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At least 127 records · Page 7Linked to original sources
PubMed1998

Efficacy of the ruby laser in the treatment of Ota's nevus previously treated using other therapeutic modalities.

Ruby laser treatment, especially with a Q-switched laser, is remarkably effective for Ota's nevus, although a wide variety of other therapeutic modalities have had limited success. Consequently, laser treatment is now considered the treatment of choice. However, for Ota's nevus previously treated with dry ice cryotherapy (carbon dioxide snow), dermabrasion, free skin grafting, or other methods, therapy is still a challenge, even with the ruby laser. In this study, 14 patients with Ota's nevus previously treated using other modalities were treated using a Q-switched ruby laser. Eight patients previously underwent dry ice cryotherapy, three patients underwent free skin grafting, two patients underwent dermabrasion, and one patient received a cosmetic tattoo. The study group was composed of five male and nine female patients. The ages of the patients at the start of treatment ranged from 5 to 62 years. We concluded, based on the findings of this study, that Q-switched ruby laser therapy can provide favorable results even with lesions previously treated by other therapeutic modalities, provided that the treatment sessions are repeated more frequently and over a longer period of time than those used for untreated lesions and that they are combined with plastic surgical techniques such as scar resection or local flaps.

Adolescent↗
PubMed2001

Light, carbon dioxide, and octenol-baited mosquito trap and host-seeking activity evaluations for mosquitoes in a malarious area of the Republic of Korea.

Two field trials for commercially available and experimental mosquito traps variously baited with light, carbon dioxide, octenol, or combinations of these were evaluated in a malarious area at Paekyeon-Ri near Tongil-Chon (village) and Camp Greaves, Paju County, Kyonggi Province, Republic of Korea. The host-seeking activity for common mosquito species was determined using hourly aspirator collections from a human- and propane lantern-baited Shannon trap. The total number of mosquitoes and number of each species captured during the test were compared using 8 x 8 and 5 x 5 Latin square designs based on trap location. Significant differences were observed for the total number of mosquitoes collected in the 8 x 8 test, such that counterflow geometry (CFG) with CO2 > or = CFG with CO2 and octenol > or = Shannon trap > or = Mosquito Magnet with octenol > American Biophysics Corporation (ABC) light trap with light, CO2 (500 ml/min), and octenol > or = ABC light trap with light and dry ice > or = ABC light trap with light and CO2 > ABC light trap with light only. A concurrent 5 x 5 test found significant differences in trap catch, where Mosquito Magnet with octenol > New Jersey light trap > or = EPAR Mosquito Killer with CO2 > or = ABC light trap with light and dry ice > Centers for Disease Control (CDC) light trap (manufactured by John W. Hock) with light and octenol. Significant differences in trap catch were noted for several species including: Aedes vexans, Anopheles sinensis, An. yatsushiroensis, An. lesteri, Culex pipiens, and Cx. orientalis. Traps baited with octenol captured significantly fewer Cx. pipiens than those not baited with octenol. Likewise, no Cx. orientalis were captured in octenol-baited traps. Host-seeking activity showed a similar bimodal pattern for all species captured. Results from these field trap evaluations can significantly enhance surveillance efforts. Significantly greater numbers of mosquitoes were captured with mosquito traps using counterflow technology (e.g., Mosquito Magnet and CFG traps) when compared to standard light and carbon dioxide-baited traps. Additionally, field evaluations demonstrate that various traps can be utilized for isolation and detection of arboviruses and other pathogens.

Animals↗
PubMed1978

Method for maintaining viability of Clostridium perfringens in foods during shipment and storage: collaborative study.

A collaborative study was conducted in 12 laboratories to determine the effectiveness of a new method for maintaining vegetative cells of Clostridium perfringens in viable condition during storage and transport of food specimens to the laboratory. The collaborative results showed that treatment of brown gravy and roast beef samples with an equal amount by weight of sterile buffered glycerol-sodium chloride solution to give a final 10% glycerol concentration and storage with Dry Ice for 10 days at -56 degrees C resulted in plate counts of C. perfringens which were 2-4 log cycles higher with 2 different strains than counts with untreated specimens stored by the usual method at -20 degrees C. Plate counts obtained with the treated specimens stored with Dry Ice were less than 1 log cycle lower than counts made with identical specimens before freezing for storage and shipment to the collaborators. The results with treated specimens were also more uniform among the different laboratories. Because the new method for storage and shipment of food samples was so effective for maintaining viability of the organism, the official first action method for C. perfringens (46.B01) was changed to incorporate these procedures as part of the method.

