G protein beta2 subunit antisense oligonucleotides inhibit cell proliferation and disorganize microtubule and mitotic spindle organization

The association of G protein beta2 subunit (Gbeta2) with mitotic spindles in various mammalian cells has been demonstrated previously. Recently, we have identified the association of Gbeta2 protein with microtubules (Wu et al., [1998] J. Cell. Biochem. 70: 552-562). In the present experiment we have demonstrated the possible functional role of Gbeta2 in microtubule and mitotic spindle organization in mammalian cells. When Gbeta2 antisense phosphorothioate oligonucleotides were transfected into mammalian cells, inhibition of cell proliferation with cell death after a 4-day treatment was observed. If the transfected cells were incubated for two days and their Gbeta2 and microtubules were examined by Western blotting and immunofluorescence localization, marked reduction of the Gbeta2 protein, fragmentation and disassembly of cytoplasmic microtubules, and disorganized mitotic spindles were found. We conclude that the Gbeta2 protein is closely associated with microtubule assembly and may play a potential role in the regulation of cell proliferation and microtubule and mitotic spindle organization in mammalian cells.

Is patients' perception of time spent with the physician a determinant of ambulatory patient satisfaction?

BACKGROUND

Time management in ambulatory patient visits is increasingly critical. Do patients who perceive a longer visit with internists report increased satisfaction?

METHODS

Prospective survey of 1486 consecutively encountered ambulatory visits to 16 primary care physicians (PCPs) in an academic primary care clinic. Patients were queried regarding demographics, health status, perception of time spent before and after ambulatory visits, whether the physician appeared rushed, and visit satisfaction. Physicians were queried regarding time spent, estimated patient satisfaction, and whether they felt rushed.

RESULTS

In 69% of 1486 consecutive visits, patient previsit expectation of visit duration was 20 minutes or less. Patient and PCP postvisit estimates of time spent significantly exceeded patient previsit time expectation. Patients who estimated that they spent more time than expected with the PCP were significantly more satisfied with the visit. When patient postvisit estimate of time spent was less than the previsit expectation, visit satisfaction was significantly lower independent of time spent. Patient worry about health and lower self-perceived health status were significantly associated with patient expectation for longer visits. Primary care physicians felt rushed in 10% of encounters. Although PCPs estimated patient satisfaction was significantly lower when they felt rushed, patient satisfaction was identical when PCPs did and did not feel rushed. Patients indicated that PCPs appeared rushed in 3% of encounters, but this perception did not affect patient satisfaction.

CONCLUSION

Perceived ambulatory visit duration and meeting or exceeding patient expectation of time needed to be spent with the physician are determinants of patient satisfaction in an ambulatory internal medicine practice.

The effects of the flow pattern on organic oxidation and nitrification in aerated submerged biofilters

Previous research has shown that a submerged biofilter is effective in removing organic matter and total organic nitrogen. Upflow and downflow biofilters were set up to investigate the different oxidative efficiencies on organic matter and ammonia nitrogen of different biofilter positions and to compare the biological activities of the upflow and downflow patterns. A comparison of the operational characteristics of the two types of biofilters is discussed. The main COD removal zone is 0-20 cm in the upflow biofilter, but in the downflow biofilter it occurs in the submerged zone. The nitrification process is dependent on the HRT and the residual COD. In the downflow biofilter, the efficiency of the nitrification increases with the HRT. The growth of nitrifying bacteria has a tendency to take place in higher zones in the downflow biofilter, especially for a longer HRT. Batch tests measured the biological activity of heterotrophs and nitrifying autotrophs with decomposition rates. In the upflow biofilter, the nitrification rates increased while the COD oxidative rates decreased with the height of the biofilter, so the effect of the HRT on the activity of the nitrifying autotrophs is significant. However, in the down biofilter, the activity of the nitrifying autotrophs was similar at different heights in the same HRT runs with the maximum nitrifying autotrophs activity being at an HRT of 6 hours.

Value of human papillomavirus deoxyribonucleic acid testing after conization in the prediction of residual disease in the subsequent hysterectomy specimen

OBJECTIVE

Our aim was to evaluate human papillomavirus deoxyribonucleic acid testing after conization in predicting residual disease in the subsequent hysterectomy specimen.

