A case of hypereosinophilia with digital ischaemia successfully treated with intravenous prostaglandin E1

In the therapeutic management of eosinophilic disorder, it is important to prevent hypereosinophilia (HE)-related organ damage even in the process of diagnosis. We describe here a unique clinical and histopathological findings of the patient with HE accompanied with digital ischaemia. Treatment with intravenous prostaglandin E1 was essential for digital ischaemia in our case while benralizumab, humanized monoclonal antibody against interleukin-5 receptorα, did not affect. Our case suggests an earlier intervention for digital ischaemia in the therapeutic management of eosiniphilic disorder.

Composite Si-Ni nanoparticles produced by plasma spraying physical vapor deposition for negative electrode in Li-ion batteries

Si-Ni composite nanoparticles have been produced by a single and continuous plasma spray physical vapor deposition (PS-PVD) from Si and Ni powder feedstocks and their electrochemical performances as anode in lithium-ion batteries (LiB) are investigated. Si nanoparticles with 20-40 nm on which Ni is directly attached with Si/NiSi₂epitaxial interface are formed spontaneously through co-condensation of high temperature elemental gas mixtures during PS-PVD. When only a little amount of Ni is added to Si, the effect of the epitaxial Ni attachment on the Si nanoparticles becomes evident; the cycle capacity is appreciably improved to reach a 1.6 times higher capacity than that of the Si only cell after 50 cycles, due to reduced charge-transfer resistance and nanosized Si particle. In contrast, excessive Ni addition to Si feedstock leads to formation of various silicides as a result of the accelerated silicidation during PS-PVD, which results in a significant decrease in the cycle capacity due to reduction of the active Si phase amount despite reduced charge-transfer resistance.

Contraction Stress in Dentin Adhesives Bonded to Dentin

Adhesives cured under constrained conditions develop contraction stresses. We hypothesized that, with dentin as a bonding substrate, the stress would reach a maximum, followed by a continuous decline. Stress development was determined with a tensilometer for two total-etch systems and two systems with self-etching primers. The adhesives were placed in a thin layer between a glass plate and a flat dentin surface pretreated with phosphoric acid or self-etching primer. After an initial maximum shortly after light-curing, the stress decreased dramatically for the total-etch systems (70%) and, to a lesser extent, for the adhesives with self-etching primers (30%). The greater stress decrease for the total-etch systems was ascribed to water and/or solvents released into the adhesives from the fully opened dentinal tubules by the pulling/sucking action of the contraction stress. This happened less with the adhesives with self-etching primers, where the tubules remained mainly closed.

Peroral endoscopic myotomy (POEM) for esophageal achalasia

BACKGROUND

Peroral endoscopic myotomy (POEM) was developed by our group to provide a less invasive permanent treatment for esophageal achalasia.

PATIENTS AND METHODS

POEM was performed in 17 consecutive patients with achalasia (10 men, 7 women; mean age 41.4 years). A long submucosal tunnel was created (mean length 12.4 cm), followed by endoscopic myotomy of circular muscle bundles of a mean total length of 8.1 cm (6.1 cm in distal esophagus and 2.0 cm in cardia). Smooth passage of an endoscope through the gastroesophageal junction was confirmed at the end of the procedure.

RESULTS

In all cases POEM significantly reduced the dysphagia symptom score (from mean 10 to 1.3; P = 0.0003) and the resting lower esophageal sphincter (LES) pressure (from mean 52.4 mmHg to 19.9 mmHg; P = 0.0001). No serious complications related to POEM were encountered. During follow-up (mean 5 months), additional treatment or medication was necessary in only one patient (case 17) who developed reflux esophagitis (Los Angeles classification B); this was well controlled with regular intake of protein pump inhibitors (PPIs).

CONCLUSIONS

The short-term outcome of POEM for achalasia was excellent; further studies on long-term efficacy and on comparison of POEM with other interventional therapies are awaited.

Molecular analysis of the cutaneous Malassezia microbiota from the skin of patients with atopic dermatitis of different severities

Cutaneous Malassezia is an exacerbating factor in patients with atopic dermatitis. We analysed the Malassezia microbiota of adult patients with head and neck atopic dermatitis of different severities (mild, moderate and severe). Of the nine human-associated Malassezia species, the number detected was similar (3.5-4.2 species per case) among the members of all severity groups. However, the ratio of the two major Malassezia species, M. globosa and M. restricta, was different in the severe group.

Shrinkage dynamics of a vesicle in surfactant solutions

We develop a theory for shrinkage dynamics of a vesicle interacting with surfactant molecules. A stepwise shrinkage is formulated in such a way that it consists of two processes. One is a nucleation process of a pore under increasing of the membrane tension. The other is a closure process of the pore due to the line tension of the pore edge after leakage of the inner fluid. We carry out numerical simulations and show that the results agree with experiments semi-quantitatively. An analytical study is also carried out to understand the periodic shrinkage.

Endoscopic in vivo evaluation of tissue atypia in the esophagus using a newly designed integrated endocytoscope: a pilot trial

BACKGROUND AND STUDY AIMS

A newly designed magnifying endoscope featuring an endocytoscopy function provided by ultrahigh magnification was evaluated in a pilot study in patients with various types of benign and malignant pathology in the esophagus.