Bacteriological Techniques↗
PubMed1979

[Vitamin A in irradiated foodstuffs (author's transl)].

Vitamin A losses induced by 10 MeV electrons in cream cheese, calf liver sausage, pig liver, whole egg powder and margarine continued to increase during storage for 4--8 weeks in presence of air. Thus vitamin A loss in sausage irradiated with 5 Mrad was 22% on the day after irradiation, 61% after 4 weeks. Irradiation and storage at 0 degrees C instead of at ambient temperature reduced these losses considerably. Exclusion of air (vacuum, nitrogen) or irradiation on dry ice (approx. -80 degrees C) were even more effective in preventing destruction of vitamin A. After 4 weeks of storage, cream cheese irradiated at 5 Mrad had lost 60% when irradiated and stored in air at ambient temperature, 20% in nitrogen atmosphere, 5% in vacuum package, and 5% when irradiated on dry ice and stored at ambient temperature.

Drug Stability↗
PubMed2005

[Residual particle free surfaces after shot peening in modular hip arthroplasty are feasible].

INTRODUCTION: Shot peening with steel balls is used for introduction of compressive stress in the production of morse taper junctions of modular hip endoprostheses. After this procedure, significant contamination with residual particles can be detected, which may lead to increased corrosion and third body wear. Additionally, the European norm EN 12010 requires surfaces free of residual particles. The aim of this study is to evaluate the effects of several cleaning procedures with regard to complying with EN 12010. MATERIAL AND METHOD: The surfaces of 12 Ti6Al7Nb rods with a diameter of 15 mm was shot peened with steel balls (GS VERA, Fa. Würth, Bad Friedrichshall, Germany). A field emission scanning electron microscopy (SEM, LEO 1525) was used for the detection of residual particles on the surface of the rods with a backscattered electron detector. After SEM examination, one sample each was cleaned using shot peening with sugar or dry ice and 10 rods using a pH dependent cleaning procedure. After these cleaning procedures, the samples were again analysed with the SEM for residual particle contamination. RESULTS: The surface of all rods showed a considerable contamination with steel particles after shot-peening with steel balls. After the cleaning procedure with dry ice or sugar steel contamination was lower, however, only the pH dependent cleaning procedure was able to achieve surfaces free of residual particles. DISCUSSION: For smooth shot-peened surfaces in modular hip arthroplasty Euro Norm EN 12010 can be fulfilled using shot peening with steel balls followed by a pH dependent cleaning procedure.

Hip Prosthesis↗
PubMed1996

Activity of antibodies against Salmonella dublin, Toxoplasma gondii, or Actinobacillus pleuropneumoniae in sera after treatment with electron beam irradiation or binary ethylenimine.

Viral contamination of biological material may constitute a risk when samples are exchanged between countries, and it may be necessary to subject the material to an inactivation treatment. The present study investigated possible adverse effects on antibody activity subsequent to either electron beam irradiation or binary ethylenimine (BEI) treatment. The treatments were performed with sera obtained from pigs or cattle. For each treatment level, the posttreatment activity was plotted against the pretreatment activity, and regression analyses were carried out. The slope of the regression line was used as an estimate for the relative posttreatment activity. For a Toxoplasma gondii indirect enzyme-linked immunosorbent assay (ELISA) and agglutination assay as well as for a Salmonella dublin indirect ELISA, the posttreatment activity was more than 89% of the pretreatment activity when the samples were irradiated in the frozen state (on dry ice) with up to 46. kGy or when they were treated with 5 or 10 mM BEI for up to 48 h. The samples were more sensitive to irradiation in the liquid state. Thus, samples irradiated with 22.6 kGy retained 98% of their activity in the indirect ELISA when they were irradiated in the frozen state on dry ice but only 35% of their activity when they were irradiated in the liquid state at 0 degrees C. The patterns seen in an S. dublin blocking ELISA and an Actinobacillus pleuropneumoniae complement fixation assay differed in that samples with a low level of pretreatment activity were subject to a relatively greater decrease in activity than samples with a high level of pretreatment activity. The complement fixation assay was particularly sensitive to irradiation of serum. It is concluded that serum samples retain sufficient activity by both methods of virus inactivation, especially when used in indirect ELISA or in the T. gondii agglutination assay.

