Detailed dynamical features of the slow hydration water in the vicinity of poly(ethylene oxide) chains.

Poly(ethylene oxide) (PEO) is a well-known biocompatible polymer and has widely been used for medical applications. Recently, we have investigated the dynamic behavior of hydration water in the vicinity of PEO chains at physiological temperature and shown the presence of slow water with diffusion coefficient one order of magnitude less than that of bulk water. This could be evidence for the intermediate water that is critical for biocompatibility; however, its detailed dynamical features were not established. In this article, we analyze the quasi-elastic neutron scattering from hydration water through mode distribution analysis and present a microscopic picture of hydration water as well as its relation to cold crystallization.

Transnasal endoscopic surgery of post-operative maxillary cysts.

OBJECTIVE: The present study investigates the indications for transnasal endoscopic surgery in treating post-operative maxillary cysts. METHODS: In this retrospective study, the records of 118 patients with post-operative maxillary cysts (88 unilateral and 30 bilateral) consisting of 148 procedures were reviewed. RESULTS: A transnasal endoscopic approach was performed in 144 lesions (97.3 per cent). A combined endonasal endoscopic and canine fossa (external) approach was performed in 4 of 148 lesions, because the cysts were located distant from the nasal cavity and had a thick bony wall. A ventilation stent was placed in four patients (four cysts) to avoid post-operative meatal antrostomy stenosis. Recurrence was observed in five patients (4.2 per cent), all of whom subsequently underwent transnasal endoscopic revision surgery. CONCLUSION: Transnasal endoscopic surgery is an effective treatment for post-operative maxillary cyst with the exception of cysts located distant from the nasal cavity.

Endonasal endoscopic surgery with combined middle and inferior meatal antrostomies for fungal maxillary sinusitis.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of the combination of inferior and middle meatal antrostomies for treatment of a maxillary sinus fungus ball by functional endoscopic sinus surgery. METHODS: A retrospective analysis including 28 patients with non-invasive fungal maxillary sinusitis was performed. Fourteen patients underwent FESS with both middle and inferior meatal antrostomies (combined group). The remaining 14 patients were treated with FESS through only the middle meatal antrostomy (control group). RESULTS: Post-operative computed tomography showed normal maxillary sinuses in all patients in the combined group. In contrast, in the control group, five patients (36 per cent) exhibited a normal maxillary sinus, seven (50 per cent) showed maxillary mucosal thickening and two (14 per cent) had persistent fungus balls in the maxillary sinus. CONCLUSION: FESS with a combination of middle and inferior meatal antrostomies proved more effective for treating fungal maxillary sinusitis.

Association between mouth opening and upper body movement with intake of different-size food pieces during eating.

Head rotation is coordinated with mandibular movement during mouth opening, and the range of head rotation and mouth opening change with food size. However, past research did not include upper body movement, and no reports have related head and mandibular movement during realistic eating. The purpose of this study was to analyse head and mandibular movements with intake of different-sized food pieces during realistic eating. The test food consisted of apple cut into two different cube sizes (10mm and 20mm). Head and mandibular movements of 20 healthy young adults eating the apple pieces were simultaneously recorded in three dimensions by a wireless opto-electronic system. Reflective markers were attached to the upper lip and chin to measure the mouth opening range. Five markers were attached to eyeglasses frames to measure linear motion and rotation of the head. One marker was attached to the jugular notch of the sternum to measure linear motion of the upper body. Linear motion, and the inclination angle of the head and upper body, and mouth opening range were compared during intake of different-sized apple pieces. Mouth opening, head-neck rotation angle and the amount of upper body forward translation and inclination increased with larger apple pieces. However, isolated relative head motion was stabilized. We conclude that upper body forward motion and head-neck rotation assist mouth opening whilst stabilizing head orientation, and that the range of head-neck rotation angle, upper body translation and range of mouth opening change with food size during realistic eating.

Fluorinated Langmuir monolayers are more viscous than non-fluorinated monolayers.

