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PubMed1998

The incidence of a positive ice water test in bladder outlet obstructed patients: evidence for bladder neural plasticity.

PURPOSE: The ice water test triggers a C fiber, capsaicin sensitive spinal micturition reflex. We postulated that the ice water test is positive in a high proportion of patients with compared to those without bladder outlet obstruction. MATERIALS AND METHODS: Prospective evaluation of 111 consecutive patients was undertaken. Symptoms of urgency, urge incontinence, nocturia and daytime frequency as well as the presence of neurological disease were obtained from history and physical examination. Fluorourodynamics, including ice water cystometry, and pressure-flow studies were done for all 111 subjects. Obstruction was defined using the Abrams-Griffith nomogram and urethral resistive index. A positive ice water test was defined as presence of uninhibited bladder contraction with instillation of 0C saline at 50 cc per minute up to a maximum of 250 cc. Detrusor instability was defined according to the International Continence Society criteria using room temperature saline instillation. RESULTS: When patients with neurological disease were excluded, a positive ice water test was found in 71% of subjects with bladder outlet obstruction (12 of 17), which was significantly higher (p <0.0005, Yates corrected chi-square test) than the 7% positive ice water test rate in nonobstructed subjects (3 of 44). Conversely, the incidence of positive detrusor instability was not statistically different between the patients with or without bladder outlet obstruction. Of the subjects with neurological disease 85% (42 of 50) had a positive ice water test. The incidence of a positive ice water test was only 5 to 9% in patients with storage lower urinary tract symptoms. CONCLUSIONS: A positive ice water test has been previously described in infants and individuals with neurogenic bladders. However, subjects with bladder outlet obstruction had a significantly higher incidence of a positive ice water test compared to those without it, supporting the hypothesis of an enhanced spinal micturition reflex possibly due to plasticity of bladder afferents after bladder outlet obstruction. The ice water test may be useful in prognosticating bladder outlet obstruction treatment outcomes and determining the etiology of treatment failure.

Female↗
PubMed1997

Role of ICE-like proteases in endothelial cell hypoxic and reperfusion injury.

Because of its location between blood and tissue, the endothelium is particularly vulnerable to hypoxic/reperfusion injury, but the mechanisms responsible for this injury are not known. A number of recent findings suggest that hypoxia and reperfusion injures neuronal cells via apoptosis. Apoptosis has recently been shown to depend on the activation of a class of proteases with homology to Interleukin-1 beta converting enzyme (ICE) protease. Therefore, we examined the effect of specific inhibitors of ICE-like proteases on hypoxic and reperfusion injury in cultured EAhy926 endothelial cells. Pretreatment of cells with ICE inhibitor II (Ac-YVAD-CMK), ICE inhibitor III (Z-Asp-2,6-dichlorobenzoyloxy-methylketone-Z-Asp-CH2-DCB+ ++), or ICE inhibitor IV (Ac-YVKD-CHO) (all at 10-100 microM) did not protect cells from hypoxic injury. However, pretreatment of cells with ICE inhibitor III and to a lesser extent with ICE inhibitor II, but not with ICE inhibitor IV, protected cells from reperfusion injury. The protective effect of ICE inhibitor III was not dependent upon pH, but was associated with decreased release of arachidonic acid from cells. These findings suggest that reperfusion injury to EAhy926 endothelial cells involves ICE-like proteases. The identity of the protease(s) is not known but it does not appear to be a YAMA-type protease based upon ICE inhibitor specificity. Our data also indicate that a potential target of this protease is phospholipase A2 (PLA2).

Arachidonic Acid↗
PubMed2001

Isolation and identification of an ice-nucleating bacterium from the gills of the intertidal bivalve mollusc Geukensia demissa.

