Phosphorus flame retardants in indoor dust and their relation to asthma and allergies of inhabitants.

Organophosphate esters are used as additives in flame retardants and plasticizers, and they are ubiquitous in the indoor environment. Phosphorus flame retardants (PFRs) are present in residential dust, but few epidemiological studies have assessed their impact on human health. We measured the levels of 11 PFRs in indoor floor dust and multi-surface dust in 182 single-family dwellings in Japan. We evaluated their correlations with asthma and allergies of the inhabitants. Tris(2-butoxyethyl) phosphate was detected in all samples (median value: 580 µg/g in floor dust, 111 µg/g in multi-surface dust). Tris(2-chloro-iso-propyl) phosphate (TCIPP) was detected at 8.69 µg/g in floor dust and 25.8 µg/g in multi-surface dust. After adjustment for potential confounders, significant associations were found between the prevalence of atopic dermatitis and the presence of TCIPP and tris(1,3-dichloro-2-propyl) phosphate in floor dust [per log10 -unit, odds ratio (OR): 2.43 and 1.84, respectively]. Tributyl phosphate was significantly associated with the prevalence of asthma (OR: 2.85 in floor dust, 5.34 in multi-surface dust) and allergic rhinitis (OR: 2.55 in multi-surface dust). PFR levels in Japan were high compared with values reported previously for Europe, Asia-Pacific, and the USA. Higher levels of PFRs in house dust were related to the inhabitants' health status.

Relationships between mite allergen levels, mold concentrations, and sick building syndrome symptoms in newly built dwellings in Japan.

UNLABELLED: This study investigated the possible relationships between exposures to mite allergen and airborne fungi with sick building syndrome (SBS) symptoms for residents living in newly built dwellings. We randomly sampled 5709 newly built dwellings in six prefectures from northern to southern Japan. A total of 1479 residents in 425 households participated in the study by completing questionnaire surveys and agreeing to environmental monitoring for mite allergen (Der 1), airborne fungi, aldehydes, and volatile organic compounds. Stepwise logistic regression analyses adjusted for confounders were used to obtain odds ratios (OR) of mite allergen and fungi for SBS symptoms. Der 1 had a significantly high OR for nose symptoms. Rhodotorula had a significantly high OR for any symptoms, and Aspergillus had significantly high OR for eye symptoms. However, the total colony-forming units had a significantly low OR for throat and respiratory symptoms. Eurotium had a significantly low OR for skin symptoms. In conclusion, dust-mite allergen levels and indoor airborne Rhodotorula and Aspergillus concentrations may result in SBS symptoms in newly built dwellings. PRACTICAL IMPLICATIONS: Various factors can cause sick building syndrome symptoms. This study focused on biologic factors such as dust-mite allergen and airborne fungi in newly built dwellings in Japan. Dust-mite allergen levels were significantly associated with higher rates of nose symptoms, airborne Rhodotorula concentrations were significantly associated with higher rates of any symptoms, and Aspergillus concentrations were significantly associated with higher rates of eye symptoms. Measures should be taken to reduce mite allergen levels and fungal concentrations in these dwellings.

Regional differences in residential environments and the association of dwellings and residential factors with the sick house syndrome: a nationwide cross-sectional questionnaire study in Japan.