PATIENTS AND METHODS

Seventy-five consecutive patients were included in the study from 15 March to 21 December 2005. Twenty-nine patients with specific esophageal lesions that had been detected by regular or narrow-band imaging, or both, were further evaluated using endocytoscopy, followed by tissue biopsy or resection. During the endocytoscopic examinations, the esophageal mucosa was stained with 0.5 % methylene blue. The endocytoscopic findings were graded from 1 to 5 in an endocytoscopic atypia (ECA) classification. The final histopathological diagnoses based on biopsies or resected specimens were as follows: category 1 in the Vienna classification, n = 4; category 2, n = 6; category 3, n = 1; category 4, n = 10; and category 5, n = 7. The endocytoscopic diagnoses were compared with the histopathological diagnoses.

RESULTS

Clear endocytoscopic images were obtained in all cases. In definitely malignant lesions, the cell nuclei had an enlarged and irregularly arranged appearance (grade ECA 5). The positive predictive value for malignancy (grades ECA 4 and 5) was 94 %; the false-negative rate was 16.7 %, and the false-positive rate was 6.3 %. The overall accuracy of endocytoscopy for differentiating between nonmalignant tissue (categories 1 - 3 in the Vienna classification) and malignant tissue (categories 4 and 5) was 82 %.

CONCLUSIONS

These preliminary results suggest that incorporating endocytoscopy facilities into a standard endoscope may be helpful in characterizing tissue in a variety of esophageal lesions. The potential clinical impact of this method in relation to other gastrointestinal organs requires further study.

Dental adhesive compounds alter glutathione levels but not glutathione redox balance in human THP-1 monocytic cells

The use of hydrophilic dental monomers in dentin bonding agents has vastly improved resin-dentin bond strengths, but incomplete polymerization of these monomers and their leaching into adjacent (pulpal) oral tissues has raised concerns about their biocompatibility. The sublethal effects of these resins are virtually unknown, but their electrophilic nature led to the hypothesis that they may alter cellular oxidative stress pathways. Glutathione balance between reduced (GSH) and oxidized (GSSG) is a major mechanism by which cells maintain redox balance and was therefore the focus of the current investigation. THP-1 human monocytic cells were exposed to hydroxyethyl methacrylate (HEMA), benzoyl peroxide (BPO), camphorquinone (CQ), or triethyelene glycol dimethacrylate (TEGDMA) for 24 h at sublethal doses, then GSH and GSSG levels were measured by means of Ellman's method adapted for cell culture. The results indicate that these dental resin compounds act at least partly via oxidative stress by increasing GSH levels at sublethal concentrations. However, the GSH-GSSG ratio was relatively unaffected. Only BPO altered the GSH-GSSG ratio at 24 h, again at sublethal levels (7.5-15 micromol/L). The results support the hypothesis that resin monomers act, at least in part, via oxidative stress, and that oxidative-stress pathways should be one focus of future investigations of monomer biocompatibility.

Fluid movement across the resin-dentin interface during and after bonding

This study evaluated the extent of water penetration through resin-dentin interfaces before and after being sealed with adhesives. Four adhesive resin systems (2 total-etch adhesives and 2 self-etching primer adhesives) were used in this study. Dentin disks were placed in a split-chamber device, and in situ fluid movement across dentin was measured, with and without physiological pressure, during bonding procedures or 24 hrs after bonding. The fluid movement across dentin occurs via dentin tubules after acid-etching. Large outward or inward fluid shifts across dentin were observed during air-drying and light-curing for resin application. The amount of fluid movement across resin-bonded dentin when total-etch adhesives were used was significantly greater than that with self-etching adhesives. The milder acid-etching effects of self-etching primers may retain hybridized smear plugs within the tubules that reduce outward fluid flow, resulting in superior dentin sealing.

In vitro effect of nanoleakage expression on resin-dentin bond strengths analyzed by microtensile bond test, SEM/EDX and TEM

This study evaluated the effect of multiple consecutive adhesive resin coatings of adhesive bonded to human dentin on nanoleakage and resin-dentin bond strength. Resin bonded dentin specimens were prepared using a total-etch adhesive (One-Step Plus) applied as multiple consecutive coating, or using two self-etch adhesive systems (iBond or Fluoro Bond). For the total-etch adhesive, resin application and air evaporation were performed 1, 2, 3, or 4 times. The self-etch adhesives were applied according to manufacturers' instructions. Resin-dentin bonded beams were prepared and immersed in water (control) or ammoniacal silver nitrate. After storage, microtensile bond strengths were measured. The fractured surfaces were examined by scanning and transmission electron microscopy (SEM and TEM), and energy-dispersive X-ray spectrometry (EDX). No significant differences in bond strength were found between water and silver nitrate storage groups. Several types of silver depositions (spotted, reticular, or water trees) were found in adhesive joints. The bond strengths of the single coated specimens of the total-etch adhesive were significantly lower than those receiving 2-4 coatings. Single coats produced more nanoleakage than multiple coats. However, no correlation was found between the bond strengths and nanoleakage between the different adhesives (total-etch adhesive with different conditions or self-etch adhesives).