The surface shear viscosity of the liquid expanded phase in Langmuir monolayers of fluorinated alcohols differs by orders of magnitude from the corresponding surface shear viscosity of Langmuir monolayers of their non-fluorinated counterparts. The line tension between the liquid expanded and the gaseous phase on the other hand is of similar magnitude for both fluorinated and non-fluorinated surfactants. The difference of fluorinated versus non-fluorinated monolayers is measured by active microrheology and by observing the shape relaxation of distorted liquid expanded domains toward a circular shape. Our microrheology measurements are supported by measurements of the relaxation rates of distortions, which in fluorinated liquid expanded phases are proportional to the deviation of the curvature from the mean curvature, whereas they are proportional to the square of the deviation of the curvature from the mean curvature in non-fluorinated monolayers.

Lipopolysaccharide inhalation exacerbates allergic airway inflammation by activating mast cells and promoting Th2 responses.

BACKGROUND: Bacterial infection occasionally exacerbates asthma, although the cellular and molecular mechanisms have not been well defined. An involvement of mast cells has been suggested, as lipopolysaccharides (LPS)-induced cytokine production from mast cells in vitro. OBJECTIVE: This study was undertaken to examine the effects of LPS inhalation on mast cell functions and allergen-specific immune responses in a murine model of asthma. METHODS: Female BALB/c mice or mast cell-deficient W/W(v) mice were immunized intraperitoneally with ovalbumin (OVA). Mice were challenged with aerosolized OVA or OVA with LPS daily from day 21 to day 24. Twenty-four hours after the last challenge, airway inflammation and OVA-specific immune responses were examined. Allergen-specific T cell responses were further analysed by adoptively transferring OVA-specific CD4(+) T cells. Expression of chemokines in the lung was also examined. RESULTS: LPS inhalation with OVA resulted in exacerbated airway infiltration, which was not evident in mast cell-deficient mice. IL-5 production by mast cells in the lung was enhanced by LPS inhalation. OVA-specific IgE production as well as proliferation, cytokine production and local infiltration of OVA specific T-helper lymphocytes type 2 (Th2) were also enhanced. Up-regulated expression of Th2- and/or eosinophil-attracting chemokines was observed in the lung of mice inhalated with LPS. CONCLUSIONS: LPS inhalation exacerbates airway inflammation, which is accompanied by mast cell activation and enhanced Th2 responses. These observations provide clues towards understanding the mechanisms of bacterial infection-induced exacerbation of the clinical features of asthma.

Treatment of oesophageal ulcerations using endoscopic transplantation of tissue-engineered autologous oral mucosal epithelial cell sheets in a canine model.

BACKGROUND: With the recent development of endoscopic submucosal dissection (ESD), large oesophageal cancers can be removed with a single procedure, with few limits on the resectable range. However, after aggressive ESD, a major complication that arises is postoperative inflammation and stenosis that can considerably affect the patient's quality of life. AIMS: To examine a novel treatment combining ESD and the endoscopic transplantation of tissue-engineered cell sheets created using autologous oral mucosal epithelial cells, in a clinically relevant large animal model. METHODS: Oral mucosal epithelial cells, harvested from beagle dogs, were cultured under normal conditions at 37 degrees C, on temperature-responsive dishes. After ESD (5 cm in length, 180 degrees in range), cell sheets were harvested by a simple reduction in temperature to 20 degrees C, and transplanted by endoscopy. RESULTS: The transplanted cell sheets were able to adhere to and survive on the underlying muscle layers in the ulcer sites, providing an intact, stratified epithelium. Four weeks after surgery, complete wound healing, with no observable stenosis, was seen in the animals receiving autologous cell sheet transplantation. By contrast, noticeable fibrin mesh and host inflammation, consistent with the intermediate stages of wound healing, were observed in the control animals that received only ESD. CONCLUSIONS: These findings in a clinically relevant canine model show the effectiveness of a novel combined endoscopic approach for the potential treatment of oesophageal cancers that can effectively enhance wound healing and possibly prevent postoperative oesophageal stenosis.

