Clinical evaluation of and parental satisfaction with resin-faced stainless steel crowns

PURPOSE

This study evaluated the clinical success and parental acceptance of anterior primary dentition caries treatment with prefabricated resin-faced stainless steel crowns.

METHODS

A retrospective analysis of maxillary anterior primary dentition caries treatment using Whiter Biter II Crowns was performed. Each crown was evaluated for retention, fracture, interface failure, color match, marginal integrity, and surface texture. Parental satisfaction regarding the esthetics of the crowns was evaluated by survey.

RESULTS

Thirty-eight crowns were evaluated in 12 children. The average crown age at time of examination was 20.7 months. Three teeth were lost to trauma with all other crowns remaining intact. Twelve crowns (32%) showed loss of at least some facial resin. Nine crowns (24%) had complete loss of the resin facing. Overall parental satisfaction with the treatment was excellent, however, satisfaction with crown esthetics received the lowest rating.

CONCLUSIONS

While parental satisfaction with treatment of anterior primary dentition caries with prefabricated resin-faced stainless steel crowns is excellent, the high failure rate of the resin facings is problematic.

A novel gene conserved from yeast to humans is involved in sterol biosynthesis

The ERG28 gene was originally identified by microarray expression profiling as possibly involved in the Saccharomyces cerevisiae sterol pathway. Microarray analyses suggested that the transcription pattern of ERG28 closely followed that of genes involved in sterol synthesis. ERG28 was also found in Schizosaccharomyces pombe and Arabidopsis as well as humans, and in the latter was shown to be highly expressed in adult testis tissue. All four proteins contain potential transmembrane domain(s). Gas chromatography-mass spectrometry analysis of an ERG28-deleted S. cerevisiae strain (which is slow growing but not auxotrophic for ergosterol) indicates a lesion in sterol C-4 demethylation. Sterol profiles indicate accumulation of 3-keto and carboxylic acid sterol intermediates, which are involved in removing the two C-4 methyl groups from the sterol A ring. Similar intermediates have previously been demonstrated to accumulate in erg26 (sterol dehydrogenase/decarboxylase) and erg27 (3-ketoreductase) mutants in yeast. We speculate that the role of the Erg28 protein (Erg28p) may be either to tether Erg26p and Erg27p to the endoplasmic reticulum or to facilitate interaction between these proteins.-Gachotte, D., J. Eckstein, R. Barbuch, T. Hughes, C. Roberts, and M. Bard. A novel gene conserved from yeast to humans is involved in sterol biosynthesis. J. Lipid Res. 2001. 42: 150;-154.

Disparities in cancer diagnosis and survival

BACKGROUND

Concern has been raised over the disproportionate cancer mortality among minority and low-income persons. The current study examined differences in disease stage at the time of diagnosis and subsequent survival for patients who are medically indigent compared with the rest of the population of cancer patients in Michigan.

METHODS

The authors linked three Michigan statewide data bases: the Cancer Registry, Medicaid enrollment files, and death certificates. The analysis focused on female breast, cervix, lung, prostate, and colon carcinoma, and differences were analyzed in the incidence, disease stage at the time of diagnosis, and survival between younger women and older women who were either insured or not insured by Medicaid. To estimate the risk of late stage diagnosis and death, the authors used logistic regression, controlling for age, race, and Medicaid enrollment. Ordered logit models also were used as a refinement of disease stage prediction.

RESULTS

Medically indigent persons had a disproportionately larger share of cancer. Persons age < 65 years who were insured by Medicaid had the greatest risk of late stage diagnosis and death across all five disease sites analyzed. African-American women had a greater risk of death from breast carcinoma compared with other women independent of Medicaid status. No interaction effects were found between age, race, and/or gender and Medicaid enrollment.

CONCLUSIONS

The results of this study showed that the disparities in cancer outcomes may be greater than previously thought and are consistent across disease sites. If advancements made in cancer control are to be shared by the low-income population, then improvements clearly are needed in cancer prevention, early detection, and treatment for the poor.

