Two randomized, double-blind, placebo-controlled studies of fluticasone propionate lotion 0.05% for the treatment of atopic dermatitis in subjects from 3 months of age.

A novel lotion formulation of fluticasone propionate 0.05% has recently become available. Two large, randomized, placebo-controlled, double-blind studies involving 438 subjects demonstrated its efficacy and safety when applied once daily in the treatment of atopic dermatitis in subjects from 3 months to 87 years of age. The studies were limited to 4 weeks duration of use of fluticasone lotion and did not assess longer term efficacy or side effects.

Identification of two Mycobacterium tuberculosis H37Rv ORFs involved in resistance to killing by human macrophages.

BACKGROUND: The ability of Mycobacterium tuberculosis to survive and replicate in macrophages is crucial for the mycobacterium's ability to infect the host and cause tuberculosis. To identify Mycobacterium tuberculosis genes involved in survival in macrophages, a library of non-pathogenic Mycobacterium smegmatis bacteria, each carrying an individual integrated cosmid containing M. tuberculosis H37Rv genomic DNA, was passed through THP-1 human macrophages three times. RESULTS: Two of the clones recovered from this enrichment process, sur2 and sur3, exhibited significantly increased survival relative to wild-type bacteria. In coinfection experiments, the ratio of sur2 colonies to wild-type colonies was 1:1 at 0 hours but increased to 20:1 at 24 hours post phagocytosis. The ratio of sur3 colonies to wild-type colonies was 1:1 at 0 hours and 5:1 at 24 hours. The M. tuberculosis ORFs responsible for increased survival were shown to be Rv0365c for the sur2 clone and Rv2235 for the sur3 clone. These ORFs encode proteins with as-of-yet unknown functions. CONCLUSIONS: We identified two M. tuberculosis ORFs which may be involved in the ability of tubercle bacilli to survive in macrophages.

Alterations in hypothalamic insulin-like growth factor-I and its associations with gonadotropin releasing hormone neurones during reproductive development and ageing.

Insulin-like growth factor-I (IGF-I) is thought to play a role in the onset of reproductive ability at puberty and the control of reproductive function throughout adult life. It is believed that these effects are mediated at least in part by the activation of gonadotropin releasing hormone (GnRH) neurones by IGF-I, but the interactions of IGF-I with GnRH neurones in vivo are largely unknown. We first examined the anatomical relationship between GnRH and IGF-I cells in neuroendocrine regions. Using double-label immunocytochemistry, we observed that in the preoptic area-anterior hypothalamus (POA-AH), the site of GnRH perikarya, the majority (78%) of GnRH cell bodies expressed IGF-I immunoreactivity. IGF-I immunoreactivity was also high in the median eminence, the site of GnRH release, and GnRH neuroterminals were seen to interweave among IGF-I-immunopositive cells. Due to this substantial overlap of GnRH and IGF-I immunoreactive elements, we then tested the hypothesis that changes in IGF-I may regulate the GnRH system. Animals were examined at the two important reproductive life transitions: puberty and reproductive senescence. IGF-I mRNA levels were measured in POA-AH and medial basal hypothalamus-median eminence (MBH-ME) and effects of IGF-I treatment on GnRH mRNA levels were quantified by RNase protection assay. Although IGF-I treatment did not alter GnRH gene expression, there were significant alterations in hypothalamic IGF-I gene expression at both puberty and reproductive senescence. During puberty, IGF-I mRNA levels in the MBH-ME of rats increased from the juvenile stage (P25) to the day of vaginal opening (P35), and from the day of vaginal opening to young adulthood (P45) in the POA-AH. During reproductive ageing, IGF-I mRNA levels were significantly lower in middle-aged than young rats, particularly in the MBH-ME. At all ages, IGF-I expression was greater in the MBH-ME than in the POA-AH. These experiments demonstrate that: (i) the majority of adult GnRH neurones are immunopositive for the IGF-I protein; (ii) hypothalamic IGF-I levels increase at the onset of reproductive function and decrease at reproductive senescence in a regionally specific manner; and (iii) despite the presence of IGF-I in GnRH perikarya, IGF-I does not affect GnRH gene expression, suggesting that IGF-I may act at the level of GnRH release rather than gene expression.

Implant abutment screw rotations and preloads for four different screw materials and surfaces.

