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Foliar boron applications increase the final number of branches and pods on branches of field-grown soybeans.

Our previous work demonstrated that boron (B) supplied to soybeans (Glycine max [L.] Merrill cv ;Williams 82') by a stem infusion technique increased the number of pods on branches and led to a significant yield increase. Therefore, research was continued to determine whether soil or foliar applications of B could be used to achieve the same results. Field experiments were completed with both soil and foliar applications of B. Only the foliar applications of B resulted in a significant increase in the number of pods/branch. When split foliar treatments were applied twice during flowering, the total application of 0.56 kilograms of B per hectare was the optimal treatment for increasing pods/branch. In a second field experiment in 1987, soybeans were treated weekly from flowering through podfill with six split foliar applications of aqueous H(3)BO(3) solutions so that total applications were either 0, 1.1, or 2.24 kilograms of B per hectare. Foliar applications increased the number of branches/plant at the end of the season and significantly stimulated the formation of pods on branches, with 1.12 kilograms of B per hectare being the optimal treatment for these variables. This rate also tended to increase the number of seeds/plant and seed yield/plant. A duplicate experiment with minor modifications was conducted during the summer of 1988, and again the 1.12 kilograms of B per hectare application rate resulted in significant increases in number of branches at harvest as well as number of pods on branches. The 2.24 kilograms of B per hectare application rate also significantly increased these parameters. Foliar B applications induced increases in leaf B concentration far above the 60 micrograms per gram level that was previously accepted as the upper level of tolerance for soybeans. Since optimal branching and per plant yield parameters were achieved by plants with B leaf concentrations greater than 160 micrograms per gram, the accepted range of soybean tolerance for B must be reconsidered when B is foliarly applied.

Journal Article↗

Ultrasound applicators with internal water-cooling for high-powered interstitial thermal therapy.

Internal water-cooling of direct-coupled ultrasound (US) applicators for interstitial thermal therapy (hyperthermia and coagulative thermal therapy) was investigated. Implantable applicators were constructed using tubular US sources (360 angular acoustic emittance, approximately 7 MHz) of 10 mm length and 1.5, 1.8, 2.2, and 2.5 mm outer diameter (OD). Directional applicators were also constructed using 2.2 mm OD tubes sectored to provide active acoustic sectors of 90 degrees and 200 degrees. A water-cooling mechanism was integrated within the inner lumen of the applicator to remove heat from the inner transducer surface. High levels of convective heat transfer (2100-3800 W/m2K) were measured for practical water flow rates of 20-80 mL/min. Comparative acoustic measurements demonstrated that internal water-cooling did not significantly degrade the acoustic intensity or beam distribution of the US transducers. Water-cooling allowed substantially higher levels of applied electrical power (> 45 W) than previous designs (with air-cooling or no cooling), without detriment to the applicators. High-temperature heating trials performed with these applicators in vivo (porcine liver and thigh muscle) and in vitro (bovine liver) showed improved thermal penetration and coagulation. Radial depth of coagulation from the applicator surface ranged from 12 to 20 mm for 1-5 min of sonication with 28-W applied power. Higher powers (41 W) demonstrated increased coagulation depths (approximately 9 mm) at shorter times (15 s). Thermal lesion dimensions (angular and axial expanse) produced with directional applicators were controlled and directed, and corresponded to the active zone of the transducer. These characteristic lesion shapes were also generally unchanged with different sonication times and power, and were found to be consistent with previous coagulation studies using air-cooled applicators. The implementation of water-cooling is a significant advance for the application of ultrasound interstitial thermal therapy (USITT), providing greater treatment volumes, shorter treatment times, and the potential for treatment of highly perfused tissue with shaped lesions.

Acoustics↗

Tetracycline demineralization of dentin: the effects of concentration and application time.

