Regulation of cell differentiation by hNUDC via a Mpl-dependent mechanism in NIH 3T3 cells

Thrombopoietin receptor (Mpl) belongs to the cytokine receptor surperfamily with a large extracellular N-terminal portion responsible for cytokine recognition and binding. Thrombopoietin (TPO) has so far been the only widely studied cytokine for Mpl. However we have recently identified human NUDC (hNUDC), previously described as a human homolog of a fungal nuclear migration protein, as another putative binding partner of Mpl. The purpose of this study is to test the extent of the functioning of hNUDC by identifying protein-protein interactions with Mpl in mammalian cells. The full-length cDNAs encoding Mpl and hNUDC were cloned into pEGFP-N1 and pDsRed2-N1 respectively which were subsequently expressed as Mpl-EGFP (green) and hNUDC-DsRed (red) fusion proteins. Using ELISA and immunofluorescence studies, we have demonstrated the direct binding of hNUDC to cell surface-captured Mpl. We also observed that hNUDC induced significant changes in cellular morphology in NIH 3T3 cells stably transfected with pMpl-EGFP. Interestingly, these morphological changes were characteristic of cells undergoing megakaryocyte differentiation. Extracellular-signal-regulated protein kinases 1 and 2 (ERK1/2) have been shown to mediate such megakaryocyte-like differentiation. In addition, co-expression of Mpl-EGFP and hNUDC-DsRed led to the release of hNUDC-DsRed into the culture medium.

Assessment of Autofluorescence to Detect the Remineralization Capabilities of Sodium Fluoride, Monofluorophosphate and Non-Fluoride Dentifrices

The purpose of the study was to determine if longitudinal measurements of enamel autofluorescence (quantitative light-induced fluorescence, QLF) could detect differences in remineralization of early enamel caries on buccal surfaces of anterior teeth following supervised daily brushing with either sodium fluoride (NaF; 1,450 ppm F), sodium monofluorophosphate (MFP; 1,450 ppm F) dentifrices or a herbal, non-fluoride placebo dentifrice. The study was a pragmatic cluster-randomized controlled trial with schools as the unit of randomization. Twenty-one schools in Chengdu, China, comprised the clusters; 296 children with at least 1 visible white-spot lesion were examined using QLF at baseline and after 3 and 6 months. Each of the 21 clusters was randomly assigned 1 of the 3 dentifrices, and the children brushed under supervision once per day for 2 min. The primary outcome measure was deltaQ (product of fluorescence loss and area) at a 5% threshold after 6 months of product use. A multi-level model was fitted to the data at the site level, taking into account the hierarchical structure with baseline deltaQ, age and sex as covariates. After 3 months there was a significant difference between the MFP group and placebo (p = 0.02) and after 6 months between the NaF group (p = 0.002), MFP group (p < 0.001) and the placebo. QLF methodology could detect, within 3- and 6-month periods of supervised brushing, a difference in remineralization between fluoride-containing and non-fluoride-containing dentifrices. Typically lesions in all 3 treatment groups demonstrated improvement. Groups receiving fluoride experienced a more rapid and more substantial remineralization than those in the placebo group.

[Effects of shock lymph inducing the mesentery micro-lymphatic endothelial cells apoptosis of rats]

The model of serious hemorrhagic shock was established in the condition of asepsis and mesentery lymph was taken out. As control, normal mesentery lymph fluid, normal portal vein blood and shock portal vein blood of rats were taken out. The primary mesentery micro-lymphatic endothelial cells (MMLECs) of passages 3 were treated by different treatment factors, respectively. The cells proliferation by shock lymph and normal lymph of different final concentrations was measured using MTT method. The cell cycle arrest was analyzed by flow cytometry, and the electrophoresis analyze on DNA of cell nucleus was observed. The expressions of relative genes of apoptosis such as fas, fasL, bcl-2 and bax of MMLECs were detected by RT-PCR. The results showed that the MMLECs proliferation was decreased when the concentration of shock lymph increased to some extent and showed statisticly significant difference compared with normal lymph group. The cells cocultured with shocking lymph fluid at 4% final concentration showed that apoptosis rate of MMLECs was (35.4 +/- 1.6)%, and G0-G1 cell population was higher and the proportion of S+G2-M cell population was lower than that of other groups, and the DNA ladder was observed in electrophoresis of cell nucleus DNA at same time. And the expressions level of fas, fasL and bax mRNA were higher and bcl-2 mRNA was lower in shock lymph group than that of control group. The results demonstrated that shock lymph could reduce the cells proliferation, interfere with cell cycle, and accelerate high expression of apoptosis accelerative genes. As a result, shock lymph could induce the MMLECs apoptosis.

