Periodontal disease and atherosclerosis from the viewpoint of the relationship between community periodontal index of treatment needs and brachial-ankle pulse wave velocity

BACKGROUND

It has been suggested that periodontal disease may be an independent risk factor for the development of atherosclerosis. However, the relationship between periodontal disease and atherosclerosis has not been fully elucidated. This study aimed to assess the effects of periodontal disease on atherosclerosis.

METHODS

The study design was a cross-sectional study. Subjects were 291 healthy male workers in Japan. We used the Community Periodontal Index of Treatment Needs (CPITN) score, average probing depth and gingival bleeding index (rate of bleeding gums) to assess the severity of periodontal disease. We also used the Brachial-Ankle Pulse Wave Velocity (baPWV) as the index for the development of atherosclerosis.

RESULTS

The unadjusted odds ratio (OR) of atherosclerosis in relation to the CPITN score was 1.41 [95% CI: 1.16-1.73]. However, after adjustment for age, systolic blood pressure and smoking, the CPITN score had no relationship with atherosclerosis (adjusted OR: 0.91 [0.68-1.20]).

CONCLUSION

Our results show no relationship between mild periodontal disease and atherosclerosis after appropriate adjustments.

Surgical correction of ventricular septal defect with aortic regurgitation in a dog

An 8-month-old entire Miniature Dachshund, weighing 4.2 kg, was presented for examination following delvelopment of a cough. Ventricular septal defect had been diagnosed tentatively in its infancy on the basis of a cardiac murmur detected by auscultation and echocardiography. Echocardiography using a B mode right parasternal long-axis view showed a defect at the atrioventricular junction and a thickened cusp of the aortic valve prolapsing into the defect. Colour-flow Doppler showed shunt blood flow across the defect at the level of the atrioventricular junction, from left to right. The sinus of Valsalva was dilated, with turbulent blood flow. Aortic regurgitation was also observed. Cardiac catheterisation studies confirmed the diagnosis of a supracristal ventricular septal defect with aortic regurgitation. Despite medication with digoxin, enalapril and aminophylin, started from the first admission, left ventricular internal dimensions gradually increased, and fractional shortening of the left ventricle gradually decreased. Surgery, with the aid of extracorporeal circulation, to close the ventricular septal defect, was performed 1 year after the initial examination. The aortic valve was left untreated. Postoperatively, the systolic murmur disappeared. Shunt flow from the left to the right ventricle was no longer observed on echocardiography, however there was still a small amount of aortic regurgitation during diastole visualised with colour-flow Doppler echocardiography. The prolapse of the cusp of the aortic valve on B-mode echocardiography was no longer observed and thickening of the cusp had not progressed. Left ventricular function measurement using M mode echocardiography showed a reduced left ventricular volume overload with reduced left ventricular internal dimensions and increased fractional shortening. The cough was relieved and no follow-up medication was scheduled. Early surgical closure of the ventricular septal defect improved the patient's condition and controlled prolapse and thickening of the aortic valve.

Involvement of brain protein kinase C in nitrous oxide-induced antinociception in mice

Exposure of mice to the anesthetic gas nitrous oxide (N(2)O) produces a marked antinociceptive effect. Protein kinase C is a key regulatory enzyme that may be targeted by general anesthetics. However, a relationship between N(2)O-induced antinociception and protein kinase C has yet to be established. The present study was conducted to identify whether protein kinase C might influence N(2)O-induced antinociception in mice. Regular exposure (11 min) to N(2)O produced concentration-dependent antinociception in mice, as determined using the abdominal constriction test. N(2)O-induced antinociception was attenuated by i.c.v. pretreatment with phorbol 12,13-dibutyrate, a protein kinase C activator. This phorbol 12,13-dibutyrate antagonism of N(2)O-induced antinociception was reversed by i.c.v. pretreatment with calphostin C, a protein kinase C inhibitor. Long-term exposure (41 min in total, including 30 min prior to, and 11 min of analgesic testing) to 70% N(2)O produced reduced analgesic effects, compared with regular exposure to 70% N(2)O, thus indicating acute tolerance to N(2)O-induced antinociception. However, mice pretreated with calphostin C, chelerythrine, which is another protein kinase C inhibitor, and phorbol 12,13-dibutyrate, did not develop acute tolerance. Regarding activation of protein kinase C, regular exposure to 70% N(2)O did not increase protein kinase C within the membrane fraction of brain tissue, as determined by immunoblot analysis, but long-term exposure to 70% N(2)O did. The i.c.v. pretreatment with calphostin C and phorbol 12,13-dibutyrate prevented the increase in protein kinase C observed with long-term exposure to 70% N(2)O. These results suggest that brain protein kinase C negatively regulates the antinociceptive effect of N(2)O, and that activation of brain protein kinase C is related to the development of acute tolerance to N(2)O-induced antinociception in mice.

