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At least 415 records · Page 23Linked to original sources
PubMed2001

Neuromuscular rehabilitation of a female Olympic ice hockey player following anterior cruciate ligament reconstruction.

STUDY DESIGN: Case study. OBJECTIVE: To demonstrate the unique aspects of rehabilitating a female athlete participating in ice hockey following anterior cruciate ligament (ACL) reconstruction. BACKGROUND: The patient was a 28-year-old female who sustained a traumatic injury to her left knee while playing ice hockey. After 6 weeks of rehabilitation (15 visits), the athlete elected to undergo ACL reconstruction following buckling episodes that she experienced during both skating and walking. METHODS AND MEASURES: Following ACL reconstruction using a patellar tendon autograft, the patient was treated for 6 months in 44 visits. Initial treatments consisted of effusion management, neuromuscular control of lower extremity muscles, and regaining passive range of motion, especially extension. Although instability testing revealed a negative pivot shift and a 2-millimeter side-to-side difference on KT-1000 examination, the patient reported a sensation of buckling when she attempted skating at 4 months (27 visits) following ACL reconstruction. Off-ice strength and functional testing of the lower extremity did not demonstrate deficits. At that time, a specific neuromuscular program for returning a patient to ice hockey was implemented. RESULTS: Following 17 physical therapy visits, which combined sport-specific and sex-specific neuromuscular rehabilitation, the patient was able to return to competitive ice hockey. Six months following ACL reconstruction, the patient reported no feeling of instability during skating. The patient reported a Lysholm score of 100 and Tegner activity score of 9. An on-ice functional test revealed the athlete's score was 80% of her pre-injury score. CONCLUSIONS: Failure of static knee stabilizers can be a cause of instability. Following ACL reconstruction, a neuromuscular rehabilitation program may prevent residual knee instability once the static stabilizers have been restored. A sport-specific neuromuscular rehabilitation program for the athlete participating in ice hockey should be considered.

Adult↗
PubMedDate not supplied

Effect of ice water ingestion on asthmatic children after exercise challenge.

Both exercise and ice water ingestion are known to be trigger factors for an asthma attack in ethnic Chinese asthmatic children. The purpose of this study was to investigate whether ice water ingestion further deteriorates pulmonary function of asthmatic children after exercise. Thirty Chinese asthmatic children underwent exercise challenge by ergocyclometer for 6 minutes and then were further challenged by immediate ingestion of ice water (200 ml, 0-4 degrees C), warm water (200 ml, 37 degrees C) or no ingestion on three different days in one week. Each patient completed the three different water ingestion tests after exercise challenge. The FEV1, FEF25-75%, and PEF tests were performed at baseline and again at 5, 15, 30, 60, 90 minutes after exercise plus water ingestion challenge. After the spirometric test at 90 minutes, 3 puffs (0.6 mg) of hexoprenaline from a metered dose inhaler were given and then a further spirometric test was performed 15 minutes later. The FEV1 and PEF were significantly decreased after exercise plus the 3 different water ingestion challenge except for the FEV1 in the patients who ingested nothing (p = 0.051) and PEF in the patients who ingested warm water (p = 0.163). FEF25-75% of the three tests was not significantly decreased. Exercise-induced asthma (EIA) developed in about two thirds of the 30 patients, regardless of whether ice water, warm water or nothing at all was ingested after exercise challenge. There was no statistically significant difference in spirometric data among the 3 different water tests at various time points. The mean percentage increase of FEV1, FEF25-75% and PEF after bronchodilator therapy were all the lowest in the ice water test, and the greatest in the warm water test. A statistically significant difference was found between ice water and warm water tests for FEV1 and PEF (p = 0.0293 and p = 0.0308 respectively). In conclusion, about two thirds of the asthmatic children in this series had EIA. Those who ingested warm water after exercise had a better bronchodilator response than those who ingested ice water.

Adolescent↗
PubMed1995

Pathology of the iridocorneal-endothelial syndrome. The ICE-cell.

