Effects of mechanical stress and deficiency of dihydrotestosterone or 17ß-estradiol on Temporomandibular Joint Osteoarthritis in mice.

OBJECTIVE: To observe and analyze the interaction between excessive mechanical stress (MS) and decreased sex hormones on Temporomandibular Joint Osteoarthritis (TMJ-OA), and to discover TMJ-OA disease susceptibility genes by molecular biological analysis to elucidate part of the mechanism of TMJ-OA onset. DESIGN: For experimental groups, orchiectomy (ORX) or ovariectomy (OVX) was performed on sexually mature 8-week-old mice. A metal plate was attached to the posterior surface of the maxillary incisors to apply excessive MS on mandibular condyles. Male mice were divided into control, ORX, MS, and ORX + MS groups, while female mice were divided into control, OVX, MS, and OVX + MS groups. Mandibular condyles were evaluated by histology and molecular biology. RESULTS: Histomorphometric analysis of the TMJ in ORX + MS and OVX + MS groups revealed the thinnest chondrocyte layers, highest modified Mankin scores, and significant increases in the number of osteoclasts. Gene expression analysis indicated upregulation of Angptl7 and Car1 genes in the mandibular condyles of mice subjected to the combined effects of excessive MS and reduced sex hormones. In vitro analysis suggested that cartilage-like cells overexpressing Angptl7 enhanced calcification, and osteoblast-like cells overexpression Car1 suppressed cell proliferation and calcification. CONCLUSIONS: A severe TMJ-OA mouse model was successfully developed by applying excessive MS on the mandibular condyle of male and female mice with reduced sex hormones. Disease-susceptibility genes Angptl7 and Car1 were newly discovered in the experimental groups, suggesting their involvement in the onset mechanism of TMJ-OA.

Associations of sleep bruxism with age, sleep apnea, and daytime problematic behaviors in children.

OBJECTIVES: The aims of this study were to investigate the prevalence of sleep bruxism in children in Japan, and its relationships with sleep-related factors and daytime problematic behavior. SUBJECTS AND METHODS: Guardians of 6023 children aged 2-12 years completed the Japanese Sleep Questionnaire. Multiple regression analysis and structural equation modeling were performed. RESULTS: Sleep bruxism was reported in 21.0% children (n = 1263): the prevalence was highest in the age group of 5-7 years (27.4%). Multiple regression analysis showed that sleep bruxism had significant correlations with age 5-7 years (OR: 1.72; P < 0.0001), 'Moves a lot during sleep' (OR: 1.47; P < 0.0001), 'sleeps with mouth open' (OR: 1.56; P < 0.0001), and 'snores loudly' (OR: 1.80; P < 0.0001). In structural equation modeling, sleep bruxism had a significant but weak direct effect on daytime problematic behavior, while sleep bruxism significantly correlated with obstructive sleep apnea, which had a higher direct effect on daytime problematic behavior. CONCLUSIONS: Sleep bruxism was reported in 21.0% of Japanese children and had independent relationships with age, movements during sleep, and snoring. A comorbidity of sleep-disordered breathing might be related to daytime problematic behavior in children with sleep bruxism.

Functional Analysis of PTH1R Variants Found in Primary Failure of Eruption.