Association of prostaglandin-endoperoxide synthase 2 gene polymorphisms with asthma and atopy in Chinese children

BACKGROUND

Cyclooxygenase-2 (COX-2) plays essential roles in inflammation. Previous studies have suggested associations between prostaglandin-endoperoxide synthase 2 (PTGS2) polymorphisms and prostaglandins production in asthma.

OBJECTIVE

We have investigated the effects of Chinese tagging single nucleotide polymorphisms (SNPs) of PTGS2 on asthma traits in 299 Chinese asthmatic children and 175 controls.

METHODS

Plasma total and allergen-specific IgE were measured by enzyme immunoassay. PTGS2.8473T-->C in the 3'-untranslated region of exon 10 and three tag SNPs covering most of the variations in PTGS2 haplotypes in Chinese were genotyped by restriction fragment length polymorphism.

RESULTS

Among the four SNPs, only PTGS2.8473 showed significant association with asthma (P = 0.034) and atopy (P = 0.005 when compared with non-atopic controls; P = 0.023 with all controls). Carriers of the C allele had a 1.5-fold (95% confidence interval: 1.01-2.30) risk of developing asthma than those homozygous for the T allele. Multivariate regression revealed significant correlations between PTGS2.8473 and forced expiratory volume in 1 s (FEV(1); P = 0.002) and peak expiratory flow rate (PEFR; P = 0.001) with age and gender adjusted. Patients with the C allele of PTGS2.8473 had significantly lower FEV(1) (median: 90.0%vs 98.0%; P = 0.0047) and PEFR (70.0%vs 73.5%; P = 0.0065) than those homozygous for the T allele. No significant association between plasma total and allergen-specific IgE and these SNPs or with their haplotypes was found.

CONCLUSIONS

PTGS2.8473 polymorphism is associated with asthma, atopy and lung function but not plasma IgE in Chinese children. This may help to explore the pharmacogenetics of COX-2 inhibitors.

[Damage effects of shock lymph on the pulmonary micro-vascular endothelial cells of rats]

The model of serious hemorrhagic shock was established under the condition of asepsis and mesentery lymph was taken out. As control, normal mesentery lymph fluid, normal portal vein blood, and shock portal vein blood of rats were taken out. The primary pulmonary microvascular endothelial cells (PMVECs) of passages 3 were treated by different treatment factors, respectively. The morphology and ultrastructure changes of PMVECs were observed under optics microscope, transmit electronic microscope and scan electronic microscope. The cells proliferation under different final concentrations of shock lymph and normal lymph were measured with MTT method. The cell cycle arrest was analyzed by flow cytometry and the DNA of cell nucleus was analyzed by electrophoresis. The results showed that shock lymph played a role in damaging PMVECs. The contracted cells and condensed nucleus were found, and apoptosic bodies were observed under a transmission electron microscope. The proliferation of PMVECs was decreased when the concentration of shock lymph increased to some extent and showed statistic significance compared with normal lymph group. The cells cocultured with shocking lymph fluid at 4% final concentration showed that G0-G1 cell population was higher and the proportion of S+G2-M cell population was lower than that of other groups, and the DNA ladder was observed in electrophoresis of cell nucleus DNA at same time. The results demonstrated that shock lymph could damage the morphology and ultra-structure of PMVECs, reduce the cells proliferation, interfere with cell cycle, and induce the apoptosis.