PURPOSE: The iridocorneal-endothelial (ICE) syndrome is characterized by glaucoma, corneal failure, and iris destruction. Specular photomicroscopy of the corneal endothelium in this disease shows a population of abnormal cells named ICE-cells. Comparison between ultrastructural examination and specular photomicroscopy demonstrates that the histologic equivalent of ICE-cells are cells with an epithelial phenotype. The authors have studied the differentiation markers expressed by ICE-cells using an ultrastructural immunocytochemical technique. METHODS: Seven keratoplasty specimens from patients with the ICE syndrome were examined by scanning and transmission electron microscopy and light and electron microscopic immunocytochemistry. Comparison was made with three normal corneas. Immunocytochemical studies were performed with monoclonal antibodies to broad-spectrum cytokeratins, cytokeratins 3, 5/8, 8/18 and 19, vimentin, and epithelial membrane antigen. RESULTS: ICE-cells were morphologically similar to epithelial cells and expressed the same profile of differentiation markers as did normal limbal epithelial cells. CONCLUSIONS: ICE-cells may arise from an embryologic ectopia of ocular surface epithelium. Alternatively, these findings are consistent with a metaplastic stimulus resulting in a profound change in the phenotype of normal corneal endothelial cells.

Adult↗
PubMed1995

IL-1 beta converting enzyme (ICE) is not required for apoptosis induced by lymphokine deprivation in an IL-2-dependent T cell line.

Clonal T cells undergo programmed cell death (PCD) or apoptosis when cultured without the appropriate cytokines. The cysteine protease, IL-1 beta converting enzyme (ICE), is implicated in apoptosis based on its structural similarity to the PCD gene, ced-3, in Caenorhabditis elegans and the induction of PCD in fibroblasts transfected with recombinant ICE. We show that the murine IL-2-dependent CTLL T cell line expresses ICE but not IL-1 beta. Interestingly, ICE mRNA and protein levels increase during apoptosis. Yet inhibition of ICE enzymatic activity (> 90%) with either of two cell-permeable ICE inhibitors does not abrogate or delay apoptosis following IL-2 deprivation, as measured by DNA fragmentation and viability. Our results suggest that ICE is not required for apoptosis in lymphokine-deprived T cells.

Amino Acid Sequence↗
PubMed1997

In vitro and in vivo studies of ICE inhibitors.

Interleukin-1 beta-converting enzyme (ICE) is a cysteine protease responsible for proteolytic activation of the biologically inactive interleukin-1 beta precursor to the proinflammatory cytokine. ICE and homologous proteases also appear to mediate intracellular protein degradation during programmed cell death. Inhibition of ICE is a new antiinflammatory strategy being explored by the design of both reversible inhibitors and irreversible inactivators of the enzyme. Such compounds are capable of blocking release of interleukin-1 beta from human monocytes. ICE inhibitors that cross react against multiple ICE homologs can also block apoptosis in diverse cell types. ICE inhibitors impart protection in vivo from endotoxin-induced sepsis and collagen-induced polyarthritis in rodent models. Further optimization of the current generation of peptidyl ICE inhibitors will be required to produce agents suitable for administration in chronic inflammatory and neurodegenerative diseases.

Animals↗
PubMed2000

The role of the integument as a barrier to penetration of ice into overwintering hatchlings of the painted turtle (Chrysemys picta).

Hatchlings of the North American painted turtle (Chrysemys picta) spend their first winter of life inside a shallow, subterranean hibernaculum (the natal nest) where they may be exposed for extended periods to ice and cold. Hatchlings seemingly survive exposure to such conditions by becoming supercooled (i.e., by remaining unfrozen at temperatures below the equilibrium freezing point for body fluids), so we investigated the role of their integument in preventing ice from penetrating into body compartments from surrounding soil. We first showed that hatchlings whose epidermis has been damaged are more likely to be penetrated by growing crystals of ice than are turtles whose cutaneous barrier is intact. We next studied integument from a forelimb by light microscopy and discovered that the basal part of the alpha-keratin layer of the epidermis contains a dense layer of lipid. Skin from the forelimb of other neonatal turtles lacks such a layer of lipid in the epidermis, and these other turtles also are highly susceptible to inoculative freezing. Moreover, epidermis from the neck of hatchling painted turtles lacks the lipid layer, and this region of the skin is readily penetrated by growing crystals of ice. We therefore conclude that the resistance to inoculation imposed by skin on the limbs of hatchling painted turtles results from the presence of lipids in the alpha-keratin layer of the epidermis. Neonates apparently are able to avoid freezing during winter by drawing much of the body inside the shell, leaving only the ice-resistant integument of the limbs exposed to ice in the environment. The combination of behavior and skin morphology enables overwintering hatchlings to exploit an adaptive strategy based on supercooling.