Closed suction surgical wound drainage after orthopaedic surgery

BACKGROUND

Closed suction drainage systems are frequently used to drain fluids, particularly blood, from surgical wounds. The aim of these systems is to reduce the occurrence of wound haematomas and infection.

OBJECTIVES

To evaluate the effectiveness of closed suction drainage systems for orthopaedic surgery.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Injuries Group specialised register (May 2001), MEDLINE (1996-May 2001) and references from articles.

SELECTION CRITERIA

All randomised or quasi-randomised trials comparing the use of closed suction drainage systems with no drainage systems for all types of elective and emergency orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

Both reviewers independently assessed trial quality, using a nine item scale, and extracted data. Wherever appropriate and possible, the data are presented graphically.

MAIN RESULTS

Twenty-one studies involving 2772 patients with 2971 wounds were included in the analysis. The types of surgery involved were hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. Many of the studies had poor methodology and reporting of outcomes. Pooling of results indicated no difference in the incidence of wound infection, haematoma or dehiscence between those allocated to drains and the un-drained wounds. There was a tendency to an increased risk of re-operation for wound complications in the group with drains (relative risk (RR) 2.25, 95% confidence intervals (CI) 0.95 to 5.33), but due to the small numbers of cases involved definite conclusions cannot be made for this outcome. Blood transfusion was required more frequently in those who received drains (RR 1.41, 95% CI 1.10 to 1.80). The need for reinforcement of wound dressings (RR 0.22, 95% CI 0.13 to 0.40) and bruising around the operation site was more common in the group without drains.

REVIEWER'S CONCLUSIONS

There is insufficient evidence from randomised trials to support or refute the routine use of closed suction drainage in orthopaedic surgery. Further randomised trials are required before definite conclusions can be made.

Chorionic villus sampling for sex determination in a western lowland gorilla (Gorilla gorilla gorilla)

Chorionic villus sampling was undertaken on an anesthetized gorilla (Gorilla gorilla gorilla) to determine the fetal sex in the first trimester of pregnancy. The tissue samples were subject to sex determination by polymerase chain reaction, fluorescent in situ hybridization, and cell culture with cytogenetic analysis. Polymerase chain reaction testing was found to be the most accurate and rapid method of sex determination on this tissue sample.

A case of maternal uniparental disomy of chromosome 9 diagnosed prenatally and the related problem of residual trisomy

Non-mosaic trisomy 9 was found in a chorionic villus (CV) sample taken from a 43-year-old woman referred for prenatal chromosome analysis due to advanced maternal age. Follow-up amniocentesis revealed level 2 mosaicism for trisomy 9. Trisomy 9 was not detected at fetal blood sampling. Molecular analysis of fetal (amniocyte) DNA showed maternal uniparental heterodisomy (UPD) for chromosome 9. Two crossovers resulted in a region of isodisomy in the distal long arm. Trisomy rescue of a meiosis 1 segregation error seems to have been responsible for the uniparental disomy of chromosome 9. The pregnancy continued and neonatal blood testing showed a mosaic trisomy 9 karyotype, i.e. 4/50 cells analysed. Clinical postnatal follow-up for a period of 1 year has documented only minor facial dysmorphism and skeletal abnormalities. Development appears unremarkable. This case is the second report of maternal uniparental disomy for chromosome 9 detected prenatally and is the first case followed up post-term. This report highlights the difficulty of making informed prognostic assessments in such cases despite extensive laboratory investigation.

