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At least 19 recordsLinked to original sources

Evaluation of the effectiveness of wet ice, dry ice, and cryogenic packs in reducing skin temperature.

The purposes of this study were to evaluate and compare the ability of wet ice (WI), dry ice (DI), and cryogenic packs (CGPs) to reduce and maintain the reduction of skin temperature directly under the cooling agent and to determine whether the cooling effect on skin extended beyond the surface area in contact with the cooling agent. Ten female volunteers participated in the study, and each of the three cold modalities was applied randomly to the skin overlying the right triceps surae muscle. After 15 minutes of cold application, mean skin temperatures recorded under WI, DI, and CGP decreased 12 degrees, 9.9 degrees, and 7.3 degrees C, respectively. The only significant differences in cooling were between WI and DI and between WI and CGP. Fifteen minutes after removal of the cold modalities, no significant differences were found in mean skin temperature between WI, DI, and CGP. The residual mean decrease in skin temperature between the pretreatment rest interval (time 0) and 15 minutes after removal of the cold modality (time 30) was significant for WI only. No cooling was demonstrated 1 cm proximal or distal to any of the cooling agents after 15 minutes of cold application. These findings provide valuable information for the use of cryotherapy in the clinical setting.

Adult↗

Environmental Conditions in a Chamber with Dry Ice.

Dry ice is used in research laboratories as a source of CO2 for euthanasia of rodents. The present study was performed to evaluate environmental conditions created in a standard (9-liter) bell jar. By using a portable gas analyzer and measuring at 7.5 cm above the platform, we evaluated the chamber filling rate at room temperature with a known quantity of dry ice, maintenance of 70% CO2, and concentration of CO2 maintained when the top of the chamber was removed and replaced. Ambient temperature in the chamber and temperature of the platform were also measured. Results indicated that 500 g dry ice was required to maintain the filling rate and CO2 concentration at levels recommended by the American Veterinary Medical Association Panel on Euthanasia; that after removal of an animal, the lid should be replaced for 1 min before placing another animal in the chamber; and that although ambient temperature in the chamber never fell below 178C during an 80-min period, the platform temperature decreased to 08C. If a chamber must be used as described above for more than 1 h, consideration should be given to alternating between two chambers and allowing a chamber to warm to room temperature before reuse.

Journal Article↗

Scimitar-horned oryx (Oryx dammah) spermatozoa are functionally competent in a heterologous bovine in vitro fertilization system after cryopreservation on dry ice, in a dry shipper, or over liquid nitrogen vapor.

A heterologous bovine in vitro fertilization (IVF) system was used to study the functional competence of scimitar-horned oryx spermatozoa after cryopreservation. Four sperm-freezing methods were compared after dilution of ejaculates from six oryx with an equine semen extender: 1) dry ice, 2) dry shipper one-step, 3) dry shipper two-step, and 4) liquid nitrogen vapor. Post-thaw sperm motility, longevity, and acrosomal status were assessed and zona pellucida penetration, fertilization, and embryo cleavage were evaluated after coincubation of thawed oryx spermatozoa with in vitro-matured domestic cow oocytes. Sperm motility index (SMI) decreased (p < 0.05) over a 6-h period, but a high percentage (>/= 65%) of spermatozoa contained intact acrosomes in all treatments. Despite differences in sperm motility among methods, oocyte penetration, fertilization, and embryo cleavage did not differ (p >/= 0.05). However, cleavage success was < 50% across all treatments. There were positive correlations (p < 0.05; r = 0.81-0.97) between sample SMI at 3 and 6 h and fertilization, penetration, and cleavage, but no correlations (p >/= 0.05) between SMI at 0 or 1 h and IVF success. This study demonstrates that compatible heterologous gamete interaction allows thorough assessment of post-thaw sperm function in an endangered antelope. Scimitar-horned oryx spermatozoa appear relatively tolerant of varied cryopreservation methods, and preserved samples exhibit adequate post-thaw function to warrant use for assisted reproduction.