In the fall, freeze tolerant intertidal invertebrates usually produce ice-nucleating proteins that are secreted into the hemolymph. These proteins help protect against freeze damage by insuring that ice formation is limited to extracellular spaces. Geukensia demissa, a freeze tolerant, salt marsh bivalve mollusc was examined for the presence of ice nucleating proteins. The ice-nucleating temperature (INT) of the hemolymph was not significantly different from artificial seawater of the same salinity indicating the lack of an ice nucleating protein in the hemolymph. The palial fluid did have an elevated INT, indicating the presence of an ice nucleator. The INT of the palial fluid was significantly reduced by boiling and filtration through a 0.45-&mgr;m filter. High INT was also observed in the seawater associated with the bivalves, and was demonstrated in water samples collected from salt marshes but not sand and pebble beaches. Moreover, the INT of water samples collected from a salt marsh decreased in the summer. All of these data suggest that the ice-nucleating agents in the hemolymph and the seawater are ice-nucleating bacteria. One species of ice-nucleating bacteria, Pseudomonas fulva was isolated from the gills of Geukensia. These bacteria could perform the same function as hemolymph ice-nucleating proteins by limiting ice formation to extracellular compartments.

Journal Article↗
PubMed1997

Interleukin-1 beta converting enzyme (ICE) is preferentially expressed in neuroblastomas with favourable prognosis.

To determine whether interleukin-1 beta converting enzyme (ICE) plays a role in the programmed cell death of neuroblastoma, we studied ICE expression in primary tumours. In patients in stages I, II and IVS, ICE mRNA was detected in 22 of 32 (69%) tumours, while only 5 of 26 (19%) tumours expressed ICE in stages III and IV (P < 0.001). ICE mRNA was expressed in 27 of 47 (57%) tumours without MYCN amplification, but it was not detected in any tumours with MYCN amplification (P < 0.01). Immunohistochemically, the cytoplasm was stained in all 15 neuroblastomas examined. The nuclei were stained in 12 neuroblastomas without MYCN amplification, whereas only 1 of 3 tumours with MYCN amplification had positive staining in the nuclei. In ganglioneuromas, high levels of ICE mRNA were expressed, but immunostaining showed that the protease expression was confined to the cytoplasm. These observations suggest that ICE may be associated with the spontaneous regression often seen in favourable neuroblastomas and that localisation of ICE protease in the cell may be important for the cell death pathway. Double staining for ICE and TUNEL showed that they were co-localised in some nuclei, but the distribution of ICE protease expression was not necessarily the same as that of DNA fragmentation, suggesting that the protease expression probably preceded DNA fragmentation during the apoptotic process. ICE may play an important role in regulating the apoptotic process of neuroblastoma.

Blotting, Northern↗
PubMed2006

Comparative studies of O2 and N2 in pure, mixed and layered CO ices.

We present laboratory data on pure, layered and mixed CO and O2 ices relevant for understanding the absence of gaseous O2 in space. Experiments have been performed on interstellar ice analogues under ultra high vacuum conditions by molecular deposition at 14 K on a gold surface. A combination of reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) is used to derive spectroscopic and thermodynamic properties of the ices. It is found that for pure ices the desorption energy of O2 is larger than that of CO and N2. TPD spectra reveal similar desorption processes for all examined CO-O2 ice morphologies. The different amorphous and crystalline components of pure 13CO RAIR spectra are analyzed. The RAIRS data of the 13CO stretching vibration show a significant difference between layered and mixed CO-O2 ices: layered CO-O2 ices resemble that of pure 13CO whereas the spectra of mixed ices are broadened. The experiments also show that the sticking probabilities of O2 on CO and O2 on O2 are close to unity. These new results are compared with recently analyzed data of CO-N2 ices. The differences in the TPD and RAIRS spectra of the CO-N2 and CO-O2 ice systems are explained by differences in quadrupole intermolecular interactions and by different crystallization processes of these ices.

Journal Article↗
PubMed2005

Unusual Gruneisen and Bridgman parameters of low-density amorphous ice and their implications on pressure induced amorphization.