DDS for anti-aging and regenerative medicine (review)

In this paper we summarized, first the present status and history of the development of research in anti-aging and regenerative medicine in Japan, and secondly some of our research using DDS in the field of both medicine. The regenerative medicine has been developed in Japan by using the fund from the Government, particularly as the Millennium Project. While anti-aging medicine developed following the social interest on it in Japan and it was influenced by American Society (A4M). Next, we summarized our research on DDS for anti-aging and regenerative medicine. In most cases we used oily or solid nanoparticles as carriers of drug. Those particles have a property of both of targeting and slow release in the DDS technology. The two properties are important for anti-aging and regenerative medicine, since drugs have to be administered safely and for long time. We applied prostaglandin E1, granulocyte-colony stimulate factor (G-CSF), and retinoid into the systems.

Case study of a pregnant woman with decidualized ovarian endometriosis whose preoperative findings suggested malignant transformation

BACKGROUND

Because both decidualization and malignant transformation of endometriosis are characterized by mural nodules on the wall of the cyst, the preoperative differential diagnosis is reportedly difficult.

CASE

A 31-year-old woman was referred to our hospital at ten weeks of gestation. Sonographic examination revealed an intrauterine gestational sac and ovarian endometrial cyst. At 21 weeks of gestation, characteristic findings associated with malignant transformation of ovarian endometriosis were seen on color-flow Doppler sonography and contrast magnetic resonance imaging. Under the diagnosis of malignant transformation of ovarian endometriosis, right salpingo-oophorectomy was performed at 22 weeks' gestation. However, histopathologic examination revealed ovarian endometriosis with marked decidual changes but no evidence of malignancy.

CONCLUSION

During pregnancy, intracystic vascularized excrescences of an endometrial cyst indicate not only malignant transformation but also decidualization. Thus, the preoperative differential diagnosis is reportedly difficult. However, the present findings of decidualization on magnetic resonance imaging seemed to be slightly different from those of malignant transformation, and therefore, might help distinguish decidualized endometriosis from malignant transformation preoperatively.

Osteoarthritis development in novel experimental mouse models induced by knee joint instability

OBJECTIVE

Although osteoarthritis (OA) is induced by accumulated mechanical stress to joints, little is known about the underlying molecular mechanism. To apply approaches from mouse genomics, this study created experimental mouse OA models by producing instability in the knee joints.

METHODS

The models were of four types: severe, moderate, mild, and medial, depending on the severity and direction of instability imposed by combinations of ligament transection and menisectomy. OA development was evaluated by X-ray and histology by Safranin-O staining, and quantified using our original gradings. Expressions of type II, IX and X collagens and matrix metalloproteinase (MMP)-2, -3, -9 and -13 were further examined by immunohistochemistry and in situ hybridization (ISH).

RESULTS

The severe, moderate and mild models exhibited OA development in the posterior tibial cartilage. The severe model showed cartilage destruction at 2 weeks and osteophyte formation at 4-8 weeks after surgery; however, the mild model showed only a partial cartilage destruction at 8 weeks. The grading confirmed that the OA disorders progressed depending on the severity of joint instability. In the medial model, the OA development in the medial tibial cartilage was similar to that in the posterior cartilage of the mild model. Among the collagens and MMPs, type X collagen and MMP-13 were markedly induced and colocalized in the early stage OA cartilage.