Acrosome↗

[Growth inhibition of Vibrio parahaemolyticus in seafood by tabletop dry ice cooler].

Tabletop dry ice coolers (three types; dome model, cap model and tripod model), which are used in kitchens and hotel banquet halls to refrigerate fresh seafood, were investigated to determine whether growth of Vibrio parahaemolyticus was inhibited by their use. On TSA plates containing 1.8% NaCl and fresh seafood (fillets of squid, pink shrimp and yellowtail), V. parahaemolyticus (O3:K6, TDH+) inoculated at 4 to 5 log CFU/sample and left at ambient temperature (25 degrees C) grew by 1.0 to 2.8 orders in 4 hours. In contrast, with tabletop coolers no significant increase in viable count occurred in 3 to 4 hours, confirming that tabletop coolers inhibited the growth of V. parahaemolyticus. The temperature in each tabletop cooler was kept below 10 degrees C for 80 to 135 min, though the CO2 gas concentration in them remained high for only a short time (0 to 75 min). It was presumed that the refrigeration function mainly contributed to growth inhibition. Our results indicate that tabletop dry ice coolers are helpful for prevention of food-borne disease due to V. parahaemolyticus in food-service locations, such as kitchens and banquet halls.

Dry Ice↗

Permanent marking of colored mice using dry ice.

Freeze marking, using dry ice, was successfully applied to colored mice for permanent, individual, identification. By this method, a 5-8 mm piece of dry ice is pressed against the skin of mice for 10 seconds. About 3 weeks after this treatment, spots of white hair growing at the site of treatment became recognizable to the naked eye, and allowed permanent identification of individual animals thereafter. The white spots were very clear in colored mice, and greatly facilitated animal identification as compared to conventional marking methods. Treatment of the animals with dry ice for 10 seconds has no discernible effects on the site of the treatment or the general condition of the animals.

Animal Identification Systems↗

Quantitative and qualitative studies on the bacteriological quality of Indian white shrimp (Penaeus indicus) stored in dry ice.

Indian white shrimp (Penaeus indicus) stored in dry ice at the 1:1 ratio were found to be organoleptically suitable for consumption when they were stored for 24 h without reicing. Shrimp stored in water ice at the 1:1 ratio (as control) were acceptable up to 18 h. Shrimp stored in a combination of dry ice and water ice at the ratio of 1:0.2:0.5 were also found to be acceptable up to 24 h. Total bacterial load ranged from 10(6) to 10(9) cfu g(-1), while total psychrophiles ranged from 10(3) to 10(6) cfu g(-1). Total lactics were found in the levels of 10(2)-10(6) cfu g(-1). H(2)S producers were from 10(3) to 10(5) cfu g(-1). Lowest temperature of -4.8 degrees C was observed in shrimps stored in dry ice at 1:1 ratio. Bacterial flora associated with fresh raw shrimp were Aeromonas, Pseudomonas, Vibrio, Flavobacterium and Serratia. Aeromonas constituted 38% of the flora in raw shrimp. Flavobacterium (43%), Pseudomonas (47%) and Pseudomonas (38%) were the dominant bacterial flora in the shrimp stored in dry ice at 1:1 ratio, in the combination package, and in water ice at 1:1 ratio, respectively.

Animals↗

Physical and thermal properties of blood storage bags: implications for shipping frozen components on dry ice.