Comparison of computational analysis with clinical measurement of stresses on below-knee residual limb in a prosthetic socket

Interface pressures and shear stresses between a below-knee residual limb and prosthetic socket predicted using finite element analyses were compared with experimental measurements. A three-dimensional nonlinear finite element model, based on actual residual geometry and incorporating PTB socket rectification and interfacial friction/slip conditions, was developed to predict the stress distribution. A system for measuring pressures and bi-axial shear stresses was used to measure the stresses in the PTB socket of a trans-tibial amputee. The FE-predicted results indicated that the peak pressure of 226 kPa occurred at the patellar tendon area and the peak shear stress of 50 kPa at the anterolateral tibia area. Quantitatively, FE-predicted pressures were 11%, on average, lower than those measured by triaxial transducers placed at all the measurement sites. Because friction/slip conditions between the residual limb and socket liner were taken into consideration by using interface elements in the FE model, the directions and magnitudes of shear stresses match well between the FE prediction and clinical measurements. The results suggest that the nonlinear mechanical properties of soft tissues and dynamic effects during gait should be addressed in future work.

Latent adenoviral infection modifies the steroid response in allergic lung inflammation

BACKGROUND

Steroid-resistant asthma develops after adenoviral bronchiolitis.

OBJECTIVE

We sought to determine the effect of steroids on allergic lung inflammation in the presence of latent adenoviral infection.

METHODS

Guinea pigs with latent adenoviral (n = 12) or sham (n = 12) infections were sensitized and challenged with ovalbumin (OA) or sham sensitized and challenged with saline solution. The effect of steroids (20 mg/kg administered intraperitoneally) on OA-induced lung inflammation was examined by using quantitative histology as the outcome measure.

RESULTS

Latent adenoviral infection increased CD8(+) cells in the airway wall and CD8(+) cells, macrophages, B cells, and CD4(+) cells in the lung parenchyma. Ovalbumin challenge, on the other hand, increased eosinophils, macrophages, B cells, and CD4(+) cells in both the airway wall and lung parenchyma independent of the effect of latent adenoviral infection. In the sham-infected groups steroid treatment caused the expected reduction in the eosinophilic infiltrate induced by OA challenge in the airways without affecting the other cells. In the presence of both latent adenoviral infection and OA challenge, steroid treatment had no effect on allergen-induced eosinophilia but reduced CD8(+) cells in the airways and CD8(+) cells, CD4(+) cells, and B cells in the parenchyma.

CONCLUSION

Latent adenoviral infection and OA challenge result in different types of lung inflammation, and the presence of latent adenoviral infection causes OA-induced eosinophilic airway inflammation to become steroid resistant.

Peripheral corneal contour measured by topography influences soft toric contact lens fitting success

PURPOSE

Empirical fitting success is important to expanding the soft toric contact lens market. Previous study has lead to the hypothesis that lens flexure may alter expected fitting relationships and back vertex power (BVP) in situ. In this study, baseline topographic features as potential variables in predicting soft toric fitting success were analyzed.

METHODS

One-hundred forty-nine eyes were empirically fit with back surface toric soft lenses after placido-based videokeratography was performed. Measurements recorded from baseline instantaneous maps included: flat simulated keratometry (Sim-K) value (in diopters) and axis, steep Sim-K value (in diopters) and axis, eccentricity of the flat meridian, and the form of corneal astigmatism. Astigmatism was classified as types I-V based upon differences between central and peripheral corneal toricity.

RESULTS

Ninety-three of 149 (62.4%) eyes were successfully fit empirically with the first trial lens. One-hundred thirty-five of 149 (90.6%) eyes were ultimately successful after unsuccessful trial lenses were adjusted and reordered. There were no differences between the empirically fit success and failure groups in instrument reported eccentricity, Sim-K values, or Sim-K axes (P>0.05). Of 115 eyes classified for form of corneal astigmatism, 76 (66%) were classified with high or irregular peripheral astigmatism (types IV and V). There was a significant association between fitting success and the form of corneal toricity (P=0.0327). Thirty-nine of 115 (34%) eyes were classified as corneal types I-III (spherical or minimally toric corneal periphery) and were associated with empirical fitting success (P=0.0092).

