Generation of multiple angiogenesis inhibitors by human pancreatic cancer.

A primary inoculum of human pancreatic cancer cells (BxPC-3) has the ability to inhibit the growth of a secondary tumor in an in vivo animal model. Such ability suggests that the primary tumor is producing inhibitors that act at the site of the secondary tumor. Accordingly we attempted to discover which inhibitors are produced by pancreatic cancer cells. We determined that pancreatic cancer cells process angiostatin isoforms from plasminogen. Additionally, we isolated and characterized an uncleaved "latent" antiangiogenic antithrombin (aaAT) molecule processed from systemically available AT by pancreatic cancer cells as well as a cleaved form of aaAT processed from systemically available AT by pancreatic cancer cells. Human AT, cleaved with human neutrophil elastase, inhibits angiogenesis in the chorioallantoic membrane assay. This human aaAT molecule is able to inhibit the growth of pancreatic tumors in immune-compromised mice. Our work represents the first demonstration of multiple angiogenesis inhibitors from a single tumor and suggests that antiangiogenic therapies may provide an avenue for future treatment of pancreatic cancer.

A comparison of the efficacy of 2 powered toothbrushes in affecting plaque accumulation, gingivitis, and gingival bleeding.

BACKGROUND: The purpose of this 30-day blinded, parallel-design study was to compare the effect of 2 powered toothbrushes, the Rowenta MH700 and the Braun Plak Control Ultra, on reducing plaque accumulation, gingivitis, and gingival bleeding in a cohort of 60 healthy adults. METHODS: After baseline evaluation of plaque, gingivitis, and gingival bleeding, subjects were randomly assigned to one of the experimental groups, provided written and verbal toothbrushing instructions, and had their teeth polished. At 2 weeks (follow-up 1) and 4 weeks (follow-up 2), all clinical parameters were again evaluated. RESULTS: The Braun group demonstrated a nearly significant reduction in gingival index (GI) and a significant reduction in GI at follow-up 2. The Rowenta group demonstrated significant reductions in GI, plaque index (PI), and bleeding index (GBI) at both follow-up 1 and 2 examinations. At follow-up 1, the Braun group demonstrated a nearly significant reduction in GI, a significant reduction in PI, and a non-significant reduction in GBI. At follow-up 2, the Braun group demonstrated a significant reduction in GBI, but not a significant reduction in PI. The reduction in GI for the Rowenta group was significantly greater (P values of 0.0001 and 0.0001, respectively) than that demonstrated in the Braun group. However, the Rowenta group did not demonstrate a significantly greater reduction in PI (P values of 0.7135 and 0.3184 for follow-up 1 and follow-up 2, respectively) or GBI than the Braun group at either examination (P values of 0.0663 and 0.3397 for follow-up 1 and 2, respectively). CONCLUSIONS: The results of this study support the findings of numerous other studies that powered toothbrushes have great potential to remove plaque and improve gingival health and that the improvement can be demonstrated in a relatively short period of time.

Structural and kinetic studies of a cisplatin-modified DNA icosamer binding to HMG1 domain B.

The high mobility group (HMG) domain is a DNA-binding motif found in the non-histone chromosomal proteins, HMG1 and HMG2, and some transcription factors. Experimental evidence has demonstrated that HMG-domain proteins can play a role in sensitizing cells to the anticancer drug cisplatin. Fluorescence resonance energy transfer (FRET) experiments were performed in the present study to investigate structural changes that accompany complex formation between the HMG domain B of HMG1 and a cisplatin-modified, 20-base pair double-stranded DNA probe containing fluorescein and rhodamine tethered at its two ends. The binding affinity of HMG1 domain B for the cisplatin-modified DNA probe was investigated in fluorescence titration experiments, and a value of 60 +/- 30 nM was determined for the dissociation constant. Single photon counting methods were employed to measure the fluorescence lifetime of the fluorescein donor in the presence and absence of HMG1 domain B. These FRET experiments revealed a distance change that was used to estimate a bend angle of 80-95 degrees for the cisplatin-modified DNA upon protein binding. Stopped-flow fluorescence spectroscopic experiments afforded kinetic parameters for HMG1 domain B binding to the cisplatin-modified DNA probe, with kon = 1.1 +/- 0.1 x 10(9) M-1 s-1 and koff = 30 +/- 4 s-1.

A single HMG domain in high-mobility group 1 protein binds to DNAs as small as 20 base pairs containing the major cisplatin adduct.