Actinobacillus pleuropneumoniae↗
PubMed2001

Preanalytical factors in human plasma ascorbate assay.

Estimation of vitamin C (ascorbic acid) in various samples of fresh and frozen human plasma has shown that freezing in a regular freezer at -25 degrees C causes an approximately 14% loss of ascorbate in the sample. Freezing the same samples in a deep freezer at -75 degrees C causes less of an ascorbate loss amounting to about 9%. On the other hand, using the dry ice alcohol bath freezing, which shortens the freezing process to a fraction of seconds produced loss of ascorbate by 3.5% only. The storage time of previously frozen samples at -25 degrees C or -75 degrees C, from 2 to 14 days does not produce noticeable differences in the sample ascorbate concentration. Loss of ascorbate in samples frozen in the dry ice alcohol bath may be acceptable assuming analytical variability of ascorbate assay amounting to about 4% and broad biological variability of ascorbate concentration in various clinical conditions. Use of frozen plasma samples for ascorbate assays may essentially facilitate running this analysis in clinical laboratories.

Adult↗
PubMed1991

Field evaluation of carbon dioxide baits for sampling Ornithodoros turicata (Acari: Argasidae) in gopher tortoise burrows.

Field studies were conducted to assess the reliability of carbon dioxide baits in sampling Ornithodoros turicata Duges. Tick response to about 50 g of dry ice placed at various distances away from tick-infested burrows was monitored over a 2-h period. In addition, tick attraction to different flow rates of carbon dioxide was monitored. Tests were conducted over a 15-mo period, during which seasonal effects on O. turicata response to CO2 were assessed. The efficacy of the baits was evaluated at night and in daytime. Ticks responded to dry ice baits placed up to 8 m away from the burrows. There was no significant difference in the total number of ticks attracted in a 1-h period using 500 to 2,000 ml CO2/min. At night, ticks were attracted to CO2 bits throughout the year except in December and January. By contrast, ticks were attracted to CO2 baits during daytime only between May and mid-December.

Animals↗
PubMedDate not supplied

Histopathologic studies on wound healing caused by scalpel incision, cryosurgery and electrocautery on hamsters.

Scalpel incision, cryosurgery as demonstrated by the use of dry ice, and electrocautery have different effects both clinically and histologically. Twelve hamsters of equal weight were divided into four study groups to compare which of the three methods of incision initiates a faster healing capacity. Surgical incisions were made of equal depths and were observed after 2, 5, 10 and 12 days. Results showed a marked cellular infiltration in electrocautery as compared with the scalpel incision method and the dry ice incision.

Animals↗
PubMed1992

Evaluation of high volume particle sampling and sample handling protocols for ambient urban air mutagenicity determinations.

An investigation of high volume particle sampling and sample handling procedures was undertaken to evaluate variations of protocols being used by the U.S. Environmental Protection Agency. These protocols are used in urban ambient air studies which collect ambient and source samples for subsequent mutagenicity analysis of the organic extracts of the aerosol fraction. Specific protocol issues investigated include: (a) duration of sampling period, (b) type of filter media used to collect air particles, (c) necessity for cryogenic field site storage and dry ice shipping of filter samples, and (d) sample handling at the receiving laboratory. Six PM10 Hi-Vol samplers were collocated at an urban site in downtown Durham, North Carolina and operated simultaneously to evaluate 12 h versus 24 h collection periods and filter media choices of glass fiber, Teflon impregnated glass fiber (TIGF), and quartz fiber. Filters from the samplers plus field blanks were collected during each of 25 sampling periods. TIGF filters from two samplers were immediately placed on dry ice in the field and transported directly to cryogenic storage. TIGF, quartz, and glass fiber filters from three samplers were transported at ambient and maintained at room temperature for three to six days prior to cryogenic storage. One TIGF sample, which was collected on a previously tared filter, was subjected to controlled environment equilibration (40 percent relative humidity, 22 degrees C) for 8 to 24 h and weighed prior to cryogenic storage. All filters were subsequently stored at -70 degrees C to -80 degrees C prior to a one-time extraction and Salmonella (Ames) mutagenicity bioassay of the entire sample set.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1979

Effect of sample transport systems on survival of bacteria in ground beef.