A novel dimeric zinc(II) complex: bis[mu-1,2-bis(1H-1,2,4-triazol-1-yl)ethane-kappa(2)N(4):N(4')]bis[diisothiocyanatozinc(II)]

The coordination geometry of the Zn(II) atom in the title complex, [Zn(2)(NCS)(4)(C(6)H(8)N(6))(2)], is that of a distorted tetrahedron, in which the Zn(II) atom is coordinated by four N atoms from the triazole rings of two symmetry-related 1,2-bis(1,2,4-triazol-1-yl)ethane ligands and two thiocyanate ligands. Two Zn(II) atoms are bridged by two organic ligands to form a dimer. The dimer lies about an inversion center.

Can we use 1H MRS shimming values to obtain 31P spectra?

The perfect shimming of 31P magnetic resonance spectroscopy (MRS) is not easy in vivo. The purpose of this study was to examine the feasibility of using 1H MRS shimming values to obtain 31P spectra in a same sequence. Both phantom and volunteer studies were carried out in this study. Phantom was a sphere filled with physiological metabolites of brain. In vivo study was performed on 4 healthy volunteers. The studies were performed on a 3-T GE scanner. A same localizer and a same cursor were used for both 1H and 31P scans. A spin echo MRS sequence was utilized for both 1H scans with a standard head coil and 31P scans with a GE service coil. 1H scan was performed using first and automatic shimming and water linewidth (FWHM) of 3 Hz for phantom and 5 Hz for the volunteer were obtained. Shimming values of 1H scan in x, y, z directions were copied to 31P scan. A routine procedure of 31P scan without value coping was also performed. Spectra were analyzed using SAGE/IDL program. Signal to noise ratio (SNR) was defined as the ratio of the signal height / maximum noise height. Good 1H spectra and 31P spectra were obtained for both phantom and volunteer studies. The 31P spectra with 1H MRS shimming values were similar with the 31P spectra obtained with routine procedure. Lower SNRs of 31P spectra were obtained in phantom with 1H MRS shimming values, compared with routine procedure scan. Average SNR for Pi of 31P spectra was 7.45:1 in the volunteer study with routine procedure, and 7.275:1 with 1H MRS shimming values. 1H MRS shimming values can be used to obtain useful 31P spectra in a same sequence.

Combination 3D TOP with 2D PC MRA Techique for cerebral blood flow volume measurement

To demonstrate the discrepancy of cerebral blood flow volume (BFV) estimation with 2D phase-contrast (2D PC) MRA guided with 3D time-of-flight (3D TOF) MR localization by using an "internal" standard. 20 groups of the common (CCA), internal (ICA), and external (ECA) carotid arteries in 10 healthy subjects were examined with 2D PC MRA guided by 3D TOF MR angiograms. The sum BFV of the internal and external carotid arteries was then compared with the ipsilateral common carotid artery flow. An accurate technique would demonstrate no difference. The difference was therefore a measure of accuracy of the method. 3D TOF MRA localization is presented to allow the determination of a slice orientation to improve the accuracy of 2D PC MRA in estimate the BFV. By using the combined protocols, there was better correlation in BFV estimate between the sum of ICA+ECA with the ipsilateral CCA (R2=0.729, P=0.000). The inconsistency (mean +/- SD) was found to be 6.95 +/- 5.95% for estimate the BFV in ICA+ECA and ipsilateral CCA. The main inconsistency was contributed to the ECA and its branches. Guided with 3D TOF MRA localization, 2D PC MRA is more accurate in the determination of blood flow volume in the carotid arteries.