Proteolytic release of CD44 intracellular domain and its role in the CD44 signaling pathway.

CD44 is a widely distributed cell surface adhesion molecule and is implicated in diverse biological processes. However, the nature of intracellular signaling triggered by CD44 remains to be elucidated. Here, we show that CD44 undergoes sequential proteolytic cleavage in the ectodomain and intracellular domain, resulting in the release of a CD44 intracellular domain (ICD) fragment. Consequently, CD44ICD acts as a signal transduction molecule, where it translocates to the nucleus and activates transcription mediated through the 12-O-tetradecanoylphorbol 13-acetate-responsive element, which is found in numerous genes involved in diverse cellular processes. Expression of an uncleavable CD44 mutant as well as metalloprotease inhibitor treatment blocks CD44-mediated transcriptional activation. In search of the underlying mechanism, we have found that CD44ICD potentiates transactivation mediated by the transcriptional coactivator CBP/p300. Furthermore, we show that cells expressing CD44ICD produce high levels of CD44 messenger RNA, suggesting that the CD44 gene is one of the potential targets for transcriptional activation by CD44ICD. These observations establish a novel CD44 signaling pathway and shed new light on the functional link between proteolytic processing of an adhesion molecule at the cell surface and transcriptional activation in the nucleus.

Algal-lytic activities encoded by Chlorella virus CVK2.

Using a halo assay with E. coli lysates expressing Chlorella virus CVK2 genes on a cosmid contig, two different algal-lytic activities against Chlorella strain NC64A cells were found to be encoded on the CVK2 genome. The gene for vAL-1, one of the two activities, encoded a 349-aa ORF, which was homologous to PBCV-1 A215L and CVN1 CL-2. The vAL-1 gene was expressed at relatively early stages of the virus life cycle; transcripts and translation products appeared at 60 and 90 min postinfection, respectively. The vAL-1 protein was not incorporated into the viral particles but remained in the cell lysate, suggesting a role in the digestion of the cell wall before viral release at the final stage of infection. Cell wall materials isolated from Chlorella strain NC64A cells were digested by vAL-1 and degradation products were detected on TLC. In addition to Chlorella strain NC64A, vAL-1 lysed cells of four C. vulgaris strains as well as Chlorella sp. SAG-241-80.

Ras oncoprotein induces CD44 cleavage through phosphoinositide 3-OH kinase and the rho family of small G proteins.

CD44 is a cell surface adhesion molecule for several extracellular matrix components. We previously showed that CD44 expressed in cancer cells is proteolytically cleaved at the ectodomain through membrane-anchored metalloproteases and that CD44 cleavage plays a critical role in cancer cell migration. Therefore, cellular signals that promote the migration and metastatic activity of cancer cells may regulate the CD44 ectodomain cleavage. Here, we demonstrate that the expression of the dominant active mutant of Ha-Ras (Ha-Ras(Val-12)) induces redistribution of CD44 to the newly generated membrane ruffling area and CD44 ectodomain cleavage. The migration assay revealed that the CD44 cleavage contributes to the Ha-Ras(Val-12)-induced migration of NIH3T3 cells on hyaluronate substrate. Treatment with LY294002, an inhibitor for phosphoinositide 3-OH kinase (PI3K), significantly inhibits Ha-Ras(Val-12)-induced CD44 cleavage, whereas that with PD98059, an inhibitor for MEK, does not. The active mutant p110 subunit of PI3K has also been shown to enhance the CD44 cleavage, suggesting that PI3K mediates the Ras-induced CD44 cleavage. Moreover, the expression of dominant negative mutants of Cdc42 and Rac1 inhibits the Ha-Ras(Val-12)-induced CD44 cleavage. These results suggest that Ras > PI3K > Cdc42/Rac1 pathway plays an important role in CD44 cleavage and may provide a novel molecular basis to explain how the activated Ras facilitates cancer cell migration.

The effect of 2G on mouse circadian rhythms.