BACKGROUND: Frozen blood components are shipped on dry ice. The lower temperature (-70 degrees C in contrast to usual storage at -30 degrees C) and shipping conditions may cause a rent in the storage bag, breaking sterility and rendering the unit useless. The rate of loss can reach 50 to 80 percent. To identify those bags with lower probability of breaking during shipment, the thermal and physical properties of blood storage bags were examined. STUDY DESIGN AND METHODS: Blood storage bags were obtained from several manufacturers and were of the following compositions: PVC with citrate, di-2-ethylhexylphthalate (DEHP), or tri-2-ethylhexyl-tri-mellitate (TEHTM) plasticizer; polyolefin (PO); poly(ethylene-co-vinyl acetate) (EVA); or fluorinated polyethylene propylene (FEP). The glass transition temperature (Tg) of each storage bag was determined. Bag thickness and measures of material strength (tensile modulus [MT] and time to achieve 0.5 percent strain [T0.5%]) were evaluated. M(T) and T0.5% measurements were made at 25 and -70 degrees C. Response to applied force at -70 degrees C was measured using an impact testing device and a drop test. RESULTS: The Tg of the bags fell into two groups: 70 to 105 degrees C (PO, FEP) and -50 to -17 degrees C (PVC with plasticizer, EVA). Bag thickness ranged from 0.14 to 0.41 mm. Compared to other materials, the ratios of M(T) and T0.5% for PVC bags were increased (p < or = 0.001) indicating that structural changes for PVC were more pronounced upon cooling from 25 to -70 degrees C. Bags containing EVA were more shock resistant, resulting in the lowest rate of breakage (10% breakage) when compared with PO (60% breakage, p = 0.0573) or PVC (100% breakage, p = 0.0001). CONCLUSIONS: Blood storage bags made of EVA appear better suited for shipping frozen blood components on dry ice and are cost-effective replacements for PVC bags. For the identification of blood storage bags meeting specific storage requirements, physical and thermal analyses of blood storage bags may be useful and remove empiricism from the process.

Blood Preservation↗

Homogeneous sample preparation of raw shrimp using dry ice.

Sample homogeneity is critical to accurate and reproducible analysis of trace residues in foods. A method of uniform sample preparation using dry ice is described for shrimp. Other sample preparation techniques for raw shrimp produce nonhomogeneous samples. Sample homogeneity was determined through analysis of chloramphenicol added to intact tiger or white shrimp prior to sample preparation. Simulated chloramphenicol residue levels were 50, 15, 10, and 5 ppb. No significant differences were noted when analyses of shrimp inoculated with chlor-amphenicol prior to sample preparation with dry ice were compared with analyses of shrimp spiked after grinding with dry ice. Grinding shrimp with dry ice produced samples with homogeneous chloramphenicol residues. This technique should be applicable to other tissues and vegetable products.

Animals↗

Dermabrasion using CO2 dry ice.

BACKGROUND: The cosmetic dermatologic surgeon can improve facial scars by using a variety of techniques. Chemical peels, lasers, and dermabrasion are among the most common modalities used. In recent years, laser resurfacing has enjoyed great popularity; however, there is still a role for the time-honored and effective technique of dermabrasion. The recent withdrawal of Freon from the market has made dermabrasion more difficult. OBJECTIVE: To introduce a novel technique of using solid carbon dioxide (CO2) to freeze the skin before dermabrasion. METHOD: Twenty-five consecutive patients with facial acne scars underwent a combination of procedures including chemical peeling and CO2 laser resurfacing, followed by freeze-dermabrasion. Compressed CO2 was then used to make a solid ball of dry ice. The ice was used to freeze the skin prior to dermabrasion. After the application of the dry ice ball to the skin for about 4 seconds, the scares were dermabraded with the large mushroom wheel. As the tissue defrosted, the operator started at the outer edge of the freeze and planed into the center. This procedure was repeated until the desired improvement was achieved. RESULTS: With dry ice, a good skin turgor was achieved. This provided a good foundation for the sanding of the acne scars. The patients were pleased with the results and complications were minimal. CONCLUSION: "Home-made" dry ice works as well as Freon in providing skin turgor for dermabrasion. CO2 dry ice has the added benefits of being inexpensive and environmentally friendly.

Adult↗

Oral mucosal blood flow following dry ice stimulation in humans.

