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At least 1,153 records · Page 64Linked to original sources
PubMed1997

Reconstruction of calvarial defects by bioresorbable ceramics: an experimental study in rats.

This study evaluated bioresorbable ceramics in the reconstruction of calvarial defects. Full-thickness defects were made in the calvaria of 40 adult Sprague-Dawley rats (350-450 g) with a standard 8-mm trephine drill. Three different materials were used for defect repair: (a) pure alpha-tricalcium phosphate (TCP), (b) surface-treated glass ceramic, (c) surface-treated glass ceramic plus 70/30 L/DL polylactic acid (volume ratio 45/55). The implants were pellets of 7.9 mm diameter and 2 mm thickness and were inserted press fit into the calvarial defects. Each of these materials was inserted into ten animals. Five animals were evaluated each after 6 weeks and 26 weeks. For each interval there was a control group of five animals. After 6 weeks the control defects exhibited negligible bone regeneration at the defect margins but showed substantially more bone regeneration after 26 weeks extending up to 2.5 mm into the defect space. The TCP specimens showed a number of multinuclear cells on the material surface and direct bone/implant contact in a few locations but no signs of gross degradation or volume reduction after 6 weeks. The amount of bone ingrowth and cellular behavior had not changed after 26 weeks with resorption still going on. Glass ceramic implants by contrast appeared to be even better tolerated after 6 weeks with remarkable bone ingrowth and broad osseous fixation of the pellet to the defect margins and beyond, while highly vascular connective tissue filled the remaining pores of the implant. After 26 weeks the material had been extensively degraded, leaving behind only a few remnants, which were surrounded by seams of highly vascularized and cell-rich resorptive connective tissue with newly formed bone tissue nearly bridging the defect. The polylactic acid/ceramic composite implants showed hardly any tissue ingrowth or degradation either after 6 or after 26 weeks. Hence all tested materials appeared to be well tolerated at the site of implantation. However, gradual replacement by bone ingrowth tended to occur only in implants without polylactic acid.

Animals↗
PubMed1977

Critical evaluation of prosthetic materials in repair of abdominal wall hernias: new criteria of tolerance and resistance.

Six different materials (3 mesh and 3 cloth) commonly used for the repair of abdominal wall hernias were evaluated in 180 rats after implantation through musculature and peritoneum. Serial macroscopic and bacteriologic investigations were done, and bursting strength of the wound was determined in all groups at intervals with an original device. Histologic criteria were used to characterize the resistance of the wound and the tolerance of the host to the foreign material. Statistical analysis of the results demonstrated: (1) after postoperative day 15, the resistance of the wound was similar for each material tested; (2) during this early period mesh materials exhibited more resistance to bursting pressures than cloth materials; (3) the incorporation of mesh material was constant, whereas encystment or extrusion was always observed after implantation of cloth material; (4) no infection occurred with mesh material, but significant bacteria were found in 18 per cent of cloth material implantations; (5) the extent of the cellular reaction, the enumeration of giant, inflammatory, and fibroblastic cells showed the superiority of mesh materials; and (6) the ratio of fibroblasts to inflammatory cells reflected closely the mechanical resistance and tolerance of the foreign material.

Abdominal Muscles↗
PubMed1994

Tensile strength of the end-weave flexor tendon repair. An in vitro biomechanical study.

A study was designed to investigate the tensile strength of the end-weave method of tendon repair. Flexor tendons were removed from 13 fresh-frozen human cadavers, transected and repaired with the end-weave technique varying from one to five weaves, with two suture techniques, the commonly used horizontal mattress suture and a new method we have termed the cross stitch. The repairs were then tested in tension to failure on a Materials Test System (MTS) biomechanical testing device. Comparisons were also made to tensile strengths of intact whole tendons, tendon-bone insertions, and distal reinsertion techniques. Tensile strength increased linearly with the number of weaves for both suture methods. The cross stitch was found to have significantly greater strength per weave compared to the horizontal mattress suture (P < 0.05). Three out of five trials of five weaves done with the cross stitch actually failed at the tendon itself first, rather than through the repair, which was the failure mode for all other trials. The results from this in vitro model suggest that active rehabilitative exercises might safely be performed in the immediate post-operative period after procedures that involve tendon weaving.