The current investigation was initiated to study the effect concentration and application time has on the rate of tetracycline demineralization of dentin. Buccal and lingual surfaces of extracted bovine molars were ground to a smooth flat dentin surface using wetted silicon carbide discs. Standardized depressions were made in the dentin surface with a #909-055 diamond round wheel. Fresh tetracycline HCl (TTC-HCl) (Flavine Int. Inc.) solutions, i.e., 0, 25, 50, 75, 100, 125 and 150 mg/ml were prepared. A 30% citric acid solution was used as a positive control. The pH of each solution was recorded. 7 microl of each solution were pipetted into a depression and remained undisturbed for 1, 3, or 5 min. At the end of each application time period a fresh #3 cotton pellet was placed in the depression, once every 20 s for 1 min, to soak up the solution. The 3 pellets were placed in a 2.00 ml of 18 M omega H2O sample. As a measure of the rate of demineralization, the parts per million calcium (ppm Ca++) found in each sample were determined using atomic absorption spectrophotometry. Two-way analysis of variance was used to determine effects of TTC-HCI concentration and time on the rate of demineralization. No significant differences were found in the mean ppm Ca++ released at 1-, 3- and 5-min application times for 0, 25, or 50 mg/ml TTC. No significant differences were found in the mean ppm Ca++ released (i) between 3- and 5-min application times for 75, 100, 125 and 150 mg/ml TTC-HCl solutions and (ii) between 75, 100, 125 and 150 mg/ml TTC-HCl solutions within either the 3- or 5-min application times. The mean ppm Ca++ released at 3- and 5-min application times for 75, 100, 125 and 150 mg/ml TTC-HCI solutions were all significantly greater than the respective readings at the 1-min application time. The mean ppm Ca++ recorded for the 30% citric acid solution for all 3 application times were 3 to 5.5 x greater than the highest mean ppm Ca++ recording for TTC-HCl. The results of this study show that a 3-min application time of 75 mg/ml TTC-HCl solution is equally as effective at demineralizing dentin as is higher concentrations and/or longer application times, but was far less effective than a 30% citric acid solution.

Animals↗

Endovascular treatment of internal carotid artery stenosis: effect of primary stent application on debris particle release in human cadaveric specimens.

PURPOSE: To compare debris release with primary stent application (self-expanding stent application at stenosis and then balloon dilation through the opened stent) and that with secondary stent application (balloon angioplasty of stenosis and afterward additional stent application) for high-grade internal carotid artery stenosis in human cadaveric specimens. MATERIALS AND METHODS: Fresh human cadaveric internal carotid artery specimens were attached to a tube system. High-grade stenoses (>66%) were selected, randomized for primary or secondary stent application, and then treated, with fluoroscopic guidance, while the system was rinsed in a pulsating flow. Fluid was collected and filtered, and debris particles were examined with a light microscope. Particles were analyzed according to those consecutively caught by 100 x 100-microm and 11 x 11-microm mesh filters. Results were evaluated in relation to stent application. For statistical analyses of group differences, the exact Mann-Whitney U test was used. RESULTS: Thirteen high-grade human cadaveric internal carotid artery stenoses were analyzed. Five specimens were randomly assigned to secondary stent application, and eight were assigned to primary stent application. No significant difference could be demonstrated for debris release with primary or secondary stent application. P values ranged from.051 to.754. CONCLUSION: The reported superiority of primary stent application may not be related to debris reduction.

Arteriosclerosis↗

Topical application of 5-aminolevulinic acid and its methylester, hexylester and octylester derivatives: considerations for dosimetry in mouse skin model.

Ester derivatives of 5-aminolevulinic acid (ALA-esters) have been proposed as alternative drugs for ALA in photodynamic therapy. After topical application of creams containing ALA, ALA methylester (ALA-Me), ALA hexylester (ALA-Hex) and ALA octylester (ALA-Oct) on mouse skin, typical fluorescence excitation and emission spectra of protoporphyrin IX (PpIX) were recorded, exhibiting a similar spectral shape for all the drugs in the range of concentrations (0.5-20%) studied. The accumulation kinetics of PpIX followed nearly a similar profile for all the drug formulations. The fluorescence of PpIX peaked at around 6-12 h of continuous cream application. Nevertheless, some differences in pharmacokinetics were noticed. For ALA cream, the highest PpIX fluorescence was achieved using 20% of ALA in an ointment. Conversely, 10% of ALA-Me and ALA-Hex, but not of ALA-Oct, in the cream was more efficient (P < 0.05) than was 20%. The cream becomes rather fluid when 20% of any of these ALA-esters is used in ointment, whereas 10% and lower concentrations of ALA-esters do not significantly increase fluidity of the cream. The dependence of PpIX accumulation on the concentration of ALA and ALA-ester in the applied cream followed (P < 0.002) kinetics as described by a mathematical model based on the Michaelis-Menten equation for enzymatic processes. Under the present conditions, the PpIX amount in the skin increased by around 50% by the application of ALA-Me, ALA-Hex or ALA-Oct for 4-12 h as compared with ALA for the same period. Observations of the mice under exposure to blue light showed that after 8-24 h of continuous application of ALA, the whole mouse was fluorescent, whereas in the case of ALA-Me, ALA-Hex and ALA-Oct the fluorescence of PpIX was located only at the area of initial cream application. The amount of the active compound in the applied cream necessary to induce 90% of the maximal amount of PpIX was determined for normal mouse skin. Optimal PpIX fluorescence can be attained using around 5% ALA, 10% ALA-Me and 5% ALA-Hex creams during short application times (2-4 h). Topical application of ALA-Oct may not gain optimal PpIX accumulation for short applications (<5 h). For long application times (8-12 h), it seems that around 1% ALA, 4% ALA-Me, 6% ALA-Hex and 16% ALA-Oct can give optimal PpIX fluorescence. But for long application times and high concentrations, systemic effect of ALA applied topically on relatively large areas should be considered.

