The permeability transition pore triggers Bax translocation to mitochondria during neuronal apoptosis.

Cerebellar granule neurons (CGNs) require depolarization for their survival in culture. When deprived of this stimulus, CGNs die via an intrinsic apoptotic cascade involving Bim induction, Bax translocation, cytochrome c release, and caspase-9 and -3 activation. Opening of the mitochondrial permeability transition pore (mPTP) is an early event during intrinsic apoptosis; however, the precise role of mPTP opening in neuronal apoptosis is presently unclear. Here, we show that mPTP opening acts as an initiating event to stimulate Bax translocation to mitochondria. A C-terminal (alpha9 helix) GFP-Bax point mutant (T182A) that constitutively localizes to mitochondria circumvents the requirement for mPTP opening and is entirely sufficient to induce CGN apoptosis. Collectively, these data indicate that the major role of mPTP opening in CGN apoptosis is to trigger Bax translocation to mitochondria, ultimately leading to cytochrome c release and caspase activation.

The pain control infusion pump for postoperative pain control in shoulder surgery.

PURPOSE: This study was initiated to evaluate the effect of a pain control infusion catheter in managing postoperative pain. TYPE OF STUDY: In a prospective, randomized trial, 62 consecutive patients undergoing arthroscopic subacromial decompression had an indwelling pain control infusion catheter placed at the operative site. MATERIALS AND METHODS: Thirty-one patients received 0.25% bupivacaine and 31 patients received saline infusions, each at a constant rate of 2 mL per hour. Patients evaluated their pain by visual analog scale, and also tabulated the amount of narcotic and nonnarcotic medication used each day in the first week of surgery. RESULTS: There was a statistically significant difference in pain in all parameters tested in the bupivacaine group as compared with the saline control group (P <.05). CONCLUSIONS: The bupivacaine pain control infusion pump is an effective means of decreasing postoperative pain.

Temperature and humidity effects on bond strength of a dentinal adhesive.

Dentin specimens from 46 extracted human molar teeth were used in a matched-pair design examining the factors of temperature/humidity on shear bond strength of a dentinal adhesive to dentin. For one tooth-half, all procedures using restorative materials were accomplished in a controlled temperature and humidity chamber (humidity 95.0 +/- 2.0%, temperature 37.0 +/- 0.3 degrees C). For the other matched tooth-half all procedures were performed at ambient room conditions (humidity 52%, temperature 23.3 degrees C/74 degrees F). Oil-free air and water were used in all restorative procedures. Application of Scotchbond Multi-Purpose Adhesive System was followed by placement of Z100 Restorative Resin, and thermocycling 1000 cycles from 5 to 55 degrees C. Each matched specimen was tested 24 hours later in an Instron Testing Machine. A paired t-test was performed for comparison of bond strength set values, since they were obtained from matching halves of the same teeth. Paired t-test comparison showed that the average humidity/temperature chamber mean of 7.14 +/- 3.12 MPa was significantly less than the ambient conditions mean of 14.29 +/- 5.07 (P = 0.0000). Bond strength testing under simulated oral conditions may produce significantly different findings than customary bench-top laboratory experiments.

Influence of different etchants and etching times on shear bond strength.

This study compared the shear bond strength to enamel of Scotchbond Multi-Purpose Dental Adhesive System's bonding resin following etching of enamel with 10% maleic, 1.6% oxalic, 10% phosphoric, and 35% phosphoric acids for 15, 30, and 60 seconds. Three hundred and sixty human molar teeth were used to create 12 groups of 30 enamel specimens per group (n = 30). Flattened enamel surfaces were treated with the different etchants for the time periods indicated, the surfaces primed, and adhesive resin applied according to the manufacturer's recommendations. The specimens were completed with Silux Plus resin and subjected to 1000 thermocycles (5-55 degrees C) followed by shear stress in an Instron Testing Machine to failure within a 24-hour period. A two-way ANOVA revealed significant differences for shear bond strength values by type of etchant (10% phosphoric, 35% phosphoric > 10% maleic > 1.6% oxalic acid) (P < 0.005) and by length of application time (P < 0.005). The interaction term for these two treatments was statistically significant (P < 0.005).

Microleakage of five dentinal adhesives.

This study compared the microleakage characteristics of four dentinal adhesives against Scotchbond 2 as a control and discusses the results in light of recently reported bond strengths for these same materials. Dentin specimens from 100 caries-free extracted human molar teeth were used in a matched pair design. In each of the four test materials, 25 tooth sides were treated along with the matching control, subjected to 500 thermocycles (5 to 55 degrees C), followed by AGNO3 dye penetration, specimen sectioning, and evaluation by low-power stereomicroscopy. Mean microleakage values were as follows (microns): Scotchbond Multipurpose, 498.0; All-Bond 2, 530.8; Syntac, 748.0; X-R Bond, 844.9; and the Scotchbond 2 control (a composite score created by averaging four sets of 25 tooth sides), 1095.2. Paired t-tests showed that Scotchbond Multipurpose, Syntac, and All-Bond 2 had significantly lower microleakage than the control (P=0.0001); however, X-R Bond had no significant difference from the control (=0.4634).