Biomechanical Phenomena↗
PubMed2006

Orthodontic bracket bonding: enamel bond strength vs time.

INTRODUCTION: Tests of bond strength between orthodontic brackets and enamel are generally conducted after at least 24 hours storage in water. However, debonding might occur soon after bracket placement during orthodontic treatment. We investigated the rate of bond strength development for orthodontic adhesives in bracket bonding. METHODS: Four orthodontic adhesive systems were examined. Bovine incisors were mounted in self-curing acrylic resin, and the facial surfaces were wet-ground to expose flat enamel. Orthodontic brackets were bonded according to the manufacturers' instructions. Shear bond strengths were measured after storage in water for 5, 10, and 60 minutes, and 24 hours. Differences between bond strengths at 24 hours and the other test periods were statistically analyzed. RESULTS: All materials tested had the highest bond strengths at 24 hours, and bond strength increased with storage time. The earliest time point at which there was no significant difference in bond strength compared with that at 24 hours was defined as the initial stable time. Differences in this value might have clinical implications for the assessment of orthodontic adhesives, which can incur high stresses immediately after placement. CONCLUSIONS: The rate of development of enamel bond strength must be considered to ensure sufficient maturation of orthodontic adhesives before functional loading.

Animals↗
PubMedDate not supplied

An anatomic and biomechanic study of the wrist extensor retinaculum septa and tendon compartments.

PURPOSE: The anatomy of the extensor retinaculum of the wrist has been described previously; the purpose of this study was to describe the specific anatomy of the septal attachments on the radius and to investigate the mechanical strength of each septal attachment on the radius and each of the 6 compartments of the extensor retinaculum. METHODS: Thirty-four wrists from 24 fresh-frozen and 10 embalmed cadavers were used. First, anatomic measurements of the individual extensor retinaculum septums were performed with calipers and a 3-dimensional digitizer. Next each extensor retinaculum septum was excised as a bone-retinaculum-bone autograft and was tested in tension to failure with a materials testing machine. Finally the 6 extensor retinaculum compartments were tested to failure. RESULTS: Septum 1/2 had the largest radial surface area and septum 3/4 had the smallest. Septum 1/2 also was found to have the highest failure strength at 51.3 +/- 15.3 N. In compartment testing, compartments 1 and 2 had the highest overall resistance to failure and compartment 5 had the lowest. Compartment 6, which was thought to be the weakest because of clinically observed subluxation of the extensor carpi ulnaris tendon, had stronger failure data than expected. CONCLUSIONS: This study offers detailed analysis of the extensor retinaculum compartments and 3-dimensional anatomy of the septal attachments. Clinically this study lends insight to the strength of bone-retinaculum-bone autografts and the etiology of extensor carpi ulnaris subluxation.

Aged↗
PubMed2005

Contact stresses in the knee joint in deep flexion.

The contact stresses in the knee that arise from activities involving deep flexion have not been given due consideration in view of social and cultural practice amongst many Asians that frequently cause the engagement of these activities. Excessively large stresses (>25 MPa) can cause cartilage damage and may be the precursor to the development of degenerative disease of the joint. In this study, forces in the knee derived from previous studies of human walking and squatting were applied to five cadaver knees that underwent quasi-static mechanical testing. This was conducted using a materials-testing machine and a custom-made apparatus that allowed secure and consistent loading of the knee specimen in flexion beyond 120 degrees. A thin-film electronic pressure transducer was inserted into the cadaver tibiofemoral joint space to measure force and area. Throughout the various positions simulating specific phases of walking, it was found that stresses peaked to 14 MPa (standard deviation was 2.5 MPa). In deep flexion, the peak stresses were significantly larger by over 80%, reaching the damage limits of cartilage. The results from this biomechanical study suggest that the adequacy of articular cartilage to support loads in the knee joint during deep flexion may be questionable.

Cadaver↗
PubMedDate not supplied

Primary fixation strength of rotator cuff repair techniques: a comparative study.