STUDY DESIGN

A prospective study was conducted on 75 patients with grade 3 cervical intraepithelial neoplasia who had cone margins or endocervical curettage specimens showing disease and who elected to undergo hysterectomy after conization. All patients underwent high-risk human papillomavirus deoxyribonucleic acid testing by the Hybrid Capture II (Digene Corporation, Gaithersburg, MD) system before conization and at the time of hysterectomy (within 2-7 weeks after conization). The presence of human papillomavirus deoxyribonucleic acid in cells obtained by endocervical brush before hysterectomy was correlated with residual disease in the hysterectomy specimens.

RESULTS

Of the 92 patients enrolled, 75 were eligible. Of these 75 patients, 52 (69.3%) had persistent human papillomavirus deoxyribonucleic acid after conization, and 27 (36.0%) of the 75 patients had residual cervical neoplasia in the hysterectomy specimens. Those with negative results for human papillomavirus deoxyribonucleic acid after conization were all (23/23) without residual disease in the uterus (100% negative predictive value). All those who had residual disease (27/27) had positive results for human papillomavirus deoxyribonucleic acid at the time of hysterectomy (100% sensitivity). Postconization human papillomavirus deoxyribonucleic acid status (odds ratio, 4.000; 95% confidence interval, 1.531-10.449; P =.005) and grade of dysplasia after endocervical curettage (classified as grade 2 cervical intraepithelial neoplasia or less severe disease vs grade 3 cervical intraepithelial neoplasia: odds ratio, 6.612; 95% confidence interval, 2.837-15.409; P =.0002) were significantly associated with residual tumor in the uterus.

CONCLUSIONS

This prospective study confirms an excellent sensitivity and negative predictive value of human papillomavirus deoxyribonucleic acid testing after conization in predicting residual cervical neoplasia. A strategy of managing patients with grade 3 cervical intraepithelial neoplasia, based on postconization human papillomavirus deoxyribonucleic acid findings and endocervical curettage results, is proposed.

Generation and analysis of canine retinal ESTs: isolation and expression of retina-specific gene transcripts

Canine generalized progressive retinal atrophies (gPRA) are a group of degenerative retinal diseases that are a major cause of hereditary blindness in a number of dog breeds. The expressed sequence tag (EST) approach was used to identify and characterize potential candidate genes from canine retinal cDNA libraries. Both conventional and subtractive canine retinal cDNA libraries were constructed and analyzed. Differential hybridization was performed to identify abundantly retinal expressed cDNA clones. Sequences of both random and abundantly expressed clones were analyzed using GCG software and searched against GenEMBL databases. For genes of interest isolated from the libraries, Northern blotting and RT-PCR were performed to determine mRNA expression of the genes. DNA sequences from 85 differentially expressed clones and 100 random cDNAs were obtained and analyzed. A higher percentage of abundantly retina-expressed clones showed homology to database sequences compared with random clones (72 versus 43%). Five retinal genes and 2 anonymous retinal ESTs were selected to analyze mRNA expression. The five known genes, namely HRG4/unc119, cGMP-PDEA, transducin 1A, opsin, and sFRP2 showed retina-specific expression. In anonymous ESTs, clone p81 revealed retina-specific expression, while p3 showed expression in each of 14 canine tissues. Transcripts of the canine secreted frizzled related protein 2 (sFRP2) gene showed surprisingly high abundance in the canine retina. The isolated retinal ESTs here will be useful resources for further investigation of canine retinal function and canine genome mapping.

Resonant spin excitation in an overdoped high temperature superconductor

An inelastic neutron scattering study of overdoped Bi(2)Sr(2)CaCu(2)O(8+delta) ( T(c) = 83 K) has revealed a resonant spin excitation in the superconducting state. The mode energy is E(res) = 38.0 meV, significantly lower than in optimally doped Bi(2)Sr(2)CaCu(2)O(8+delta) ( T(c) = 91 K, E(res) = 42.4 meV). This observation, which indicates a constant ratio E(res)/k(B)T(c) approximately 5.4, helps resolve a long-standing controversy about the origin of the resonant spin excitation in high temperature superconductors.

Personalized remedial intensive training of one medical student in communication and interview skills

BACKGROUND

Medical students found to be deficient in communication and interview skills pose a difficult remediation challenge. There is no standard way to address such deficiencies. The authors describe the development and implementation of an intensive remedial curriculum.

DESCRIPTION

A 2nd-year student found deficient in communication skills was held back for a year and paired with a clinical preceptor for intensive skills training, including a weekly precepted clinic, structured readings, standardized patient (SP) exercises, communications workshops, and end-of-year standardized clinical evaluations.