STATEMENT OF PROBLEM: Chronic implant screw loosening remains a problem in restorative practices. Some implant manufacturers have introduced abutment screws with treated surfaces in an effort to increase preload and reduce potential loosening. Purpose. This study evaluated the materials and surfaces of 4 commercially available abutment screws on preload generation. MATERIAL AND METHODS: Twenty of each of the following abutment screws-Gold-Tite (Gt), TorqTite (Tt), gold alloy (Ga), and titanium alloy (Ta)-were divided into 2 groups. Measurements were recorded for each abutment screw on a mounted 3.75 x 18 mm external hex implant with a titanium abutment. Rotational angle measurements were conducted on the 4 abutment screws at 20 and 32 Ncm. Removal torque values were recorded and used to indirectly generate preload values. Random implant block specimens were sectioned and qualitatively evaluated with an SEM. RESULTS: At 20 and 32 Ncm, the largest rotational angles were recorded for the Tt groups: 21.2 +/- 3.1 degrees and 38.1 +/- 8.7 degrees, respectively. The greatest preload values at 20 and 32 Ncm were calculated for the Gt groups: 596.8 +/- 101.2 N and 1015.3 +/- 191.2 N, respectively. SEM analysis of the 4 implant block specimens revealed mating thread contacts located in the middle portion of the superior surface of the abutment screw thread. The greatest number of mating thread contacts were seen in the Gt implant block specimen (14 of 20 possible thread contacts). CONCLUSION: The Gt and Tt abutment screws with enhanced surfaces that help reduce the coefficient of friction produced greater rotational angles and preload values than the conventional gold alloy and titanium alloy screws.

Efficacy and tolerance of adapalene cream 0.1% compared with its cream vehicle for the treatment of acne vulgaris.

Adapalene gel 0.1% is approved for use in the treatment of acne vulgaris. A new cream formulation, adapalene cream 0.1%, has been developed. Our objective was to evaluate the efficacy and tolerability of adapalene cream 0.1% in comparison with its cream vehicle, applied once daily for 12 weeks to patients with facial acne vulgaris. We used a 12-week, multicenter, randomized, double-blind, vehicle-controlled, comparative phase 3 study of adapalene cream 0.1% and cream vehicle. The study enrolled 237 patients (125 males and 112 females), aged 12 through 30 years, with mild-to-moderate acne vulgaris. Adapalene cream 0.1% demonstrated superior efficacy compared with its cream vehicle. Significantly lower numbers of total inflammatory and noninflammatory lesion counts were observed at the end of the study period in patients using adapalene cream 0.1% as opposed to those using cream vehicle (P<.05 compared with baseline, for all 3 parameters). Adapalene cream 0.1% caused more cutaneous side effects than the cream vehicle, but these were tolerated in most patients. In summary, the results of this study indicate that adapalene cream 0.1% demonstrates superior efficacy over cream vehicle for the treatment of acne vulgaris. Adapalene cream 0.1% also has excellent tolerability and is associated with a low incidence of cutaneous adverse events.

A comparison of shear bond strengths of three visible light-cured orthodontic adhesives.

The purpose of this study was to evaluate the shear bond strength and the site of bond failure for 2 visible light-cured composites (Transbond XT and Enlight) and a resin-modified glass ionomer cement (RMGIC; Fuji Ortho LC). Seventy-five extracted human premolars were collected and randomly divided into 3 test groups. Brackets were bonded to the teeth in each test group with the respective adhesive according to the manufacturers' instructions. Each specimen was debonded using an Instron Universal Testing Machine at a crosshead speed of 0.1 mm/min. The mode of bond failure was observed by using light microscopy. The results of this study demonstrated that the light-cured composites had a higher shear bond strength than the RMGIC. The adhesive-remnant scores were similar for the composites with the mean values at about 2, which indicates that more than half of the adhesive remained on the tooth. The RMGIC had a mean score of 3, which was significantly different from the composites and indicated that all of the adhesive remained on the tooth with a distinct impression of the bracket.

In vitro tensile bond strength of adhesive cements to new post materials.

PURPOSE: The purpose of this study was to measure the in vitro tensile bond strength of 3 types of adhesive resin cements to stainless steel, titanium, carbon fiber-reinforced resin, and zirconium oxide post materials. MATERIALS AND METHODS: Disks of post materials were polished to 600 grit, air abraded, and ultrasonically cleaned. Zirconium oxide bonding surfaces were pretreated with hydrofluoric acid and silanated. Bis-Core, C&B Metabond, and Panavia cements were bonded to the post specimens and placed in a humidor for 24 hours. Post specimens were debonded in tension. Means and standard deviations (n = 5) were analyzed by 2-way analysis of variance. Tukey-Kramer intervals at the 0.05 significance level were calculated. Failure modes were observed. RESULTS: Panavia 21 provided the highest bond strengths for all types of post materials, ranging from 22 MPa (zirconium oxide) to 37 MPa (titanium). C&B Metabond bonded significantly more strongly to stainless steel (27 MPa) and titanium (22 MPa) than to zirconium oxide (7 MPa). Bis-Core results were the lowest, ranging from 16 MPa (stainless steel) to 8 MPa (zirconium oxide). In most cases, bonds to carbon fiber post materials were weaker than to stainless steel and titanium, but stronger than to zirconium oxide. In general, higher bond strengths resulted in a higher percentage of cohesive failures within the cement. CONCLUSION: Panavia 21 provided the highest bond strengths to all post materials, followed by C&B Metabond. In most cases, adhesive resins had higher bond strengths to stainless steel, titanium, and carbon fiber than to zirconium oxide.