UNLABELLED: This study was conducted to clarify regional differences in residential factors and the association of those factors with dwellings having sick house syndrome (SHS) problems. The survey was conducted in six areas of northern and southern Japan. In terms of regional differences, dampness was not as severe in the dwellings in Sapporo as compared with that in areas in the south. SHS was defined using five categories of nasal, throat and respiratory, skin and general symptoms, which appeared frequently or not frequently and improved upon leaving the home. The dampness index was estimated by the sum of the presence of several indicators: condensation on the window panes and/or wall, visible mold growth, moldy odor, slow-drying wet towels in the bathroom, and water leakage. The dwellings where inhabitants showed any symptoms of SHS comprised 3.7% of all surveyed dwellings. We found significant associations between SHS and dampness index, odors, and stuffiness of the air. For dampness, the adjusted odds ratio (OR) increased with increased dampness index, adjusting for the age of the house, pets indoors, stuffiness of the air, and odors. These results showed an increased risk when several dampness indicators appeared simultaneously. PRACTICAL IMPLICATIONS: To evaluate the associations of residential environments and Sick House Syndrome (SHS), this cross-sectional questionnaire study was conducted on 2297 dwellings in six areas in Japan from 2003 to 2004. The dwellings where inhabitants showed any of nasal, throat and respiratory, skin and general symptoms comprised 3.7% of all surveyed dwellings, and an increased risk for SHS was found when several dampness indicators, 'condensation', 'visible mold growth', 'moldy odor', 'slow drying wet towels in the bathroom' and 'water leakage', appeared simultaneously.

Synergistic effect of dolichyl phosphate and human recombinant granulocyte colony-stimulating factor on recovery from neutropenia in mice treated with anti-cancer drugs.

Severe hematopoietic injury in mice was induced by using either 5-fluorouracil, adriamycin, mitomycin C, or vinblastine. Daily subcutaneous administration of purified human recombinant granulocyte colony-stimulating factor (rG-CSF; 0.3-10.0 micrograms/day) markedly accelerated recovery from the drug-induced granulocytopenia in a dose-dependent manner, as reported previously. On the other hand, daily intraperitoneal administration of dolichyl phosphate (Dol-P) also enhanced granulopoiesis to accelerate recovery from granulocytopenia, although the effect of Dol-P was relatively moderate as compared with that of rG-CSF. A synergistic recovery of granulopoiesis was observed when Dol-P was administered together with rG-CSF to the mice treated with anti-cancer drugs. Joint use of Dol-P (1 mg/day) and rG-CSF (0.3 micrograms/day) was as effective as a higher dose of rG-CSF (3 micrograms/day). Joint use of Dol-P (1 mg/day) and rG-CSF (3 micrograms/day) was sometimes more effective.

Mechanical properties of a bioabsorbable nerve guide tube for long nerve defects.

The mechanical properties of nerve guide tubes must be taken into consideration when they are being developed. We previously reported the feasibility of using 50:50 tubes in a canine 40mm peroneal nerve defect model, where 50:50 represents the proportion of poly(L-lactic) acid (PLLA) and polyglycolic acid (PGA). The aim of the current study was to show that 50:50 tubes have suitable mechanical properties for repairing long nerve defects. Four types of nerve guide tubes made with PLLA to PGA fiber ratios of 100:0 (i.e. 100% PLLA) (100:0 tube), 50:50 (50:50 tube), 10:90 (10:90 tube), and 0:100 (0:100 tube) were designed and created using a tubular braiding machine. Their mechanical properties were examined in vitro (up to 16 weeks). In compression testing, 50:50 tubes had the highest normalized force value, followed in order by the 100:0, 10:90, and 0:100 tubes up to 8 weeks after immersion. From the point of view of biomechanics and bioresorbability, out of the 4 tube types tested, 50:50 tubes appeared to have the optimal mechanical properties for longer nerve defects.

Cortical myoclonus: sensorimotor hyperexcitability.

Cortical or cortical reflex myoclonus is characterized by abnormally enlarged cortical somatosensory evoked potentials (giant SEPs), which most likely reflect pathologically hyperexcitable sensorimotor cortex. To clarify the pathogenesis of myoclonus of cortical origin, we simultaneously recorded SEPs and whole head somatosensory evoked magnetic fields (SEFs) following electric stimulation of the median nerve at the wrist in six patients with cortical myoclonus. N20m and enlarged P30m were observed in all patients and were localized at the posterior bank of the central sulcus (Brodmann area 3b of the primary somatosensory cortex). In addition, P25m and N35m components of SEFs were recognized in five and four patients, respectively. P25m component, that is, the magnetic counterpart of P25 in EEG, was the earliest cortical component showing enhancement in patients. Multidipole analysis combined with magnetic resonance imaging (MRI) coregistration revealed that the generators of P25m were in the precentral gyrus in four patients and in the postcentral gyrus in one patient. The second SEFs around 200 msec after the single stimulus were recorded in three patients at area 3b (repetitive SEFs); two of whom showed negative as well as positive myoclonus. The importance of motor cortex for the generation of cortical reflex myoclonus was thus demonstrated. The pathologic features of SEFs suggest abnormal excitability of primary sensorimotor cortex.