Rapid separation of Sudan dyes by reverse-phase high performance liquid chromatography through statistically designed experiments

Central composite design (CCD) was effectively employed to decide optimum conditions for the rapid separation of Sudan dyes using reverse-phase high performance liquid chromatography (HPLC). Twenty experiments, taking the minimum resolution and retention time of the last eluted peak as the responses with three important factors, mobile phase composition, flow rate and column temperature, were used to design a mathematical model. The experimental responses were fitted into a second order polynomial and used to predict the optimum conditions for the effective separation of the studied compounds. Further, chromatographic separation efficiency was tested through generation of Pareto-optimal points. The validity of using modified central composite design in predicting the optimization conditions was experimentally verified. The optimum conditions were: acetonitrile/0.1% aqueous formic acid (90/10, %v/v) as the mobile phase, at a flow rate of 1.2mL/min and column temperature of 15 degrees C, respectively. While using this optimum condition, baseline separation with a minimum resolution more than 1.5 and a separation time of less than 6min were achieved.

Cells enriched in markers of neural tissue-committed stem cells reside in the bone marrow and are mobilized into the peripheral blood following stroke

The concept that bone marrow (BM)-derived cells participate in neural regeneration remains highly controversial and the identity of the specific cell type(s) involved remains unknown. We recently reported that the BM contains a highly mobile population of CXCR4+ cells that express mRNA for various markers of early tissue-committed stem cells (TCSCs), including neural TCSCs. Here, we report that these cells not only express neural lineage markers (beta-III-tubulin, Nestin, NeuN, and GFAP), but more importantly form neurospheres in vitro. These neural TCSCs are present in significant amounts in BM harvested from young mice but their abundance and responsiveness to gradients of motomorphogens, such as SDF-1, HGF, and LIF, decreases with age. FACS analysis, combined with analysis of neural markers at the mRNA and protein levels, revealed that these cells reside in the nonhematopoietic CXCR4+/Sca-1+/lin-/CD45 BM mononuclear cell fraction. Neural TCSCs are mobilized into the peripheral-blood following stroke and chemoattracted to the damaged neural tissue in an SDF-1-CXCR4-, HGF-c-Met-, and LIF-LIF-R-dependent manner. Based on these data, we hypothesize that the postnatal BM harbors a nonhematopoietic population of cells that express markers of neural TCSCs that may account for the beneficial effects of BM-derived cells in neural regeneration.

Optimization and characterization of chitosan-coated alginate microcapsules containing albumin

In order to obtain small microcapsules with high protein encapsulation efficiency and extended release characteristics various processing factors were studied. Bovine serum albumin-loaded alginate microcapsules were prepared by an emulsion method and further incubated in chitosan. Many process factors were tested including the concentration and molecular weight of alginate, the concentration and pH of chitosan, and surfactants, etc. Microcapsules were achieved with diameters less than 2 microm, high encapsulation efficiency (> 80%) and high loading rate (> 10% w/w). The results also showed that the initial BSA amount of 20%-30% loaded alginate microcapsules coated with 0.2%-0.5% chitosan solutions at pH 4 by the two-stage procedure present the best sustained releasing characteristics.

Local blockade of Rydberg excitation in an ultracold gas

In the laser excitation of ultracold atoms to Rydberg states, we observe a dramatic suppression caused by van der Waals interactions. This behavior is interpreted as a local excitation blockade: Rydberg atoms strongly inhibit excitation of their neighbors. We measure suppression, relative to isolated atom excitation, by up to a factor of 6.4. The dependences of this suppression on both laser irradiance and atomic density are in good agreement with a mean-field model. These results are an important step towards using ultracold Rydberg atoms in quantum information processing.

Dissociation energies of molecular hydrogen and the hydrogen molecular ion

We have obtained improved values for the dissociation energies of molecular hydrogen and its ion by using a high-resolution pulse-amplified laser to probe the second dissociation limit. The onset of the vibrational continuum is observed by state-selective detection of the atomic products of dissociation, and several auxiliary measurements link the results to the ground state. The dissociation energies are accurate to 0.010-0.026 cm(-1), improving previous measurements by a factor of 3-7. Agreement with ab initio calculations is good for H2, D2, and their ions, but not for HD and HD+.