This study examined the effect of chronic 2G exposure on the regulation of body temperature (T(b)), activity (ACT), and circadian rhythms of mice. Five mice were implanted with biotelemetry units to record T(b) and ACT. The mice exhibited a stable daily mean of T(b) (37.1 +/- 2.1 degrees C) and ACT and robust circadian rhythms during the control 1G period. Mice exhibited a significant decline in T(b) (30.1 +/- 1.5 degrees C; t(4)=8.32, p<.01) and cessation of ACT within two hours following 2G onset. After 6 hours of continuous 2G exposure there was a recovery in T(b) (34.4 +/- 1.6 degrees C) that remained significantly below that of baseline (t(4)=3.66, p<.05). A similar pattern of recovery was seen following 12 hours of continuous 2G for ACT. A slower pattern of adaptation toward baseline levels occurred steadily over the next 6-13 days. Exposure to 2G also caused an immediate 4 day loss in circadian rhythm amplitude in both T(b) and ACT. Recovery to new steady state levels was achieved by 8 days and 13 days, respectively. These results demonstrate that under chronic 2G, the recovery time for the homeostatic steady-state values and circadian rhythms are shorter for the mouse than for the rat. These differences may be related to the scaling effects of 2G resulting from the mass difference between mice and rats.

Effects of square-wave and simulated natural light-dark cycles on hamster circadian rhythms.

Circadian rhythms of activity (Act) and body temperature (Tb) were recorded from male Syrian hamsters under square-wave (LDSq) and simulated natural (LDSN, with dawn and dusk transitions) light-dark cycles. Light intensity and data sampling were under the synchronized control of a laboratory computer. Changes in reactive and predictive onsets and offsets for the circadian rhythms of Act and Tb were examined in both lighting conditions. The reactive Act onset occurred 1.1 h earlier (P < 0.01) in LDSN than in LDSq and had a longer alpha-period (1.7 h; P < 0.05). The reactive Tb onset was 0.7 h earlier (P < 0.01) in LDSN. In LDSN, the predictive Act onset advanced by 0.3 h (P < 0.05), whereas the Tb predictive onset remained the same as in LDSq. The phase angle difference between Act and Tb predictive onsets decreased by 0.9 h (P < 0.05) in LDSN, but the offsets of both measures remained unchanged. In this study, animals exhibited different circadian entrainment characteristics under LDSq and LDSN, suggesting that gradual and abrupt transitions between light and dark may provide different temporal cues.

Development of circadian rhythms in rat pups exposed to microgravity during gestation.

Ten pregnant Sprague Dawley rat dams were exposed to spaceflight aboard the Space Shuttle (STS-70) for gestational days 11-20 (G 11-20; FLT group). Control dams were maintained in either a flight-like (FDS group) or vivarium cage environment (VIV group) on earth. All dams had ad lib access to food and water and were exposed to a light-dark cycle consisting of 12 hours of light (approximately 30 lux) followed by 12 hours of darkness. The dams were closely monitored from G 22 until parturition. All pups were cross-fostered at birth; each foster dam had a litter of 10 pups. Pups remained with their foster dam until post natal day 21 (PN 21). Pup body mass was measured twice weekly. At PN 14 FLT pups had a smaller body mass than did the VIV pups (p < 0.01). Circadian rhythms of body temperature and activity of pups from two FLT dams (n = 8), two FDS dams (n = 9) and two VIV dams (n = 7) were studied starting from age PN 21. All pups had circadian rhythms of temperature and activity at this age. There were no significant differences in rhythms between groups that could be attributed to microgravity exposure. These results indicate that exposure to the microgravity environment of spaceflight during this embryonic development period does not affect the development of the circadian rhythms of body temperature and activity.

Chronic 2G exposure affects c-Fos reactivity to a light pulse within the rat suprachiasmatic nucleus.