CONCLUSION

Empirical soft toric fitting success can be anticipated in spherical corneas, central astigmatism, or corneas with peripheral toricity which matches the central toricity. However, high and irregular peripheral corneal toricity occurs in the majority of astigmatic patients. Corneal topography is a valuable tool to assess peripheral astigmatism which may be one factor influencing unexpected lens performance.

The effect of SB-236057-A, a selective 5-HT1B receptor inverse agonist, on in vivo extracellular 5-HT levels in the freely-moving guinea-pig

5-HT1B autoreceptors are involved in the control of extracellular 5-HT levels from both the terminal and cell body regions of serotonergic neurones. In this study we report on the effect of a selective and potent 5-HT1B receptor inverse agonist, SB-236057-A (1'-ethyl-5-(2'-methyl-4'-(5-methyl- 1,3,4-oxadiazolyl-2-yl)biphenyl-4-carbonyl)-2,3,6,7-tetrahydros piro [furo[2,3-f]indole-3,4' -piperidine] hydrochloride), on extracellular 5-HT levels in the cortex and dentate gyrus of the freely-moving guinea-pig, using the technique of in vivo microdialysis. SB-236057-A had ca. 23% bioavailability following oral drug administration. In vivo hypothermia pharmacodynamic assays demonstrated it was brain penetrant with a duration of action in excess of 18 h. SB-236057-A (0.75 mg/kg p.o.) increased extracellular 5-HT levels in the dentate gyrus to a maximum of 167+/-7% of basal but had no effect in the frontal cortex. However, a small increase in cortical 5-HT levels (117+11% of basal) was evident at 2.5 mg/kg p.o. In addition, SB-236057-A (0.75 mg/kg and 2.5 mg/kg p.o.) antagonised the sumatriptan-induced inhibition of extracellular 5-HT levels in the guinea-pig frontal cortex. These differences were attributed to MRN-innervated regions (e.g. dentate gyrus) being more responsive to 5-HT1B receptor-mediated negative feedback than DRN-innervated regions (e.g. frontal cortex). In the dentate gyrus, the increase in 5-HT release induced by SB-236057-A (0.75 mg/kg p.o.) was comparable to that after 14 days of paroxetine (10 mg/kg p.o.) administration, reaching a maximum of 183+/-13% of basal. These data suggest that acute 5-HT1B receptor blockade, by virtue of increased 5-HT release in the dentate gyrus, may provide a rapidly acting antidepressant.

The obstetrician-gynecologist's role in vaccine-preventable diseases and immunization

OBJECTIVE

To assess by survey the immunization role currently played obstetrician-gynecologists in the state of Michigan.

METHODS

Masked questionnaires requesting demographic, knowledge-based, practice, and attitudinal data were sent to 850 ACOG-registered fellows.

RESULTS

Three hundred sixty-five physicians responded, 313 of whom were in active practice. Most were male (70%) and graduated from medical school between 1970 and 1989 (68%). The majority provided both obstetric and gynecologic services. The minority (47%) specifically identified themselves as primary care providers. Only 15% of respondents considered screening for vaccine-preventable diseases to be outside the realm of routine obstetric-gynecologic care. In practice, however, 19% did not screen their obstetric patients for any vaccine-preventable diseases, and only 10% assessed their patients for all nine vaccine-preventable diseases listed in the questionnaire. In gynecologic patients, almost 40% of physicians did not assess for any vaccine-preventable disease. A wide range in knowledge level was identified concerning vaccine-preventable diseases, immunization recommendations, and vaccine safety.

CONCLUSION

These data show a discrepancy between perceived responsibilities and actual practice patterns of obstetrician-gynecologists regarding vaccine-preventable diseases and the immunization of women. Limitations in current knowledge and practical concerns specific to vaccine administration contribute to this disparity.