The effects of two transport systems and cryoprotective agents on the survival of bacteria in ground beef samples were evaluated. Survival of Clostridium perfringens in ground beef samples after simulated transport (72 h) was higher (about 99%) in Dry Ice than in Trans Temp shipping units (-3 degrees C). There were no significant differences between the two transport systems in survival of coliforms, Escherichia coli, Staphylococcus aureus, or aerobic bacteria. Mixing ground beef samples at a ratio of 1:1 (wt/vol) with 10, 20, or 30% buffered solutions of dimethyl sulfoxide or glycerol before freezing improved the survival of C. perfringens and coliforms in both transport systems. Recovery of E. coli was significantly higher with the addition of 10% dimethyl sulfoxide before Dry Ice transport. Addition of 10% dimethyl sulfoxide resulted in a 100% recovery of both S. aureus and aerobic bacteria from ground beef after simulated transport in Trans Temp shipping units. The use of cryoprotective agents can improve the survival of bacteria during transport of ground beef samples.

Animals↗
PubMed1978

A comparison of procedures to determine free fatty acids in rat heart.

The level of free fatty acids in intact tissues has been found to be low but is known to rise in proportion to the extent of autolysis. Therefore, the high levels of free fatty acid reported in the cardiac lipids of rats fed rapeseed oil were reinvestigated using two different procedures for homogenization. Quick freezing and pulverization at dry ice temperature followed by lipid extraction was found to give lower values of free fatty acids (200 microgram/g of wet heart tissue) than the more commonly used technique of employing rotating blade-type homogenizers (greater than 1700 microgram/g of wet heart tissue). The amount of diglycerides was found to be 3 times greater when the latter method was used. The high levels of free fatty acid and diglyceride suggest that extensive autolysis occurs during homogenization with a rotating blade-type homogenizer. Freezing and pulverization at dry ice temperature is therefore recommended for determining intact lipid classes in rat heart.

Animals↗
PubMed1981

Technical problems associated with the production of technetium Tc 99m tin(II) pyrophosphate kits.

The amount of tin(II) required for adequate reduction, complexation, and stability of technetium Tc 99m pertechnetate in radiopharmaceutical kits, and methods of preventing the loss of tin(II) during formulation of these lyophilized kits are investigated. Tin(II) loss from stannous chloride solutions was studied under several conditions, including room air versus nitrogen atmospheres, during vial filling in a laminar-flow hood with samples frozen on dry ice versus samples at room temperature, during lyophilization, and during storage under refrigerated, ambient, and elevated temperatures. Various amounts of stannous chloride, ranging from 5 to 1000 microgram/ml, were used in formulating sodium pertechnetate Tc 99m kits containing 100 mCi technetium Tc 99m and 0.4 microgram total technetium. Samples were removed at various times; hydrolyzed technetium, pertechnetate, and technetium Tc 99m pyrophosphate were isolated on instant thin-layer chromatography-silica gel and quantified with a scintillation counter. The time necessary to deoxygenate distilled water by nitrogen purging was measured. Several sources of stannous chloride were assayed for tin(II) content. Tin(II) loss occurs rapidly in solution (15% in one hour) unless continuously protected with nitrogen, and during vial filling in a laminar-flow hood unless frozen with dry ice. No substantial loss of tin(II) was detected during lyophilization or during storage of lyophilized product at any of the three temperatures. A minimum of 400 microgram tin(II) was required to provide 90% technetium Tc 99m pyrophosphate at six hours after preparation. Adequate deoxygenation of small quantities (450 ml) of water was accomplished in less than one hour. Some stannous chloride salts were highly oxidized in the dry state, and only high-purity elemental tin wire gave acceptable yields of tin(II).

Chemistry, Pharmaceutical↗
PubMed2001

Development and validation of a gamma interferon ELISPOT assay for quantitation of cellular immune responses to varicella-zoster virus.

