unknown. SDSE possesses a gene hylD encoding a hyaluronate lyase (HylD), whose homologue (HylB) is involved in pathogenicity of GBS, while the role of HylD has not been characterized. In this study, we focused on the enzyme HylD produced by SDSE; HylD cleaves hyaluronate (HA) and generates unsaturated disaccharides via a β-elimination reaction. Hyaluronate-agar plate assays revealed that SDSE promoted dramatic HA degradation. SDSE expresses both HylD and an unsaturated glucuronyl hydrolase (UGL) that catalyzes the degradation of HA-derived oligosaccharides; as such, SDSE was more effective at HA degradation than other β-hemolytic streptococci, including GAS and GBS. Although HylD shows some homology to HylB, a similar enzyme produced by GBS, HylD exhibited significantly higher enzymatic activity than HylB at pH 6.0, conditions that are detected in the skin of both elderly individuals and those with diabetes mellitus. We also detected upregulation of transcripts from hylD and ugl genes from SDSE wild-type collected from the mouse peritoneal cavity; upregulated expression of ugl was not observed in ΔhylD SDSE mutants. These results suggested that disaccharides produced by the actions of HylD are capable of triggering downstream pathways that catalyze their destruction. Furthermore, we determined that infection with SDSEΔhylD was significantly less lethal than infection with the parent strain. When mouse skin wounds were infected for 2 days, intensive infiltration of neutrophils was observed around the wound areas infected with SDSE wild-type but not SDSEΔhylD. Our investigation suggested that HylD and UGL play important roles in nutrient acquisition from hosts, followed by the bacterial pathogenicity damaging host tissues.

Distinct Skin Microbiome and Skin Physiological Functions Between Bedridden Older Patients and Healthy People: A Single-Center Study in Japan

With the increase in the older populations, the number of bedridden older patients is becoming a matter of concern. Skin microbiome and skin physiological functions are known to change according to lifestyle and community; however, such changes in case of movement- and cleaning-restricted bedridden older patients have not yet been revealed. To address this issue, we analyzed skin microbiome and skin physiological functions, including pH, hydration, sebum level, and transepidermal water loss (TEWL), of bedridden older patients, compared with those of ambulatory older and young individuals. For this analysis, we enrolled 19 healthy young and 18 ambulatory older individuals from the community and 31 bedridden older patients from a single, long-term care hospital in Japan. The area of interest was set to the sacral (lower back) skin, where pressure injuries (PIs) and subsequent infection frequently occurs in bedridden older patients. We observed a higher number of gut-related bacteria, fewer commensals, higher skin pH, and lower TEWL on the sacral skin of bedridden older patients than on that of young or ambulatory older individuals. In addition, we observed that 4 of the 31 bedridden older patients developed PIs during the research period; a higher abundance of pathogenic skin bacteria were also observed inside the PI wounds. These findings imply distinct skin microbiome and skin physiological functions in bedridden older patients in comparison with healthy individuals and may suggest the need for more stringent cleaning of the skin of bedridden older patients in light of the closeness of skin and wound microbiome.

Pathogenicity Characterization of Prevalent-Type Streptococcus dysgalactiae subsp. equisimilis Strains

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging human pathogen that causes severe invasive streptococcal diseases. Recent reports have shown that SDSE exhibits high pathogenicity with different mechanisms from that of Streptococcus pyogenes, although the two streptococci possess some common virulence factors such as streptolysin, streptokinase, and cell-binding proteins. To date, only a few studies have examined the variety of mechanisms expressing the pathogenicity of SDSE. Among nine SDSE clinical isolates sequenced in this study, we present in vitro and in vivo analyses of KNZ01 and KNZ03, whose emm and multilocus species types (MLSTs) are prevalent in Japan and other countries. For the comparison of pathogenicity, we also utilized the ATCC 12394 strain. The whole-genome analysis showed that KNZ03 and ATCC 12394 are categorized into an identical clonal complex by MLST and are phylogenetically close. However, the three strains exhibited different characteristics for pathogenicity in vitro; ATCC 12394 showed significant cytotoxicity to human keratinocytes and release of streptolysin O (SLO) compared to KNZ01 and KNZ03; KNZ03 exhibited significantly high hemolytic activity, but did not secrete SLO. KNZ01 and KNZ03 adhered to human keratinocytes at a higher rate than ATCC 12394; KNZ03 showed a higher rate of survival after a brief (30 min) incubation with human neutrophils compared to the other two strains; also, KNZ01 grew more rapidly in the presence of human serum. In vivo subcutaneous infection commonly resulted in ulcer formation in the three strains 7 days after infection. KNZ01-infected mice showed significant body weight loss 2 days after infection. Besides, on post-infection day 2, only KNZ01 remained in the cutaneous tissues of mice. Scanning electron microscopy analysis revealed that KNZ01 formed an extracellular structure (biofilm), which was probably composed of cell wall-anchoring proteins, in the presence of glucose and human serum. The extracellular structure of ATCC 12394 was also changed dramatically in response to culture conditions, whereas that of KNZ03 did not. Our study proposed that each SDSE strain possesses different virulence factors characteristics for mediating pathogenicity in humans.