EVALUATION

The student's self-assessment and the preceptor's assessments of communication skill gradually improved over the year. The student improved through a progression of SP exercises focusing on specific communication skills. The student passed a final evaluation exercise with an excellent rating from the SP and the preceptor.

CONCLUSIONS

This multistrategy approach to improve communication skills can be applied to other students and in other institutions. Based on the Bayer Institute communication workshops and integrated coaching techniques, the material forms a framework to help deficient students to become proficient in communication and interviewing skills.

Thermo-debonding mechanisms in dentin bonding systems using finite element analysis

The finite element method (FEM) has been extensively used in evaluating the interfacial status of biomaterials. We used FEM to explore the microscopic debonding mechanism of the dentin/hybrid layer/resin adhesive interface. The stress status of the local material was used as an index to judge whether the adhesive interface would develop a debonding mechanism. To generate the local stress concentration, the thermal boundary condition was applied to the model which has the phenomenon of the coefficient of thermal expansion (CTE) mismatch. The thermal boundary condition was used to emulute a previous study conducted with a laser thermoacoustic technique (LTAT). The materials, Scotchbond MP, Optibond, and Tenure bonding systems, used in the previous experiment were also tested in this study. The results show that interfacial debonding in the finite element model occurred through the hybrid layer for both the Scotchbond MP and Tenure systems, as well as within the adhesive layer itself for the Optibond system. These findings are compatible with observations by SEM obtained by LTAT. Another transformed model was created to test the "elastic cavity wall" concept. The result also confirms the importance of the elastic cavity wall concept. These compatible results between FEM and LTAT indicate that FEM can be a very useful supplement to thermoacoustic testing.

National survey of internal medicine residency programs of their 1st-year experience with the electronic residency application service and national resident match program changes

BACKGROUND

The residency recruitment and selection process is a critical one for residency programs and medical students. In 1999, internal medicine programs conducted the residency match on the Web for the first time using the Electronic Residency Application Service (ERAS).

PURPOSE

The authors wished to study the impact of this change on house staff recruitment and quality of match.

METHOD

A Web-based survey with e-mail, paper, and fax reminders was sent to all 407 internal medicine residency programs after the 1999 match.

RESULTS

Eighty-six percent of reporting programs found the screening of applicants easier. The overall number of applicants varied greatly (48% of programs reported more applicants; 32% reported fewer). The quality of final match was rated the same as previous years by 47%, better by 38%, and worse by 15%.

CONCLUSIONS

The transition to ERAS was successful in internal medicine. However, there are several areas that were identified that will improve the ERAS process as it evolves.

Effect of temperature and flux concentration on soldering of base metal

The present study used the acoustic emission (AE) technique to evaluate interactions among soldering temperature, flux treatment, and the resultant ultimate tensile strength (UTS). Scanning electron microscopy (SEM) was used to examine fracture surfaces of the solder joints. Specimens were cast from removable partial denture alloy and then placed in a jig with a gap distance of 1.0 mm. A high-frequency soldering machine with an optical pyrometer was used for soldering at 1150 degrees C and 1200 degrees C, respectively. The flux concentrations were 67% and 75%. The soldered specimens were subjected to tensile test at a crosshead speed of 0.05 mm/min. During testing, acoustic emissions in the frequency range of 100--1200 kHz were collected, filtered, recorded, and processed by a sensing device. The results were analysed by ANOVA and Tukey LSD test. UTS at different temperatures showed no significant difference according to either mechanical or acoustic results. But in the 1200 degrees C group, the UTSs and AE counts showed significant differences (P<0.05) at both flux concentrations. SEM showed that the 1200C group had better dendritic crystal structure than did the 1150 degrees C group. In the 1200 degrees C group specimens with 67% flux had fewer flux inclusion bodies and dendritic crystals than did specimens with 75% flux. The 75% flux subgroup produced high-amplitude (60--70 dB) acoustic signals within the elastic deformation zone, while the 67% flux subgroup produced similar signals within the plastic deformation zone, either beyond the 0.2% yield point or before fracture.