Adaptation, Physiological↗
PubMed2003

SEM studies of the morphology and chemistry of polar ice.

Determining the microphysical location of impurities in natural ice from the polar regions is necessary for understanding the physical properties of ice and for assuring the integrity of ice core records. SEM, using a cold stage and X-ray microanalytical techniques, has proved to be the most powerful method so far for undertaking such work. Methods are adapted from those used to study frozen hydrated biological material. Sublimation within the cryo-chamber is often needed in order to concentrate impurities onto a plane, but this can lead to artifacts that must be recognized. Over 100 samples from different depths and sites in Greenland and Antarctica have been examined. Typical physical features, including air bubbles, clathrate hydrates of air, and dust particles are identified. The dust is found preferentially at grain boundaries in some samples; by pinning the boundaries, it can slow grain growth. Of the soluble material, chloride seems to be found most frequently in the ice lattice. Other impurities are found at grain boundaries, and only when the bulk concentration exceeds a threshold, at triple junctions. These findings give new insights into processes determining the physical properties of ice samples and of ice sheets, and new impetus for theoretical studies of the energetics that lead to this distribution.

Cold Climate↗
PubMed2000

Vitrification enhancement by synthetic ice blocking agents.

Small concentrations of the synthetic polymer polyvinyl alcohol (PVA) were found to inhibit formation of ice in water/cryoprotectant solutions. Ice inhibition improved with decreasing molecular weight. A PVA copolymer of molecular weight 2 kDa consisting of 20% vinyl acetate was found to be particularly effective. PVA copolymer concentrations of 0.001, 0.01, 0.1, and 1% w/w decreased the concentration of glycerol required to vitrify in a 10-ml volume by 1, 3, 4, and 5% w/w, respectively. Dimethyl sulfoxide concentrations required for vitrification were also reduced by 1, 2, 2, and 3% w/w, respectively. Crystallization of ice on borosilicate glass in contact with cryoprotectant solutions was inhibited by only 1 ppm of PVA copolymer. Devitrification of ethylene glycol solutions was also strongly inhibited by PVA copolymer. Visual observation and differential scanning calorimeter data suggest that PVA blocks ice primarily by inhibition of heterogeneous nucleation. PVA thus appears to preferentially bind and inactivate heterogeneous nucleators and/or nascent ice crystals in a manner similar to that of natural antifreeze proteins found in cold-hardy fish and insects. Synthetic PVA-derived ice blocking agents can be produced much less expensively than antifreeze proteins, offering new opportunities for improving cryopreservation by vitrification.

Calorimetry, Differential Scanning↗
PubMed1993

The condensation and vaporization behavior of ices containing SO2, H2S, and CO2: implications for Io.

In an extension of previously reported work on ices containing CO, CO2, H2O, CH3OH, NH3, and H2, measurements of the physical and infrared spectral properties of ices containing molecules relevant to Jupiter's moon Io are presented. These include studies on ice systems containing SO2, H2S, and CO2. The condensation and sublimation behaviors of each ice system and surface binding energies of their components are discussed. The surface binding energies can be used to calculate the residence times of the molecules on a surface as a function of temperature and thus represent important parameters for any calculation that attempts to model the transport of these molecules on Io's surface. The derived values indicate that SO2 frosts on Io are likely to anneal rapidly, resulting in less fluffy, "glassy" ices and that H2S can be trapped in the SO2 ices of Io during night-time hours provided that SO2 deposition rates are on the order of 5 micrometers/hr or larger.

Carbon Dioxide↗
PubMed1999

Evolution of interstellar ices.

Infrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Ices in molecular clouds are dominated by the very simple molecules H2O, CH3OH, NH3, CO, CO2, and probably H2CO and H2. More complex species including nitriles, ketones, and esters are also present, but at lower concentrations. The evidence for these, as well as the abundant, carbon-rich, interstellar, polycyclic aromatic hydrocarbons (PAHs) is reviewed. Other possible contributors to the interstellar/pre-cometary ice composition include accretion of gas-phase molecules and in situ photochemical processing. By virtue of their low abundance, accretion of simple gas-phase species is shown to be the least important of the processes considered in determining ice composition. On the other hand, photochemical processing does play an important role in driving dust evolution and the composition of minor species. Ultraviolet photolysis of realistic laboratory analogs readily produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(=O)NH2 (formamide), CH3C(=O)NH2 (acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including amides, ketones, and polyoxymethylenes (POMs). Inclusion of PAHs in the ices produces many species similar to those found in meteorites including aromatic alcohols, quinones and ethers. Photon assisted PAH-ice deuterium exchange also occurs. All of these species are readily formed and are therefore likely cometary constituents.