Synthesis and biological evaluation of the methyl esters of (+)-12-fluoro-13,14-dihydroprostaglandin F2alpha and (+)-15-epi-12-fluoro-13,14-dihydroprostaglandin F2alpha.

(+)-12-Fluoro-13,14-dihydroprostaglandin F2alpha methyl ester (2a) and (+)-15-epi-12-fluoro-13,14-dihydroprostaglandin F2alpha methyl ester (2b) were prepared from the readily available (-)-7-fluorospiro[bicyclo[2.2.1]hept-5-ene-2,2'-[1,3]dioxolane]-7-methanol (3). Fluoroprostaglandins 2a and 2b possess truly significant separations of antifertility activity from smooth-muscle stimulating properties. In addition, our studies showed that 2a and 2b were totally inert toward the placental 15-hydroxyprostaglandin dehydrogenase.

A special blocker reveals the presence and function of the hyperpolarization-activated cation current IH in peripheral mammalian nerve fibres.

Electrotonic responses recorded extra- or intracellularly from peripheral nerve preparations show a "sag" to hyperpolarizing current pulses. The biophysical nature of this "inward rectification" is still under discussion since the phenomenon has not been noted at voltage-clamped single nerve fibres, and since Cs+, which reduces inward rectification, is not a specific ion channel blocker. In this study, we found that low micromolar concentrations of ZD 7288, a specific blocker of the hyperpolarization-activated cationic current (Ih) in the soma of central mammalian neurons, result in a complete block of inward rectification in the electrotonic responses of isolated rat spinal dorsal roots. In addition, ZD 7288 enhanced the activity-dependent slowing of conduction seen in compound C fibre action potentials of isolated rat vagus nerves and augmented the post-tetanic hyperpolarization following trains of action potentials in unmyelinated and myelinated axons. The data suggest that ZD 7288 is a potent blocker and a useful research tool for the study of hyperpolarization-activated inward rectification (Ih) of peripheral nerve preparations.

Mechanical properties of artificial tracheas composed of a mesh cylinder and a spiral stent.

Much work has been done on the materials used for mesh-type artificial tracheas, but a precise mechanical evaluation of these structures has not yet been performed. In the present study, we determined the mechanical properties of typical mesh-type artificial tracheas and compared them with those of native trachea. Four types of artificial trachea were made and used for the mechanical tests. The basic frame of all the specimens was composed of a mesh cylinder and a spiral stent. The specimen whose mesh was sealed with collagen sponge showed almost the same behavior in the force-strain curve under compression, suggesting that collagen sealing has little effect on mechanical properties. Agreement between measured and estimated mechanical properties was good, especially in the low strain region, suggesting that artificial tracheas can be designed in terms of mechanical properties by mainly considering the basic frame structure.

Increases in K+ conductance and Ca2+ influx under high glucose with suppressed Na+/K+-pump activity in rat myelinated nerve fibers.