Influence of silanization and filler fraction on aged dental composites

The effect of silanization and filler fraction on the mechanical properties of aged dental composites was investigated. Experimental composites (75/25 Bis-GMA/TEGDMA resin reinforced with 0, 12.6, 30.0, and 56.5 vol% 8 microm silanized/unsilanized BaSiO6) were fabricated into 4.7 mm diameter x 2.2 mm thick discs and 3.5 mm diameter x 7.3 mm thick discs for diametral tensile and compressive tests, respectively. The effect of immersion in 75% ethanol at 37 degrees C for 0-30 days on the diametral tensile strength (DTS) and compressive strength (CS) of the samples was evaluated and analysed by ANOVA and Tukey LSD test. The fracture interface between filler and resin matrix was then examined by scanning electron microscope. Results and subsequent statistical evidence from DTS (18.6+/-7.6 MPa, silanized versus 11.7+/-2.6 MPa, unsilanized) and CS (85.1+/-29.7 MPa, silanized versus 56.0+/-11.3 MPa, unsilanized) strongly implies that silanization may greatly enhance the mechanical properties of the resin composites. Furthermore, it also shows that both DTS and CS increased proportionally as the filler fraction of the composites increased. However, in the unsilanized groups, DTS decreased (up to 40%) as the filler fraction increased, and CS showed no relevance to the filler fraction at all. As for the influence of aging, it was found that both DTS and CS showed a significant decrease after immersion in 75% ethanol, and silanization heavily correlated with the filler fraction of aged-resin composites. Microscopic examination of the fractured samples showed that failure primarily occurred within the resin matrix per se for silanized composites and adjacent to the filler particles for unsilanized composites. All the evidence points to the conclusion that mechanical properties of aged-resin composites can be greatly influenced by silanization and the filler fraction.

Mechanism of abnormal elastin gene expression in the pinguecular part of pterygia

Elastodysplasia and elastodystrophy are two known manifestations in the conjunctival, ie, pinguecular, part of pterygia. But the mechanisms are still not understood. The purpose of this study is to investigate the mechanism of enhanced elastin gene expression in fibroblasts from the pinguecular part of pterygia, which is related to abnormal elastic fiber expression in the pinguecular part of pterygia. Elastin in surgical specimens of normal conjunctiva and the pinguecular part of pterygia from age-matched patients was detected by immunohistochemical staining. Northern hybridization and quantification of radiolabeled tropoelastin were performed in conjunctival fibroblasts cultured under different doses of ultraviolet (UV) B irradiation, and in cultured pinguecular fibroblasts from pterygia. In vitro translation was also performed to analyze the tropoelastin production in rabbit reticulocyte lysate. The level of tropoelastin in reticulolysates from UV-treated conjunctival and pinguecular fibroblasts of pterygia was higher than in normal conjunctival fibroblasts. The coding sequence and 3'- untranslated region of tropoelastin mRNAs were amplified by reverse transcription-polymerase chain reaction, and mutations were checked by DNA sequencing. Immunohistochemical staining revealed elastin in pinguecular subepithelial connective tissues of pterygia, but not in normal conjunctiva. Tropoelastin mRNA levels were not elevated in cultured pinguecular or conjunctival fibroblasts with or without ultraviolet B irradiation. However, tropoelastin synthesis was enhanced in culture medium of pinguecular and UV-irradiated conjunctival fibroblasts, but not in normal conjunctival fibroblasts. Direct DNA sequencing revealed mutations in the 3'-untranslated region but not in the coding sequence of tropoelastin mRNA, in both pinguecular and UV-irradiated conjunctival fibroblasts. The increased expression of tropoelastin in pinguecular and UV-irradiated fibroblasts is not a result of increased levels of steady-state mRNA, but is a result of posttranscriptional modification of tropoelastin.

Taxol reduces cytosolic E-cadherin and beta-catenin levels in nasopharyngeal carcinoma cell line TW-039: cross-talk between the microtubule- and actin-based cytoskeletons

Taxol affects microtubule dynamics by promoting microtubule assembly. To obtain a better insight into possible cross-talk between the microtubule- and actin-based cytoskeletons, we studied the short-term effects of Taxol treatment on the expression of actin and the E-cadherin/catenin complex in the nasopharyngeal carcinoma cell line TW-039 using immunofluorescence, immunoprecipitation, and immunoblotting methods. Morphologic changes in actin filaments, including ventral actin clumps and perijunctional actin blebs, were seen at Taxol concentrations > or =1 microM. Levels of detergent-soluble E-cadherin fell to 53% or 58% compared to controls in cells treated, respectively, with 1 or 5 microM Taxol, while levels of detergent-soluble beta-catenin fell to 76% or 74%. Levels of the detergent-soluble pool of alpha- and gamma-catenin and the detergent-insoluble pool of the E-cadherin/catenin complex were unchanged by Taxol treatment and no significant difference was seen in the levels of adenomatous polyposis coli or glycogen synthase-3beta or tyrosine phosphorylation patterns. These results suggest that modulation of microtubule dynamics by Taxol may have effects on the expression of actin and the cytosolic E-cadherin and beta-catenin in nasopharyngeal carcinoma cells through pathways not involving the phosphorylation of beta-catenin.