Administration, Topical↗

Effect of manure application timing, crop, and soil type on nitrate leaching.

Timing of manure application affects N leaching. This 3-yr study quantified N losses from liquid manure application on two soils, a Muskellunge clay loam and a Stafford loamy sand, as affected by cropping system and timing of application. Dairy manure was applied at an annual rate of 93 800 L ha(-1) on replicated drained plots under continuous maize (Zea mays L.) in early fall, late fall, early spring, and as a split application in early and late spring. Variable rates of supplemental sidedress N fertilizer were applied as needed. Manure was applied on orchardgrass (Dactylis glomerata L.) in split applications in early fall and late spring, and early and late spring, with supplemental N fertilizer topdressed as NH4NO3 in early spring at 75 kg N ha(-1). Drain water was sampled at least weekly when lines were flowing. Three-year FWM (flow-weighted mean) NO3-N concentrations on loamy sand soil averaged 2.5 times higher (12.7 mg L(-1)) than those on clay loam plots (5.2 mg L(-1)), and those for fall applications on maize-cropped land averaged >10 mg L(-1) on the clay loam and >20 mg L(-1) on the loamy sand. Nitrate-N concentrations among application seasons followed the pattern early fall > late fall > early spring = early + late spring. For grass, average NO3-N concentrations from manure application remained well below 10 mg L(-1). Fall manure applications on maize show high NO3-N leaching risks, especially on sandy soils, and manure applications on grass pose minimal leaching concern.

Agriculture↗

Personality and gender influences on faculty ratings and rankings of oral and maxillofacial surgery residency applicants.

This study examined effects of applicants' personality and gender on faculty rankings and matching to an Oral and Maxillofacial Surgery (OMS) residency program. Forty-seven applicants completed a standardized personality measure (Adjective Check List, ACL), and faculty interviewers rated each applicant on five personality dimensions during their onsite interview. Applicants were found to be similar to the normative population on all ACL personality dimensions, indicating that there is no distinctive personality profile characteristic of individuals seeking an OMS residency position. Male applicants were rated by interviewers as being more capable of dealing with stress effectively and more affiliative and deferent to authority than female applicants. Applicant ACL scores were unrelated to faculty rankings, but applicants rated as more friendly, motivated, assertive, confident, and tolerant of stress received more favorable rankings. Compared to applicants who did not match at this site, matched applicants were more likely to seek emotional support from others and were rated as being more assertive. Study limitations as well as implications for the use of personality measures and interviews in the selection of OMS residency candidates are discussed.

Adult↗

Surface biosolids application: effects on infiltration, erosion, and soil organic carbon in Chihuahuan Desert grasslands and shrublands.

Land application of biosolids is a beneficial-use practice whose ecological effects depend in part on hydrological effects. Biosolids were surface-applied to square 0.5-m2 plots at four rates (0, 7, 34, and 90 dry Mg ha(-1)) on each of three soil-cover combinations in Chihuahuan Desert grassland and shrubland. Infiltration and erosion were measured during two seasons for three biosolids post-application ages. Infiltration was measured during eight periods of a 30-min simulated rain. Biosolids application affected infiltration rate, cumulative infiltration, and erosion. Infiltration increased with increasing biosolids application rate. Application of biosolids at 90 dry Mg ha(-1) increased steady-state infiltration rate by 1.9 to 7.9 cm h(-1). Most of the measured differences in runoff among biosolids application rates were too large to be the result of interception losses and/or increased hydraulic gradient due to increased roughness. Soil erosion was reduced by the application of biosolids; however, the extent of reduction in erosion depended on the initial erodibility of the site. Typically, the greatest marginal reductions in erosion were achieved at the lower biosolids application rates (7 and 34 dry Mg ha(-1)); the difference in erosion between 34 and 90 dry Mg ha(-1) biosolids application rates was not significant. Surface application of biosolids has important hydrological consequences on runoff and soil erosion in desert grasslands that depend on the rate of biosolids applied, and the site and biosolids characteristics.