CONCLUSION

We established four types of mouse models exhibiting various speeds of OA progression. By applying a mouse genomics approach to the models, molecular backgrounds in various stages of OA development can be clarified.

Milk/dairy products consumption, galactose metabolism and ovarian cancer: meta-analysis of epidemiological studies

Ovarian cancer is the fifth most common cause of cancer death among women and the leading cause of gynaecological cancer death in the United States. Milk/dairy products consumption was considered to be a risk factor for ovarian cancer mainly because milk carbohydrate-lactose and galactose metabolism is toxic to oocytes. However, recent evidence does not support this hypothesis completely. We collected epidemiological studies related to the association between milk/dairy products consumption or galactose metabolism (lactose, galactose, galactose-1-phosphate uridyltransferase, lactose/transferase) and ovarian cancer published between January 1966 and August 2003 and found 27 items from 22 independent studies. Twenty studies were case-control studies and the other two were cohort studies. A meta-analysis method was conducted to estimate relative risk combining all relative data. In general, we did not find any association between milk/dairy products or galactose metabolism and ovarian cancer risk in this meta-analysis. The consumption of whole milk and butter, which contain relatively high amounts of fat, was positively (relative risk > 1.2), but not significantly, associated with an increased risk.

Acute effect of milnacipran on the relationship between the locus coeruleus noradrenergic and dorsal raphe serotonergic neuronal transmitters

The present studies sought to investigate the effect of milnacipran called the serotonin (5-HT) and noradrenaline (NA) reuptake inhibitor (SNRI) on the interaction of central locus coeruleus noradrenergic and dorsal raphe nucleus serotonergic functional activity by utilizing in vivo microdialysis. A single administration of milnacipran (60 mg/kg, s.c.) markedly decreased the levels of NA and its metabolite, 4-hydroxy-3-methoxymandelic acid (HMMA), in the locus coeruleus and the levels of, a metabolite of 5-hydroxytryptamine (5-HT), 5-hydroxyindole-3-acetic acid (5-HIAA) in the dorsal raphe nucleus. Combined administration of yohimbine (2 mg/kg, s.c.),?alpha(2)-adrenoceptor?antagonist, at 2 h after milnacipran (60 mg/kg, s.c.) led to a significant increase in NA levels in the locus coeruleus, although yohimbine alone had no effect on these levels. Under similar experimental condition, 5-HIAA levels in the dorsal raphe nucleus remained unchanged. NAN-190 (1 mg/kg, s.c.), 5-HT(1A) receptor partial agonist, alone markedly decreased the levels of 5-HIAA in the dorsal raphe nucleus, although this level was not affected by WAY100635, the selective 5-HT(1A) receptor antagonist. WAY100635 recovered the milnacipran-induced decrease of 5-HIAA levels in the dorsal raphe nucleus to control levels. On the other hand, NAN-190 did not affect the milnacipran-induced decrease of 5-HIAA levels. Behavioral signs (locomotion and rearing) were markedly observed following milnacipran alone or combined administration of milnacipran and yohimbine. However, the behavioral signs after coadministration of milnacipran and WAY100635 or NAN-190 were relatively poor. These results may suggest that an increase of NA in the locus coeruleus with the treatment of yohimbine after milnacipran results from negative feedback following the blockade of alpha(2)-adrenoceptors achieved with yohimbine, and that WAY100635 but not NAN-190 recovered milnacipran-induced decrease of 5-HIAA in the dorsal raphe nucleus to control levels by preventing the activation for the presynaptic 5-HT(1A) autoreceptor.