Degradation of resin-dentin bonds using NaOCl storage

OBJECTIVE

Several recent studies have reported collagen hydrolysis within bonds over the long-term. This may be one reason for the degradation of the bonds. This study therefore aimed to determine the effects of NaOCl on adhesive system bonds (total-etch bonding system vs. self-etching primer system) to dentin in order to accelerate the durability testing.

METHODS

Resin-dentin bonded specimens were produced using Liner Bond 2V (Kuraray), a self-etching primer system, and OptiBond SOLO (Kerr), a total-etch bonding system, according to the manufacturers' instructions. The bonded specimens were serially sectioned in both x and y directions across the adhesive interface to obtain beams (adhesive area: 0.9 mm(2)). The specimens were immersed in 10% NaOCl solution for 1-5h after being stored in water at 37 degrees C for 24h. Control specimens were tested without exposure to NaOCl. After storage, micro-tensile bond tests were performed. Results were analyzed by two-way ANOVA and Fisher's PLSD tests (p<0.05). All fractured surfaces were observed by SEM, and examined using an image analyzer.

RESULTS

The bond strengths decreased with increasing storage time in NaOCl. Fractography showed that NaOCl had a greater effect on the bond structure of OptiBond SOLO than on that of Liner Bond 2V, although both adhesives were susceptible.

SIGNIFICANCE

Deterioration of the bonds was responsible for the effect of NaOCl on the hybrid layer. This deterioration may occur in humans in cases of deproteinization within the bonds.

Low-dose, long-term exposures of dental material components alter human monocyte metabolism

The short-term degradation of dental polymers and alloys in biological environments has been well documented, but recent evidence indicates that oral tissues may be chronically exposed to low levels of these released components. The effect of these chronic exposures on the ability of cells to respond to a subsequent challenge is not known. To investigate this idea, we exposed human THP-1 monocytes to sublethal concentrations of HEMA, TEGDMA, Hg(2+), and Ni(2+) for 2 weeks and then assessed the monocytic response to subsequent 24-h challenge with the same components at higher concentrations. Chronic (2 week) exposures of monocytes to HEMA and both metal ions significantly altered monocyte response to short-term (24 h) secondary exposures, even when overt effects of the chronic exposures were not apparent. However, cellular responses were highly variable depending on the material and its concentrations. For TEGDMA, no effects were seen. These results demonstrate that the chronic effects of materials must be considered even when the chronic exposure has no initial overt effect. The effect on cells may only be apparent if the cell is challenged by a secondary exposure.

Components of dentinal adhesives modulate heat shock protein 72 expression in heat-stressed THP-1 human monocytes at sublethal concentrations

Few studies have investigated the ability of dental resins to induce cellular stress at sublethal concentrations. Cellular stress, especially in immune cells such as monocytes, may modulate the biological response to materials or the host's ability to respond to bacterially mediated inflammation. The current study examined the ability of sublethal concentrations of 2-hydroxylethylmethacrylate (HEMA) and triethyleneglycol dimethacrylate (TEGDMA) to induce heat shock protein 72 (HSP72) in human monocytes. HEMA and TEGDMA significantly suppressed heat-induced HSP72 expression, even at sublethal levels, but did not induce HSP72 by themselves. The results of the current study suggest that components released from dental resin could modulate the HSP stress response without altering cellular metabolic activity.

Fractured surface characterization: wet versus dry bonding

OBJECTIVE

Fractographic analysis was conducted to evaluate the resin-dentin bond structures made under wet and dry conditions.

METHODS

Resin-dentin bonded specimens were prepared using two adhesive resin systems (Single Bond/SB; 3M and All Bond 2/AB2; Bisco Inc) under wet and dry conditions. The specimens were sectioned perpendicular to the adhesive interface to produce a square bar-shaped specimen (adhesive area: 0.9 mm(2)) by means of a diamond saw. The mean bond tensile test was then conducted at a crosshead speed of 1.0 mm/min. The mean bond strengths were statistically compared with two-way ANOVA and Fisher's PLSD test (p<0.05). Subsequently, the fractured surfaces of all specimens were examined using SEM and the area fractions of failure modes (%) were measured using an image analyzer on SEM microphotographs.

RESULTS

No significant differences in tensile-bond strength were observed between SB (60.1+/-16.4MPa) and AB2 (69.8+/-17.4MPa) (p>0.05) under wet conditions. However, the bond strength either of SB or AB2 made under wet conditions was significantly greater than those made under dry conditions (SB: 26.2+/-12.5MPa and AB2: 6.8+/-3.3MPa) (p<0.05). Under fractographic analysis, the major portion at the fractured surface was occupied by the cohesive failure of bonding resin and the resin composite for the wet conditions, and the top of the hybrid layer for the dry conditions in both systems.

SIGNIFICANCE

The interaction between the top of the hybrid layer and the bonding resin influenced the bond integrity.

Over-etching effects on micro-tensile bond strength and failure patterns for two dentin bonding systems

OBJECTIVES

The purpose of this study was to determine (1) the weakest zone of resin-dentin bonds and (2) the relation between bond strength and failure mode to clarify the effect of demineralized dentin.