Although many variants of the parathyroid hormone 1 receptor (PTH1R) gene are known to be associated with primary failure of eruption (PFE), the mechanisms underlying the link remains poorly understood. We here performed functional analyses of PTH1R variants reported in PFE patients-namely, 356C>T (P119L), 395C>T (P132L), 439C>T (R147C), and 1148G>A (R383Q)-using HeLa cells with a lentiviral vector-mediated genetic modification. Two particular variants, P119L and P132L, had severe reduction in a level of N-linked glycosylation when compared with wild-type PTH1R, whereas the other 2 showed modest alteration. PTH1R having P119L or P132L showed marked decrease in the affinity to PTH1-34, which likely led to severely impaired cAMP accumulation upon stimulation in cells expressing these mutants, highlighting the importance of these 2 amino acid residues for ligand-mediated proper functioning of PTH1R. To further gain insights into PTH1R functions, we established the induced pluripotent stem cell (iPSC) lines from a patient with PFE and the heterozygous P132L mutation. When differentiated into osteoblastic-lineage cells, PFE-iPSCs showed no abnormality in mineralization. The mRNA expression of RUNX2, SP7, and BGLAP, the osteoblastic differentiation-related genes, and that of PTH1R were augmented in both PFE-iPSC-derived cells and control iPSC-derived cells in the presence of bone morphogenetic protein 2. Also, active vitamin D3 induced the expression of RANKL, a major key factor for osteoclastogenesis, equally in osteoblastic cells derived from control and PFE-iPSCs. In sharp contrast, exposure to PTH1-34 resulted in no induction of RANKL mRNA expression in the cells expressing P132L variant PTH1R, consistent with the idea that a type of heterozygous PTH1R gene mutation would spoil PTH-dependent response in osteoblasts. Collectively, this study demonstrates a link between PFE-associated genetic alteration and causative functional impairment of PTH1R, as well as a utility of iPSC-based disease modeling for future elucidation of pathogenesis in genetic disorders, including PFE.

Severe mandibuloacral dysplasia caused by novel compound heterozygous ZMPSTE24 mutations in two Japanese siblings.

Mandibuloacral dysplasia (MAD) is a rare autosomal recessive progeroid syndrome, characterized by mandibular hypoplasia, acroosteolysis affecting distal phalanges and clavicles, delayed closure of the cranial sutures, atrophic skin, and lipodystrophy. Recently, mutations in lamin A/C (LMNA) and zinc metalloprotease (ZMPSTE24), involved in post-translational processing of prelamin A to mature lamin A, have been identified in MAD kindreds. We now report novel compound heterozygous mutations in exon 1 (c.121C>T; p.Q41X) and exon 6 (c.743C>T; p.P248L) in ZMPSTE24 in two Japanese sisters, 7- and 3-year old, with severe MAD and characteristic facies and atrophic skin. The older sister had lipodystrophy affecting the chest and thighs but sparing abdomen. Their parents and a brother, who were healthy, had heterozygous mutations. The missense mutation, P248L, was not found in 100 normal subjects of Japanese origin. The mutant Q41X was inactive in a yeast halo assay; however, the mutant P248L retained near normal ZMPSTE24 activity. Immunoblots demonstrated accumulation of prelamin A in the patients' cell lysates from lymphoblasts. The lymphoblasts from the patients also revealed less intense staining for lamin A/C on immunofluorescence. We conclude that ZMPSTE24 deficiency results in accumulation of farnesylated prelamin A, which may be responsible for cellular toxicity and the MAD phenotype.

Partial purification and properties of porcine thymus lactosylceramide beta-galactosidase.

Porcine thymus lactosylceramide beta-galactosidase was purified by a simple procedure. In the final step of isoelectric focusing the enzyme was separated into two peaks of pI 6.3 (peak I) and 7.0 (peak II), which showed 3,600- and 4,000-fold enhancement of lactosylceramide-hydrolysing activity, respectively. The two peaks had identical mobility on polyacrylamide gel electrophoresis. The apparent molecular weight was 34,000. Neither monosialoganglioside (GM1) nor galactosylceramide was hydrolysed by the purified enzyme fractions. The optimal pH was at 4.6, and sodium taurocholate was essential for the reaction. The apparent Km was 2.3 x 10-5 M. The reaction was stimulated by sodium chloride and linoleic acid, while it was strongly inhibited by Triton X-100 and bovine serum albumin. Galactosylceramide, p-nitrophenyl beta-galactoside, and p-nitrophenol were weak inhibitors. No effects of GM1 and galactose were observed on the hydrolysis of lactosylceramide.

Non-invasive assessment of otolith formation during development of the Japanese red-bellied newt, Cynops pyrrhogaster.