Measuring the Antimicrobial Activity of Lauric Acid against Various Bacteria in Human Gut Microbiota Using a New Method

Lauric acid (LA) has a broad spectrum of anti-microbiological activities against enveloped viruses and various bacteria, and might be useful to protect against microbial infection and control the balance and distribution of bacteria in human gut microbiota. It is not necessarily more difficult to measure antimicrobial activity the traditional way, but it is, however, more laborious. In the present study, we developed a new method to measure the antimicrobial activity of LA in multiple samples with a microplate reader. A "test complex" (TC) was produced consisting of 100 μL of agar medium with LA in the bottom layer and 300 μL of broth in the top layer in 96-well deep-well microplates. Afterward, analysis of the broth in the top layer showed that the antimicrobial activity was the same as that of the "control complex," (CC) which consisted of 100 μL of agar medium in the bottom layer and 300 μL of broth with LA in the top layer. Furthermore, evaluation of the antimicrobial effect of the TC when using a microplate reader was the same as that with the use of the colony counting method. The colony counting method has confirmed that the antimicrobial activity of LA when bacteria are inoculated into the broth was equivalent between CC and TC, and we validated this by correlating the number of bacteria with absorbance. In addition, the broth itself in TC was transparent enough that the turbidity of broth can be used as an index of the number of bacteria, which enabled the use of a microplate reader for multiple samples. For human gut microbes, LA was shown to have low antimicrobial activity against commensal lactic acid bacteria, but high antimicrobial activity against pathogenic Bacteroides and Clostridium, suggesting that LA might modulate intestinal health, as confirmed by the proposed method.

A Comparison of Techniques for Collecting Skin Microbiome Samples: Swabbing Versus Tape-Stripping

The swabbing and tape-stripping methods have traditionally been used for collecting skin microbiome samples for skin bacterial analysis, although no reports have compared the outcome of these methods for collecting skin bacteria. Our purpose was to show the differences in microbial composition between samples collected using the swabbing and tape-stripping methods, by both the next generation sequencing and culture studies. The skin microbiome was collected by both methods, and the samples were processed for a sequence-based microbiome analysis and culture study. The next-generation sequencing results showed that skin bacteria collected using the tape-stripping method were comparable to those collected using the swabbing method. In the culture study, the tape-stripping method collected a greater number and wider variety of viable skin bacteria than the swabbing method. These results suggest that the tape-stripping method is comparable to the swabbing method for collecting viable skin bacteria, without losing fidelity to the composition of skin microbiome.

Phonon dispersion curves of a BC3 honeycomb epitaxial sheet

The entire phonon-dispersion curves along the Gamma-M direction of a BC3 honeycomb sheet have been determined both experimentally and theoretically for the first time. Most of the observed curves agreed with the theoretical ones calculated on the basis of ab initio theory. From the stretching force constants of the nearest-neighbor C-C and B-C bonds, together with that of the B-B bond, we clarified the characteristic feature of the C-C and B-C bonds. From the experimental and theoretical results, we discussed the possibility of high T(c).