METHODS

Human premolars were sectioned to expose the dentin surfaces, and the dentin surfaces were conditioned with phosphoric acid for 15, 60, 120, or 180s. Resin-dentin bonded specimens were produced using two adhesives: One-Step (Bisco) and OptiBond Solo (Kerr). Each sample was sectioned to produce a beam (adhesive area: 0.9mm(2)). Microtensile bond tests were then conducted, and the mean bond strengths (n=12 for each group) were statistically compared using two-way ANOVA and Duncan's multiple-range test (p<0.05). The fractured surfaces of all specimens were examined using SEM, and the areas of failure were measured using an image analyzer.

RESULTS

For One-Step, the bond strength decreased with increase in acid-conditioning time (15s: 50.7+/-9.7, 60s: 40.8+/-11.0, 120s: 23.6+/-4.9 and 180s: 12.1+/-4.6MPa) (p<0.05). For OptiBond Solo, the bond strength in the case of 15s acid-conditioning time (42.6+/-7.9MPa) was significantly greater than that for the other times (60s: 31.9+/-10.3, 120s: 31.8+/-14.4 and 180s: 31.8+/-7.4MPa) (p<0.05). Fractography showed that the area percentage of the hybrid layer increased with increase in etching time for both systems.

CONCLUSIONS

The integrity of the hybrid layer, especially the top part, has an effect on bond strength.

Diagnosis of Alexander disease in a Japanese patient by molecular genetic analysis

Alexander disease is a leukodystrophy that is neuropathologically characterized by the presence of numerous Rosenthal fibers in astrocytes. Recently, mutations in the gene encoding glial fibrillary acidic protein (GFAP) were identified in patients with Alexander disease. We sequenced the GFAP gene of a Japanese girl who presented with typical symptoms of Alexander disease but in whom the diagnosis was not proven by histopathology. We identified a missense mutation, R239C, which is identical to the mutation previously reported to be most frequent. As was the case in previously described patients, our patient was also heterozygous for the de novo mutation. Interestingly, despite the fact that this is a de novo mutation, R239C was found to be common in different ethnic groups, implying that the site is a "hot spot" for mutagenesis. Molecular genetic analysis now makes the antemortem diagnosis of Alexander disease possible.

Delayed eruption of premolars with periodontitis of primary predecessors and a cystic lesion: a case report

Apical periodontitis after pulp therapy in a primary tooth can cause delayed eruption of the permanent successor. A case of bilateral delayed eruption of mandibular premolars is presented. The patient. a 13-year-old girl, was referred by her dentist. Oral findings showed that the right first and left second primary molars were retained. Other premolars had erupted. An orthopantomogram revealed apical periodontitis, affecting both retained primary molars. The right first mandibular premolar was impacted against the alveolar bone and root of the second premolar, and there was a large cystic lesion in close association with the left second mandibular premolar. Both primary molars were extracted, and the cystic lesion was treated by marsupialization. Fenestration and traction were performed on the right first premolar. Correct tooth alignment was achieved with orthodontic appliances. If the problem had been detected earlier, treatment of the premolars might have been easier. Clinical and radiological follow-up, therefore, of primary teeth that have undergone pulp therapy procedures should be performed until eruption of succedaneous teeth.

The extent to which resin can infiltrate dentin by acetone-based adhesives

The combined methodologies of fractography and laser-Raman spectroscopic analysis were used for evaluation of the resin-dentin bonds made with wet and dry bonding. Resin-dentin-bonded beams were produced by means of 2 acetone-based adhesives (One-Step and Prime & Bond NT). The micro-tensile bond test was conducted, and the fractured surfaces of all specimens were examined by SEM and an image analyzer. The amount of resin infiltration within the hybrid layer was quantified by means of a laser-Raman spectroscope. In Raman analysis, the amount of resin impregnation within the hybrid layer of the dry bonding was found to be significantly lower (approximately 50%) than that in the wet one. Under fractographic analysis, a correlation was found between the bond strength and the failure mode. Based on those findings, it was suggested that the integrity between the bonding resin and the top of the hybrid layer played a major role in bond strength.

Mechanical ventilation care in severe childhood neurological disorders

Forty-five patients underwent long-term life-sustaining mechanical ventilation care in the Child Neurology Ward, National Center Hospital for Mental, Nervous and Muscular Disorders from 1990 to 2000. Twenty patients had chronic respiratory insufficiency due to neuromuscular disorders, nine of whom underwent home mechanical ventilation care. Nineteen of the 45 patients had chronic respiratory insufficiency due to progressive central nervous system disorders, three of whom underwent home mechanical ventilation care. Six patients with chronic respiratory insufficiency due to the sequelae of transient events were on ventilation, two of whom underwent home mechanical ventilation care. In some patients, especially ones with neuromuscular disorders, mechanical ventilation care is very useful for improving their daily activity and quality of life. In other patients, however, mechanical ventilation care is merely a means of prolonging life without visible improvement of their quality of life. As medical resources are limited, home mechanical ventilation care is a recommended method for patients who need life-sustaining mechanical ventilation care. Considering an individual or social consensus, the indication of long-term life-sustaining mechanical ventilation care for chronic respiratory insufficiency due to severe childhood neurological disorders should be further discussed.

Fractographical analysis of resin-dentin bonds

PURPOSE

To characterize resin-dentin bond structures of three adhesive resin systems using fractographic analysis to measure the area of failure at the fractured surface.