Pre-mated adult female newts and embryos have been flown on the International Microgravity Laboratory-2 (IML-2) Space Shuttle flight in 1994 (Wiederhold et al., 1992b). With the specimens available from this flight, the calcification of otoliths, ulna, radius and backbone of the flown larvae and adult newts were analyzed. The experiments presented here studied the development of the otoliths on the ground. Otoliths of living newts, from embryo to adult, were observed in situ with the application of a new X-ray and bio-imaging analyzer system. For the establishment of this method, newts at different developmental stages were used. An imaging plate temporarily stores the X-ray energy pattern at the bio-imaging analyzer. A latent image on the imaging plate was transformed into a digital time series signal with an image reader. Acquired digital information was computed with the image processor. The processed information was recorded on film with an image recorder, in order to visualize it on an enlargement computed radiograph. To analyze development of the otoliths, photo-stimulated luminescence level was detected by an image analyzer, using transmitted X-ray photons. A single clump of otoconia could first be seen at stage 33. Stage-36 embryos first have distinguishable otoliths, with the utricle in front and saccule behind. Our results show that this X-ray method detects the otoliths equally as well as sectioning. In the newt, the mandibular/maxillary bone formed before the spine. It is suspected that for the newt embryo, living in water, feeding becomes necessary prior to support of the body.

Superficial cemental curettage: its efficacy in promoting improved cellular attachment on human root surfaces previously damaged by periodontitis.

This study was designed primarily to determine whether or not gingival fibroblasts attach to curetted cemental surfaces in periodontally-involved human teeth. Ten periodontally-involved human teeth were used. The superficial cementum from 5 teeth was removed by light mechanical curettage while no root treatment was performed on the remaining 5 teeth. Subsequently, the roots of all teeth were cut longitudinally to create 800 microns thick sections (slabs). Prepared slabs were then placed in 35 mm culture dishes, seeded with human gingival fibroblasts (HGF), and after 4 weeks processed for transmission electron microscopy (TEM). TEM results revealed flattened HGF on the noncuretted cemental surfaces that failed to attach. Fibrillar material was not seen between the HGF and cemental surfaces. In contrast, the HGF that grew on previously curetted cementum exhibited typical morphology of healthy, functional fibroblasts. Newly synthesized fibrillar material and collagen fibrils were noted, and both were apparently oriented towards the curetted cemental surface. Results strongly suggest that improved cellular attachment can be promoted on areas of root surface previously damaged by periodontitis if superficial cementum is first removed by mechanical curettage.

Possible involvement of bone cells in a new cementum formation.

Cells from the gingival lamina propria, bone-derived granular tissues and periodontal ligament (PDL) were isolated after periodontal surgery and subsequently cultured in vitro. The resulting cells were defined as gingival cells, bone cells and PDL cells, respectively. Under a phase contrast microscope, the cultured cells exhibited a spindle and/or a polyhedral shape. On the basis of their appearance under an electron microscope, spindle-shaped cells and polyhedral-shaped cells were identified as fibroblasts and osteoblasts, respectively. Bone cells, a homogeneous population of osteoblasts, had a more rapid growth ability than PDL cells, which were a heterogeneous population of fibroblasts and osteoblasts. Of particular interest was that only bone cells produced bone matrix in the multilayers in vitro. These results support the hypothesis that the phenotype expressed by cells from the alveolar bone establishes a new concept for progenitor cells in the formation of cementum.

Chemotactic response of fibroblasts to root surface components in wound healing following flap surgery.