Proteins containing a relatively new DNA-binding motif known as the high-mobility group (HMG) domain bind specifically to DNA modified by the anticancer drug cisplatin, but not to unmodified DNA (McA'Nulty & Lippard, 1995). Southwestern-blot analyses of the binding of proteolytic fragments of HMG1 to a 123-bp globally platinated DNA demonstrate that the HMG domains A and B of HMG1 are responsible for its specific interactions with cisplatin-modified DNA. An 81 amino acid recombinant protein representing a single HMG motif, HMG1 domain B, binds with an affinity (Kd = 10(-7) M) equal to that of HMG1 itself to 92- and 100-bp DNAs containing the major adduct of cisplatin, a cis-[Pt(NH3)2-[d(GpG)-N7(1), -N7(2)]] intrastrand cross-link, at a specific site. The isolated HMG domain B binds with comparable affinity to cisplatin-modified DNAs having as few as 20 bp. The related human mitochondrial HMG domain protein mtTFA also recognizes the 123-bp globally platinated DNA, providing further evidence that HMG domains are responsible for modulating binding of this class of proteins to cisplatin-modified DNA. This work provides direct biochemical evidence in support of conclusions drawn previously from analyses of sequence conservation (Bruhn et al., 1992) that HMG domains are the key elements in protein binding to cisplatin-modified DNA.

A clinical comparison of the efficacy of an electromechanical flossing device or manual flossing in affecting interproximal gingival bleeding and plaque accumulation.

This one-month clinical trial was designed to compare the effect of an electromechanical flossing device and manual flossing on reducing interproximal gingival bleeding and plaque accumulation in a cohort of 60 healthy adults. After baseline evaluation of interproximal gingival bleeding, soft tissue trauma and plaque, patients were randomly assigned to one of the two experimental groups, given flossing instructions, and had their teeth cleaned. At 30 days all three clinical parameters were again evaluated. The results showed a reduction in GI from baseline to follow-up in each group. This effect is significant (p<0.0001) in the analysis of variance. There was no overall difference in the groups (p=0.93). There was no difference in the reduction in GI from baseline to follow-up between the two groups (p=0.91); interaction). As with the GI, there was a significant reduction in PI from baseline to follow-up in each group (p<0.0001). There was no overall difference between the groups (p=0.24). There was no difference in the reduction in PI from baseline to follow-up between the two groups (p=0.59; interaction). No soft tissue trauma was noted at the baseline examination or at the follow-up examination after 30 days.

Effectiveness of sealed dental prophylaxis angles inoculated with Bacillus stearothermophilus in preventing leakage.

It was the purpose of this in vitro investigation to evaluate the effectiveness of several brands of sealed, reusable prophylaxis angles to keep internal materials within the internal portions of the head of the prophylaxis angle, and not allowing contaminates to leak out. Three brands of sealed, reusable dental prophylaxis angles were autoclaved and then taken apart under a biocontainment flow hood. Testing conditions were designed to prevent a "worst case scenario" by inoculating dental prophylaxis angles with 10(6) of the heat resistant spores of Bacillus stearothermophilus and 20% bovine serum albumin to simulate the presence of human serum. The concentration of Bacillus stearothermophilus spores was verified before testing procedures were initiated. The internal portions of the sterile prophylaxis angles were inoculated with a 1:1 mixture of the Bacillus stearothermophilus spores and bovine serum albumin, at a concentration of 1.15 x 10(6) spores/inoculation. The prophylaxis angles were reassembled under sterile conditions, and a sterile rubber cup was inserted into each of the prophylaxis angles. The prophylaxis angles were attached to a sterile dental handpiece and then submerged in a 50 ml tube containing sterile trypticase soy broth and run at 3000 rpm for 30 seconds. The tube of medium was incubated for 7 days. No growth of Bacillus stearothermophilus spores could be cultured from one of the brands of prophylaxis angles at any time during the incubation period. The other two brands of prophylaxis angles did produce some leakage of the Bacillus stearothermophilus spores.

Enamel roughness after air-powder polishing.

The purpose of this study was to quantify differences in enamel surface roughness following treatment with an air abrasive system when compared to a rubber cup and pumice. The coronal portion of 40 bovine teeth were tested. Half of the teeth were placed in a control group and cleansed with a rubber cup and pumice, the other half or "test" group were treated with an air-powder polisher. All teeth were exposed to the given cleansing agent for a time equivalent to a 15-year recall program. Pre- and post-treatment surface evaluation was completed using a surface profilometer. In addition, representative samples were evaluated before and after cleansing under the scanning electron microscope (SEM). The results of this study showed no statistically significant increase in enamel surface roughness in teeth cleansed with the air polisher when compared to the roughness of the control teeth. This was confirmed visually by use of SEM taken at magnifications of up to x1000. The findings of this study indicate there is no significant alteration of the enamel surface when a tooth is treated with an air-powder polisher for the equivalent of a 15-year recall program.

A comparison of the Braun Oral-B Plaque Remover (D5) electric and a manual toothbrush in affecting gingivitis.