Acoustic emissions generated in aged dental composites using a laser thermoacoustic technique

The heating up of dental composites by laser will produce acoustic emissions (AEs) that may be related to fracture mechanisms in the composites. It has been proved that the mechanical properties of dental composites are affected by storage in food simulating liquids, i.e. 75% ethanol, which has a solubility parameter approximating to that of bisphenol glycidyl dimethacrylate (BisGMA) resin. A new method was innovated to evaluate the laser-induced AEs in dental composites aged by 75% ethanol solution. Model systems (50/50 BisGMA/TEGDMA resin filled with 0% and 75 wt.% 5-10 microm silanized BaSiO6) as well as three commercial composites (Marathon One, Z100 and Herculite XRV) were used in this study. Nine samples acting as the control group were tested to establish the correlation of AEs to laser power. The effect of ageing by immersion in 75% ethanol on AEs and diametral tensile strength (DTS) was then evaluated. A quasi-continuous wave CO2 laser was used to heat up the composites. AEs of frequency 100-200 kHz were collected, filtered, recorded and processed using a 4610 Smart Acoustic Monitor. Burst patterns, which formally were assumed to be correlated to fracture mechanisms, were also identified from the data obtained at laser power > or = 5 W for commercial composites and > or = 4 W for model systems. Higher laser powers cause the AE to increase for all composites except unfilled model resin. AEs as a function of power for all aged systems were flat (< 100 events) below 4 W. Emissions then rose sharply to > 1000 events at 7.1 W. Statistically significant differences were found between the AEs obtained at 5 W (commercial composites) and those at 4.3 W (model systems) for material systems and storage times. Marathon One was less affected by the laser and an abrupt change in AE was found between days 0 and 7 of storage for all commercial composites. The AE value from the unfilled model resin was found to be significantly different from that of the model composites. However, they showed an increase in AEs with length of storage time, which was inversely associated with the decreased tendency of their immersed DTS values. Laser-induced AEs may be a valuable adjunct to conventional mechanical testing.

Molecular cloning, characterization, and expression of a cDNA coding Copper/Zinc superoxide dismutase from black porgy

A full-length complementary DNA (cDNA) clone encoding a putative copper/zinc superoxide dismutase (Cu/Zn-SOD) was amplified by a Polymerase Chain Reaction (PCR) based technique from cDNA synthesized from black porgy, Acanthopagrus schlegeli, mRNA. Nucleotide sequence analysis of this cDNA clone revealed that it comprised a complete open reading frame coding for 154 amino acid residues. The deduced amino acid sequence showed slightly higher identity (72.8-78.1%) with shark and swordfish Cu/Zn-SOD than with Cu/Zn-SOD from mammalian (68.1-70.7%) and plant (55.5-56.5%) sources. The residues required for coordinating copper and zinc are conserved as they are among all reported Cu/Zn-SOD sequences. The deduced amino acid sequence lacks mitochondria targeting sequence, which suggests that the black porgy cDNA clone encodes a cytosolic Cu/Zn-SOD. The coding region of Cu/Zn-SOD from black porgy was introduced into an expression vector, pET-20b(+), and transformed into Escherichia coli AD494(DE3)pLysS. A predominant achromatic zone was detected by activity staining of native PAGE. This indicates that the Cu/Zn-SOD cDNA clone can express active Cu/Zn-SOD enzyme in E. coli.

Response of nasopharyngeal carcinoma cells to Epstein-Barr virus infection in vitro