Bond strength of six dentinal adhesives.

This study compared the shear bond strengths on dentine of five dentine adhesives against Scotchbond 2 as a control. Dentine specimens from 225 extracted human permanent molar teeth were used in a matched-pair design, such that 45 tooth sides were treated along with the matching control for each of the five test materials. Shear bond strength testing was conducted 24 h after the completion of each specimen. Results showed that mean force (MPa) for the materials were: XR Bond, 17.1 +/- 5.1; Scotchbond Multi-Purpose, 15.9 +/- 6.5; Syntac, 13.5 +/- 8.6; All-Bond 2, 6.2 +/- 4.1; Scotchbond 2 (control composite score), 4.9 +/- 3.0; Denthesive, 3.4 +/- 1.7. Matched pair t-test comparisons with Scotchbond 2 control were: XR Bond, P = 0.0005; Scotchbond Multi-Purpose, P = 0.0005; Syntac, P = 0.0005; All-Bond 2, P = 0.0368; Denthesive, P = 0.005. Analysis of variance determined a statistically significant difference (P = 0.05) between the means of the bond strengths, which fell into four groups: Group A, XR Bond and Scotchbond Multi-Purpose; Group B, Syntac; Group C, All-Bond 2 and Scotchbond 2; Group D, Scotchbond 2 and Denthesive. In Group C, there was no significant difference between Scotchbond 2 and All-Bond 2. In Group D there was no significant difference between Scotchbond 2 and Denthesive, however, there was significant difference between All-Bond 2 and Denthesive. It was concluded that XR Bond and Scotchbond Multi-Purpose had significantly better shear bond strength than the other dentine adhesives.

Marketing home health care medical services: the physician's view.

The authors surveyed physicians serving the Jackson, Mississippi home health care market. They identified problems and studied physician perceptions regarding services provided by home health care agencies, private duty nursing agencies, and durable medical equipment suppliers. Respondents perceived home health care as providing: (1) increased patient satisfaction, (2) greater patient convenience, (3) earlier discharge, and (4) lowered patient costs. They least liked: (1) lack of control and involvement in the patient caring process, (2) paperwork, (3) quality control potential, and the possibility that patient costs could increase. Two sets of implications for health care marketers are presented that involve both national and regional levels. Overall results indicate that a growing and profitable market segment exists and is being served in an effective and socially responsible manner.

Measuring customer perceptions of emergency facility services: a qualitative approach.

The purpose of this study was to use a qualitative research technique and define problems faced by one hospital that was attempting to increase demand for its emergency services. A telephone survey of 450 affluent and well-educated suburban residents was conducted to determine their perceptions of six major facilities. Topics included actual and preferred facility use by injury type, general perceptions concerning staff and facility, and other components of service quality. Results indicated that a variety of sociological, psychological, environmental, and situational factors interacted when the respondents formed attitudes concerning hospital emergency use and service. They were often uncertain of their real attitudes and conveyed varying opinions about the desirability or effectiveness of similar services. Health care providers should note these differences and modify the marketing mixes in a manner that best conveys their unit's competitive advantages. They could also benefit from using the qualitative research technique described in this paper and from adopting the marketing concept.

Microleakage and marginal placement of a glass-ionomer liner.

Glass-ionomer cements, with their ability to bond to dentin, have been reported to produce less microleakage than several other restorative resin materials. This matched-pair study reports the effect on microleakage of placement of a light-curing glass-ionomer cement used as a liner when extended out to the dentinal cervical cavosurface margin or held short of that margin. Pairs of circular Class V cavities involving 50% enamel, with bevel, and 50% cementum were cut in 31 extracted third molars. After placement of the glass-ionomer cement, etching of the bevel, and placement of a resin bonding system, microfilled resin was placed over the bonding agent in one increment, light-cured, finished, and given 500 thermocycled 500 times between 5 and 55 degrees C. A silver nitrate staining technique was used to evaluate microleakage measured in graticular units (gu) along the dentinal interface under stereomicroscopy. The extension of the glass-ionomer liner out to the dentinal cavosurface margin did not significantly improve microleakage performance compared to performance of the liner when it was placed short of that margin and covered by a resin veneer. From other considerations, such as the potential for mechanical breakdown of the glass-ionomer cement when exposed to the oral environment and abrasion, and the possibility for improved esthetics, the clinician should consider holding the glass-ionomer liner short of the dentinal cavosurface margin and covering it with a composite resin veneer of a thickness consistent with structural integrity.