Long-range molecular resonances in a cold Rydberg gas

We present evidence for molecular resonances in a cold dense gas of rubidium Rydberg atoms. Single UV photon excitation from the 5s ground state to np Rydberg states (n=50-90) reveals resonances at energies corresponding to excited atom pairs (n-1)d+ns. We attribute these normally forbidden transitions to avoided crossings between the long-range molecular potentials of two Rydberg atoms. These strong van der Waals interactions result in avoided crossings at extremely long range, e.g., approximately 58 000 times the Bohr radius (a(0)) for n=70.

Bermuda Grass as a Potential Reservoir Host for Grapevine fanleaf virus

Grapevine fanleaf virus (GFLV) was detected in samples of Bermuda grass (BG) from Iran by reverse transcription-polymerase chain reaction (RT-PCR) using two different pairs of GFLV-specific primers, and also by enzyme-linked immunosorbent assay (ELISA) using antiserum specific for a North American isolate of the virus. RT-PCR detected GFLV in both fresh and dried BG tissues and in virus preparations purified from these plants. Cloning and sequencing of the RT-PCR products confirmed that the amplified sequences were sections of the GFLV coat protein gene. Similar results were obtained when random and oligo(dT) primers were used on viral RNA templates recovered from BG to synthesize cDNA for cloning and sequencing. The virus induced few or no symptoms in BG, but could nonetheless be transmitted from BG to Chenopodium quinoa by mechanical inoculation. Some isolates induced systemic chlorotic spots and leaf deformation; others remained symptomless in this plant. Both symptomatic and symptomless C. quinoa plants were found to be infected with GFLV, giving positive ELISA and RT-PCR tests. A North American isolate of GFLV was found to be mechanically transmissible to BG as indicated by positive RT-PCR results from root samples of inoculated plants. GFLV-infected BG was widely distributed in the Fars province of Iran.

Dicumarol inhibition of NADPH:quinone oxidoreductase induces growth inhibition of pancreatic cancer via a superoxide-mediated mechanism

NADPH:quinone oxidoreductase (NQO(1)), a homodimeric, ubiquitous, flavoprotein, catalyzes the two-electron reduction of quinones to hydroquinones. This reaction prevents the one-electron reduction of quinones by cytochrome P450 reductase and other flavoproteins that would result in oxidative cycling with generation of superoxide (O(2)(.-)). NQO(1) gene regulation may be up-regulated in some tumors to accommodate the needs of rapidly metabolizing cells to regenerate NAD(+). We hypothesized that pancreatic cancer cells would exhibit high levels of this enzyme, and inhibiting it would suppress the malignant phenotype. Reverse transcription-PCR, Western blots, and activity assays demonstrated that NQO(1) was up-regulated in the pancreatic cancer cell lines tested but present in very low amounts in the normal human pancreas. To determine whether inhibition of NQO(1) would alter the malignant phenotype, MIA PaCa-2 pancreatic cancer cells were treated with a selective inhibitor of NQO(1), dicumarol. Dicumarol increased intracellular production of O(2)(.-), as measured by hydroethidine staining, and inhibited cell growth. Both of these effects were blunted with infection of an adenoviral vector containing the cDNA for manganese superoxide dismutase. Dicumarol also inhibited cell growth, plating efficiency, and growth in soft agar. We conclude that inhibition of NQO(1) increases intracellular O(2)(.-) production and inhibits the in vitro malignant phenotype of pancreatic cancer. These mechanisms suggest that altering the intracellular redox environment of pancreatic cancer cells may inhibit growth and delineate a potential strategy directed against pancreatic cancer.

Stereotactic radiosurgery for primary trigeminal neuralgia using the Leksell Gamma unit

OBJECTIVE

Previous papers have reported Gamma Knife radiosurgery to be a safe, effective method for primary trigeminal neuralgia. Since November 1996, we have treated primary trigeminal neuralgia using the Leksell Gamma Knife at the Tianjin Medical University. The present study reports clinical results of Gamma Knife radiosurgery in the treatment of trigeminal neuralgia in 80 cases.