Conservation of Natural Resources↗

Ankle and thigh skin surface temperature changes with repeated ice pack application.

OBJECTIVE: Most of the research on cold applications has been performed on nonexercising supine subjects during a single cold pack application. Most athletic injuries occur during exercise, which increases skin temperature. Exercise before ice application will also increase ankle skin temperature during the rewarming phase. The purpose of this study was to examine the effects of activity on subsequent ice pack applications and rewarming using standard immediate care procedures. DESIGN AND SETTING: Three experimental conditions (20-, 30-, and 40-minute ice pack applications) were applied to 12 subjects in a repeated measures design. Subjects rode a bicycle ergometer for 15 minutes before ice application to the ankle and opposite thigh, and were active (walking with crutches, simulated showering and dressing) for 20 minutes following application. Subjects rested with the limb elevated for an additional 40 minutes. Ice packs were then reapplied for the appropriate time (20, 30, or 40 minutes) followed by 60 minutes of rest with the limb elevated. SUBJECTS: Twelve (8 males, 4 females) college-aged volunteers. Only subjects with good-to-high fitness levels were accepted for this study. MEASUREMENTS: Ankle skin, thigh skin, and atmospheric temperatures were measured every minute using an Isothermex (Columbus Instruments, Columbus, OH). RESULTS: Thigh temperature changes during the first ice application were greater during the 30- and 40-minute conditions than the 20-minute condition. Ankle and thigh temperature changes during the first ice application and rewarming, and for the entire trial were greater during the 40-minute condition than the 20-or 30-minute conditions. Throughout the first ice application and rewarming, and the entire trial, thigh temperature changes were greater during the 30-minute condition than the 20-minute condition. CONCLUSIONS: During immediate care procedures following injury, ice packs should be reapplied immediately following showering, changing clothes, and returning home.

Journal Article↗

[Effects of P application on P concentrations in paddy soil and its surface water: a simulation test].

An anaerobic incubation test was conducted to study the effects of different P application rate on the P concentrations in paddy soil and its surface water. The results showed that soil available P (Olsen-P) decreased rapidly at the beginning, but approached to stable after 60 days of P application. Both Olsen-P and residual P increased with increasing P application rate, and Olsen-P had a positive correlation with P application rate, suggesting that the test soil had a strong P adsorption capacity. After P application, the total P (TP) in soil surface water increased rapidly, and then decreased slowly, showing that there was a P exchange between soil and its surface water. After 120 days of P application, there was an exponential relationship between soil surface water TP and P application. The TP in soil surface water increased rapidly when the P application rate was 400 - 800 kg x hm (-2) , and easy to be lost when the P application rate was higher than 800 kg x hm(-2). The simulation with split line model on the relationship between soil Olsen-P and soil surface water TP showed that the change point of soil Olsen-P, which induced a sharp increase of soil surface water TP concentration, was 82. 7 mg x kg( -l) , corresponding to a P application rate being about 712 x kg hm(-2). Soil Olsen-P could be a good indicator in forecasting the P loss from soil surface water.

Fertilizers↗

The effects of applicant's health status and qualifications on simulated hiring decisions.

The effects of having diabetes or obesity on simulated job decisions was evaluated in a two (qualifications, high v. marginal) by three (diabetes, mildly obese, or normal) design. Subjects were 295 adults, averaging 5.02 years of full-time employment in white-collar settings, recruited in advanced level graduate or undergraduate business classes. Each subject examined a job description and a resume of the 'applicant' and viewed a 5-minute videotape. The applicant's face was never seen and an off-camera voice, constant across all conditions, was dubbed in for the applicant's responses to the interviewer's questions. Subjects were then asked to rate the applicant's qualification level and demeanor during the interview and to recommend whether or not to hire the individual. Subjects were also asked to make ratings about the applicant's work habits, work reliability and absenteeism, and interpersonal skills (e.g. emotional problems, likeability). Results indicated that level of quantification affected decisions to hire the applicant in the predicted direction. However, the obese applicant was rated as less qualified for the job, and both the diabetic and obese applicant were less likely to be hired, although they were rated similarly on personal appearance, attitude during the interview, and communication skills. Additionally, both the obese and the diabetic applicant were viewed as having poorer work habits. The diabetic was rated as much more likely to have medically-related job absences, whereas the obese applicant was rated as more likely to have other absences (e.g. abusing company privileges by feigning illness) and to have emotional and interpersonal problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The examination of vaginally inserted plastic tampon applicators for genetic markers and evidence of prior sexual intercourse.