Carbon Monoxide↗
PubMed2004

Molecular adaptation in the ice worm, Mesenchytraeus solifugus: divergence of energetic-associated genes.

The ice worm, Mesenchytraeus solifugus, is the largest glacially obligate metazoan and among only a few metazoan species that complete their life cycle at 0 degrees C. We conducted a large-scale sequencing analysis of cDNAs isolated from ice worm anterior segments. Sequence comparisons among an available group of ice worm, arthropod, chordate, and nematode homologues suggest that ice worms encode proteins that are less bulky, are less polar, and contain fewer charged residues. Also, subunits of the catalytic F1 ATP synthase complex appear to have diverged more rapidly than other ice worm genes examined, suggesting a role in cold-temperature adaptation. Modeling of F1 ATP synthase beta and gamma subunits identified nonconservative, ice worm-specific amino acid substitutions at subunit contact sites and at sites proximal to the catalytic site.

Amino Acid Sequence↗
PubMed2000

Ice crystallization by Pseudomonas syringae.

Several bacterial species can serve as biological ice nuclei. The best characterized of these is Pseudomonas syringae, a widely distributed bacterial epiphyte of plants. These biological ice nuclei find various applications in different fields, but an optimized production method was required in order to obtain the highly active cells which may be exploited as ice nucleators. The results presented here show that P. syringae cells reduce supercooling of liquid or solid media and enhance ice crystal formation at sub-zero temperatures, thus leading to a remarkable control of the crystallization phenomenon and a potential for energy savings. Our discussion focuses on recent and future applications of these ice nucleators in freezing operations, spray-ice technology and biotechnological processes.

Biotechnology↗
PubMed2003

Recovery of a northern New England salt marsh plant community from winter icing.

High latitude salt marsh plant communities are frequently exposed to conspicuous winter ice disturbances, which trigger secondary succession. In this paper, we document the recovery of a northern New England salt marsh from a severe winter icing event in 1998. Ice disturbances that killed plants but that left the underlying peat intact recovered rapidly. However, ice damage that killed plants and removed the underlying peat, led to areas of physiologically harsh edaphic conditions, specifically waterlogged and anoxic soils that limited plant recolonization. A transplant experiment revealed that only the most stress-tolerant plants were capable of invading the most stressful portions of ice disturbances. A second experiment that artificially dried disturbance patches accelerated patch recovery. These data suggest that recovery from intense ice disturbance is dependent on stress-tolerant plants invading edaphically harsh disturbances, eventually facilitating the recolonization of the community. This process likely takes longer than a decade for full recovery to occur in the areas where both plants and the peat base are removed.

Ecosystem↗
PubMed1995

The electrolytical processes in dirty ices: implications for origin and chemistry of minor bodies and related objects.

Many moonlike bodies (M approximately or = 1 Moon) beyond the Martian orbit contain large amounts of dirty ice (approximately 50%) forming thick mantle with the solid phase thermal convection. When a body moves through the inter- or nearplanetary magnetized plasma, electric current is generated in the body and its environment. The current passing through a dirty ice containing up to 10% of organic admixtures produces a lot of electrochemical effects which have a profound impact on its composition. At this stage one can hardly say something definite concerning changes experienced by organics. The changes must occur inevitably and can be of a rather unexpected and far-reaching nature, so deserving a close study. Another obvious effect is a volumetric electrolysis of ice containing alien inclusions. The electrolysis products accumulate in ice in the form of a solid solution which is capable of detonation at 15-20 wt.% of 2H2 + O2. If M > or = 1 Moon (Galilean satellites, Titan), the body loses in explosion a part of its mass in the form of vapor and ice fragments (=short-period comet nuclei), whereas if M < or = 0.2 Moon, the body breaks up totally (the Main Belt asteroids origin approximately 3.9 Byr ago). 2H2 + O2 containing cometary nuclei are capable of burning or suffer new explosions when receiving an additional energy. The combustion in the sublimation products containing also light organics and 2H2 + O2 explains unexpected energetics and nearnuclear chemistry of Comet P/Halley (e.g. great abundances of negative and positive ions, atomic carbon, CO over CO2, origin of CHON particles etc) and its distant outbursts correlated, possibly, with the Solar activity. Thus the electrochemical processes in the dirty ice with organics, along with its subsequent thermal, radiative etc. processing, open up new potentials for explanation and prediction of quite unexpected discoveries.