Cardiac myxoma of the tricuspid valve in a dog

A case of cardiac myxoma arising from the tricuspid valve is described in an 8-year-old dog that had suffered intermittent episodes of syncope. At surgical operation, a large, irregular, gelatinous mass was found attached to the septal leaflet of the tricuspid valve. The excised tumour, measuring 5x4x3.5 cm, had a grey-to-yellow, friable, mucoid, multilobulated and polypoid appearance, with focal haemorrhage. Histologically, the tumour consisted of a hypocellular mass of a myxoid matrix, rich in acid mucopolysaccharides, with a supporting structure of spindle-like, elongated or stellate cells scattered in an abundant stroma. The surface of the mass was covered by a single layer of endothelial-like cells. Immunohistochemistry revealed that the surface cells of the mass were positive for the endothelial marker CD34 and the constituent cells within the mass reacted positively and uniformly with antibodies to vimentin and alpha-smooth muscle actin. The dog died 36 h after the operation and, at necropsy, wide dissemination of myxomatous embolization to the intrapulmonary arteries was found.

Comparison between in vivo and in vitro pharmacokinetics of succinylcholine in humans

PURPOSE

To compare the in vivo and in vitro pharmacokinetics of succinylcholine (SCh) in humans.

METHODS

A bolus of SCh 1 mg.kg(-1) (n = 7) or 2 mg.kg(-1) (n = 11) was given to 18 patients anesthetized with thiopental. Arterial blood samples for determination of in vivo SCh concentrations were collected every 30 s for 5 min. Another 20-ml blood sample was obtained before induction of anesthesia for determination of in vitro SCh. Concentrations of SCh were measured by high-performance liquid chromatography. In vivo and in vitro concentrations of SCh vs time data were analyzed by the one-compartment model.

RESULTS

The respective in vivo and in vitro pharmacokinetic parameters (SCh 1 mg.kg(-1) vs SCh 2 mg.kg(-1)) were as follows: Plasma clearance was 4.17 +/- 2.37 and 1.85 +/- 0.28 l.min(-1), P < 0.05, vs 2.91 +/- 2.01 and 1.27 +/- 0.43 l.min(-1), P < 0.05. Elimination half-life was 25.4 +/- 10.6 and 47.4 +/- 5.4 s, P < 0.002 vs 26.3 +/- 10.0 and 75.2 +/- 21.8 s, P < 0.00005.

CONCLUSION

These results suggest that the rapid disappearance of SCh from the circulation is due to diffusion out of the blood vessels rather than to enzymatic hydrolysis.

Surgical correction of cor triatriatum dexter in a dog under extracorporeal circulation

A shiba inu dog with marked abdominal distension was diagnosed with cor triatriatum dexter and surgical correction was performed under extracorporeal circulation. The total duration of cardiac arrest was 11 minutes and total perfusion time was 34 minutes. The dog had an uneventful postoperative recovery. Postoperative contrast radiography of the caudal vena cava revealed normal flow into the right heart. Abdominal distension was no longer observed. Although several methods have been used to treat cor triatriatum dexter in dogs, the authors consider surgical correction under extracorporeal circulation to be a reliable approach.

Comparison between tube compensation and pressure support ventilation techniques on respiratory mechanics

In the intubated patient, the presence of an endotracheal tube increases the work of breathing during spontaneous breathing. The tube compensation technique was developed as a new ventilator mode that can compensate for that additional the work of breathing. We investigated the respiratory parameters during the pressure support ventilation 0, 5, 10 cmH2O and tube compensation 100% modes of the Puritan Bennett 840 ventilator in ten postoperative patients who had undergone radical surgery for oesophageal cancer. Measurements were performed just before extubation. The tidal volume, respiratory rate and other respiratory parameters were measured with a Ventrak respiratory monitor, and the duty ratio, mean inspiratory flow, and rapid shallow breathing index were calculated. In particular, we performed a comparison between pressure support ventilation 5 cmH2O and tube compensation 100%, because pressure support ventilation 5 cmH2O is the usual ventilating mode before the extubation in our intensive care unit. The tidal volume of pressure support ventilation 10 cmH2O was significantly larger and the respiratory rate was significantly lower than the other three modes. There was no significant difference in the minute volume, tidal volume, and respiratory rate between pressure support ventilation 5 cmH2O and tube compensation 100%. The duty ratio of pressure support ventilation 10 cmH2O was significantly smaller than the other three modes. There was no significant difference in the duty ratio and rapid shallow breathing index between pressure support ventilation 5 cmH2O and tube compensation 100%. It was concluded that the assist levels of pressure support ventilation 5 cmH2O and tube compensation 100% were almost equal for clinical purposes.