Vaginally inserted plastic tampon applicators were obtained from 42 female volunteers. The applicators were examined for the presence of ABH blood group substances, phosphoglucomutase (PGM), amylase, acid phosphatase, P30, and intact spermatozoa. Each applicator was accompanied by a control blood sample, a saliva specimen, a brief sexual and menstrual history, and method of birth control of the donor. Eight of the male sexual partners of the donors submitted blood and saliva samples. One male sexual partner submitted only a saliva sample. ABH blood group substances corresponding to the donor were recovered from 36 of the 42 applicators. The remaining 6 applicators revealed a combination of the donor's and sexual partner's ABH substances. The female's PGM type was recovered from 34 of the applicators. The remaining 8 applicators failed to show PGM activity. Of the applicators, 15 indicated evidence of prior sexual intercourse by the detection of ABH substances not consistent with the applicator donor (6 samples), high levels of acid phosphatase (11 samples), or recovery of spermatozoa (8 samples) or some combination of these. All applicator samples failed to show the presence of either P30 activity or PGM factors foreign to the female.

Acid Phosphatase↗

[A clinical study on the effect of fluoride topical application by using of F-ion for caries prevention and desensitization of tooth].

The authors have studied on fluoride topical application effect clinically by using of fluoride ion applicator (F-ion) for the purpose of increasing dental caries prevention effect and desensitization efficiency of hypersensitive tooth. We have compared physical components of F-ion to Rivet ion and Pyocure which were made in Japan. And then, we have examined 40 extracted teeth applied 2% NaF solution with F-ion and calculated relative CaF2 production amounts by using of X-ray diffractometer after dividing total samples into 3 parts as control group, one time F-ion application group and 10 times F-ion application group. Otherwise, we have experimented 40 patients who have had hypersensitive teeth applying 10% SnF2 solution with the use of F-ion and found the patient's response for desensitization effects. The obtained results are as follows; 1. There were no obvious differences between F-ion fluoride applicator and other products, Rivet ion or Pyocure in aspect of physical components. 2. CaF2 production amounts were relatively higher in a group of one time 2% NaF application with the use of F-ion than those of control group as only fluoride solution applicated and it were the most in a group of 10 times fluoride application with the use of F-ion, through the examining by X-ray diffractometer, so it was estimated that F-ion technique of fluoride application would increase the fluoride penetration effect. 3. It was estimated that the desensitization effect for several application of 10% SnF2 solution with the use of F-ion would be recognized through the examination by Electro Pulp Tester and patient's response as 85.0% of desensitized persons. 4. The use of F-ion for increasing caries prevention and desensitization effect was recommended to dental clinics.

Clinical Trials as Topic↗

Self-application of podophyllin resin for penile condylomata acuminata.

Two methods of podophyllin application, namely hospital-application (regimen A) and self-application (regimen B) of 25% podophyllin in tincture of benzoin compound for the treatment of penile condylomata were compared. The objective was to compare the response and safety of self-application with traditional hospital-application. A total of 100 men were selected, of which 64 were valid for evaluation of response. At six weeks' follow-up 66% and 72% of patients treated with regimen A and B, respectively were cured. Patients treated with regimen A were less compliant making only 58% of the required number of applications as compared with those treated with regimen B who made 92% of the applications. Of the patients successfully treated, 43% and 20% of those treated with regimens A and B, respectively were cured after only one or two applications (p greater than 0.1). Three patients--two treated with regimen A and one treated with regimen B suffered local reactions to the first application of podophyllin. All these patients recovered without sequelae. Self-application of podophyllin can therefore be used safely and effectively in selected men with penile condyloma acuminata.

Administration, Topical↗

Job-specific applicant pools and national norms for cognitive ability tests: implications for range restriction corrections in validation research.