The aim of the current pilot study was to establish a procedure that would allow the investigation of microcirculatory changes in the oral cavity. The authors studied the effects of painful stimulation using dry ice (CO2). To investigate potential regional differences in the change of blood flow, recordings were made for the tongue and at the mucosa of the hard palate, lip, and oral vestibule. The authors investigated 26 patients divided into groups of younger subjects (10 men, 3 women; age range 21-31 y) and older patients (2 men, 11 women; age range 54-74 y). Mucosal blood flow (mBF) was obtained at the hard palate, at the tip of the tongue, on the midline of the oral vestibule, and at the lip. Measurements were made during rest and for 2 minutes after application of dry ice for a 10-second duration, using a pencil-shaped apparatus. Blood pressure, heart rate, cutaneous blood flow, transcutaneous partial pressure of carbon dioxiode (PCO2) and partial pressure of oxygen (PO2) were recorded. Mucosal blood flow increased at all sites in response to application of dry ice (p <0.001), with peak flow at 0.5 minute to 1.5 minutes after onset of stimulation. During the 1.5 minutes to 2 minutes, blood flow decreased at all measurement sites with a tendency to return to baseline. Heart rate, blood pressure, pCO2, PO2, and cutaneous blood flow did not show significant changes. Overall, responses in older patients showed more variance when compared with younger patients. Stimulation by dry ice appears to be an effective, noninvasive, and tolerable means to investigate mucosal blood flow at different mucosal sites. Preliminary data indicate different levels of responsiveness to painful cold stimulation at different sites on the oral and perioral mucosa; particularly, mucosal blood flow response at the tongue was least pronounced. Therefore, assessment of stimulated mucosal blood flow appears to be a promising tool to investigate the pathophysiology of a number of neurologic symptoms, eg, the burning mouth syndrome.

Adult↗

Dry ice fixation of myofibrils for scanning electron microscopy.

A rapid method of fixation of myofibrils using dry ice is reported. A glass slide or coverslip containing a drop of glutaraldehyde-fixed suspension of myofibrils is placed on dry ice causing the myofibrils to adhere to the glass surface. The specimens are then dehydrated through the alcohols, air dried and metal coated. This technique gives the myofibrils a corrugated appearance under the scanning electron microscope corresponding to the sarcomere banding.

Animals↗

THE SURVIVAL OF PASTEURELLA PESTIS IN MATERIALS PRESERVED BY SOLID CARBON DIOXIDE (DRY-ICE).

In the investigation of outbreaks of plague it is frequently more satisfactory to send specimens of suspected material collected in the field to a central laboratory, where usually better facilities for their more detailed examination are available. In the present study the authors have investigated the suitability of solid CO(2) (dry-ice) for the preservation of such material during transit. Three types of preparation were tested: broth suspensions of Pasteurella pestis, the livers and spleens of guinea-pigs dying after being infected with two different strains of P. pestis, and whole carcasses of mice and ground-squirrels infected with the organism. An additional test to ascertain the rate at which animal specimens became frozen and thawed was also carried out.These studies showed that (1) organisms in the various tissues frozen in dry-ice were not adversely affected by such treatment; (2) the survival of P. pestis cells did not depend on the number of organisms present in broth cultures or tissue suspensions, small numbers surviving equally well as large; and (3) plague bacilli contained in whole carcasses, even when present in small numbers, were also successfully preserved. It is concluded from these results, and also from the authors' practical use of the method over several years, that for the transport of plague-suspect materials from the field to the laboratory freezing with dry-ice can be confidently recommended.

Animals↗

Pilot surveys for proficiency testing of semen analysis. Comparison of dry-ice vs liquid nitrogen shipments.

Two pilot surveys involving routine semen analysis were provided to eight and nine selected laboratories. The laboratories were selected for expertise and geographic diversity. Manual and computer-assisted semen analysis were performed by the participating laboratories on pooled cryopreserved human semen samples following shipment either on dry-ice pellets or in liquid nitrogen (dry shippers). Coefficient of variation values obtained were 13% to 39% for concentration, 19% to 127% for motility, and 42% to 90% for viability. Motility was impaired for sperm shipped on dry ice. However, variances and performance criteria can be established for all analyses. A semen analysis survey is feasible but expensive owing to the shipping costs of cryopreserved semen.