Placental site trophoblastic tumor: p53 gene analysis

BACKGROUND

Placental site trophoblastic tumor (PSTT) is the rarest type of trophoblastic neoplasm. Because of its rarity, the clinical behavior and pathogenesis of PSTT are still unclear.

CASE

A 20-year-old woman presented with secondary amenorrhea and irregular vaginal bleeding. Examination of the patient revealed elevated serum hCG and a uterine mass. The specimen obtained by curettage was diagnosed as possible PSTT. The patient was treated with two cycles of EMA/CO, but her uterine mass increased in size. Subsequently, she underwent total abdominal hysterectomy. Microscopic observation revealed a PSTT. To estimate the status of expression of p53 protein and to determine whether p53 gene mutation was present in this PSTT, we carried out immunohistochemical staining for p53 and PCR-SSCP analysis. Immunohistochemical staining for p53 revealed intense nuclear labeling, but no p53 gene mutation was detected in exons 5-8.

CONCLUSION

Analysis of the p53 gene may aid understanding of the pathogenesis of PSTT.

Vitamin K stimulates osteoblastogenesis and inhibits osteoclastogenesis in human bone marrow cell culture

Accumulating evidence indicates that menaquinone-4 (MK-4), a vitamin K(2) with four isoprene units, inhibits osteoclastogenesis in murine bone marrow culture, but the reason for this inhibition is not yet clear, especially in human bone marrow culture. To clarify the inhibitory mechanism, we investigated the differentiation of colony-forming-unit fibroblasts (CFU-Fs) and osteoclasts in human bone marrow culture, to learn whether the enhancement of the differentiation of CFU-Fs from progenitor cells might relate to inhibition of osteoclast formation. Human bone marrow cells were grown in alpha-minimal essential medium with horse serum in the presence of MK-4 until adherent cells formed colonies (CFU-Fs). Colonies that stained positive for alkaline phosphatase activity (CFU-F/ALP(+)) were considered to have osteogenic potential. MK-4 stimulated the number of CFU-F/ALP(+) colonies in the presence or absence of dexamethasone. The stimulation was also seen in vitamin K(1) treatment. These cells had the ability to mineralize in the presence of alpha-glycerophosphate. In contrast, both MK-4 and vitamin K(1) inhibited 1,25 dihydroxyvitamin D(3)-induced osteoclast formation and increased stromal cell formation in human bone marrow culture. These stromal cells expressed ALP and Cbfa1. Moreover, both types of vitamin K treatment decreased the expression of receptor activator of nuclear factor kappaB ligand/osteoclast differentiation factor (RANKL/ODF) and enhanced the expression of osteoprotegerin/osteoclast inhibitory factor (OPG/OCIF) in the stromal cells. The effective concentrations were 1.0 microM and 10 microM for the expression of RANKL/ODF and OPG/OCIF respectively. Vitamin K might stimulate osteoblastogenesis in bone marrow cells, regulating osteoclastogenesis through the expression of RANKL/ODF more than through that of OPG/OCIF.