Many nasopharyngeal carcinoma (NPC) biopsy specimens contain Epstein-Barr virus (EBV). However, the response of NPC cells to EBV infection in vitro and in vivo is not well characterized. In this experiment we infected NPC cells with EBV particles through endocytosis of a complex of EBV immunoglobulin A (IgA) secretory component (SC) protein to observe the response of host cells to the foreign viral infection in vitro. We found that EBV particles were endocytosed and stabilized in NPC nuclei 24 hours after infection; the EBV genomes were then gradually decreased after serial passages within 3 to 4 weeks by the following pathway: the EBV genomes first moved toward the nuclear envelope from the center of the nucleus; after crossing the nuclear envelope, they moved into the cytoplasm and toward the plasma membrane and were discharged by exocytosis. At the 10th day of EBV infection, EBV-latent membrane protein-1 and Epstein-Barr nuclear antigen (EBNA)-1 protein expressions could be detected, but not EBV-viral capsid antigen. Observation of EBNA-1 protein and host growth factor and cytokine gene expressions in the weeks after incubation revealed that the EBNA-1 protein expression was decreased proportionally with decrease of EBV genome. The mRNA expression of epithelial growth factor receptor, transforming growth factor (TGF)-alpha, interleukin (IL)-1beta, IL-6, and granulocyte-macrophage colony-stimulating factor increased within 1 to 2 weeks after infection, and gradually recovered to the original level at 3 to 4 weeks, whereas the mRNAs of TGFbeta1, TGFbeta receptor type I (TGFbetaRI), TGFbetaR type II, IL-8, and tumor necrosis factor-alpha remained unchanged. It is concluded that in vitro EBV infection in NPC cells results in increase of certain growth factor and cytokine gene expressions in host cells. The change in gene expression returns to the original level approximately 3 to 4 weeks after infection because of exocytosis of EBV DNA by the infected cells through an unidentified mechanism.

Alternative/complementary medicine: wider usage than generally appreciated

OBJECTIVE

To test the hypothesis that there is substantial use of a practitioner of alternative/complementary medicine by patients traditionally considered to be underserved.

DESIGN

Cross-sectional, self-administered survey study.

SETTINGS

Three university hospital-affiliated general ambulatory clinics serving patients of different socioeconomic status and racial origin.

SUBJECTS

Five hundred and thirty-six (93% of those attending) consecutive clinic attendees.

OUTCOME MEASURES

Past use and desired future use of one or more practitioners of five modalities of alternative/complementary medicine and willingness to pay for these modalities out-of-pocket.

RESULTS

Past usage and desired future usage of one or more practitioners of alternative/complementary medicine was comparable at the three clinic sites despite wide differences in socioeconomic status and willingness/ability to pay out-of-pocket for these services. Multivariable analyses revealed lower self-rated health status and female gender (both p < 0.006) but not income, race, age or education as independent, significant predictors of use of a practitioner of alternative/complementary medicine.

CONCLUSION

Usage of alternative/complementary medicine is not confined to any well-circumscribed socioeconomic group and is common in patients often considered to be underserved. Self-assessed lower health status is significantly and independently associated with use of a practitioner of alternative/complementary care.

Laser-induced acoustic emissions in experimental dental composites

A laser thermoacoustic technique was innovated to evaluate laser-induced acoustic emissions (AEs) in experimental dental composites aged with 75% ethanol solution. Experimental composite systems of 75/25 BisGMA/TEGDMA resin filled with 0, 12.6, 30.0, and 56.5 vol% of 8-microm silanized and unsilanized BaSiO6 were analyzed. The sample size was 4.65 mm (diameter) x 0.5 mm (thick). Aging effects of immersing in 75% ethanol for up to 14 h on AEs were then evaluated. A continuous-wave CO2 laser was used to heat the samples. Acoustic emissions were collected as a function of filler fraction, laser power, silanization, and immersion time. Onset of burst-pattern acoustic signals characteristic of fracturing occurred at different laser powers for different tested groups. Acoustic emissions generally increased with laser power, in which lower laser powers produced low-amplitude (45-50 dB) signals; the amplitude distribution (50-85 dB) became more extensive as laser powers increased. After immersion, the lower laser powers could produce the same phenomenon. The higher the filler fraction, the fewer AEs generated. A large percentage AE reduction due to silanization was noted as a function of filler fraction. Unsilanized specimens showed more thermal damages than did silanized ones.