Cell-mediated immunity appears to be critical for the prevention and control of varicella-zoster virus (VZV) infection and complications arising from zoster. Current assays of VZV-specific cell-mediated immunity are cumbersome or lack sensitivity. We have developed a gamma interferon ELISPOT assay that provides a direct measure of the number of T cells secreting a cytokine following stimulation with antigen. This assay is extremely sensitive and specific, with the ability to detect gamma interferon spot-forming cells (SFC) in the range of 10 to 1,000 SFC per million peripheral blood mononuclear cells (PBMCs). This assay has been validated by demonstrating the following: (i) the response detected is mediated almost entirely by CD4+ T cells, (ii) ELISPOT responses from fresh-frozen PBMCs are equivalent to those from freshly isolated cells, (iii) frozen PBMCs can be shipped on dry ice for up to 48 h without loss of activity, (iv) frozen PBMC samples can be stored in liquid nitrogen over long periods (>22 months) without any significant change in response, and (v) the numbers of ELISPOTs counted using a computer-based imaging system are equivalent to those counted by humans but have lower variability. The ability to use frozen cells is facilitated by the use of a recombinant nuclease (Benzonase) that can prevent cell clumping when samples are thawed. Frozen PBMC samples can be cycled through multiple changes in storage between liquid nitrogen and dry ice without any change in response being detected. This facilitates collection of samples at one site and testing performed at a remote location. This VZV ELISPOT assay provides a new versatile tool for monitoring cellular immune responses either during a herpes zoster disease outbreak or following vaccination.

Antibodies, Monoclonal↗
PubMed1995

Survival and fertility of ram spermatozoa frozen in pellets, straws and minitubes.

The post-thaw survival and fertility of ram spermatozoa frozen in pellets, 0.25- and 0.5-ml PVC straws, and 0.25-ml minitubes were examined. In 5 experiments, a freezing height of 6 cm above the level of liquid nitrogen was optimal for 0.25- and 0.5-ml straws, whereas 4 cm was best for the 0.25-ml minitubes. Post-thaw motility of spermatozoa was lower for semen frozen in straws and minitubes than in pellets (Experiment 1: 43.7 vs 53.4%, P < 0.001), but after freezing was better in 0.5-ml straws and 0.25-ml minitubes than in 0.25-ml straws (Experiment 1: 44.9 vs 41.3%, P < 0.05; Experiment 2: 49.6 vs 46.8%, P < 0.01). Sperm motility was also better for 1:8 (semen:diluent) pre-freezing dilution rate (50.5%) than for 1:4 (45.6%, P < 0.01) and 1:2 (39.8%, P < 0.001) but not the 1:16 (49.5%) dilution rate. Dry ice was a better freezing medium than liquid nitrogen vapor (49.2 vs 46.9% motile spermatozoa, P < 0.001). The post-thaw motility of spermatozoa was similar for the three freezing packages if the semen was loaded at 5 degrees C, but motility was poorer for semen loaded into 0.25-ml straws than 0.25-ml minitubes at 30 degrees C (P < 0.05). In a fertility test, pregnancy rates were influenced by rams (3 rams, P < 0.05) and freezing package (pellets vs 0.25-ml minitube vs 0.25-ml straw vs 0.5-ml straw, P < 0.05) but not freezing medium (liquid nitrogen vapor vs dry ice). More ewes were pregnant after insemination with pellet-frozen semen (106/150, 71%) than with semen frozen in 0.25-ml straws (85/150, 57%; P < 0.05) and in 0.5-ml straws (83/150, 55%; P < 0.01) but not minitubes (98/150, 65%). It was concluded that minitubes provide a useful alternative to pellets as a storage package for ram spermatozoa, allowing for individual dose identification and easier storage while maintaining a fertility rate indistinguishable from that obtained with pellet-frozen semen.

Journal Article↗
PubMed1989

Comparison of flagging, walking, trapping, and collecting from hosts as sampling methods for northern deer ticks, Ixodes dammini, and lone-star ticks, Amblyomma americanum (Acari:Ixodidae).