PURPOSE: The goal of the study was to compare the primary fixation strength of transosseous suture, suture anchor, and hybrid repair techniques for rotator cuff repair. TYPE OF STUDY: Animal model experiment. METHODS: Thirty-two sheep shoulders were divided into 4 homogeneous groups, according to bone density and tendon dimensions. Infraspinatus tendons were transected from their insertions and reattached using 4 different techniques. Group 1 was repaired with a single Mason-Allen stitch and 2 transosseous tunnels for each end of the suture, knotted on the lateral cortex of proximal humerus; group 2 was repaired with double Mason-Allen stitches and 2 transosseous tunnels; group 3 was repaired with 2 Corkscrews (Arthrex, Germany); and group 4 was repaired with 2 Corkscrews combined with a single Mason-Allen transosseous suture. All specimens were tested for their fixation strengths with a material testing system. RESULTS: The mode of failure in group 1 was mainly suture breakage. In groups 3 and 4, the tendons pulled out from the sutures. In group 2, sutures broke the bony bridge between the 2 tunnels. The mean load to failure value was 160.31 +/- 34.59 N in group 1, 199.36 +/- 11.73 N in group 2, 108.32 +/- 15.98 N in group 3, and 214.24 +/- 28.52 N in group 4. Anchor fixation was significantly weaker compared with other groups (P <.001). Combination of a transosseous suture and anchor fixation (group 4) was significantly stronger than the single transosseous suture (group 1) and double anchor techniques (group 3) (P <.001). CONCLUSIONS: Hybrid technique was the strongest among the tested rotator cuff repair techniques. With the addition of one transosseous suture to two anchors, the strength of the repair could be doubled.

Animals↗
PubMed1997

Near-infrared (NIR) monitoring of H2O2 vapor concentration during vapor hydrogen peroxide (VHP) sterilisation.

PURPOSE: There is an increasing use in the pharmaceutical industry of barrier systems such as transfer isolators, sterilisation tunnels and work station isolators. As Vapor Hydrogen Peroxide (VHP) sterilisation of isolators and lyophilizers becomes an important sterilisation method, there is an acute need for a VHP monitoring system to be used for in-process control and validation. In this study, near infrared (NIR) spectrofotometry was evaluated as a potential technique to monitor hydrogen peroxide. Additionally the H2O2 vapor permeability of different packaging materials, commonly used in steam and ethylene oxide sterilisation, was evaluated. METHODS: NIR spectrofotometry, using a gas cell connected with optic fibres, was evaluated as a potential technique to monitor hydrogen peroxide vapor and water vapor during VHP sterilisation of an isolator. A NIR spectrum was taken every 30 s during VHP sterilisation of an isolator. The influence of injection rate, air flow rate, working temperature and gas distribution was investigated. The H2O2 vapor permeability of different packaging materials was determined by placing the gas cell in the sterilisation bags and sealing the bags hermetically. The sterilisation bag was then subjected to VHP sterilisation. RESULTS: The NIR spectra taken at steady state sterilization conditions showed 4 absorption peaks: at 1364, 1378 and 1400 nm attributed to water and at 1420 nm attributed to H2O2 vapor. By measuring the absorbance level at these wavelengths, the actual concentration of H2O and H2O2 vapor in the isolator was calculated. The water vapor permeation of the sterilisation bags, measured with NIR, appeared to be equal for all materials tested. Whereas Tyvek was the most permeable material for hydrogen peroxide vapor (82.7% of the reference concentration outside the bag), only 30% was found in bags made of medical paper. Sterilisation bags consisting of laminate films and PVC sealed to medical paper showed intermediate permeability. CONCLUSIONS: Near-infrared (NIR) spectroscopy using a gas cell with optic fibres is a useful technique to monitor VHP sterilisation cycles. There was a difference in H2O2 vapor permeability of different packaging materials, commonly used in steam and ethylene oxide sterilisation.

Hydrogen Peroxide↗
PubMed2000

Effect of compression ratio on speech recognition and speech-quality ratings with wide dynamic range compression amplification.