Finite element analysis of thermo-debonding mechanism in dental composites

Finite element method (FEM) has been extensively used for evaluating interfacial status inside biomaterials. This study using FEM was designed to evaluate the thermal stress behavior of a filler-matrix interface. The results were then compared to those of a previous study obtained by a laser thermoacoustic technique (LTAT). The experimental systems (75/25 Bis-GMA/TEGDMA resin reinforced with 0, 25, 50, and 75 wt% 8-microm silanized/unsilanized BaSiO6) as used in the previous study were modeled in this study. The established finite element models were based on coefficient of thermal expansion (CTE) Mismatch Phenomenon. The mechanical properties of the silane coupling agent, such as elastic modulus and thermal expansion coefficient used in the silanized model, were assumed to have optimal heat flux transfer. A third (imaginary) material was proposed to block the transfer of thermal stress between the filler and matrix in the unsilanized model. The thermal load simulation was based on steady-state thermal analysis. The results showed that: (1) The strain energy and interfacial shearing stress calculated from FEM validate the results from the previous LTAT study. (2) Comparing the stress distribution of silanized and unsilanized FEM models, the acoustic signals in LTAT study are mainly derived from debonding of the filler-matrix interface of silanized specimens, and from the matrix area of unsilanized specimens. Based on results to date, we conclude that the finite element method may be a powerful tool for exploring thermoacoustic mechanisms of dental composites.

Patient desire and reasons for specialist referral in a gatekeeper-model managed care plan

OBJECTIVE

To describe patient desire and reasons for specialist referrals in a gatekeeper-model managed care plan.

STUDY DESIGN

Cross-sectional prospective study.

PATIENTS AND METHODS

We developed a patient questionnaire to gather demographic data and to gauge patients' desire for specialist referral and their reasons for seeking such referral. The survey was administered at 2 sites--an ambulatory care facility of a university hospital and an internal medicine clinic in a suburban ambulatory care site. Patients asked to complete the questionnaire at the university hospital site were enrolled in a gatekeeper-model managed care plan (called CU Gold); those seen at the internal medicine clinic were enrolled in a group-model health maintenance organization. Patients were asked to complete the 1-page questionnaire in the waiting room before being seen by their primary care physician.

RESULTS

Among the 860 CU Gold patients who met the inclusion criteria during the 3-month study period (September to December 1997), 112 (13%) reported a definite desire to see a specialist and 274 (32%) indicated a possible desire to see a specialist at the time of their primary care visit. Compared with the CU Gold patients, significantly fewer patients in the health maintenance organization indicated a definite desire to see a specialist (3% versus 13%), but a similar percentage expressed a possible desire to see a specialist (30% versus 32%). The difference in definite desire for referral between the 2 groups could not be explained by patient or primary care physician characteristics. The principal health concerns for which patients sought referral were musculoskeletal, genitourinary or gynecologic, or dermatologic problems. Need for reassurance (cited by 67% of patients), seeing a specialist before (56%), and believing the primary care physician lacked expertise (49%) were the primary reasons patients sought referral. Seventy-four percent of patients referred by their primary care provider and 54% of those not referred agreed it was a good idea to see their primary care physician first before seeing a specialist.

CONCLUSIONS

Patients have a significant desire for specialist referral, driven by their need for reassurance, previous specialist referral, and belief that their primary care physician does not have the requisite expertise. Patients' expectations for referral varied significantly, depending on the healthcare system (academic primary care clinic or health maintenance organization) in which they were enrolled.

Cloning and expression of a cDNA coding for catalase from zebrafish (Danio rerio)

A full-length complementary DNA (cDNA) clone encoding a catalase was amplified by the rapid amplication of cDNA ends-polymerase chain reaction (RACE-PCR) technique from zebrafish (Danio rerio) mRNA. Nucleotide sequence analysis of this cDNA clone revealed that it comprised a complete open reading frame coding for 526 amino acid residues and that it had a molecular mass of 59 654 Da. The deduced amino acid sequence showed high similarity with the sequences of catalase from swine (86.9%), mouse (85.8%), rat (85%), human (83.7%), fruit fly (75.6%), nematode (71.1%), and yeast (58.6%). The amino acid residues for secondary structures are apparently conserved as they are present in other mammal species. Furthermore, the coding region of zebrafish catalase was introduced into an expression vector, pET-20b(+), and transformed into Escherichia coli expression host BL21(DE3)pLysS. A 60-kDa active catalase protein was expressed and detected by Coomassie blue staining as well as activity staining on polyacrylamide gel followed electrophoresis.

High-risk HPV DNA detection by Hybrid Capture II. An adjunctive test for mildly abnormal cytologic smears in women > or = 50 years of age

OBJECTIVE

To determine whether high-risk human papillomavirus (HPV) DNA testing could improve the detection of cervical intraepithelial neoplasia (CIN) and cancer in older women (> or = 50 years old) with mildly abnormal results on conventional cytology.