The low-temperature limiting value of the Grüneisen parameter for low-frequency phonons and the density dependence of the thermal conductivity (Bridgman parameter) of low-density amorphous (LDA) ice, high-density amorphous (HDA) ice, hexagonal ice Ih, and cubic ice Ic were calculated from high-pressure sound velocity and thermal conductivity measurements, yielding negative values for all states except HDA ice. LDA ice is the first amorphous state to exhibit a negative Bridgman parameter, and negative Grüneisen parameters are relatively unusual. Since Ih, Ic, and LDA ice all transform to HDA upon pressurization at low temperatures and share the unusual feature of negative Grüneisen parameters, this seems to be a prerequisite for pressure induced amorphization. We estimate that the Grüneisen parameter increases at the ice Ih to XI transition, and may become positive in ice XI, which indicates that proton-ordered ice XI does not amorphize like ice Ih on pressurization.

Journal Article↗
PubMed2001

Adaptation of Arctic and Antarctic ice metazoa to their habitat.

Sea ice is a unique habitat in polar seas. A diverse assemblage of plants and animals lives in its interior parts and at the ice-water interface. Their distribution is to a large extent controlled by abiotic parameters such as light, salinity and space, as well as food availability. In both the Arctic and Antarctic, the highest metazoan concentrations occur mostly in the bottom centimetres of the sea ice. Dominant metazoans are nematodes, turbellarians, rotifers and crustaceans. The ice-water interface itself houses in addition to endemic amphipods migrants from both the ice and the pelagic realm. To survive with the environmental conditions of the sea ice habitat, the ice biota is adapted, specifically to seasonal salinity variations from below 5 to above 60 PSU. Sea ice metazoans feed mainly on the algae growing within the sea ice. The loss of habitat during ice melt periods can lead to substantial sedimentation of ice fauna to the sea floor, where it might act as food source for the benthos.

Journal Article↗
PubMed2006

Hydrogen bond topology and the ice VII/VIII and Ih/XI proton ordering phase transitions.

Ice Ih, ordinary ice at atmospheric pressure, is a proton-disordered crystal that when cooled under special conditions is believed to transform to ferroelectric proton-ordered ice XI, but this transformation is still subject to controversy. Ice VII, also proton disordered throughout its region of stability, transforms to proton-ordered ice VIII upon cooling. In contrast to the ice Ih/XI transition, the VII/VIII transition and the crystal structure of ice VIII are well characterized. In order to shed some light on the ice Ih proton ordering transition, we present the results of periodic electronic density functional theory calculations and statistical simulations. We are able to describe the small energy differences among the innumerable H-bond configurations possible in a large simulation cell by using an analytic theory to extrapolate from electronic DFT calculations on small unit cells to cells large enough to approximate the thermodynamic limit. We first validate our methods by comparing our predictions to the well-characterized ice VII/VIII proton ordering transition, finding agreement with respect to both the transition temperature and structure of the low-temperature phase. For ice Ih, our results indicate that a proton-ordered phase is attainable at low temperatures, the structure of which is in agreement with the experimentally proposed ferroelectric structure. The predicted transition temperature of is in qualitative agreement with the observed transition at on KOH-doped ice samples.

Journal Article↗
PubMed1992

Ice Nucleation Activity in Fusarium acuminatum and Fusarium avenaceum.

Twenty fungal genera, including 14 Fusarium species, were examined for ice nucleation activity at -5.0 degrees C, and this activity was found only in Fusarium acuminatum and Fusarium avenaceum. This characteristic is unique to these two species. Ice nucleation activity of F. avenaceum was compared with ice nucleation activity of a Pseudomonas sp. strain. Cumulative nucleus spectra are similar for both microorganisms, while the maximum temperatures of ice nucleation were -2.5 degrees C for F. avenaceum and -1.0 degrees C for the bacteria. Ice nucleation activity of F. avenaceum was stable at pH levels from 1 to 13 and tolerated temperature treatments up to 60 degrees C, suggesting that these ice nuclei are more similar to lichen ice nuclei than to bacterial ones. Ice nuclei of F. avenaceum, unlike bacterial ice nuclei, pass through a 0.22-mum-pore-size filter. Fusarial nuclei share some characteristics with the so-called leaf-derived nuclei with which they might be identified: they are cell free and stable up to 60 degrees C, and they are found in the same kinds of environment. Highly stable ice nuclei produced by fast-growing microorganisms have potential applications in biotechnology. This is the first report of ice nucleation activity in free-living fungi.