The purpose of this study was two-fold; first to investigate the chemotactic response of periodontal cells to root surface components during wound healing following flap surgery; second, to investigate the chemoattractive effect of the root components on cell migration. Cells were obtained by culturing cells from monkey periodontal tissues and rat calvarial cells. Root surface components were obtained from teeth extracted at 4, 7, 10 and 14 days after flap surgery. The chemotactic response of the isolated cells to root surface components was quantitated by an in vitro assay using a 48 well microchemotaxis chamber. The effect of root components or other growth factors on the cell migration was evaluated using a three-dimensional gel system. Cemental components produced a strong chemotactic response for gingival fibroblasts, alveolar bone cells and rat calvarial cells. Kinetics of the chemotactic potential of cementum was characterized by an initial increase (up to 7 days after surgery), a transient decline (at 10 days after surgery) and a second increase (at 14 days after surgery). Cemental components obtained 7 days after surgery most profoundly facilitated invasion of gingival fibroblasts with comparable effects induced by PDGF and TGF-beta. These results suggest that cemental components influence the chemotactic migration of gingival fibroblasts at the initial stage of wound healing, and therefore, cementum plays an important role in periodontal regeneration.

A unique dosage form to evaluate the mechanical destructive force in the gastrointestinal tract.

The purpose of this study was to prepare tablets that could evaluate the destructive force in the gastrointestinal (GI) tract. Many factors are known to affect in vivo drug release from oral dosage forms. There is still relatively little information on the mechanical destructive force in the GI tract. Press-coated tablets with an extremely brittle outer layer were developed using a unique, highly hydrophobic Teflon powder that could be shaped with weak compression force. A marker drug contained in the tablets was released only when the tablets received a force larger than its predetermined crushing strength. We referred to this type of tablet as a 'destructive force dependent release system' (DDRS). A total of nine healthy, male subjects were orally administered the tablets under fed and/or fasting conditions. Tablets with a predetermined crushing strength of 1.50 N were crushed by all of the four subjects who took them under fed conditions and two of the five subjects under fasting conditions. Tablets with a crushing strength of 1.89 N were crushed by two of the six subjects who took them under fed conditions and none of the five subjects under fasting conditions. The range of mechanical destructive force in the human stomach was obtained.

Isolated interruption of the aortic arch.

We report a case of a 4-year-old girl with interruption of the aortic arch without a patent ductus arteriosus or intracardiac shunts. The anomaly was successfully corrected with the use of a 14 mm Dacron prosthetic graft to bypass the interrupted segment. The postoperative course was uneventful.

PMEA coating of pump circuit and oxygenator may attenuate the early systemic inflammatory response in cardiopulmonary bypass surgery.

We investigated the effects of coating a cardiopulmonary bypass (CPB) circuit and oxygenator with poly-2-methoxy-ethyl acrylate (PMEA) on the systemic inflammatory response during and after CPB. Thirty patients undergoing elective cardiac surgery were randomized into three groups (each group n = 10): noncoated (group N), heparin coated (group H), and PMEA coated circuit and oxygenator (group X). Bradykinin (BK), complement 3 activation (C3a) and interleukin-6 (IL-6) levels were measured as early phase indicators of inflammatory response, as were maximum C reactive proteins (CRP) and white blood cell (WBC) levels. The alveolar-arterial oxygen gradient (A-a DO2) was measured as a parameter of respiratory function. IL-6 levels after CPB were significantly higher in group N than in groups H and X (p < 0.05). Serum BK and C3a levels showed similar patterns in all groups. A-a DO2 was lower at the end of and 3 hours after CPB in groups H and X than in group N (p < 0.05). Maximum CRP levels were lower in group X than in groups N (p < 0.05). This prospective study suggests that PMEA coated CPB may improve respiratory function and decrease systemic inflammatory response after cardiac surgery, possibly because this circuit is as biocompatible as heparin coated CPB circuit.

A magnetically suspended centrifugal pump. In vitro and in vivo assessment.