STUDY DESIGN

The study was based on 119 patients aged over 50 (median, 62; range, 50-78) referred for colposcopy with Pap smears reported as atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesion (LSIL) from February 1997 to September 1998. The presence of high-risk HPV DNA (including HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) was determined with the Hybrid Capture II (Digene, Inc., Silver Spring, Maryland) microplate method. Cytologic examination by Pap smear was based on the Bethesda System and, cervical biopsy was done via colposcopy.

RESULTS

High-risk HPV DNA was demonstrated in 75.6% (34/45) of patients with LSIL and 52.7% (39/74) with ASCUS. Those who were HPV positive were significantly more likely to have CIN or cancer (odds ratio, 33.40; 95% confidence interval, 11.89-93.97; P < .0001). The sensitivity of HPV assay for detection of lesions more severe than CIN 2 was 100%, specificity 64.8%, positive predictive value 66.7% and negative predictive value 100%.

CONCLUSION

The addition of a high-risk HPV DNA assay to cytologic examination appears to provide excellent sensitivity and negative predictive value for early detection of high grade CIN or cancer in older women with minimally abnormal Pap smears.

Randomized trial of neoadjuvant cisplatin, vincristine, bleomycin, and radical hysterectomy versus radiation therapy for bulky stage IB and IIA cervical cancer

PURPOSE

To compare the efficacy of neoadjuvant chemotherapy (NAC) followed by radical hysterectomy with that of radiotherapy (R/T) for bulky early-stage cervical cancer.

PATIENTS AND METHODS

Women with previously untreated bulky (primary tumor >/= 4 cm) stage IB or IIA non-small-cell carcinoma of the uterine cervix were randomly assigned to receive either cisplatin 50 mg/m(2) and vincristine 1 mg/m(2) for 1 day and bleomycin 25 mg/m(2) for 3 days for three cycles followed by radical hysterectomy (NAC arm) or receive primary pelvic radiotherapy only (R/T arm). The ratio of patient allocation was 6:4 for the NAC and R/T arms. Women with enlarged para-aortic lymph nodes on image study were ineligible unless results of cytologic or histologic studies were negative.

RESULTS

Of the 124 eligible patients, 68 in the NAC arm and 52 in the R/T arm could be evaluated. The median duration of follow-up was 39 months. Thirty-one percent of patients in the NAC arm and 27% in the R/T arm had relapse or persistent diseases after treatment, and 21% in each group died of disease. Estimated cumulative survival rates at 2 years were 81% for the NAC arm and 84% for the R/T arm; the 5-year rates were 70% and 61%, respectively. There were no significant differences in disease-free survival and overall survival.

CONCLUSION

NAC followed by radical hysterectomy and primary R/T showed similar efficacy for bulky stage IB or IIA cervical cancer. Further study to identify patient subgroups better suited for either treatment modality and to evaluate the concurrent use of cisplatin and radiation without routine hysterectomy is necessary.

Recognition of patient referral desires in an academic managed care plan frequency, determinants, and outcomes

OBJECTIVE

To determine the frequency and determinants of provider nonrecognition of patients' desires for specialist referral.

DESIGN

Prospective study.

SETTING

Internal medicine clinic in an academic medical center providing primary care to patients enrolled in a managed care plan.

PARTICIPANTS

Twelve faculty internists serving as primary care providers (PCPs) for 856 patient visits.

MEASUREMENTS AND MAIN RESULTS

Patients were given previsit and postvisit questionnaires asking about referral desire and visit satisfaction. Providers, blinded to patients' referral desire, were asked after the visit whether a referral was discussed, who initiated the referral discussion, and whether the referral was indicated. Providers failed to discuss referral with 27% of patients who indicated a definite desire for referral and with 56% of patients, who indicated a possible desire for referral. There was significant variability in provider recognition of patient referral desire. Recognition is defined as the provider indicating that a referral was discussed when the patient marked a definite or possible desire for referral. Provider recognition improved significantly (P <.05), when the patient had more than one referral desire, if the patient or a family member was a health care worker and when the patient noted a definite desire versus a possible desire for referral. Patients were more likely (P <.05) to initiate a referral discussion when they had seen the PCP previously and had more than one referral desire. Of patient-initiated referral requests, 14% were considered "not indicated" by PCPs. Satisfaction with care did not differ in patients with a referral desire that were referred and those that were nor referred.

CONCLUSIONS

These PCPs frequently failed to explicitly recognize patients' referral desires. Patients were more likely to initiate discussions of a referral desire when they saw their usual PCP and had more than a single referral desire.