Journal Article↗
PubMed2004

Characteristics of ice hockey-related injuries treated in US emergency departments, 2001-2002.

OBJECTIVE: Ice hockey, a popular sport in some regions, has potential for injury due to the velocities of players, pucks, and sticks. Previous studies conducted worldwide have shown that the rate of injury increases as the size and the speed of players increase, as well as when checking is allowed. However, national data about the annual number and types of injuries among ice hockey players are lacking. Data from previous studies were collected from regional tournaments, collegiate teams, local emergency departments (EDs), and different countries. The purpose of this article is to examine ice hockey injuries using a national US database to determine the age distribution of total injuries, injury types, and body regions injured, with a particular focus on ice hockey players <18 years old. METHODS: Data regarding ice hockey-related injuries treated in US EDs between January 1, 2001, and December 31, 2002, were extracted from the National Electronic Injury Surveillance System (NEISS). Data considered included age, gender, race, injury diagnosis, and body region injured. Ice hockey-related injury cases were identified using the consumer product code for ice hockey and the narrative description of the incident in NEISS. RESULTS: An estimated 32,750 individuals with ice hockey-related injuries were treated in US EDs in 2001-2002, including >18,000 youths <18 years old. The number of injuries peak through adolescence (ages 12-17; 47% of all injuries). Males experienced 90% of all injuries. A very small percentage of individuals were hospitalized after injury (1.2% of individuals <18 years old; 0.5% of individuals > or =18 years old). The incidence of head injuries increased as age decreased, although the trend was not statistically significant. The upper extremity (44%) accounted for the highest total percentages of body regions injured for youths <18 years old, and trunk (14%) and facial injuries (10%) represented the smallest total percentages. Players > or =18 years old had significantly more lacerations than younger players (38% of injuries for 18- to 24-year-olds; 25% for 25- to 34-year-olds; 50% for 35- to 44-year-olds compared with 19% for 6- to 11-year-olds and 14% for 12- to 17-year-olds). CONCLUSIONS: Adolescents had the greatest number of ice hockey-related injuries treated in NEISS hospital EDs in 2001-2002; thus, ongoing efforts to develop injury prevention strategies should focus on this age group. Players < or =17 years old had a lower percentage of lacerations compared with all older players and a higher percentage of upper extremity injuries. The percentage of individuals hospitalized after injury was very low, yet youths <18 years old had twice the percentage of hospitalization after injury compared with individuals > or =18 years old. Males experienced the vast majority of all ice hockey-related injuries, with females representing a higher percentage of injuries among youths than among adults. Children and adults alike can reap the physical fitness and social benefits from ice hockey, when they are able to avoid predictable and preventable injuries.

Adolescent↗
PubMed1997

Role of interleukin-1 beta converting enzyme (ICE) in acute myelogenous leukemia cell proliferation and programmed cell death.

The proinflammatory cytokine interleukin (IL)-1 has been shown to play a pivotal role in stimulating acute myelogenous leukemia (AML) cell proliferation. The gene for its prominent IL-1 beta form produces a 31-kDa precursor protein (pro-IL-1 beta) that is biologically inactive unless cleaved to its mature form by a cytoplasmic cysteine protease termed Il- 1 beta converting enzyme (ICE). Although ICE was first thought to be a unique enzyme with a single biologic activity, several investigators have demonstrated that ICE shares sequence homology with the protein product of ced-3, the gene for cell death of the nematode Caenorhabditis elegans, and induces apoptosis in different experimental models. It was therefore hypothesized that ICE may either augment the production of mature IL-1 beta and stimulate the proliferation of cells, in which IL-1 beta acts as an autocrine growth factor, or induce apoptosis. Recent data indicate that ICE is a member of an increasingly recognized family of cysteine proteases. Unlike ICE, the other members of this family do not cleave pro-IL-1 beta but are effective inducers of apoptotic cell death, whereas ICE acts primarily as an IL-1 beta converting enzyme. Because IL-1 beta serves as either an autocrine or paracrine growth factor in AML, we recently investigated the effect of ICE inhibition on AML colony growth and found that ICE inhibition reduced the production of mature IL-1 beta and suppressed AML progenitor proliferation. Our data suggest that ICE does not function as an apoptosis gene in AML but rather increases mature Il-1 beta production and AML cell proliferation. It is possible, therefore, that ICE inhibitors may be beneficial in AML therapy.