Evaluation of Mycobacterium tuberculosis genes involved in resistance to killing by human macrophages.

A coinfection assay was developed to examine Mycobacterium tuberculosis genes suspected to be involved in resistance to killing by human macrophages. THP-1 macrophages were infected with a mixture of equal numbers of recombinant Mycobacterium smegmatis LR222 bacteria expressing an M. tuberculosis gene and wild-type M. smegmatis LR222 bacteria expressing the xylE gene. At various times after infection, the infected macrophages were lysed and the bacteria were plated. The resulting colonies were sprayed with catechol to determine the number of recombinant colonies and the number of xylE-expressing colonies. M. smegmatis bacteria expressing the M. tuberculosis glutamine synthetase A (glnA) gene or open reading frame Rv2962c or Rv2958c demonstrated significantly increased survival rates in THP-1 macrophages relative to those of xylE-expressing bacteria. M. smegmatis bacteria expressing M. tuberculosis genes for phospholipase C (plcA and plcB) or for high temperature requirement A (htrA) did not.

Finding meaning through caregiving: development of an instrument for family caregivers of persons with Alzheimer's disease.

Systematic assessment of the positive aspects of caregiving has been limited by the lack of comprehensive, theoretically based, and psychometrically sound measures. This study developed and tested a measure primarily designed to assess positive aspects and ways that caregivers find meaning through their experience of caring for a person with dementia. The measure has three subscales: Loss/Powerlessness, which identifies difficult aspects of caregiving; Provisional Meaning, which identifies how caregivers find day-to-day meaning; and Ultimate Meaning, which identifies philosophical/religious/spiritual attributions associated with the experience of caregiving. The measure is useful for understanding the close relationship between both the difficult and positive aspects of caregiving and also may be used to identify a caregiver's strengths in clinical and research settings.

Tazarotene gel is safe and effective in the treatment of acne vulgaris: a multicenter, double-blind, vehicle-controlled study.

Retinoids reverse the abnormal pattern of keratinization seen in acne vulgaris. Tazarotene is the first of a novel family of topical receptor-selective acetylenic retinoids. This study evaluates the safety and efficacy of topical tazarotene 0.1% and 0.05% gels, in comparison to vehicle gel, applied once daily for 12 weeks, in the treatment of mild-to-moderate facial acne vulgaris. A total of 446 patients with facial acne vulgaris were enrolled, and 375 patients, ranging in age from 14 to 44 years, were evaluable in this multicenter, double-blind, randomized study. In comparison to vehicle gel, treatment with tazarotene 0.1% gel resulted in significantly greater reductions in noninflammatory and total lesion counts at all follow-up visits, and inflammatory lesion counts at Week 12. Tazarotene 0.05% gel resulted in significantly greater reductions in noninflammatory and total lesion counts than vehicle gel at Weeks 8 and 12. At Week 12, treatment success rates were 68% and 51% for tazarotene 0.1% and 0.05%, respectively (40% for vehicle gel). Tazarotene gel was an effective, safe, and generally well-tolerated therapy for the treatment of acne vulgaris.

Marginal discrepancy of screw-retained and cemented metal-ceramic crowns on implants abutments.

This in vitro study quantified the marginal discrepancy of the implant-to-prosthetic-crown interface on nonsubmerged dental implants restored with either a cemented or a screw-retained approach. Metal-ceramic crowns were fabricated for 20 ITI 4.1 x 10 mm solid-screw titanium implants. Ten implants received octa abutments and screw-retained crowns fabricated on premachined gold cylinders. The remaining 10 implants were restored with 5.5-mm solid abutments and metal-ceramic crowns cemented alternately with a glass-ionomer or a zinc phosphate luting agent. Inspection of the implant-crown interface was conducted using light microscopy under x 50 magnification at selected stages in the process of crown fabrication. Statistical analysis revealed a significant difference (P < .001) in the mean marginal fit between screw-retained (8.5 +/- 5.7 microns) and luted implant-supported crowns. This difference was observed both before (54.4 +/- 18.1 microns) and after cementation with glass-ionomer (57.4 +/- 20.2 microns) or zinc phosphate (67.4 +/- 15.9 microns).