This study examined the effect of the hyperdynamic environment on the function of the retinohypothalamic tract. Rats were exposed to either 2 days or 21 days of 2G via centrifugation. During the last hour of 2G exposure, one series of rats was exposed to a 1 hour phase-shifting light pulse while the second series of rats did not receive a light pulse. In addition a groups of 1G controls was exposed to the same 1 hour lighting paradigm. All animals were processed for c-Fos within the SCN. The 1G controls showed the normal response to light in which significantly greater numbers of c-Fos positive neurons were found in the SCN of the light pulsed rats relative to that of the nonlight pulsed rats. However, rats exposed to 2 days of 2G did not show the same response to light. Light pulsed rats and nonlight pulsed rats exhibited few c-Fos positive neurons within the SCN. A recovery in the effect of light to induce c-Fos reactivity within SCN neurons occurred in the rats exposed to 21 days of 2G. These results suggest that exposure to 2G can temporarily suppress the responsiveness of the SCN to the phase-shifting effects of light mediated by the retinohypothalamic tract.

The effect of a BRN 3.1 deletion on the temperature response to 2G.

NASA: Researchers studied the effect of 2G exposure on body temperature in Wild type and BRN 3.1 Knockout mice to determine the feasibility to using BRN 3.1 Knockout mice as an animal model of the effects of altered gravitational fields on vestibular system physiology.^ieng

The effect of spaceflight on retino-hypothalamic tract development.

NASA: Researchers examined the effect of late prenatal exposure to microgravity on the development of the retina, retinohypothalamic tract, geniculo-hypothalamic tract, and suprachiasmatic nucleus. Results indicate an effect on c-fos activity in the intergeniculate leaflet between gestational day 20 and postnatal day 8, suggesting a delay in development of the circadian timing system.^ieng

Ambulatory behavior map, physical activity and biosignal monitoring system.

In this study, we have developed an ambulatory human behavior map and physical activity monitoring system. This was accomplished by equipping our portable digital biosignal memory device developed previously with GPS sensors and piezoresistive accelerometers. Using this new system, we can get a subject's behavior map, and estimate his physical activities and posture changes in daily life.

Circadian rhythms of temperature and activity in obese and lean Zucker rats.

The circadian timing system is important in the regulation of feeding and metabolism, both of which are aberrant in the obese Zucker rat. This study tested the hypothesis that these abnormalities involve a deficit in circadian regulation by examining the circadian rhythms of body temperature and activity in lean and obese Zucker rats exposed to normal light-dark cycles, constant light, and constant dark. Significant deficits in both daily mean and circadian amplitude of temperature and activity were found in obese Zucker female rats relative to lean controls in all lighting conditions. However, the circadian period of obese Zucker rats did not exhibit differences relative to lean controls in either of the constant lighting conditions. These results indicate that although the circadian regulation of temperature and activity in obese Zucker female rats is in fact depressed, obese rats do exhibit normal entrainment and pacemaker functions in the circadian timing system. The results suggest a deficit in the process that generates the amplitude of the circadian rhythm.

Molecular cloning of a group of mouse pancreatic islet beta-cell-related genes by random cDNA sequencing.

To understand the molecular basis of glucose concentration-responsive insulin synthesis and secretion from pancreatic islet beta cells, a group of pancreatic islet beta-cell-related cDNAs was cloned. A pair of cDNA libraries was constructed from a mouse pancreatic islet beta-cell line of MIN6, which was cultured in either high glucose or low glucose media. By applying a random cDNA sequencing approach, 503 and 395 independent species were obtained from a total of 1,011 and 762 clones in the high glucose and low glucose library, respectively. The unknown genes comprised the majority of about 70% independent clones in both libraries. In Northern blot analysis, 311 (69.4%) of 448 independent clones showed positive signals within 72 h of autoradiographic exposure. Surprisingly, 150 (48.2%) out of 311 positive clones showed positive signals to MIN6 cells, but not to NIH/3T3 fibroblasts. The expression level of three unknown clones were glucose-concentration dependent. Combination of a random cDNA sequencing approach and Northern blot analysis is useful to obtain a large number of novel genes and islet beta-cell-related genes.