Animals↗
PubMed1998

High-level expression of ice nuclei in Erwinia herbicola is induced by phosphate starvation and low temperature.

In laboratory cultures of ice nucleation-active (Ice+) Erwinia herbicola isolates, it has been difficult to achieve high-level expression of ice nuclei, especially nuclei active at temperatures warmer than -5 degrees C (i.e., type 1 ice nuclei). Here we demonstrate that starvation for phosphate and exposure to low temperature triggers expression of ice nuclei in E. herbicola cultures. Starvation for nitrogen, sulfur, or iron was less effective. Under optimal conditions with two different strains, essentially all cells produced ice nuclei active at -10 degrees C or warmer, with an average of 22% containing type 1 ice nuclei within 1 h of a low-temperature shift. These conditions did not greatly enhance the shedding of ice nucleation-active membrane vesicles that are known to be produced by Ice+ E. herbicola isolates. These results support the theory that the Ice+ phenotype may allow nutrient-limited epiphytes to trigger freezing damage, releasing nutrients from host plants.

Erwinia↗
PubMed2005

Injuries from the 2002 North Carolina ice storm, and strategies for prevention.

CONTEXT: In 2002, an ice storm interrupted power to 1.3 million households in North Carolina, USA. Previous reports described storm injuries in regions with frequent winter weather. [Blindauer KM, Rubin C, Morse DL, McGeehin M. The 1996 New York blizzard: impact on noninjury visits. Am J Emerg Med 1999;17(1):23-7; Centers for Disease Control and Prevention. Community needs assessment and morbidity surveillance following an ice storm--Maine, January 1998. MMRW 1998;47(17):351-5; Daley WR, Smith A, Paz-Argandona E, Malilay J, McGeehin M. An outbreak of carbon monoxide poisoning after a major ice storm in Maine. J Emerg Med 2000;18(1):87-93; Hamilton J. Quebec's ice storm'98: "all cards wild, all rules broken" in Quebec's shell-shocked hospitals. Can Med Assoc J 1998;158(4):520-4; Hartling L, Brison RJ, Pickett W. Cluster of unintentional carbon monoxide poisonings presenting to the emergency departments in Kingston, Ontario during 'Ice Storm 98'. Can J Public Health 1998;89(6):388-90; Hartling L, Pickett W, Brison RJ. The injury experience observed in two emergency departments in Kingston, Ontario during 'ice storm 98'. Can J Public Health 1999;90(2):95-8; Houck, PM, Hampson NB. Epidemic carbon monoxide poisoning following a winter storm. J Emerg Med 1997;15(4):469-73; Lewis LM, Lasater LC. Frequency, distribution, and management of injuries due to an ice storm in a large metropolitan area. South Med J 1994;87(2):174-8; Smith RW, Nelson DR. Fractures and other injuries from falls after an ice storm. Am J Emerg Med 1998;16(1):52-5]. We postulated that injuries might differ in a region where ice storms are less common. OBJECTIVE: Identify storm-related injuries. DESIGN: Emergency department (ED) charts from the storm period (defined as onset of precipitation until 99% power restoration) were retrospectively reviewed. Included injuries were: falls on ice; injuries due to darkness; cold exposure; injuries from storm-related damage; burns; or carbon monoxide/smoke exposure. SETTING: Tertiary care ED, central North Carolina. PATIENTS: All ED patients. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Mechanism of injury. RESULTS: One hundred thirty incidents occurred, most resulting from storm damage and carbon monoxide. Seven were life threatening: four spinal fractures and two intracranial hemorrhages from falling tree limbs and one hypothermia. Carbon monoxide poisoning affected one pregnant woman and all children in our series. Twenty three percent of patients were Hispanic, although Hispanics comprise only 11% of the study ED population. CONCLUSIONS: Injuries from storm-related damage and carbon monoxide exposure predominated. Available hyperbaric chambers were quickly filled to capacity. Hispanics experienced a disproportionate number of injuries.