In vitro investigation of the wear of human enamel by dental porcelain.

STATEMENT OF PROBLEM: Metal ceramic systems are advocated when both esthetics and strength are required. A major drawback to many porcelains is their wear and destruction of opposing natural dentition. PURPOSE: This study evaluated the wear of enamel opposing 1 traditional and 2 recently introduced low-fusing feldspathic dental porcelains. MATERIAL AND METHODS: Six blocks of Ceramco II, Finesse, and Omega 900 feldspathic porcelain materials were fabricated and fired according to manufacturer recommendations. Porcelain blocks were polished through 0.25 microm diamond polishing paste. Thirty-six enamel specimens were obtained and milled to a 2 mm (+0.5 mm) diameter. Enamel specimens were attached to an offset cam motor operating at 60 Hz. Enamel specimens were in constant contact with the stationary porcelain blocks under a load of 600 g and traversed a distance of 8 mm. Diameter and height of enamel specimens were measured at times of 0, 6, 12, 24, and 48 hours and subsequent determination of enamel volume loss recorded. Profilometric surface roughness of the ceramic blocks was also measured for the corresponding times. RESULTS: Statistical analysis revealed that both Finesse and Omega 900 feldspathic porcelains caused significantly less enamel volume loss when compared with Ceramco II porcelain at all time intervals. Surface roughness revealed no consistent significant differences among porcelains. CONCLUSION: Both Finesse and Omega 900 porcelains were not as destructive to human tooth structure as Ceramco II porcelain. These results suggest an advantage of the new, lower-fusing porcelains in conditions where natural dentition wear is a concern.

Accuracy of CT for the detection of pleural adhesions: correlation with video-assisted thoracoscopic surgery.

STUDY OBJECTIVE: The presence of pleural adhesions may render video-assisted thoracoscopic surgery (VATS) difficult or impossible. The aim of this study was to assess the value of chest CT in the detection of pleural adhesions prior to VATS. DESIGN: Prospective study of the accuracy of chest CT in detecting pleural adhesions prior to VATS. SETTING: Tertiary-referra; teaching hospital and Veterans Administration hospital. PATIENTS: Between July 1994 and March 1995, 63 consecutive patients undergoing 64 VATS procedures were evaluated with chest CT prior to surgery. MEASUREMENTS AND RESULTS: Preoperative scans were interpreted by consensus of two pulmonary radiologists prior to surgery. Suspected pleural adhesions and other findings related to the pleura were recorded on a form given to the surgeon prior to VATS. The surgeon confirmed or excluded each suspected adhesion during VATS, and documented any other lesions not identified preoperatively. Patient-by-patient and lesion-by-lesion analyses were performed. Pleural adhesions were correctly identified by CT in 28 of 39 cases (sensitivity, 71%) and excluded in 18 of 25 cases (specificity, 72%). On a lesion-by-lesion basis, 73 adhesions were identified during VATS, of which only 28 were identified prospectively at CT. There were 45 missed adhesions and 20 adhesions that were suggested falsely (sensitivity, 38%; specificity, 46%). Eighteen pleural spaces were correctly identified as being free of pleural adhesions. CONCLUSIONS: CT is moderately sensitive and specific for preoperative identification of pleural adhesions in patients undergoing VATS but its accuracy is poorer for individual lesions.

Marginal gap of crowns made with a phosphate-bonded investment and accelerated casting method.

STATEMENT OF PROBLEM: Numerous materials and methods have been used for complete crown fabrication. Conventional investing and casting procedures for phosphate-bonded investments require a 2- to 4-hour process before completion. Accelerated laboratory techniques have been used, but may not result in castings with equal marginal accuracy. PURPOSE: This study measured the marginal gap and determined the clinical acceptability of single castings invested in a phosphate-bonded investment with the use of conventional and accelerated methods. MATERIAL AND METHODS: Forty-four individual stone casts were poured from impressions made from a master die. Conventional and accelerated methods of investing and casting were followed in the fabrication of 44 single-unit castings. Twenty-two casts were used in each of the 2 groups. Each casting and its respective stone die were examined with a microscope at 4 predetermined sites. Perpendicular and 25-degree tilted measurements of marginal gap were documented for each. Evidence of marginal gap was then evaluated by t test. RESULTS: Measurements recorded on the perpendicular and on a 25-degree tilt showed no statistically significant difference between conventional and accelerated groups. All gap measurements except one were within the range of clinical acceptability. The measurements revealed that conventional and accelerated perpendicular gap means were 13.2 and 13.6 microm, respectively, and the average tilted gap means were 31.6 and 32.2 microm, respectively. CONCLUSIONS: A phosphate-bonded investment (Ceramigold) selected for an accelerated casting technique produced single castings within 30 minutes with marginal gaps comparable to those found that used conventional methods.