To overcome problems derived from the shaft within conventional centrifugal pumps, we have developed a new centrifugal pump, the magnetically suspended centrifugal pump (MSCP), which has no shaft and operates as a bearingless centrifugal pump. The impeller is suspended freely and centrally by magnetic force within the pump. Hemolysis tests were performed in comparison with the Biopump. Index of hemolysis and destruction of platelets were significantly lower in the MSCP than in the Biopump. Animal studies were designed to evaluate the durability and antithrombogenicity of the MSCP. Short-term animal studies were performed using two mongrel dogs. Left heart bypass was established with the MSCP. After 3 hr, the layer of thrombus adherent to the surface of the polycarbonate impeller impaired pumping efficiency. However, using the impeller coated with silicone, no thrombus was observed on the impeller after continuous pumping for 24 hr. In addition, long-term animal studies were performed using two sheep. Left heart bypass was established with the MSCP containing an impeller coated with silicone. In one sheep, the MSCP ran for 14 days without problems in pumping performance and showed no thrombus within the pump. In the other sheep, the MSCP ran for 15 days, and showed no thrombus on the impeller. During each experiment, plasma free hemoglobin levels were less than 15 mg/dl. The MSCP induced less hemolysis than did the Biopump, and the MSCP containing an impeller coated with silicone demonstrated the potential to run for 14 days without thrombus formation within the pump.

A simple membrane immunobead assay for detecting ciguatoxin and related polyethers from human ciguatera intoxication and natural reef fishes.

A simple membrane immunobead assay (MIA) for detecting ciguatoxin (CTX) and related polyethers directly from fish tissue is presented. A membrane laminated onto a solid plastic support is immersed with a piece of fish tissue in methanol. The membrane is thoroughly dried and placed into an immunobead suspension containing polystyrene particles coated with monoclonal antibody to CTX (MAb-CTX). Two beads of different diameter and color are used. The color intensity of the membrane is related to the concentration of the toxin bound to the membrane. Twelve of 13 fish implicated in human ciguatera fish poisoning showed borderline or positive responses in the assay. A Sphyraena barracuda sample that tested negative with the MIA and was highly toxic with the mouse toxicity bioassay showed only weak CTX-like toxin activity in the guinea pig atrial assay, indicating that the major toxin in the sample was not CTX-like. Examination of 154 routinely caught reef fish from Hawaii, Kosrae, and Kwajalein by MIA found 132 (86%) negative and 8 (5%) positive for CTX, with 14 (9%) giving a borderline response. Fish from Hawaii showed a higher frequency of borderline or positive responses than those from Kosrae and Kwajalein, probably because several species of fish from several islands of Hawaii were tested, whereas only one species from a single area was examined from each of the islands of Kosrae and Kwajalein.

[Effect of plasma-treatment on suppression of drug adsorption to the surface of plastic infusion bag].

Plastics has been widely used at the hospitals and dominates the field of the manufacture of infusion bag sets and packaging materials as a disposable product. Recently, it has been reported, however, that expected drug effects could not be obtained owing mainly to the drug adsorption to the surface of plastic bags observed when several injection drugs such as nitroglycerin, isosorbide dinitrate, diazepam, and insulin were injected mixedly into a certain plastic intravenous bags. And there is a possibility of the occurrence of chemical reactions between the added drugs and the surface of plastic bags. We also can not deny the possibility of the dissolution of softener from the plastic bags. On the other hand, we have been working on the nature of plasma treatment of polymer surfaces by irradiation of low temperature plasma and its pharmaceutical application studies. In this study, we obtained the data concerning the effect of plasma treatment on the reduction of adsorption of insulin to the surface of ethylene-vinylacetate (EVA) bag.

Microvascular architecture of the enamel organ of the upper major incisor in the rabbit.