Adolescent↗
PubMedDate not supplied

Patterns and trends in Southern Ontario lake ice phenology.

An analysis is presented of 46 ice break up and 15 ice free season phenology data series obtained largely through volunteer monitoring efforts in Southern Ontario. Observations spanned the years 1853-2001. Available data included dates of ice formation and ice break up as well as the number of ice free days in a year. A high degree of temporal coherence in ice phenology between lakes was observed (137/365 pairwise correlations significant at P < 0.05). Significant monotonic trends towards earlier break up dates and longer ice free seasons were observed across the region both in the entire series and in the last thirty years of data. Trends in longer series may be associated with the end of the Little Ice Age. The significantly longer ice free seasons and earlier ice break up dates observed in the study area have important implications for lakes in other parts of Canada where climate change effects are predicted to be more extreme than in South-Central Ontario.

Environmental Monitoring↗
PubMed1996

Structural basis for the binding of a globular antifreeze protein to ice.

Antifreeze proteins (AFPs) have the unique ability to adsorb to ice and inhibit its growth. Many organisms ranging from fish to bacteria use AFPs to retard freezing or lessen the damage incurred upon freezing and thawing. The ice-binding mechanism of the long linear alpha-helical type I AFPs has been attributed to their regularly spaced polar residues matching the ice lattice along a pyramidal plane. In contrast, it is not known how globular antifreeze proteins such as type III AFP that lack repeating ice-binding residues bind to ice. Here we report the 1.25 A crystal structure of recombinant type III AFP (QAE isoform) from eel pout (Macrozoarces americanus), which reveals a remarkably flat amphipathic ice-binding site where five hydrogen-bonding atoms match two ranks of oxygens on the [1010] ice prism plane in the <0001> direction, giving high ice-binding affinity and specificity. This binding site, substantiated by the structures and properties of several ice-binding site mutants, suggests that the AFP occupies a niche in the ice surface in which it covers the basal plane while binding to the prism face.

Animals↗
PubMed1999

Type I 'antifreeze' proteins. Structure-activity studies and mechanisms of ice growth inhibition.

The type I 'antifreeze' proteins, found in the body fluids of fish inhabiting polar oceans, are alanine-rich alpha-helical proteins that are able to inhibit the growth of ice. Within this class there are two distinct subclasses of proteins: those related to the winter flounder sequence HPLC6 and which contain 11-residue repeat units commencing with threonine; and those from the sculpins that are unique in the N-terminal region that contains established helix breakers and lacks the 11-residue repeat structure present in the rest of the protein. Although 14 type I proteins have been isolated, almost all research has focused on HPLC6, the 37-residue protein from the winter flounder Pseudopleuronectes americanus. This protein modifies both the rate and shape (or 'habit') of ice crystal growth, displays hysteresis and accumulates specifically at the {2 0 2; 1} ice plane. Until very recently, all models to explain the mechanism for this specific interaction have relied on the interaction of the four threonine hydroxyls, which are spaced equally apart on one face of the helix, with the ice lattice. In contrast, proteins belonging to the sculpin family accumulate specifically at the {2 1; 1; 0} plane. The molecular origin of this difference in specificity between the flounder and sculpin proteins is not understood. This review will summarize the structure-activity and molecular modelling and dynamics studies on HPLC6, with an emphasis on recent studies in which the threonine residues have been mutated. These studies have identified important hydrophobic contributions to the ice growth inhibition mechanism. Some 50 mutants of HPLC6 have been reported and the data is consistent with the following requirements for ice growth inhibition: (a) a minimum length of approx. 25 residues; (b) an alanine-rich sequence in order to induce a highly helical conformation; (c) a hydrophobic face; (d) a number of charged/polar residues which are involved in solubility and/or interaction with the ice surface. The emerging picture, that requires further dynamics studies including accurate modelling of the ice/water interface, suggests that a hydrophobic interaction between the surface of the protein and ice is the key to explaining accumulation at specific ice planes, and thus the molecular level mechanism for ice growth inhibition.