MATERIALS AND METHODS

Flat dentin surfaces were ground perpendicular to the long axis of the tooth. The prepared dentin surfaces were treated by one of three adhesive resin systems (Mac Bond II, One-Step, and Single Bond). The samples were sectioned perpendicular to the adhesive interface to produce a square bar-shaped specimen (adhesive area: 0.9 mm2) using a diamond saw. A micro-tensile test was then conducted at a crosshead speed of 1.0 mm/min. The mean tensile bond strengths were statistically compared using one-way ANOVA and Fisher's PLSD test (P< 0.05). The fractured surfaces of all specimens were examined using SEM and the area of failure was measured using an image analyzer on SEM microphotographs.

RESULTS

No significant differences in tensile bond strength were observed between Single Bond (62.1+/-18.2 MPa) and One-Step (53.8+/-13.1 MPa) (P > 0.05). However, the bond strength of Mac Bond II (36.5+/-13.7 MPa) was significantly lower than that of One-Step or Single Bond (P< 0.05). At the fractured surface, except for the cohesive failure of the bonding resin and resin-based composite, different failure patterns were observed for each resin system as follows: the failure of the hybrid layer and demineralized dentin was observed in the two wet bonding systems (One-Step and Single Bond) and of the hybrid layer but not the demineralized dentin in the self-etching primer system (Mac Bond II). The results demonstrated that the integrity of the hybrid layer depends on the adhesive system.

MaxiK channel-mediated relaxation of guinea-pig aorta following stimulation of IP receptor with beraprost via cyclic AMP-dependent and -independent mechanisms

The present study was aimed to elucidate the cellular pathway(s) controlling vascular relaxation triggered by stimulation of prostaglandin I2 (PGI2, IP) receptor with a stable PGI2 analog, beraprost. Beraprost caused a concentration-dependent relaxation in de-endothelialized guinea-pig aorta contracted with prostaglandin F2alpha (PGF2alpha). Beraprost-induced relaxation was almost abolished in high-KCl-contracted tissue, indicating a major role of K+ conductances. In contrast to other PGI2 analogs (e.g. cicaprost and iloprost), beraprost-induced relaxation was practically abolished by a selective voltage and Ca2+-activated K+ (MaxiK, BK) channel blocker Iberiotoxin (10(-7) M) or by tetraethylammonium (2 x 10(-3) M). The relaxation induced by beraprost was not significantly affected by other K+ channel blockers glibenclamide (10(-6) M) or Ba2+ (10(-5) M), but was slightly attenuated by 4-aminopyridine (10(-4) M). Beraprost increased intracellular cyclic AMP levels, suggesting a role for cyclic AMP-dependent pathways. A selective inhibitor of cyclic AMP-specific phosphodiesterase, RO-20-1724 (10(-4) M), significantly potentiated beraprost-induced relaxation. Iberiotoxin (10(-7) M) completely counteracted this potentiation. Moreover, tension decrement due to forskolin (3 x 10(-7) M) or 8-bromo-cyclic AMP (10(-2) M) was thoroughly restored by Iberiotoxin (10(-7) M), confirming a role for a cyclic AMP-dependent mechanism. However, SQ 22,536 (10(-4) M), an adenylyl cyclase inhibitor, did not affect beraprost-induced relaxation though it almost totally inhibited the elevation of cyclic AMP contents induced by beraprost, suggesting the existence of an additional mechanism that is cyclic AMP-independent. Moreover, cholera toxin (CTX, 1 microg/ml for 6 h), which activates the stimulatory G protein of adenylyl cyclase (Gs), significantly suppressed PGF2alpha-induced contraction both in the absence and presence of SQ 22,536 (10(-4) M). Iberiotoxin (10(-7) M) was also capable of restoring the relaxation induced by CTX. These findings suggest that MaxiK channel plays a primary role in mediating smooth muscle relaxation following stimulation of IP receptor with beraprost in guinea-pig aorta. Both cyclic AMP-dependent and -independent pathways contribute to the MaxiK channel-mediated relaxation following IP receptor stimulation in this vascular tissue. Direct regulation of MaxiK channels by Gs may partly account for the cyclic AMP-independent relaxant mechanism.

[Three cases of Costello syndrome presenting with intractable epilepsy and profound psychomotor retardation/regression]

We report three cases of Costello syndrome (CS) presenting with intractable epilepsy and profound psychomotor retardation/regression. Previous reports on CS described mild to moderate psychomotor retardation, and epilepsy in only 8% of the cases. The details of these neurological complications have not been reported so far. All the present cases had intractable epilepsies and profound psychomotor retardation/regression. Two of them had symptomatic localization-related epilepsies and the other had Lennox-Gastaut syndrome following West syndrome. Unusual complication of profound psychomotor retardation/regression in our cases seems to be caused by intractable epilepsy. It should be noted that CS patients with epilepsy may have more severe central nervous symptoms than those previously reported.

Resin-tooth adhesive interfaces after long-term function

PURPOSE

To characterize with scanning electron microscopy (SEM), the morphology of adhesive interfaces that had been functioning in an oral cavity for several years.

MATERIALS AND METHODS

Cavities were prepared in vivo in caries-affected primary molars under local anesthesia. After removal of the entire carious lesion, the cavity was restored with a dentin adhesive system (Scotchbond Multi-Purpose). After several yrs, as the successor permanent teeth erupted, the resin-filled teeth were extracted. Then, the extracted resin-restored primary molars were cross-sectioned perpendicular to the adhesive interface using a low speed diamond saw and then polished for SEM examination.