METHODS

The mean patient age was 67 years (range 32-92), the mean duration of facial pain was 7.6 years (range 1.5-29). The male:female ratio was 31:49. The right side of the face was involved in 45 patients (56.25%) and the left side in 30 cases (37.5%), with bilateral involvement in 5 cases (6.25%). Under local anesthesia, all patients underwent stereotactic MRI to identify the trigeminal nerve. A single isocenter, using a 4-mm collimator, was positioned at the sensory root of the trigeminal nerve entry zone of the pons, 4-6 mm from the brainstem surface, so that no more than the 20% isodose was administered to the brainstem. The maximum dose was between 70 and 90 Gy, with a mean of 75.6 Gy. For bilateral trigeminal neuralgia, two separate matrices were employed, and bilateral Gamma Knife radiosurgery was performed on the same day.

RESULTS

Follow-up ranged from 12 to 43 months (mean 23.7 months). Neurological evaluation indicated excellent response in 42 cases (52.5%), good response in 25 cases (31.25%), effective response in 8 cases (10%), so the total pain control rate was 93.75%. The latency from Gamma Knife surgery to pain relief ranged from 1 to 120 days (mean 22 days). Among the 75 patients 7 with pain control experienced pain recurrence 5-26 months after being completely free from pain. A second Gamma Knife radiosurgery was performed in 7 recurrent cases and 5 patients with treatment failure. A maximal dose ranging from 70 to 80 Gy was given (mean 74.2 Gy). After a mean follow-up of 18 months (8-33 months), 9 patients achieved excellent results, and 2 had good results. The latency interval to pain relief ranged from 1 to 120 days (mean 15 days). Nine patients developed new facial numbness, while no other complication appeared in the remainder of the patients.

CONCLUSIONS

Gamma Knife radiosurgery is a safe and effective method in the treatment of trigeminal neuralgia once diagnosis is established.

A new desensitizing dentifrice--an 8-week clinical investigation

An 8-week, double-blind, three-way clinical trial compared the dentinal hypersensitivity-reducing effectiveness of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) with a commercially available desensitizing dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.) and a nondesensitizing dentifrice containing 0.243% sodium fluoride in a silica base (Colgate Winterfresh Gel, Colgate-Palmolive Co.). One hundred nine subjects were stratified into three balanced groups according to gender, age, mean baseline tactile (Yeaple Probe), and thermal (air blast) scores. The test products were randomly assigned to each group with instructions to brush twice daily. Oral examinations with tactile and thermal assessments were repeated after 4 and 8 weeks. The new dentifrice group demonstrated statistically significant improvements in tactile and thermal sensitivity over the two control groups.

Comparative investigation of the desensitizing efficacy of a new dentifrice: a 14-day clinical study

The effect on dentinal hypersensitivity from the use of a new formulation dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) over a 14-day period was compared to a commercially available, nondesensitizing control dentifrice (Colgate Winterfresh Gel, Colgate-Palmolive Co.). A total of 66 subjects were entered into and completed the study. They were stratified into two balanced groups according to their baseline mean tactile (Yeaple Probe) sensitivity scores and air blast (thermal) sensitivity scores. The two groups were randomly assigned to use either the new formulation dentifrice or the commercially available control dentifrice. Participants were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations (tactile and air blast sensitivity) were conducted at baseline and after 3, 7, 10, and 14 days' use of the products. All examinations were conducted by the same examiner. Participants who used the new formulation dentifrice containing potassium nitrate/stannous fluoride/silica demonstrated a statistically significant improvement in both tactile sensitivity and air blast sensitivity after 10 and 14 days' use of the dentifrice (p < 0.05), as compared to a commercially available control dentifrice. It was concluded that a new dentifrice formulation containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base provided a statistically significant reduction in dentinal hypersensitivity after only 10 days, as compared to a commercially available nondesensitizing control dentifrice.