To test the combined effect of high glucose and decreased Na+/K+-pump activity, a condition which closely mimics the diabetic state, on nerve ionic currents, changes in action potential and membrane current induced by high glucose in the presence of ouabain were investigated using voltage clamp analysis in rat single myelinated nerve fibers. In the presence of 0.1 mM ouabain, 30 mM glucose caused a progressive increase in the delayed K+ current as well as persistent decreases in action potential and Na+ current, suggesting that Na+/K+ pump plays an important role in preventing the increase in the K+ current. The latter increase was suppressed by a blocker of Ca2+-activated K+ channels. Two types of voltage-dependent Ca2+ channel blockers (L and N-type) as well as a Na+/Ca2+-exchange blocker diminished the ouabain-induced increase in K+ conductance. These results suggest that high glucose with suppressed Na+/K+ pump activity might induce an increase of Ca2+ influx through either Ca2+ channels or reverse Na+/Ca2+-exchange, possibly leading to the elevation of Ca2+-activated voltage-dependent K+ channels. Both a decrease in inward Na+ current and an increase in K+ conductance may result in decreased nerve conduction. In addition, a possible increase of axoplasmic Ca2+ concentration may lead to axonal degeneration. These results provide a clue for understanding the pathophysiologic mechanism of diabetic neuropathy.

An animal model of chronic ischemic neuropathy with proliferative changes of nerve microvessel wall.

In order to produce a model of ischemic neuropathy with neural microvascular alterations, sodium laurate was injected into a femoral artery and saline into the contralateral artery at the mid-thigh level in Sprague-Dawley rats aged 11 weeks. In view of the dose-related findings, 0.3 mg sodium laurate dissolved in 0.1 ml saline was used for the main experiment. The laurate-injected leg showed paresis during the experimental period. On day 1-7, various stages of Wallerian degeneration and acute microvascular changes were found. At 1 month, regenerating myelinated nerve fibers (MNFs) were found at the central or total fascicular area mainly in the distal tibial nerve. Morphometric analyses suggested that MNFs other than regenerating fibers are atrophic ones. The proliferative changes of nutrient microvascular walls were striking. The percent of closed epineurial microvessels was significantly larger on the laurate-injected sides and inversely associated with the diameter of MNFs. At 7 months, the attenuation of MNFs was more prominent and microvascular alterations were persistently observed. These pathological findings resemble those of chronic ischemic neuropathy including diabetic neuropathy, suggesting that this neuropathy model might provide some valuable and useful clues for clarifying the pathogenesis of chronic ischemic neuropathy.

Effectivity of dolichyl phosphates with different chain lengths as acceptors of nucleotide activated sugars.

Chemical synthesis of different S-forms of dolichyl-P was performed in order to investigate the use of these polyprenes in mannosyl, glucosyl and glucosaminyl transferase reactions. Determination of the Vmax values for a series of dolichyl-P demonstrated that the velocities of transferase reactions with all those dolichyl-P derivatives present in animal tissues are largely the same. The apparent Km values for the various dolichyl-P in the transferase system studied differed, but this property does not appear to have physiological importance.

The sera from GM1 ganglioside antibody positive patients with Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy blocks Na+ currents in rat single myelinated nerve fibers.

OBJECTIVE: To determine the possible role of anti-GM1 ganglioside antisera from patients with Gullain-Barr*e syndrome (GBS) or chronic inflammatory demyelinating polyneuropathy (CIDP) in the development of nerve dysfunction. METHODS: The effect of the anti-GM1 antibody positive antisera obtained from 4 GBS patients and 1 CIDP patient on membrane potential and ionic currents in rat single myelinated nerve fibers was investigated using the voltage clamp technique and compared with that of the anti-GM1 negative antisera obtained from 3 healthy controls and 2 GBS patients. RESULTS: In the presence of active complement, anti-GM1 positive antisera from 5 patients including 4 GBS patients and 1 CIDP patient significantly suppressed Na+ current more than anti-GM1 negative antisera. CONCLUSION: This study supports the notion that anti-GM1 antibody is one of the causative factors of conduction abnormality in GBS patients.

Swelling and flow properties of tubular poly(vinyl alcohol) gels.