This three-month clinical trial was designed to compare the effect of an electric and a manual toothbrush on reducing primarily gingivitis and secondarily, plaque, in a cohort of 70 healthy adults. After baseline evaluation of gingivitis, soft tissue trauma, and plaque, patients were randomly assigned to one of the two experimental groups, shown an instructional tooth brushing videotape, and had their teeth cleaned. Soft tissue trauma was again scored at 2 weeks. At 12 weeks all three clinical parameters were again evaluated. The results showed statistically significant reductions (baseline vs. 3-month) in both whole mouth (p = 0.003) and interproximal (p = 0.008) gingivitis scores for the electric toothbrush group. No significant reduction at three months compared to baseline was seen for the manual brush group. When gingivitis reductions were compared over the three-month test period, the electric brush was significantly better than the manual toothbrush in both whole mouth (p = 0.0007) and interproximal (p = 0.002) gingivitis reduction. No increase in soft tissue trauma and no significant differences in plaque reductions were seen for either toothbrush.

Coping behaviors of children hospitalized for cardiac surgery: a secondary analysis.

While the coping behaviors of hospitalized children continue to be an area of interest for researchers, systematic documentation in the literature concerning children's coping remains limited. In this descriptive secondary analysis, 23 master's thesis case studies were analyzed to determine how researchers described the range of coping behaviors that children used while hospitalized for cardiac surgery. The analysis sought to determine patterns of coping in both preschool and school-age children. A second aim was to validate further and refine the dimensions and items of the Children's Coping Behaviors Category System developed by Ritchie, Caty, and Ellerton in 1987. Results revealed that a broad range of names and labels of behavior was used to describe children's coping. The predominant patterns of behavior that emerged were direct action and information-seeking. Differences between preschool and school-age children's reported behaviors were evident. The coping category system was validated further and refinements are suggested.

Applications of the air-powder polisher in clinical orthodontics.

Air polishers are relatively new devices that have provided dentistry with an alternative method for cleansing the tooth surface. Many publications attest to the efficacy of the instrument in plaque and stain removal while advising the practitioner of potential health risks to the patient. In spite of the information available, little research has been published concerning air polishing procedures in the treatment of the tooth surface before placement of the orthodontic bracket. In light of the research supporting the efficacy of plaque and stain removal, the use of the air polisher has been shown to have no detrimental influence on the bonding of the resin bracket cement to the tooth surface. It would appear that the system may be ideal for use in conjunction with orthodontic treatment. The air-powder polisher has been found to be the most effective method of plaque removal for orthodontic patients without causing breakage of elastics or wires or loss of zinc phosphate or composite material. Another application for the air-powder polisher in the orthodontic practice is surface preparation of the tooth before bracket placement. The instrument should be held approximately 4 to 5 mm from the tooth surface, at a 60 degree angle for anterior smooth surfaces, at an 80 degree angle for posterior smooth surfaces, and at a 90 degree angle for occlusal surfaces. A constant circular motion should be used, with an exposure time of 30 to 60 seconds.

SEM evaluation of the in-vitro effects of an air-abrasive system on various implant surfaces.

This investigation was conducted to determine the effects of an air-abrasive polishing system on various implant surfaces. Four each of the following types of implants were obtained from the manufacturer: Stryker DB (a titanium alloy implant), Denar Steri-Oss (a pure titanium implant), IMZ (pure titanium polished collar/plasma-sprayed body), and IMZ transmucosal implant extensions (highly polished pure titanium). Four samples of each type of implant material were placed in a group to be treated with an air-abrasive polishing system for 0.5, 1, 5, or 10 seconds, for a total of 16 samples. Scanning electron photomicrographs taken of each sample before and after treatment were analyzed by three examiners who were blind to the treatment conditions. They determined if the abrasion on the treated surface was greater than, equal to, or less than the pretreatment control. No perceptible difference was noted between the pretreatment and posttreatment photomicrographs regarding the surface integrity of the implant material surfaces.

Content analysis of 186 descriptive case studies of hospitalized children.

One hundred eighty-six single case studies of sick infants, children, and adolescents were analyzed to provide a substantial descriptive data base of children's responses to illness, hospitalization, and treatment over a span of more than 20 years. Units of theory of coping behavior are identified as a first phase for adding new knowledge to the field of pediatric nursing. Indicators of the significance of the data base are included.

Clinical evaluation of the Prophy-Jet as an instrument for routine removal of tooth stain and plaque.

The Prophy-Jet was evaluated for its effectiveness in removing plaque and stain from teeth and on its effects on the marginal gingiva. Using a randomized split-mouth design, half the mouth was treated with the Prophy-Jet and the contralateral side with a rubber cup and prophylaxis paste. The results indicated that the Prophy-Jet removes tooth plaque and stain as well as the rubber cup and prophylaxis paste method, and does so in less time. It was also found that there was some immediate soft tissue trauma following both treatment modalities, with a mean Trauma Index score of 0.23 not equal to 0.16 for the rubber cup and prophylaxis paste and 0.75 not equal to 0.37 for the Prophy-Jet. Within 6 days, the trauma index scores were not significantly different. Similar results were found for marginal gingival redness and bleeding on probing. The Prophy-Jet is an excellent alternative instrument for removal of tooth stain and dental plaque.