RESULTS

Morphological changes, such as digestion of the collagen fibrils and deterioration of the bonding resin and hybrid layer, were observed at the interface of the oral environment specimens. The results of this study demonstrated that degradation of resin-dentin bond structures appeared to occur in the human oral environment over time.

An isolated and sporadic auditory neuropathy (auditory nerve disease): report of five patients

Five patients of various ages with difficulty in speech discrimination were evaluated. All showed evidence of abnormal auditory brainstem responses (ABRs) beginning with the VIIIth cranial nerve. Broad summating potentials were evoked on their electrocochleograms (EcochGs) and they all exhibited almost normal cochlear outer hair cell function by otoacoustic emissions (OAEs) recordings. Behavioural audiometric testing revealed a mild to moderate elevation of pure-tone threshold in all patients. The shape of their pure-tone losses varied, being predominantly low-frequency in four patients (rising slope pattern) and flat across all frequencies in one patient. Speech intelligibility scores of all patients were poor and out of proportion to what would have been expected if threshold elevation of pure-tone was of cochlear origin (i.e. markedly poor scores on the speech audiogram with good scores on the auditory comprehension test). Patients were neurologically normal when the hearing impairment was first manifested. We suggest that this type of hearing impairment is due to an isolated and sporadic disorder of auditory nerve function. It occurs in isolation and does not seem to be part of a generalized neuropathological process.

The in vitro cytotoxicity of eluates from dentin bonding resins and their effect on tyrosine phosphorylation of L929 cells

OBJECTIVES

The aim of this study was to examine the relationship between the monomers eluted from dentin-bonding systems and their cytotoxicities, and to investigate the biochemical effect of the monomers on tyrosine phosphorylation, especially relating to the cell growth activity, of L929 cells in vitro.

METHODS

The primers, uncured or cured adhesives (3M and Kuraray) were tested to determine the cytotoxicity of confluent L929 cells cultured by Eagle's MEM medium supplemented with 10% FCS. The area of cells affected by the eluted monomers were evaluated with an image analyzer and the concentrations of monomers eluted into the medium were measured with high performance liquid chromatography (HPLC) after 24h incubation. The protein composition of the stimulated cells was compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tyrosine phosphorylation was detected by Western blot.

RESULTS

The primer and uncured adhesives revealed variable cytotoxicities. 2-hydroxyethyl-methacrylate (HEMA) was the major component eluted from uncured primers and adhesives. Small amounts of triethylene glycol dimethacrylate (TEGDMA) were also detected from the uncured adhesives. The cytotoxicities of the adhesives decreased as photo activation time increased. The amount of monomers eluted from the cured adhesives was almost undetectable and did not reach a sufficient concentration to suppress cell viability or cell growth. The cytotoxicities of the primers and adhesives correlated well with the amounts of either HEMA or TEGDMA eluted. Moreover, a high concentration of HEMA (4 mg/ml medium) affected intracellular tyrosine phosphorylation, which is related to cellular activities.

SIGNIFICANCE

Although the monomers present in dentin bonding resins are cytotoxic to L929 cells, the amount from cured bonding resin is very small and does not provide a cytotoxic dose. This data does however suggest that clinical exposure to the uncured primers and adhesives of dentin bonding resins should be minimized.

[A girl with chief compliance of "easy to forget"--cognitive neuropsychological evaluations and cerebral blood flow]

Cognitive-neuropsychological evaluations were performed on a 12-year-old girl with memory disorder to study the higher brain function of this patient. The cerebral blood flow (r-CBF) was also studied. The results showed that the auditory-verbal memory of this patient were impaired. The regional cerebral blood flow was reduced in the left hippocampus which reportedly cause memory disorder. The disturbance of visual cognition and disability of construction in this patient seem to be related to reduced cerebral blood flow in the left parietal region.

[Life-sustaining mechanical ventilation care for children with progressive or degenerative brain disorders]

In the past 10 years, we have treated 25 patients with chronic respiratory insufficiency due to a progressive or degenerative brain disorder. Ten patients died and the other 15 survived. Five of the former and 12 of the latter received life-sustaining mechanical ventilation care. Even in the terminal stage of progressive or degenerative brain disorders, patients can survive for a longer period than previously, if life-sustaining mechanical ventilation care is given. In Japan we do not have a guideline for medical indication or decision-making for children with progressive or degenerative brain disorders. Whenever we see such patients, we have great difficulty in making a decision. It may therefore be necessary to discuss whether we should have such a guideline.