Electric Conductivity↗
PubMed1980

Ice massage and transcutaneous electrical stimulation: comparison of treatment for low-back pain.

It has recently been shown that ice massage of the web between the thumb and index finger produces significantly greater relief of dental pain than a placebo control procedure. These results indicate that ice massage may be comparable to transcutaneous electrical stimulation (TES) and acupuncture, and may be mediated by similar neural mechanisms. The purpose of this study was to examine the relative effectiveness of ice massage and TES for the relief of low-back pain. Patients suffering chronic low-back pain were treated with both ice massage and TES. The order of treatments was balanced, and changes in the intensity of pain were measured with the McGill Pain Questionnaire (MPQ). The results show that both methods are equally effective: based on the Pain Rating Index of the MPQ, 67-69% of patients obtained pain relief greater than 33% with each method. The results indicate that ice massage is an effective therapeutic tool, and appears to be more effective than TES for some patients. It may also serve as an additional sensory-modulation method to alternate with TES to overcome adaptation effects. Evidence that cold signals are transmitted to the spinal cord exclusively by A-delta fibers and not by C fibers suggests that ice massage provides a potential method for differentiating among the multiple feedback systems that mediate analgesia produced by different forms of intense sensory input.

Adolescent↗
PubMed1994

High-density morphologies of ice in high-pressure frozen biological specimens.

Mouse liver tissue was rapidly cooled by high-pressure freezing at a nominal pressure of 2100 bar. Ultrathin cryosections were examined at 110 K with a cryoelectron microscope and the state of water was studied on micrographs and electron diffraction patterns. The results are compared with those from liver specimens cryofixed at ambient pressure by plunge freezing. The high-pressure frozen specimens contained crystalline frozen regions as well as areas which were vitreous. The spot diffraction patterns from crystalline regions are found to differ from those known for hexagonal ice. The comparison with powder diffraction data reveals the presence of the high-density morphologies Ice II and Ice III. Vitreous areas of biological samples frozen at ambient pressure are optically denser than areas where the water crystallised as cubic or hexagonal ice. However, on micrographs from high-pressure frozen samples, no significant contrast is found. This observation is explained by the higher specific mass of high-pressure ice compared to Ice I, an interpretation which requires a higher specific mass for high-pressure vitreous water compared to vitreous water produced at ambient pressure. The larger diffuse first ring of the diffraction pattern from high-pressure vitreous water confirms this argument.

Animals↗
PubMed2005

Ice-active proteins from the Antarctic nematode Panagrolaimus davidi.

The Antarctic nematode Panagrolaimus davidi has an ice-active protein that shows recrystallization inhibition but no thermal hysteresis. It belongs to a class of ice-active proteins found in a variety of freezing-tolerant organisms that display insignificant levels of thermal hysteresis in the context of the environmental temperatures to which they are exposed. The recrystallization inhibition activity of the P. davidi ice-active protein is present at low concentrations, is relatively heat stable, is affected more by acid than by alkaline pH, is not calcium dependant and is not affected by reagents that target carbohydrate residues or sulphydryl linkages. A hexagonal ice crystal growth form also indicates the presence of an ice-active protein. This protein could have important functions in the survival of intracellular freezing by this organism by controlling the stability of ice after its formation.

Acclimatization↗
PubMed2006

Agar plate freezing assay for the in situ selection of transformed ice nucleating bacteria.

An agar plate freezing assay is described based on the incorporation of fluorescein dye in agar medium. Upon addition of fluorescein the medium becomes transparent. This facilitates the monitoring of the ice nucleation event in vivo and the subsequent in situ selection of transformed ice nucleating bacteria. In comparison with known assays for the screening of transformants, the proposed assay is very accurate and reproducible. It may be applied in environmental samples screening for ice nucleating organisms, or in cDNA or genomic libraries for identifying novel ice nucleation genes. It may also prove useful in comparative studies of the ice nucleation activity, e.g. in directed evolution experiments involving ice nucleation genes.

Agar↗