Strength and microstructure of gallium alloys.

This study investigated the physical and mechanical properties and the microstructure of four different gallium alloys. For all gallium alloys, the compressive strengths measured at one hour (86-223 MPa) and 24 hours (265-286 MPa) after specimen preparation were found to be well within the range exhibited by many high-copper amalgams. The creep values and dimensional change of the gallium alloys were comparable to those of leading amalgams, except for the dimensional change value of one alloy. The set gallium alloys consisted of a multi-phase structure including beta-Sn, CuGa2, In4Ag9, Ag72Ga28, and Ga5Pd (except for one product that did not contain Pd) that was more complicated than the structure of dental amalgams. Although the gallium alloys had physical and mechanical properties comparable to those of high-copper amalgams, the microstructure, coupled with the instability of the element gallium itself, could make these materials more prone to corrosive attack compared to amalgams.

Intratumoral chemotherapy with fluorouracil/epinephrine injectable gel: a nonsurgical treatment of cutaneous squamous cell carcinoma.

BACKGROUND: We attempted to originate a nonsurgical treatment alternative for cutaneous squamous cell carcinoma (SCC), and we evaluated intratumoral modified-release chemotherapy with fluorouracil/epinephrine injectable gel (5-FU/epi gel). OBJECTIVE: To assess the safety and efficacy, we conducted an open-label pilot study of 5-FU/epi gel in 25 patients with biopsy-proven SCC lesions on the face, head, neck, trunk, arms, and hands. METHODS: Each tumor site was injected intradermally with up to 1.0 ml of 5-FU/epi gel. One SCC per patient was treated weekly for up to 6 weeks, then observed for 4 months at which time the tumor site and margins were excised for histologic examination. RESULTS: Overall, 96% (22 of 23) of evaluable treated tumors had histologically confirmed complete tumor clearing. No clinically significant systemic reactions or unexplained treatment-related adverse medical events occurred. The evaluations of the cosmetic appearance of the treated sites, judged subjectively by clinicians and patients, were mostly good to excellent and generally in close agreement. CONCLUSION: Treatment of superficial SCC with 5-FU/epi injectable gel results in a high rate of histologically confirmed complete tumor responses and may provide a nonsurgical treatment alternative in selected patients.

Bond strength between cements and metals used for endodontic posts.

OBJECTIVES: Adhesive cements used with metal endodontic posts may decrease fracture in non-vital teeth. Results from studies that evaluate cements for post retention by pulling posts out of extracted teeth are difficult to interpret owing to the number of interfaces where fracture might occur. The objective of this study was to isolate the metal/cement interface for tensile bond strength testing and microscopic observation. METHODS: Three metals and seven cement treatments were examined for bond strength by using a truncated cone tensile test. The bond strength data were analyzed by a two-way ANOVA and Scheffé's multiple comparison test at p = 0.05. Specimens were examined at 50x magnification to determine the failure mode and with scanning electron microscopy (500x) to observe the surfaces after debonding. RESULTS: Significant differences in tensile bond strengths were found among cements compared within two of the metal groups. One of the metal groups had no significant differences among cement bonds. When comparing within cement treatment groups, two groups had significant differences in bond strength among the metals. Microscopic observations revealed adhesive, cohesive and mixed failure modes that varied with cement treatment and metal combination. The interaction between metal and cement was a critical determinant of the strength and characteristic fracture mode of the bond achieved. SIGNIFICANCE: Some of the cement treatments performed better (i.e., higher bond strength) with some metals than with others. Other cements had similar bond strengths with all three metals. Because of this interaction, careful consideration of the materials combination should help to maximize the bond at the metal/cement interface.

The effect of cementing procedures on retention of prefabricated metal posts.

Twelve prefabricated posts were cemented in extracted teeth with zinc phosphate cement, 14 with resin cement after the canals were acid etched and 14 with zinc phosphate cement after acid etching. After thermocycling, specimens were subjected to a straight-line tensile force. The posts cemented with resin cement had significantly higher tensile strength than those cemented with the two zinc phosphate cement treatments.