Cerebral cortical dysplasia: assessment by MRI and SPECT

The objective of this study was to establish correlations between image findings and pathologic deficits in patients with cerebral cortical malformations. The results of magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) in addition to clinical data for 15 patients with cerebral cortical malformations were reviewed retrospectively. MRI led to the diagnoses of bilateral perisylvian syndrome, hemimegalencephaly, focal polymicrogyria, band-heterotopia, and focal cortical dysplasia (FCD). Interictal SPECT did not reveal hypoperfusion in any case of polymicrogyria. Ictal SPECT images revealed hyperperfusion of the lesion in three patients with polymicrogyria, with accompanying hyperperfusion of the basal ganglia in two of the three patients. On the other hand, interictal SPECT images demonstrated hypoperfusion of the lesion in four patients with FCD. Ictal SPECT images revealed hypoperfusion of the lesion in two patients, hyperperfusion of the lesion in one patient, and hypoperfusion of the basal ganglia in two patients with FCD. This difference in perfusion between polymicrogyria and FCD observed in this study may reflect histologically different characteristics. This relative hyperperfusion of the cortex and the basal ganglia observed on ictal SPECT, which was found in two polymicrogyria patients with complex partial seizures and partial seizures evolving to secondary generalized seizures, respectively, suggests that the cortical-subcortical interaction is related to the mechanism of loss of consciousness or seizure generation.

The effect of hybrid layer thickness on bond strength: demineralized dentin zone of the hybrid layer

OBJECTIVES

The purpose of this study was to evaluate the correlation between hybrid layer thickness and bond strength using specimens acid-conditioned for varying lengths of time.

METHODS

The dentin surfaces of human premolars, sectioned to remove the enamel from the labial surface, were conditioned with 35.0% phosphoric acid of an adhesive resin system (Scotchbond Multi-Purpose; 3M) for 15 (as directed by the manufacturer), 60, 120, or 180 s (experimental acid-conditioning times). The bonded specimens were then sectioned perpendicular to the adhesive interface to measure the hybrid layer thickness by SEM. The specimens for the micro-tensile test were sectioned perpendicular to the adhesive interface and trimmed to an hourglass-shape. Then, the micro-tensile test was performed at a crosshead speed of 1.0 mm/min. The bond strengths and hybrid layer thickness were statistically compared with Student's t-test (p < 0.05). All fractured surfaces were also observed by SEM.

RESULTS

Significant differences between the groups exposed to acid for 15 and 60 s, and those exposed for 120 and 180 s were observed in hybrid layer thickness and bond strength (p < 0.05). SEM observation of the fractured surfaces revealed that a demineralized dentin zone without resin impregnation remained within the hybrid layer.

SIGNIFICANCE

A demineralized dentin zone was formed in the bond structures after prolonged acid-conditioning, resulting in low bond strength. The shrinkage of the hybrid layer due to desiccation during the SEM examination process provided evidence of the presence of the demineralized dentin zone within the hybrid layer.

Semantic category discrimination and N400

14 subjects performed a semantic category-discrimination task in which they were presented pairs of words and asked to judge whether these belonged to the same category. Three semantic distance conditions, established for the word pairs on the basis of a survey, were semantically close condition (mammals and birds condition) and two semantically distant conditions (mammals and tools condition and birds and tools condition). The reaction times and the percentage of errors were significantly greatest for the mammals and bird condition. There were no significant differences among the three different conditions in N400 latency for target, but the amplitude of N400 tended to be largest for the mammal and bird condition. Comparison N400 of prime and target for each of the conditions showed that the latency for prime was longer than for target in all three conditions.

Long-term follow-up of auditory agnosia as a sequel of herpes encephalitis in a child

We report a pediatric patient with auditory agnosia as a sequel of herpes encephalitis. His early development was completely normal. He uttered three words at 12 months old. Disease onset was 1 year and 2 months of age. He was discharged from the hospital seemingly with no sequel; however, he could not recover his intelligible words even at age 2 years. He was diagnosed as having auditory agnosia caused by bilateral temporal lobe injury. We began to train him at once, individually and intensively. Adult patients with pure auditory agnosia followed by two episodes of temporal lobe infarction have impairment in central hearing but not inner language. Therefore, they can communicate by reading and writing. Moreover, impairment in hearing is not always severe and is often transient. However, despite long-term (more than 15 years) energetic education and almost normal intellectual ability (Performance IQ of Wechsler Intelligence Scale for Children-Revised was 91), our patient's language ability was extremely poor. Cerebral plasticity could not work fully on our patient, whose bilateral temporal lobe was severely injured in early childhood. The establishment of a systematic training method in such patients is an urgent objective in this field.

Otoacoustic emission in patients with neurological disorders who have auditory brainstem response abnormality

Otoacoustic emissions (OAEs) were evaluated in 51 ears of 30 patients with a severe auditory brainstem response (ABR) waveform abnormality. Thirteen ears showed no ABR to click sound of higher intensity than 100 dBSPL (group 1). Fourteen ears exhibited only wave V or a decreased amplitude pattern of ABR (group 2). Twenty-four ears showed a predominant wave I or no wave III pattern (group 3). Almost all the ears with absent ABR showed no OAE, which strongly suggested hearing loss of cochlear origin, although one patient with alternating hemiplegia of childhood exhibited definite OAEs and auditory reactions without ABR. One patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) and her mother in group 2 had OAE abnormalities, which also suggested mild to severe hearing impairment. When OAEs are present, an accompanying ABR abnormality may be produced by brainstem dysfunction of the underlying disorder such as Pelizaeus-Merzbacher disease. There was a significant relationship (chi-square test P<0.001) between the positivity of the distortion product OAE response and the clinical auditory reactions in 24 patients, although their ABR abnormalities did not reflect hearing impairment directly. Careful examination of both audiometry and OAEs might be necessary for further assessment of the hearing function in pediatric patients with neurological disorders and specific auditory nerve disease.