Inhibitory effects of YM175, a bisphosphonate, on the progression of experimental periodontitis in beagle dogs

This study examined the efficacy of YM175 [disodium dihydrogen (cycloheptylamino) methylene-1, 1-bisphosphonate] in reducing alveolar bone loss caused by experimental periodontitis in beagle dogs. Thirty-six dogs were used and divided into 6 groups. Periodontitis was induced in 30 dogs (groups 2-6) by ligating the bilateral mandibular third and fourth premolar teeth with silk ligatures and by feeding a soft diet. Six dogs were sham-operated (group 1). Saline (placebo), flurbiprofen (0.02 mg/kg) and YM175 (0.01, 0.1 and 1.0 mg/kg) were administered to the dogs (groups 2-6) 5 d/wk for 25 wk. Radiographic and morphometric analyses were performed. In placebo-treated animals (group 2), the ligation caused a significant decrease in the alveolar bone height by 0.57 and 1.91 mm at 2 and 25 wk, respectively. YM175 (1.0 mg/kg) prevented the decrease in bone height by 47 and 31% at 2 and 25 wk. YM175 (0.1 mg/kg) and flurbiprofen tended to prevent bone loss after 15 wk. Although the ligation elicited no significant change in bone mineral density, it significantly decreased bone volume. YM175 (1.0 mg/kg) and flurbiprofen tended to increase the bone volume. The number of formative or resorptive Haversian canals and the bone turnover through the periosteal bone surface were increased by the ligation, indicating the increased turnover of the cortical bone. YM175 (1.0 mg/kg) reduced the increased bone turnover. The gingival index was maximally increased at 2 wk and was suppressed by YM175. These results suggest that YM175 prevents alveolar bone loss by reducing the increased alveolar bone turnover in dogs with periodontitis.

Helix-loop-helix-type transcription factor (HES-1) is expressed in osteoblastic cells, suppressed by 1,25(OH)2 vitamin D3, and modulates 1,25(OH)2 vitamin D3 enhancement of osteopontin gene expression

The active form of vitamin D, 1,25(OH)2 vitamin D3 (D3), is a potent modulator of osteoblastic function. In this study, we examined, the expression of a negative-type basic helix-loop-helix transcription factor, HES-1, in osteoblastic cells and the regulation of its expression by D3. We found that HES-1 is expressed as a 1.7 kb mRNA in rat osteoblastic osteosarcoma ROS17/2.8 cells. Treatment with D3 suppressed HES-1 mRNA levels by about 50%. This suppression was observed within 24 h and lasted for at least 48 h. The suppressive effect was dose-dependent starting at 10(-9) mol/L and saturated at 10(-8) mol/L. The vitamin D3 suppression of HES-1 mRNA level was blocked by actinomycin D as well as cycloheximide, suggesting the involvement of transcriptional control, which requires new protein synthesis. Proteins in the crude nuclear extracts prepared from ROS17/2.8 cells bound to the N-box sequence (CACNAG). To examine the function of HES-1 in osteoblasts, HES-1 was overexpressed in ROS17/2.8 cells. Overexpression of HES-1 suppressed the vitamin D-dependent upregulation of osteopontin gene expression in these cells. Vitamin D suppression of HES-1 gene expression was also observed in normal rat calvaria-derived osteoblast-enriched cells. These results indicate that HES-1 is expressed in osteoblastic cells and is involved in vitamin D3 regulation of osteoblastic gene expression.

Interaction of lactoferrin with ascorbate and the relationship with bleomycin-dependent DNA damage

The interaction between bovine lactoferrin (bLf) and ascorbate (Asc) was investigated through malondialdehyde (MAD) formation in a solution containing DNA, bleomycin (BLM), and Fe2+ or Asc. The inhibition by bLf on MDA formation in the presence of Asc was not changed even by adding carbonate or oxalate ions to the solution. The percentage inhibition by the hydrolysates of bLf treated with pepsin, trypsin, and both enzymes on MDA formation was almost the same as that by the untreated bLf in the presence of Asc. The inhibition of MDA formation also occurred with the filtrate obtained from a solution containing bLf and Asc, but not with that from a solution of bovine serum albumin and Asc. The interaction of bLf and Asc was observed by gel filtration in a Sephadex G75 column. The binding amount of Asc was estimated to be 87 mol per mole of bLf.