Comparative efficacy of the Colgate Actibrush battery-powered toothbrush vs Oral-B CrossAction toothbrush on established plaque and gingivitis: a 6-week clinical study

The objective of this clinical program was to compare the efficacy of the Colgate Actibrush battery-powered toothbrush and the Oral-B CrossAction Toothbrush (full head, soft bristle) for the control of supragingival plaque and gingivitis. Two independent clinical studies were conducted: Study 1 (repeated 3 times) was a single-use, examiner-blind clinical study designed to measure the removal of plaque after 24 hours of no oral hygiene. Study 2 was a definitive 6-week, examiner-blind clinical study designed to determine plaque and gingivitis efficacy at 3 and 6 weeks. Sixty-one men and women, who had refrained from using oral hygiene procedures for 24 hours, were entered into the study and stratified into 2 balanced groups according to baseline (prebrushing) plaque and gingivitis scores. For Study 1, Modified Navy Plaque Index (Rustogi Refinement) scores were obtained prebrushing and after a 1-minute supervised brushing with the assigned toothbrush and a commercially available toothpaste. On 3 separate occasions, after 24 hours of no oral hygiene, the Colgate Actibrush battery-powered toothbrush removed significantly more plaque than did the CrossAction Toothbrush. For Study 2, subjects were instructed to brush their teeth twice daily for 1 minute with the assigned toothbrush. Plaque Index scores and Löe-Silness Gingival Index scores were assessed after 3 and 6 weeks. At the 6-week examination, the group using the Colgate Actibrush battery-powered toothbrush exhibited a statistically significant reduction in both supragingival plaque and gingivitis, compared with the group that used the CrossAction Toothbrush. The results of these clinical studies support the conclusion that the Colgate Actibrush battery-powered toothbrush is clinically superior for the control of both supragingival plaque and gingivitis, as compared with the Oral-B CrossAction manual toothbrush.

Clinical study to compare extrinsic stain formation in subjects using three dentifrice formulations

The purpose of this study was to compare the degree of extrinsic dental stain formed with the use of three dentifrices: (1) a new dentifrice formulation containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.); (2) a commercially available dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.); and (3) a dentifrice containing 0.243% sodium fluoride in a silica base (Colgate Winterfresh Gel, Colgate-Palmolive Co.). A total of 121 participants were entered into the study and stratified into 3 balanced groups according to baseline mean Lobene Stain Index scores. A thorough dental prophylaxis was completed on each participant after completion of the baseline examination. The three groups were randomly assigned to use one of the three dentifrices. The groups were well balanced with regard to mean baseline stain index scores, gender, and tobacco habits. Participants were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Extrinsic dental stain examinations, which measured dental stain area and dental stain intensity, were conducted at baseline and 4 and 8 weeks. Examinations were conducted by the same dental examiner at each examination. After 4 and 8 weeks' use of the test dentifrices, there was no statistically significant difference regarding extrinsic stain formation with the use of any of the dentifrices. Thus, it can be concluded from this study that the use of a new formulation dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base will not result in a greater formation of extrinsic dental staining than that which is formed by two commercially available dentifrices not known to cause extrinsic dental stain.

A randomized clinical trial of the desensitizing efficacy of three dentifrices

The effect on dentinal hypersensitivity from the use of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength Toothpaste, Colgate-Palmolive Co.) over an 8-week period was compared to a commercially available dentifrice containing 5.0% potassium nitrate and 0.243% sodium fluoride in a silica base (positive control [Sensodyne Fresh Mint Toothpaste, Block Drug Company, Inc.]) and to a commercially available nondesensitizing dentifrice containing 0.243% sodium fluoride in a silica base (negative control [Colgate Winterfresh Gel, Colgate-Palmolive Co.]). A total of 120 participants were stratified into 3 balanced groups according to baseline mean air blast (thermal) and tactile (Yeaple Probe) sensitivity scores, gender, and age. Participants brushed their teeth twice daily (morning and evening) for 1 minute. Dentinal hypersensitivity examinations were conducted at baseline, 4 weeks, and 8 weeks by the same dental examiner. After 4- and 8-weeks' use of their assigned products, participants in the new dentifrice group demonstrated statistically significant improvements (p < 0.05) in tactile and air blast sensitivity, as compared to those using the positive and negative control dentifrices.