HER-2/neu expression in ovarian clear cell carcinomas

HER-2 /neu is a 185-kDa glycoprotein and a transmembrane receptor with tyrosine kinase activity. Its overexpression is observed in 25–30% of primary breast carcinomas and is associated with a poor clinical prognosis. Recently, the U.S. Food and Drug Administration and the Japanese Ministry of Health, Welfare, and Labor approved the use of trastuzumab (Herceptin, Genentech, South San Francisco, CA) for the treatment of patients with metastatic breast carcinomas overexpressing HER-2 /neu. Results of clinical trials with Herceptin suggest that it may prolong the survival of patients with advanced metastatic breast carcinoma. Relatively little is known concerning the relationship between HER-2 /neu status and ovarian clear cell carcinoma. If HER-2 /neu overexpression status were demonstrable in ovarian clear cell carcinoma and a clinical correlation between overexpression and prognosis could be established, a rationale for clinical use of Herceptin for this tumor could be established. Our aim was to evaluate HER-2 /neu status in ovarian clear cell carcinomas. Fifteen ovarian clear cell carcinoma cases were immunostained for HER-2 /neu using HercepTest (DAKO, Glostrup, Denmark). Overexpression of HER-2 /neu was detected in only one case. Unlike in breast carcinoma, HER-2 /neu overexpression appeared to be uncommon in ovarian clear cell carcinomas. Herceptin may thus target only a small proportion of ovarian clear cell carcinomas and be of limited clinical value for treatment of this carcinoma.

HER-2/neu expression in ovarian clear cell carcinomas

HER-2 /neu is a 185-kDa glycoprotein and a transmembrane receptor with tyrosine kinase activity. Its overexpression is observed in 25-30% of primary breast carcinomas and is associated with a poor clinical prognosis. Recently, the U.S. Food and Drug Administration and the Japanese Ministry of Health, Welfare, and Labor approved the use of trastuzumab (Herceptin, Genentech, South San Francisco, CA) for the treatment of patients with metastatic breast carcinomas overexpressing HER-2 /neu. Results of clinical trials with Herceptin suggest that it may prolong the survival of patients with advanced metastatic breast carcinoma. Relatively little is known concerning the relationship between HER-2 /neu status and ovarian clear cell carcinoma. If HER-2 /neu overexpression status were demonstrable in ovarian clear cell carcinoma and a clinical correlation between overexpression and prognosis could be established, a rationale for clinical use of Herceptin for this tumor could be established. Our aim was to evaluate HER-2 /neu status in ovarian clear cell carcinomas. Fifteen ovarian clear cell carcinoma cases were immunostained for HER-2 /neu using HercepTest (DAKO, Glostrup, Denmark). Overexpression of HER-2 /neu was detected in only one case. Unlike in breast carcinoma, HER-2 /neu overexpression appeared to be uncommon in ovarian clear cell carcinomas. Herceptin may thus target only a small proportion of ovarian clear cell carcinomas and be of limited clinical value for treatment of this carcinoma.

Renin-producing serous cystoadenocarcinoma of the ovary: a case report

BACKGROUND

Only a few renin-producing ovarian tumors have been reported, and most such ovarian tumors have been sex cord/stromal tumors. Renin-producing ovarian epithelial tumors are quite rare.

CASE

A 46-year-old woman presented with hypertension and hypokalemia. Examinations of the patient revealed elevated plasma renin activity, hyperaldosteronism and a pelvic mass. Subsequently, a right ovarian tumor mass was resected. Microscopic observation of the tumor revealed a well-differentiated serous cystadenocarcinoma. Immediately after surgery, blood pressure, serum potassium, plasma renin activity and plasma aldosterone levels returned to normal ranges. RT-PCR analysis and immunohistochemical staining of this tumor indicated that it was producing renin.

CONCLUSION

This is the first report of a renin-producing ovarian serous cystadenocarcinoma.

Prenatal course and pregnancy outcome of fetuses with a transient nuchal translucency

OBJECTIVES

This study was designed to correlate fetuses in a normal prenatal population who exhibited transient nuchal translucency (NT) with both prenatal course and pregnancy outcome.

METHODS

The fetuses with abnormal NT were followed by ultrasonography at 1-2-week intervals during their prenatal course. Fetuses with NT who exhibited no detectable congenital malformations were defined as the NTO group; fetuses with abnormal NT and structural malformations but no chromosomal abnormalities were placed in the SM group; and fetuses with abnormal NT, structural malformations, and chromosomal abnormalities were categorized as the CA group. The groups were compared by: maternal age, weeks of gestation by ultrasound and the NT value at the initial exam, the maximum NT value, and the duration of abnormal NT.