Cloning and characterization of a 23-kDa stress-induced mouse peritoneal macrophage protein

Exposure of mouse peritoneal macrophages to oxidative and sulfhydryl-reactive agents in vitro enhances synthesis of a few cellular proteins that may be important in a self-defense system. A cDNA encoding a novel stress-inducible protein, designated MSP23 (macrophage 23-kDa stress protein), was cloned from a cDNA library of the macrophages by differential screening. A 1.0-kilobase mRNA transcript hybridized with the MSP23 cDNA gradually increased in macrophages upon culture in vitro. Treatment with diethylmaleate or glucose/glucose oxidase, which generates H2O2, markedly enhanced the induction of the transcript after several hours. Cadmium chloride and sodium arsenite also induced the transcript. An antiserum raised against recombinant MSP23 reacted with the 23-kDa stress-inducible protein of the macrophages. The amounts of 23-kDa protein in the cells rapidly increased during culture with diethylmaleate. The mRNA was detected in various tissues, and it was especially high in content in the liver. A search of databases revealed that six proteins of various species from bacteria to the mouse have a sequence homology to MSP23. One of the proteins is the C22 component of alkyl hydroperoxide reductase, which is induced by hydrogen peroxide in Salmonella typhimurium.

[Microbiological study in clinically characterized rapidly progressive periodontal disease]

Samples of subgingival bacteria were collected from two sites of offanteriors with greater than or equal to 6 mm deep pockets in each ten patients in a clinically characterized rapidly progressive periodontal disease. The purpose of this investigation was to study the predominant cultivable microflora at pre- and post-periodontal treatment stages, in order to monitor the clinical effects of periodontal treatment and possibly to determine the presence or absence of active disease. "Non effective site" was defined as little elimination of periodontal pocket. Some patients responded remarkably well to root curettage. However the subgingival flora of effective sites, which had been successfully treated and maintained over a period of three weeks, was still significantly different from the subgingival floras of people with healthy gingiva. The predominant cultivable microflora of diseased lesions at the pre-treatment stage, in which a similar proportion of microbiota were detected on both sites in each patient, were significantly increased proportions of Bacteroides sp., B. intermedius and B. gingivalis. Although B. gingivalis has been implicated as the etiologic agent of the disease, to which marked antibody response has been found in periodontal pockets, there were decreased proportions of B. intermedius and B. gingivalis after treatment, compared to pre-treatment stage. The results showed that non-effective lesions were associated with subgingival microflora which were populated by higher proportions of B. intermedius and E. corrodens. H. actinomycetemcomitans were detectable during the experimental periods in all sites. It was possible to indicate progressing periodontitis by examining these microflora at the pre-treatment stage. However active or progressing disease in young adults might represent not only an overgrowth of existing organisms but also an abnormality in host resistance.

[The clinical and etiological study on juvenile periodontal disease]

Seven juvenile periodontally diseased patients were evaluated for clinical, microbiologic and local or systemic host factors. Three patients showed the localized from of periodontitis clinically and radiographically and by deep periodontal pockets associated with the molars and incisors. Four were in the generalized froms, in which in most cases all teeth were affected. The results in both diseased froms on the predominant cultivable subgingival microflora, the composition of which was not different from that in adult periodontitis, consisted of significantly increased proportions of Gram-negative anaerobic rods, Bacteroides sp. and B. gingivalis, Haemophilus sp. and H. actinomycetemcomitans were detected in 1/3 of the localized and 2/4 of the generalized periodontitis. They were of no value in distinguishing activity that enhanced disease in the generalized from. Elevated serum IgG responses were noted with B. gingivalis. No markedly functional abnormalities of neutrophils from peripheral blood have been demonstrated, however it might function with systemic factors, like an insulin-dependent diabetes. Morphologic characteristics of the oral and periodontal tissue in localized periodontitis were that the pattern of destruction was confined to specific teeth groups characterized by extensive the bucco-lingual width ratio of the dental crown to alveolar bone width. These observations indicate that the generalized form of juvenile periodontitis lesions were associated not only with the presence of subgingival bacteria, but also with conditions such as local morphologic and systemic or constitutional factors, individual variation in relation to destructive and protective aspects of the defense mechanisms.