In vivo degradation of resin-dentin bonds in humans over 1 to 3 years

The longevity of resin restorations is currently an area of great interest in adhesive dentistry. However, no work has been conducted to investigate the durability of resin-dentin bond structures using human substrate in vivo. The purpose of this study was to investigate the degradation of the resin-dentin bond structures aged in an oral environment for 1, 2, or 3 years. Cavities were prepared in primary molars, and an adhesive resin system (Scotchbond Multi-Purpose) was applied to the cavity. After 1 to 3 years, following the eruption of the succedaneous permanent teeth, the resin-restored teeth were extracted. Immediately after extraction, those teeth were sectioned perpendicular to the adhesive interface and trimmed to produce an hourglass-shaped specimen. Then, a micro-tensile test was performed at a crosshead speed of 1.0 mm/min. The mean bond strengths were statistically compared with one-way ANOVA and Fisher's PLSD test (p < 0.05). Further, all fractured surfaces were observed by SEM, and the area fraction of failure mode was calculated by means of a digital analyzer on SEM photomicrographs. There were significant differences in tensile-bond strength among all 3 groups (p < 0.05), with mean values ranging from 28.3 +/- 11.3 MPa (control), to 15.2 +/- 4.4 MPa (1 to 2 years), to 9.1 +/- 5.1 MPa (2 to 3 years). Moreover, under fractographic analysis, the proportion of demineralized dentin at the fractured surface in specimens aged in an oral environment was greater than that in control specimens. Furthermore, degradation of resin composite and the depletion of collagen fibrils was observed among the specimens aged in an oral environment. Analysis of the results of this study indicated that the degradation of resin-dentin bond structures occurs after aging in the oral cavity.

Developmental changes of distortion product and transient evoked otoacoustic emissions in different age groups

The developmental changes of distortion product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) were evaluated in 275 normal subjects aged from 1 month to 39 years. The DP-grams showed an M-shaped pattern with peaks at 1587 Hz and 5042 Hz for all age groups. In subjects younger than 3 years, low frequency DPOAEs did not rise above the noise floor. The DP levels at high frequency (5042 Hz) did not change much from infancy to young adulthood (12.9-16.5 dB SPL), however, those at low and middle frequency significantly decreased with age. Total echo power (TEP) of TEOAE was greatest in early infancy, decreased rapidly before 6-7 years old, and then decreased gradually (TEP = 16.6 - 1.9 X ln (age)). Wave reproducibility was constant across age. The frequency area peak power (FAPP) to middle and high frequency sounds changed little with age, however, FAPP at low frequency sounds dramatically increased with age. FAPP at 5000 Hz was relatively depressed levels at each age. The TEOAE value was more prominent at middle and low frequencies while DPOAE was predominant at high frequencies. These two measurements may reflect different functions of outer hair cells in the developing cochlea.

Detection of Mycoplasma fermentans in saliva sampled from infants, preschool and school children, adolescents and adults by a polymerase chain reaction-based assay

Attempts were made to detect Mycoplasma fermentans in saliva sampled from 201 subjects (108 males and 93 females) aged from 4 months to 59 years by a polymerase chain reaction-based assay. M. fermentans was detected in saliva from 110 (54.7%) of 201 subjects, and 10 (28.6%) of 35 subjects aged from 4 months to 3 years. Of ten positive subjects, three were aged from 16 to 23 months and five were from 26 to 31 months. The incidence tended to increase with age up to the teens. The incidence was significantly greater in teenagers than in subjects aged from 7 to 12 years, but there was no significant difference in the incidence between the group of teenagers and each of the groups of subjects older than the teenagers. Thus, it was suggested that M. fermentans colonized the mouth at the age of about 16 months up to the age of 19 years.

[Mental health of families caring for people with developmental disabilities: the present situation and strategies for improvement]

The authors assessed the status of mental health of families caring for relatives with developmental disabilities and neurological diseases. They were caring for their children in good morale, however, "burnouts" or neurotic conditions were more frequent in these families than in the medical staffs, the latter being studied in our previous researches. Mentally healthy persons consulted their spouse about their children as well as other things, and received his/her assistance in daily care. Families helped by unrelated persons were in better mental state. Families who had utilized inpatient care before entering a school had higher expectations from their surroundings. Therefore, medical services should provide support to such families to help improve their mental health.

The value of serial auditory brainstem response in patients with subacute sclerosing panencephalitis

A total of 98 serial auditory brainstem responses from 17 patients (11 boys and 6 girls) with subacute sclerosing panencephalitis were compared with their clinical course and stages. These patients were exposed to measles early in life (at 1.8 +/- 1.4 years old) with the average onset of the disease at 8.8 +/- 0.7 years of age. The main abnormalities of their auditory brainstem responses were a prolongation of waves I, III, and V, and of the I to V interpeak interval. Wave V thresholds were also elevated. These effects on the auditory brainstem responses started 1 to 2 years after onset of neurologic signs. I to V interpeak latency became prolonged with the progress of clinical stages, especially in Jabbour's clinically advanced stage IV. In two patients with an acute progressive type of subacute sclerosing panencephalitis, very rapid deterioration with a distorted wave pattern of later components was observed. These findings suggest rostrocaudal progression in the central nervous system of both long-term and fulminant cases.