Preoperative histological classification of primary lung cancer: accuracy of diagnosis and use of the non-small cell category

AIMS

To compare the preoperative classification of lung carcinoma made on cytological and histological specimens with the postoperative classification made on the resected specimen. In addition, to find out how often the term "non-small cell lung cancer, not otherwise specified" (NSCLC) was used, and in such cases to note the final diagnosis.

METHODS

Between 1991 and 1995, 303 patients had a lung resection in Aberdeen for primary carcinoma. For each patient, the departmental records were examined for preoperative specimens (cytological and histological). A note was made of whether each specimen was positive or negative for malignancy and, if positive, what the cell type was. Where patients had more than one sample submitted, the most specific result was taken.

RESULTS

Fifty four per cent of patients had a correct specific preoperative diagnosis of malignancy, whereas 34% were labelled as NSCLC. Patients with squamous carcinoma were more likely to have a diagnosis of malignancy (88%) that was specifically correct (75%). Patients who had adenocarcinoma were less likely to have a preoperative diagnosis of malignancy (64%) that was specifically correct (35%). For those in whom a diagnosis of NSCLC was made, 55% turned out to have adenocarcinoma whereas 24% had squamous carcinoma.

CONCLUSIONS

By adhering strictly to criteria, a high accuracy of diagnosis can be achieved for squamous carcinoma, but the diagnosis of adenocarcinoma seems to be more of a challenge. NSCLC is a useful and appropriate classification, the use of which reduces the rate of inaccurate specific diagnosis. There are occasions when pathologists can provide a more accurate diagnosis by being less precise.

A new joint training programme in infectious diseases and medical microbiology

The increasing overlap between the disciplines of medical microbiology and infectious diseases prompted the Joint Royal Colleges Committee on Infection and Tropical Medicine to set up a working party to examine how trainees could obtain certification in both subjects. Following widespread consultations, a scheme was developed that entails six years of training and leads to the award of CCSTs in both microbiology and infectious diseases. Both Royal Colleges and the Specialist Training Authority have approved the scheme. Joint training will be demanding and will not be suitable for everyone; it represents an alternative approach to training in the infection disciplines that will run alongside the existing monospecialty training programmes.

In vitro frog sciatic nerve as a peripheral nerve model for studies of the mechanism of action of low energy lasers: Part one

BACKGROUND AND OBJECTIVE

There have been numerous reports of modulation of peripheral nerve action potential characteristics through application of low energy laser irradiation (LELI), although no mechanism has yet been advanced to explain these observations. In order to investigate the mechanism of LELI effects in peripheral nerve tissue, a well-characterized, reliable, and robust peripheral nerve preparation is required. The objective of this study was to evaluate the in vitro frog sciatic nerve as a candidate model for future LELI mechanism studies.

MATERIALS AND METHODS

Following 60-minute baseline recordings of compound action potential (CAP) amplitude, latency, depolarization rate, and repolarization rate, helium-neon (HeNe) laser irradiation (632 nm, 15 min, 1-7 J, 44-320 J/cm2) was delivered to one of two sites on the nerve. Laser-induced changes in CAP parameters were analyzed during irradiation and for 60 minutes post-irradiation using a repeated measures linear regression model.

RESULTS

In the treatment group that received 7 J of HeNe energy over the recording electrode, CAP latency increased relative to nonirradiated controls during the postirradiation period. No other treatment group demonstrated laser-induced changes in CAP characteristics at any time during the experiment.

CONCLUSION

HeNe irradiation demonstrated limited ability to alter the CAP under these conditions. As such, the in vitro frog sciatic nerve is an inappropriate model for mechanism of action studies.