[Effects on repaired bone with hydroxyapatite by the changes of dynamics in the alveolar bone]

Hydroxyapatite (HAP) is regarded as a useful material for grafting in procedure aimed at bone replacement. The purpose of this investigation, as a basic experiment, was to demonstrate bone formation in the dental extraction sockets during orthodontic movement of the neighboring teeth in the initial wound healing phase, and to clarify effects of indirect forces through alveolar bone on repairing bone in extraction sockets. Secondary we examined changes in the bone formation in the sockets during the tooth movement which were plugged with HAP granules and compared with the repairing bone without HAP. For this study seven dogs were used and were scarificed according to a schedule yielding observation periods up to 6 weeks. The animals were injected continuously with tetracycline during the experimental period. Undecalcified mesio-distal specimens 65-100 microns of thickness were prepared at first for microradiogram and then subjected to fluorescence microscopy. The observations indicated that the bone formation seemed to be accelerated with HAP implantation, however the alveolar trabeculae around HAP were developed during the tooth movement less than the control. The tooth movement in implanted sites was faster than in the sites without HAP implantation. The decreased response on alveolar bone formation, incident to experimental tooth movement into extraction sockets, was found in the pressure area, mesial part of socketswall. It might be induced by excessive stress during the tooth movement, amplified by the change of bone repairing due to the HAP implantation.

[Effects of composite resin materials on gingiva and pulp]

Composite resin materials are now widely used for dental therapy. The purpose of this study was to clarify the effect of composite resins on gingiva and pulp in case of application of them for temporally splint in periodontal treatment. 60 teeth in 6 female dogs ranging between 1 and 2 years of age with healty teeth and gingiva were divieded to 4 groups; (1) 12 teeth, controls; (2) 12 teeth, self-cured composite resin (Clearfil F II, CF II); (3) 18 teeth, light-cured resin (Belfel LX, BLX), curing time 20 sec. and (4) 18 teeth, BLX, 40 sec., and then 48 class V composite resins were restored supragingivally. The experimental procedure were carried out for 5 days and 30 days. Histopathological observations of 60 teeth inclusive of controls were made by applying to specimens with Hematoxylin eosin staining. For the materials and time periods in this study it was found that; 1. Light-cured composite resin was superior to self-cured composite resin on handlings. 2. There were no significant differences in periodontium between the experimentals (BLX, CF II) and controls in 5 days. At the 30 days the histologic score showed more gingivitis for the experimental teeth than for the controls (BLX-40 greater than BLX-20 greater than CF II greater than Cont.). 3. At 5 days hyperemia occurred in some cases of experimentals (both BLX and CF II). The appearance of predentin and changes of odontblastic layer were observed slightly in 30 days. But there were no significant differences between BLX and CF II. 4. The result suggested that applying to composite resin materials for temporally splint, both gingiva and pulp have to be protected.

[Morphological study of periodontal tissues in the initial stage of periodontal disease. Part 2. Analysis of morphological measurement and status of periodontal disease]

The morphological characteristics of periodontal tissue in periodontal disease have been interpreted differently by a number of clinical observers. Many have reported that the malposition and functional malocclusion of teeth is injurious to the periodontium. We reported in Part I that a system for evaluating periodontal status was developed for the diagnosis and management of the interproximal area at the initial stage of bone resorption. The patient group consisted of 36 adults, from 21 to 55 years of age. The severity score represented the calculated loss of periodontal support tissues: loss of alveolar bone, evaluated roentgenologically, bone level and pattern in vertical and horizontal form, periodontal pocket and gingival inflammation. Because poor oral hygiene and other factors caused swelling by gingival inflammation, we obtained study specimens from patients with chronic periodontal disease after a few tooth brushing instructions, and scalings during initial therapy in order to detect initial and established pathological changes in periodontal tissue. The purpose of this study was to clarify the relationship between periodontal disease status and morphological diagnostic indicators and different degrees of harmony and disharmony in the lower jaw. In all age groups the average percentage of bone loss and intraosseous defects tended to be higher in the groups categorized as Type III and Type F, and in the area that showed a very deep concave Spee curve to the occlusal plane in Pattern D. We considered that these morphological characteristics might be of secondary importance for diagnosis. Oral local factors were the primary extrinsic factor in the pathogenesis of horizontal and vertical interproximal bone absorption in the area of the premolars and molars.