The ultrastructure of the ameloblasts in the rabbit major incisor was investigated previously by Okada (1983) and the amelogenetic process was classified into six zones/stages. The present paper deals with changes in the microvascular architecture and ultrastructure of the blood capillaries in proportion to the amelogenetic process in the upper major incisor of the rabbit utilizing the acryl plastic injection method. Three different vascular layers were observed in the periodontal spaces of the major incisor of the rabbit. The inner vascular network consisted of a capillary network supplying the enamel organ and its meshes have vigorously changed during the amelogenesis. The capillary network was observed to be in the shape of a ladder with a continuous wall in the proliferation zone, to appear as round meshes with a fenestrated wall in the differentiation zone, as polygonal meshes with abundant fenestrations in the secretion zone, as ovoid meshes with fenestrations in the early maturation zone, and finally as coarse and avoid meshes with a continuous wall again in the late maturation and regression zones. In the intermediate layer, arterioles and venules were located close to the capillary network, and the arterioles were derived from the short and long branches of the anterior superior alveolar artery. In the outer layer, a sinusoid network was observed to be in contact with the alveolar wall and received blood from the capillary network as well as venous vessels in the alveolar bone. The ladder-shaped capillary network mentioned above was thought to represent an intermediate form towards the succeeding zone, in which the round meshes may be suitable for supplying the nutrient elements that are needed in the differentiation of the inner enamel epithelial cells. The polygonal and ovoid meshes may be favorable for the transport of various necessary metabolic materials that are involved in the enamel ground substance formation and calcium deposition within a very short period.

[Response characteristics of fast-adapting units innervating cat oral mucosa to ramp-shaped pressure and triangular vibratory stimuli].

In this study, responses of fast-adapting sensory units to ramp-shaped pressure and triangular vibratory stimuli were recorded in the molar lingual gingiva and the alveolar mucosa isolated from the cat mandible via the air-gap method. The receptors of the fast-adapting units were classified into five types by a morphological study and the response characteristics of the individual sensory unit were investigated by electrophysiological methods. 1. Fast-adapting units of cat oral mucosa were found to have had five types of encapsulated endings (Type I-V) via a microscopical study. Among the 1,609 endings observed, the occurrence frequency of the individual receptor type was as follows: Type I 64.1%, Type II 9.5%, Type III 13.9%, Type IV 1.2% and Type V 11.3%. Although Type V a-d receptors had not been observed in the cat oral mucosa, their presence was demonstrated in whole thickness preparation stained with methylene blue. 2. The impulse frequency-displacement velocity curves (long-long coordinated) of 32 fast-adapting units (20 animals) showed four different patterns. 9.3% of the fast-adapting units showed a proportional relationship over all ranges of displacement velocity in the impulse frequency-displacement velocity relation. 25.0% showed a proportional relationship in an initial narrow range of displacement velocity and attained a steady state in the higher range. In 21.9% of these units, the impulse frequency remained steady over all the ranges. In the remaining 43.8%, the impulse frequency remained steady in singular range over all displacement velocities tested, however their response times decreased when the displacement velocity was increased. 3. The fast-adapting units were divided into two groups by response mode: a unit group with a Type I receptor and the other with Type II-V receptors (represented by a Type III receptor). The slopes were measured from their relations (log-log coordinates) in threshold amplitude vs. displacement caused by single triangular stimulus. The slope for the Type I group was -0.796 +/- 0.099 (mean +/- S. D.) (Range: -0.593(-)-1.017, n = 22). The slope for the other group was -0.658 +/- 0.024 (Range: -0.607(-)-0.758, n = 6). The slope of the former was larger than that of the latter. 4. The threshold-frequency curves (tuning curve; semilog coordinates) for the Type I group and the other group were analyzed. Both tuning curves of these sensory units revealed no plateaus between the lower-frequency limits and the upper-frequency limits.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of extracellular matrix and serum components on cellular adhesion and growth in vitro and in vivo].