Amino Acid Sequence↗
PubMed1996

A national outbreak of Salmonella enteritidis infections from ice cream. The Investigation Team.

BACKGROUND: In September 1994, the Minnesota Department of Health detected an increase in the number of reports of Salmonella enteritidis infections. After a case-control study implicated a nationally distributed brand of ice cream (Schwan's) in the outbreak, the product was recalled and further epidemiologic and microbiologic investigations were conducted. METHODS: We defined an outbreak-associated case of S. enteritidis infection as one in which S. enteritidis was cultured from a person who became ill in September or October 1994. We established national surveillance and surveyed customers of the implicated manufacturer. The steps involved in the manufacture of ice cream associated with cases of S. enteritidis infection were compared with those of products not known to be associated with infection matched for the date of manufacture. Cultures for bacteria were obtained from ice cream samples, the ice cream plant, and tanker trailers that had transported the ice cream base (premix) to the plant. RESULTS: We estimate that S. enteritidis gastroenteritis developed in 224,000 persons in the United States after they ate Schwan's ice cream. The attack rate for consumers was 6.6 percent. Ice cream associated with infection contained a higher percentage of premix that had been transported by tanker that had carried nonpasteurized eggs immediately before (P = 0.02). S. enteritidis was isolated from 8 of 226 ice cream products (3 percent), but not from environmental samples obtained from the ice cream plant (n = 157) or tanker trailers (n = 204). CONCLUSIONS: This nationwide outbreak of salmonellosis was most likely the result of contamination of pasteurized ice cream premix during transport in tanker trailers that had previously carried nonpasteurized liquid eggs containing S. enteritidis. To prevent further outbreaks, food products not destined for repasteurization should be transported in dedicated containers.

Adolescent↗
PubMed2006

Radiation effects in water ice: a near-edge x-ray absorption fine structure study.

The changes in the structure and composition of vapor-deposited ice films irradiated at 20 K with soft x-ray photons (3-900 eV) and their subsequent evolution with temperatures between 20 and 150 K have been investigated by near-edge x-ray absorption fine structure spectroscopy (NEXAFS) at the oxygen K edge. We observe the hydroxyl OH, the atomic oxygen O, and the hydroperoxyl HO(2) radicals, as well as the oxygen O(2) and hydrogen peroxide H(2)O(2) molecules in irradiated porous amorphous solid water (p-ASW) and crystalline (I(cryst)) ice films. The evolution of their concentrations with the temperature indicates that HO(2), O(2), and H(2)O(2) result from a simple step reaction fuelled by OH, where O(2) is a product of HO(2) and HO(2) a product of H(2)O(2). The local order of ice is also modified, whatever the initial structure is. The crystalline ice I(cryst) becomes amorphous. The high-density amorphous phase (I(a)h) of ice is observed after irradiation of the p-ASW film, whose initial structure is the normal low-density form of the amorphous ice (I(a)l). The phase I(a)h is thus peculiar to irradiated ice and does not exist in the as-deposited ice films. A new "very high density" amorphous phase-we call I(a)vh-is obtained after warming at 50 K the irradiated p-ASW ice. This phase is stable up to 90 K and partially transforms into crystalline ice at 150 K.

Absorptiometry, Photon↗