Cell Survival↗

A comparative study of adult mosquito trapping using dry ice and yeast generated carbon dioxide.

Adult mosquito collections were conducted for 12 weeks in two residential areas in Kuala Lumpur. The CDC light traps were compared using dry ice and yeast as sources of carbon dioxide attractants for mosquitoes. The efficacy of the dry ice baited trap was significant over yeast generated CO2 trap. The predominant species obtained were Culex quinquefasciatus, Stegomyia albopicta and Armigeres subalbatus.

Aedes↗

Pellet freezing of in vitro produced bovine embryos using dry ice.

In vitro produced bovine embryos were frozen by pellet freezing or vitrification method. In the pellet freezing method, the embryos were cooled on the dry ice and then frozen as pellets. At warming, the pellets were immersed directly into 0.5 M sucrose. The survival rates of blastocysts frozen by the pellet freezing method were higher (P<0.01) in 40% ethylene glycol (EG) than those in the lower concentrations (20 and 30% EG). Higher survival rates of blastocysts frozen by the pellet freezing method were obtained but the development rates did not differ, as compared with those by the vitrification method. There were no significant differences between the pellet freezing and vitrification method in the frequencies of post-thaw survival of hatched blastocysts. These results demonstrate that the pellet freezing method using dry ice can be used successfully for the cryopreservation of blastocysts.

Journal Article↗

Compression of foods during freeze-drying: water plasticization at the ice-dry layer interface.

The compressive mechanical properties of freeze-dried green beans show a pronounced decrease in rigidity when moisture content and/or temperature are increased. There exist several temperature and moisture combinations which give common values for mechanical properties. These combinations also give a common compressive behavior. Using this information on mechanical properties, it is possible to predict a stress-strain relationship, if given either a temperature, a moisture content, or the value of a pertinent mechanical property. It is shown that the moisture contents and temperatures that exist in the dry layer during freeze-drying result in mechanical properties that are suitable for compression of the dry layer. From studies on compression behavior during freeze-drying, it is shown that applied compressive pressure is the main determinant of final degree of compression. Increasing the compressive pressure gave a higher compression effect and gave a more rapid drying, presumably due to improved heat transfer in the compressed dry layer. From the above information, a simple method to predict compression behavior during freeze-drying was developed.

Fabaceae↗

Cryopreservation of human platelets using 6% dimethyl sulfoxide and storage at -80 degrees C. Effects of 2 years of frozen storage at -80 degrees C and transportation in dry ice.

Platelet studies were done in healthy male volunteers and in thrombocytopenic patients. Some of the platelets used in the study were isolated by mechanical apheresis using either the Haemonetics blood processor 30, the IBM blood processor 2997 or the Fenwal CS-3000 blood processor before freezing. Other platelets were isolated from individual units of whole blood and pooled before freezing. The platelets were frozen with a 6% cryoprotectant (DMSO) in a polyvinylchloride (PVC) plastic bag or a polyolefin plastic bag at -80 degrees C in a mechanical freezer and stored for as long as 3 years. Some of the frozen platelets were transported in dry ice in polystyrene foam containers to determine whether they would be adversely affected by such treatment. Platelet recovery after freezing, thawing and washing was about 75%. In the healthy male volunteers, in vivo recovery of autologous platelets 1-2 h after transfusion was about 33%, and the life span was about 8 days. In the thrombocytopenic patients, in vivo recovery values were 50% of those from fresh platelets. The transfusion of previously frozen washed platelets reduced clinical bleeding in the thrombocytopenic patients with bleeding. There was no evidence of quality deterioration in platelets after storage at -80 degrees C for at least 2 years, as determined from in vivo recovery and in vivo survival values, nor was there any adverse effect as a result of shipment of the frozen platelets in dry ice in polystyrene foam containers from one facility to another.

Blood Platelets↗