Laser ablation of dyed acrylic bone cement

Revision surgery of cemented implants is indicated when mechanical failure causes severe pain and/or loss of function for the patient. Successful revision arthroplasty of cemented implants requires complete removal of the existing cement. Removal of old cement is an arduous task often causing damage to the surrounding bone tissue. In this study, the authors investigate the use of an Argon laser and the addition of dyes to enhance the laser ablation of bone cement. Methylene blue and red dye #13 were each added separately to polymethylmethacrylate (PMMA) bone cement powder. A continuous wave Argon ion laser (lambda = 514 nm) was used for cement ablation. Cement samples were ablated at different power levels (1.5, 2.3, and 3.0 W) and exposure times (30, 60, 90, 120 sec). The results show that the Argon laser was unable to ablate undyed PMMA. However, the addition of either methylene blue or red dye #13 greatly improved cement ablation by altering the cements' absorption characteristics. Results of Student's t-tests show a statistical difference between red and blue dyed PMMA mean ablation areas at all energy levels tested (P < .0002). As expected, all red ablation areas were greater than blue ablation areas at each energy level tested since red dye absorbs more energy at 514 nm than methylene blue dye. The results of this study suggest that by selectively altering the absorption characteristics of PMMA, laser removal of bone cement can be achieved. In addition, this study also shows that bone tissue does not absorb visible light energy at 514 nm, suggesting that bone cement may be removed with minimal damage to the surrounding bone tissue.

Importance of using rigorous statistical methods to analyze low energy laser experimental data: Part two

BACKGROUND AND OBJECTIVE

Numerous authors have reported successful alteration of peripheral nerve action potential characteristics through application of low energy laser irradiation (LELI). The statistical analysis that accompanies many of these reports frequently does not account for the special nature of the data generated in typical LELI experiments. The objective of this study was to evaluate the application of repeated measures linear regression techniques to the analysis of this type of data. Issues of analyzing raw versus normalized data, proper accounting for correlation between measurements, and discrete time point hypothesis testing were addressed.

STUDY DESIGN/MATERIALS AND METHODS

The data analyzed in this work were generated from an experiment in which in vitro frog sciatic nerves were irradiated with a helium-neon laser using a variety of treatment protocols. Compound action potential (CAP) amplitude, latency, depolarization rate, and repolarization rate were recorded at 1-minute intervals for 135 minutes for each nerve. Laser-induced changes in CAP parameters were analyzed using various repeated measures linear regression models.

RESULTS

The findings of statistical significance were highly dependent on the rigor of the regression model applied. Application of the same regression model to raw and normalized data produced different findings of significance. Determination of significant contrasts was highly dependent on how well the regression model accounted for the correlation between repeated measurements made on the same nerve. In general, models that failed to account adequately for this correlation produced more findings of significant contrasts than increasingly rigorous models. Finally, discrete time point hypothesis testing on normalized data can suggest improper statistical conclusions if the proper correlation structure is not applied to the data set.

CONCLUSION

Linear regression analysis offers advantages over discrete time point hypothesis testing in the analysis of highly correlated serial data of this type. Trends in the behavior of the measured parameters are evident, rigorous accounting for correlation between measurements is facilitated, and hypothesis testing is highly flexible.

Anopheles gambiae pilot gene discovery project: identification of mosquito innate immunity genes from expressed sequence tags generated from immune-competent cell lines

Together with AIDS and tuberculosis, malaria is at the top of the list of devastating infectious diseases. However, molecular genetic studies of its major vector, Anopheles gambiae, are still quite limited. We have conducted a pilot gene discovery project to accelerate progress in the molecular analysis of vector biology, with emphasis on the mosquito's antimalarial immune defense. A total of 5,925 expressed sequence tags were determined from normalized cDNA libraries derived from immune-responsive hemocyte-like cell lines. The 3,242 expressed sequence tag-containing cDNA clones were grouped into 2,380 clone clusters, potentially representing unique genes. Of these, 1,118 showed similarities to known genes from other organisms, but only 27 were identical to previously known mosquito genes. We identified 38 candidate genes, based on sequence similarity, that may be implicated in immune reactions including antimalarial defense; 19 of these were shown experimentally to be inducible by bacterial challenge, lending support to their proposed involvement in mosquito immunity.