Ticks were sampled by flagging, collecting from the investigator's clothing (walking samples), trapping with dry-ice bait, and collecting from mammal hosts on Fire Island, NY, U.S.A. The habitat distribution of adult deer ticks, Ixodes dammini, was the same in simultaneous collections from the investigator's clothing and from muslin flags. Walking and flagging samples can both be biased by differences between investigators, so the same person should do comparative samples whenever possible. Walking samples probably give a more accurate estimate than flagging samples of the human risk of encountering ticks. However, ticks (such as immature I. dammini) that seek hosts in leaf litter and ground-level vegetation are poorly sampled by walking collections. These ticks can be sampled by flagging at ground level. Dry-ice-baited tick-traps caught far more lone-star ticks, Amblyomma americanum, than deer ticks, even in areas where deer ticks predominated in flagging samples. In comparisons of tick mobility in the lab, nymphal A. americanum were more mobile than nymphal I. dammini in 84% of the trials. Therefore, the trapping bias may result from increased trap encounter due to more rapid movement by A. americanum, although greater attraction to carbon dioxide may also play a role. Tick traps are useful for intraspecific between-habitat comparisons. Early in their seasonal activity period, larval I. dammini were better represented in collections from mouse hosts than in flagging samples. Apparently, sampling from favored hosts can detect ticks at low population levels, but often cannot be used to get accurate estimates of pathogen prevalence in questing ticks.

Animals↗
PubMed1997

[An autopsy case of carbon dioxide intoxication].

A 44-year-old male, engaged in the transportation of dry ice, was found dead on the floor of the freezer of his refrigerator car which was parked in front of the place where he was scheduled to make a delivery. Autopsy was performed to investigate the cause of death. Apart from the signs of acute death, no other significant findings were obtained, either macro or microscopically; carbon dioxide poisoning was thus strongly suspected. We created a simulation experiment by using the refrigerator car to reproduce the events of the accident. The oxygen concentration in the freezer was 21.0% as indicated by oxygen sensors, but decreased to 17.1-17.4% when the engine was stopped. This decrease in oxygen concentration supposedly results from the production of carbon dioxide by the vaporization of dry ice. Carbon dioxide concentration in the air could be calculated from the change in the oxygen concentration in the closed space of the freezer. The concentration was assessed at 17.1-18.6%. An oxygen concentration of 17.1-17.4% does not of itself cause serious hypoxia, but a carbon dioxide concentration of 17.1-18.6% probably causes serious intoxication, because this value is beyond that of intoxication levels published in references. Therefore, we concluded that the cause of death in this case was carbon dioxide intoxication.

Adult↗
PubMed2005

Non-frozen transports of whole blood samples do not cause relevant bias for global coagulation tests in clinical trials evaluating the drug safety.

Sample shipments with dry ice have a large economic impact on clinical research. Therefore, the bias caused for global coagulation tests by non-frozen transports of whole blood instead of frozen plasma was investigated experimentally and by a meta-analysis of 6-year central laboratory data. In the experiment, aliquots from 14 healthy volunteers were kept as whole blood at 20+/-2 degrees C and as frozen plasma until an analysis of prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and antithrombin III (ATIII) at day 0, 1, 2, and 3 from collection. Within these 3 days only PT and aPTT demonstrated any changes: in blood samples kept at 20+/-2 degrees C these amounted about 10% for both. In frozen plasma, aPTT did not change whereas PT increased by 14%. In a meta-analysis of central laboratory data, PT and aPTT results were grouped across various phase II-IV trials by the type of sample transfer, either as frozen plasma on dry ice or non-frozen as whole blood. For the latter the mean difference to a reference group of phase I trials with same-day analysis was in line with the amount of bias found in the experiment (aPTT, 34.6+/-6.0 vs. 31.6+/-3.5 s; PT, 87.7+/-13.3 vs. 97.3+/-7.9%). The consistent bias resulted in shifted, but still normal distribution curves with a total rate of clinically relevant outliers of about 1.9% for aPTT and 2.4% for PT. Biases thus appear irrelevant for a common safety evaluation within clinical trials. Non-frozen whole blood transports for the measurement of global coagulation tests appear justified for this purpose, if protocols do not require frozen shipments for other reasons. However, transit time must not exceed 2 days and pre-analytical conditions should be consistent within the same trial.

Adult↗