RESULTS

During the study period, 92 fetuses with abnormal NT were found, monochorionic twins excluded. Of the 92 fetuses, 80 were in the NTO group, 10 were in the SM group, and two were in the CA group. The maternal age and the gestational weeks at the initial diagnosis were not significantly different in the NTO and the SM groups. However, the NT value at the initial diagnosis, maximum NT value, and the duration of abnormal NT were significantly greater in the SM group than those values in the NTO group.

CONCLUSIONS

Fetuses with transient nuchal translucency commonly had structural malformations, particularly fetuses with significant and large persistent NT.

Gastrointestinal diseases and halitosis: association of gastric Helicobacter pylori infection

The relationship between gastrointestinal conditions and halitosis is discussed. Few reports have suggested that gastrointestinal diseases may cause halitosis. H. pylori infection, which causes gastric ulcers, is considered as a possible cause for halitosis. Intensity of malodour of mouth air was found to be higher in H. pylori-positive patients than in negative patients. The levels of hydrogen sulphide and dimethyl sulphide in mouth air were also significantly higher in the positive patients than in the negative patients (P<0.05). When odour strength in exhaled breath was compared between the two groups, no significant difference was found. Hence, H. pylori infection might not cause a systemic condition producing breath odour. Although there were no significant differences in periodontal parameters or tongue coating between the positive and negative groups, H. pylori may be a frequent contributor to the production of malodour even though its role had not been suspected before. Further study would be necessary to clarify the reason for the increase of volatile sulphur compounds (VSCs) level in H. pylori infection.

Ultrastructural analysis of bone calcification by using energy-filtering transmission electron microscopy

In order to elucidate the mechanisms of bone calcification, embryonic rat calvariae treated with chemical or cryo-fixation were observed using transmission electron microscopy by three techniques: fine structures, various cvtochemical localizations including nonspecific proteoglycan, decorin, chondroitin 4-sulfate, hyaluronan, alkaline phosphatase (ALP), and osteonectin, as well as the elemental mapping of calcium and phosphorus by energy-filtering electron microscopy. In the calvariae, the calcification sequence ran as follows crystallization within matrix vesicles, formation of calcified nodules, collagen calcification, and finally the establishment of an expansive calcified matrix. The osteoid contained an abundance of mesh-like fibers of proteoglycans, including decorin, chondroitin 4-sulfate, and hyaluronan, around collagen fibrils approximately 50 nm in diameter. Calcium tended to localize at the proteoglycan sites, while phosphorus was often mapped to the collagen fibril-structures in the osteoid. Calcium/phosphorus co-localization was found in and around the calcified nodules, where ALP and small sized proteoglycans were observed. During this stage, native proteoglycans surrounding the collagen fibrils disappeared, with the collagen fibrils fusing laterally, and attaining a diameter of more than 400nm. The calcified nodules expanded to occupy the entire space made available by the collagen fibril-fusion, following osteonectin accumulation in the calcified nodule/collagen fibril border. In conclusion, crystals present within the matrix vesicles became calcified nodules, in a process induced by the co-localization of calcium and phosphorus. ALP and proteoglycans may participate in the calcium/phosphorus co-localization. Decreases in the native proteoglycans, and the lateral fusion of collagen fibrils are thought to be involved in the expansion of calcified areas, followed by osteonectin-mediated collagen calcification.

The characteristics of the biofilm fixed inside porous medium by sequencing batch reactor

The fixed biomass inside porous medium has two layers where biomass yield constants are different from each other when it is cultivated in the chemostat reactor. The biomass fixed inside porous medium is tested to see whether the operation type affected the structure of it. Two kinds of operation method of the reactor were used for the biofilm cultivation. One is the batch reactor. Another is the chemostat reactor. From the kinetic test, it is found that the biofilm fixed in the batch reactor does not have two layers that were observed in the biofilm from the chemostat reactor. Within the experimental conditions for type-1, the result of kinetic tests show homogeneous biofilm characteristics. It can be concluded that the reactor type (batch type or chemostat type) affects the structure of biomass fixed inside porous medium.