The recent cell-biological research have been reported the usefulness of extracellular matrix, such as collagen and fibronectin, in cell culture techniques and in vitro experiments. These matrix began to applied in medical treatments and brought many success. Fibroblast and osteoblast have characteristics to promote stabilization of implant materials in vivo. These cells revealed the additional effects to control mending and healing of surgical invasion. The role of extracellular matrix and serum components for cellular adhesion and growth have been discussed extensively. The recent studies reported that collagen and other materials promoted the cellular behavior. The author discussed the effect of extracellular matrix and serum components or the established cell lines on cellular adhesion and growth, which were performed in vitro and in vivo. The following cell lines were employed in this study, fibroblastic cell lines from mouse (3T12-3) and human (SF-TY), osteogenic cell line from mouse (MC3T3-E1) and osteogenic cell lines from human (SAOS-2, NY), osteoblastic cell line (HuO-3N1) and rabbit cell line. Different types of collagen were used as the coating material on glass surface by the method of collagen-gel culture method. Fetal calf serum, bovine serum albumin, fibronectin and proteoglycan were also employed in this study. After the cultivation, adherent cells were stained by Gimsa's method and counted microscopically. In cellular-adhesion test, the most cell number was found on the collagen type I coated glass surface to compare with the other materials, such as fetal calf serum, bovine serum albumin, proteoglycan, employed in all the tested cell lines. Growth of the defined cell-number on glass surface was compared among used materials, and all the osteogenic cell lines and fibroblastic cell lines were found to grow well on collagen type I-fibronectin, collagen type I, and fibronectin coated glass surface to compare with other materials employed in this study. Collagen-fibronectin and collagen-coated alumina ceramic tubes were embedded in the mandibular bones of rabbits, and the aspect was observed with the passage of time. These treatments promoted the osseous area in the tubes. These findings strongly indicated that surface-coated biomaterial by collagen and collagen-fibronectin enhanced cellular adhesion, and promoted the growth of fibroblast and osteoblast in vitro and in vivo.

[Influence of tooth extraction on postural stability].

A study was conducted to analyze how tooth extraction procedure would affect patient's physical equilibrium sensation, using the positional centric equilibrium measuring device. Forty-five health subjects, between the ages of 20 to 30, with no systemic nor equilibrium abnormalities were selected for this study. The results obtained were as follows. 1. No noticeable changes in the centric movement were observed during the postural change from a sitting to a standing position. 2. Centric movement was transiently increased immediately after the movement from a horizontal to standing position. The average arterial pressure was decreased immediately after the alteration in body posture, suggesting that changes in body posture may influence the controlling mechanism of BP. 3. Increases in the area and velocity of the centric movement were found immediately after and up to 10 minutes after, respectively, topical administration of the anesthetic. During this time span, no correlation found between centric movement changes and circulatory changes suggested that topical anesthesia might influence the recovery reflex via central nervous system. 4. The effect of the extraction procedure on the centric movement area and the anteroposterior centric movement speed lasted for 10 minutes after extraction. On the other hand, the increase in the velocity of bilateral centric movement as well as whole body centric movement was found up to a point immediately after extraction. No correlation was found between circulatory changes and centric movement changes. It therefore was assumed that the topical anesthesia affected the recovery reflex via central nervous system.

Platelet adhesion, contact phase coagulation activation, and C5a generation of polyethylene glycol acid-grafted high flux cellulosic membrane with varieties of grafting amounts.

Grafting of polyethylene glycol chains onto cellulosic membrane can be expected to reduce the interaction between blood (plasma protein and cells) and the membrane surface. Alkylether carboxylic acid (PEG acid) grafted high flux cellulosic membranes for hemodialysis, in which the polyethylene glycol chain bears an alkyl group at one side and a carboxyl group at the other side, have been developed and evaluated. PEG acid-grafted high flux cellulosic membranes with various grafting amounts have been compared with respect to platelet adhesion, the contact phase of blood coagulation, and complement activation in vitro. A new method of quantitating platelet adhesion on hollow-fiber membrane surfaces has been developed, which is based on the determination of lactate dehydrogenase (LDH) activity after lysis of the adhered platelets. PEG acid-grafted high flux cellulosic membranes showed reduced platelet adhesion and complement activation effects in grafting amounts of 200 ppm or higher without detecting adverse effects up to grafting amounts of 850 ppm. The platelet adhesion of a PEG acid-grafted cellulosic membrane depends on both the flux and grafting amounts of the membrane. It is concluded that the grafting of PEG acid onto a cellulosic membrane improves its biocompatibility as evaluated in terms of platelet adhesion, complement activation, and thrombogenicity.