Swelling and flow properties of tubular poly(vinyl alcohol) (PVA) hydrogels prepared with the cooling method were investigated using an inflation testing method. When the tubular hydrogel in liquid paraffin was inflated by using liquid paraffin as a pressure transmitting medium, namely in the case that the liquids inside and outside the gel are both liquid paraffin (P/P combination), the gel showed a slight volume change determined by Poisson's ratio of the gel. When the gel in water was inflated by liquid paraffin (P/W combination), the gel swelled to large extent compared with the case of P/P. The hydrogel in W/W combination, namely in the situation that the gel was immersed in water and also inflated by water, showed a very large volume change if the comparison was done at the same pressure. The origin of the volume change in P/P, P/W and W/W combinations is discussed. The volume change in P/P was governed by the Poisson ratio as a material constant (mu 0) of the PVA gels, and the gels swelled by the change in the application of pressure (or deformation) in P/W. The volume change in W/W was closely related to the flow of solvent in the gel.

[A case of cortical reflex myoclonus manifesting tremor].

A 58-year-old woman developed slowly progressive tremulous myoclonus provoked mainly by action and posture. She had neither seizure nor dementia. No one in her family had similar symptoms. The presence of giant somatosensory evoked potentials (SEP) with enhanced long loop reflex and premovement cortical spikes demonstrated by the jerk-locked averaging method suggest that the involuntary movement is cortical reflex myoclonus. Magnetoencephalogram revealed that the generator sources of giant SEPs were the post-central somatosensory cortex and probably also the pre-central motor cortex. Symptoms improved after treatment with zonisamide, clonazepam and valpolate. This kind of involuntary movement might be called cortical myoclonic tremor.

[Lifestyles related to preserving 20 or more teeth at 80 years of age].

To explore lifestyle factors related to preserving 20 or more teeth at 80 years of age, a total of 114 Japanese persons aged 80 years old (70 with 20 teeth or more (mean teeth: 25.0 +/- 2.8) and 44 with 19 teeth or less (mean teeth: 5.2 +/- 6.3)) were studied. Study subjects received a dental examination and were directly interviewed, using a questionnaire, to collect such information as past episodes of tooth and gingival conditions, past attitude to dental care and several lifestyle habits. The following major findings emerged by statistical analysis. Probability of preserving 20 or more teeth at 80 years of age was significantly high with: (1) strict upbringing in childhood (p < 0.05 in males), (2) no swollen gums around 60 years old (p < 0.01 in males), (3) early visit to a dentist around 40 years old (p < 0.05 in males), and (4) not being fond of sweets in childhood (p < 0.05 in females). The following related to a high tendency toward preserving 20 or more teeth at 80 years of age: (1) graduate from primary school only (in females), (2) having a home dentist around 20 years old (in males), (3) tended to visit a dentist earlier at 20 years old (in males), (4) not eating sweet things at 60 years old (in males), and (5) have not smoked cigarettes (in males).(ABSTRACT TRUNCATED AT 250 WORDS)

[Jaw position, head position, body posture: development of an integrated system of examination, Part I].

Recently in the field of clinical orthodontics, there has been increased interest in the relationship between jaw and head position, sleep apnea, and equivocal symptoms occurring in head, neck and shoulder. It has already been determined that a relation exists between head posture and mode of breathing. Since the craniofacial skeleton is supported by the cervical, thoracic and lumbar vertebrae, the head position might have some biomechanical connection to total body posture. Therefore, an integrated system of examining jaw position, head position and body posture is being developed.

[Effects of message and personal involvement on risk perception and acceptance].

The present study analyzed people's risk perception regarding driving a car with studded or non-studded winter tires. Subjects were 252 residents of Sapporo, where a recent municipal ordinance prohibited studded tires, allowing only non-studded ones. Questionnaire data were examined concerning (1) the relationship between risk perception and its acceptance, (2) the effect of an inserted message, which was either positive or negative about the use of non-studded tires, and (3) the role of personal involvement, assessed with Personal Involvement Inventory (Zaichkowsky, 1985), regarding winter driving. Results were as follows: (1) The use of non-studded tires was favorably judged because of social benefit, but subjects hesitated to choose them because of a higher perceived possibility of an accident. (2) The inserted message had significant effects on benefit evaluation and perceived accident possibility. The effects were weaker for drivers who had experienced driving a car with studded tires. And (3) personal involvement had a weak correlation with risk judgements of the present study.