[Morphological study of periodontal tissues in the initial stage of periodontal disease. Part 1. Application of a morphological measurement and a system for evaluating the periodontal status]

The functional aberration of occlusion, based on the morphology of the alveolar process, causes chronic irritation of the periodontium in addition to the concomitant effect of other local environment factors. This investigation was designed to study the role of morphological characteristics in the periodontal disease process. The periodontal health of 22 subjects was recorded by clinical and roentgenological measurements of the loss of periodontal tissue. The criteria for this selection were no loss of or a crowding of adjoining teeth and no disharmony in occlusal contact. Morphological data were measured around the premolars and molars of lower jaws on the study models individuals, in bucco-lingual width of the alveolar bone in relationship to the width of the crown and the sagittal figure of the Spee curve etc. by using a three-dimensional analyzer. The subjects were categorized as Type II when the records indicated a ratio of the crown width/bone width of 1/1.2. Types I and III, depended on a greater and smaller ratio, respectively. Type W symbolized the alveolar process, of which the interproximal bone showed a considerable curvature mediodistally. Type F showed a flat pattern. The sagittal figure of the Spee curve was divided into four patterns: Pattern A or B, when the cusp of the canine and first premolar leveled over or on the occlusal plane; Pattern C, when the cusp of the canine leveled over and the first premolar under the occlusal plane, and Pattern D, when all cusps, canine, premolar and molar, were under the occlusal plane. The distance from the occlusal plane to the deepest point of the Spee curve was divided into four groups: Pattern a, when the distance was 0-1.0 mm, Pattern b, 1.1-2.0 mm, Pattern c, 2.1-3.0 mm and Pattern d, 3.1-4.0 mm. These results suggest that the morphological evaluation is a useful diagnostic indicators on a rational basis. The morphological characteristics might be related to the presence of periodontal disease and allowed to speculate the pathological changes in established stage, and also to the response to periodontal treatment in the initial stage of periodontal disease.

[Group therapy for periodontal disease. 1. Practical application of CPITN and the effects of group therapy]

The purpose of this study was to determine the oral conditions in bakery workers (473 subjects) in addition to the screening system of O'Leary and CPITN, designed for rapid recording of the level of periodontal treatment needs, and to evaluate the periodontal treatments, managed by professional cleaning (scaling) and oral hygiene instruction. The assessment of the prevalence and severity of periodontal disease and resultant treatment needs in this group showed the characteristics of chronic periodontal disease in an advanced stage in persons aged 25-29 and 50-54. 228 patients were selected for treatment for nine months and examined accurately for their periodontal condition. 137 patients continued the following group therapy three times and were reevaluated. Following the group therapy, the oral hygiene status and subjective symptoms of bleeding were improved in all groups, the effectiveness of the treatment on sextants, scoring cord three, four, showed markedly high. To achieve the treatment with few individual appointments, it is necessary to increase our knowledge of how these groups live, depending on the diversity of life style and the differences in ethnic consciousness.

The reaction of peri-implant tissues to titanium alloy and apatite-coated implants during the healing phase

Oral implantation has been a controversial dental therapeutic procedure. Many implant materials and designs are presently in progress of study to evaluate the long term response of peri-implant tissues, together with anticipated loading considerations. The purpose of this examination was to make clear whether a fibrous layer would form between bone and Titanium alloy and apatite-coated Titanium implants under stressed and unstressed conditions, during the healing phase after implantation. The in vivo evaluation of 10 implants were made on two dogs. The upper 2nd and 3rd and lower 3rd and 4th premolar teeth were extracted and the sockets allowed to heal for 3 months. The implants in the unstressed condition were completely submerged, and in the stressed condition they were left with their top 2 mm above the surface of the bone, so that after suturing the top of the implant was exposed to the oral environment. After the postoperative healing phase of 3 months, the animals were killed and the specimens were prepared for histological, SEM examinations and EDX analysis of the interface zone between bone and the implants. Histological examination showed a direct contact between the apatite-coated implant and new bone, so that the implant became anchored to bone without an intervening soft tissue layer and a similar result was obtained between the Titanium implant and bone in the unstressed condition. However the high magnification electron micrographs showed a thin connective tissue between the bead-blasted surface of the Titanium implant and bone, and this peri-implant tissue could be detached from the implant. In the stressed condition, a thin layer of fibrous tissue was interposed between the Titanium implant and bone. The high magnification electromicroscopical views of the interface zone between the bone and these implants showed coarse fiber bundles developed perpendicular to the Titanium surface and their terminal ends were confluent with the rugged Titanium surface presumably as a result of micro-movement during the 3 months healing phase. In this study, an adequate space for a development of fibro-anchorage was about 20-200 microns in width. If occlusal stresses were within permissible range in healing period, the relative motion of the implant and bone was then optimal for the formation of a fibro-anchorage. It could be suggested that an ideal stress transfer from the Titanium implant to bone might be achieved by this fibro-anchorage.