Correcting validity coefficients for range restriction requires the applicant pool predictor standard deviation (SD). As this is frequently unknown, some researchers use national norm SDs as estimates of the applicant pool SD. To test the proposition that job-specific applicant pools are markedly more homogeneous than broad samples of applicants for many jobs, job-specific applicant pool SDs on the Wonderlic Personnel Test for 80 jobs were compared with a large multijob applicant sample. For jobs at other than the lowest level of complexity, job-specific applicant pool SDs average 10% lower than the broad norm group SDs. Ninety percent of the job-specific applicant pool SDs lie within 20% of the norm group SD, suggesting that reducing a norm group SD by 20% provides a conservative estimate of the applicant pool SD for use in range restriction corrections for other than low-complexity jobs.

Aptitude↗

Physician mental health and substance abuse. What are state medical licensure applications asking?

OBJECTIVE: To summarize and characterize the questions on initial applications for medical licensure (nonosteopathic) as they relate to applicants' mental health and substance abuse. DESIGN: Collection and analysis of applications for initial medical licensure (nonosteopathic) from 50 states and the District of Columbia. PARTICIPANTS: Nonosteopathic medical licensure applications of 47 states and the District of Columbia (N = 48). INTERVENTION: None. MAIN OUTCOME MEASURES: Number of questions per application relating to mental health problems and substance abuse, in addition to time qualifiers (e.g., current difficulty, specified number of years in the past, ever) and impairment qualifiers (e.g., functional impairment, treatment, hospitalization) per question or set of questions for each area. RESULTS: Of 48 applications analyzed, 41 (85%) inquired about mental health problems and 43 (90%) inquired about substance abuse. Most explored periods between the past 10 years and the present; functional impairment was the most common inquiry. CONCLUSIONS: Applications for nonosteopathic medical licensure most often inquire about physicians' recent history of mental health and substance abuse problems as well as related functional impairment. Variation of items across state applications may have important implications for some physician applicants.

Humans↗

Mortality among aerial pesticide applicators and flight instructors: follow-up from 1965-1988.

BACKGROUND: Vital status followup for a retrospective cohort mortality study of 9,961 male aerial pesticide applicators was extended beyond a previous study (1965-1979) (Cantor et al. 1991), through December 31, 1988. METHODS: Rate ratios (RR) were used to compare directly adjusted mortality rates between applicators and a comparison cohort of 9,969 flight instructors. Standardized mortality ratios (SMR) were calculated for comparisons with the U.S. white male population. RESULTS: Among applicator pilots, there were 1,441 deaths, and among instructors, 1,045. In both groups, aircraft accidents were the major cause of death (446 applicators; 234 instructors). Compared with flight instructors, aerial applicator pilots were at significantly elevated risk for all causes of death (risk ratio = 1.34) and for malignant neoplasms (1.18), non-motor vehicle accidents (1.71), motor vehicle accidents (1.69), and stroke (1.91). Pancreatic cancer (2.71) and leukemia (3.35) were significantly elevated. Applicators were at lower risk of colon cancer (0.51) and multiple myeloma (0.23) mortality. Based on U.S. rates, the SMR for all causes of death among applicators was 111 (95% confidence interval (CI) = 105-117) and among instructors, 81 (CI = 76-85). CONCLUSIONS: Aircraft accidents were a major cause of mortality in both applicator and flight instructor cohorts. Several other causes of death, some possibly related to pesticide exposure, were also elevated among pesticide applicator pilots. Published 1999 Wiley-Liss, Inc.

Accidents, Aviation↗

Effect of application frequency on epidermal ornithine decarboxylase induction by chrysarobin in SENCAR mice.

Ornithine decarboxylase (ODC EC 4.1.1.17) induction in mouse epidermis after single or multiple topical applications of chrysarobin differed from that following topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA). Following a single application of 220 nmol chrysarobin, ODC activity began to rise at 24 h reaching a peak at 56 h and returned to normal after 96 h. When 5 separate applications of 220 nmol chrysarobin were applied in multiple application protocols, an alteration in the ODC induction response was observed. With a once per week or twice per week application protocol, ODC was elevated in a multiphasic manner giving multiple peaks of activity after the last application. Interestingly, the magnitude of ODC induction was greater using the once per week, compared to the twice per week, application protocol. Preliminary results indicate that a once per week application protocol is more effective than a twice per week protocol for promoting the development of skin papillomas in SENCAR mice. Thus, the magnitude of the induced ODC response with chrysarobin, although low compared to TPA, correlated with tumor promoting activity.

Animals↗