This project examined the effect of varying compression ratio on speech recognition and quality. Both listeners with mild-to-moderate sensorineural hearing loss and a control group of listeners with normal hearing participated. Test materials were sentences from the Connected Speech Test (R. M. Cox, G. C. Alexander, & C. Gilmore, 1987) which were digitally processed with linear amplification and wide dynamic range compression amplification with 3 compression ratios. Speech-recognition scores were obtained with sentences in quiet and in noise at a 10-dB signal-to-noise ratio for each amplification condition. Additionally, the participants rated each amplification condition in terms of clarity, pleasantness, ease of understanding, and overall impression. Results indicated that, for speech in quiet, compression ratio had no effect on speech-recognition scores; however, speech-quality ratings decreased as compression ratio increased. For speech in noise, both speech-recognition scores and ratings decreased with increasing compression ratio for the listeners with hearing loss. These results suggest that selection of compression ratio on the basis of speech-quality judgments does not compromise speech recognition.

Adult↗
PubMed2005

Bonding of ceramic insert to a laboratory particle filler composite.

The push-out bond strength of cylindrical ceramic inserts (CI) to particulate filler resin composite (VC) was evaluated in this study. Various surface treatments to improve the adhesion of CI to resin composite were tested. Additionally, the effect of fiber-reinforced composite (FRC) laminate encapsulation around CI was tested. Feldspathic porcelain CI with a diameter of 3.1 mm was bonded to VC. Adhesive resin was used for bonding. In group 1, no surface treatment of CI was done. In group 2, CI was encapsulated with a thin layer of woven glass FRC. In group 3, the surface of the CI was tribochemically silica coated and silanized. In group 4, the surface of the CI was grit-blasted with 50 microm aluminum oxide and etched with hydrofluoric acid. In group 5, the grit-blasted CI was encapsulated with a layer of FRC. The specimens (n = 6/group) were either dry stored or thermocycled in water (6000 x 5-55 degrees C). The push-out test was carried out with a universal material testing machine. The highest push-out strength was achieved in group 5 (20.4 MPa) and the lowest in group 2 (11.5 MPa). ANOVA revealed that both surface treatment and storage condition had a significant effect on push-out strength (p < 0.05). We conclude that the additional glass FRC encapsulation can be used to increase the bond strength of insert to composite.

Acrylic Resins↗
PubMed2004

Measurement uncertainty associated with overall migration testing.

The results from a single laboratory that took part in a series of check-sample exercises for overall migration were used to calculate the measurement uncertainty for the overall migration methodology. The results span 10 years of proficiency testing and cover a range of plastic materials tested using a variety of time and temperature test conditions. Twelve sets of results for overall migration into olive oil and 10 sets of results for overall migration into volatile simulants were used. The measurement uncertainty associated with the determination of overall migration from plastics into olive oil was estimated as +/- 2.6 mg dm-2 for results between 1.2 and 15.4 mg dm-2. The measurement uncertainty associated with the determination of overall migration into volatile simulants was estimated as +/- 1.4 mg dm-2 for results between 2.1 and 13 mg dm-2. These estimates are within the analytical tolerances set in European Union regulations, of 3 and 2 mg dm-2, respectively. The performance of all laboratories participating in these 22 check sample exercises was also evaluated. A very large majority (93%) of the participants used official test methods, sometimes with minor modifications as stated. For the simulant olive oil, an average of 81% of laboratories (13 rounds with an average of 21 participants in each) using official methods was within the tolerance specified in regulations. For the volatile food simulants, an average of 87% of laboratories (11 rounds with an average of 38 participants in each) using official methods was within the tolerance specified. It is concluded from this evaluation of within- and between-laboratory data that the official European Standard methods for overall migration testing are suitable for the analysis of routine samples.

Dietary Fats, Unsaturated↗
PubMed2000

Cytotoxicity of root canal filling materials to three different human cell lines.

The aim of this study was to investigate the biological compatibility of five root canal sealers (Sealapex, Endion, Super-EBA, Ketac-Endo, and AH Plus) and regular and calcium hydroxide-based gutta-percha in three different human cell lines. Cultures without root canal sealers were used as controls. Cell growth, cell morphology, cell viability, protein content of the cells, and prostaglandin E2 (PGE2) release were used as parameters to determine the cytotoxicity of the materials. The protein content of the three cell lines--nasal fibroblasts, gingival fibroblasts, and epithelial tumor cells--was significantly reduced (p < or = 0.001) by all materials tested. Determinations of PGE2 release showed significant material specific differences. No significant increased PGE2 release values were found with Sealapex, Endion, and Super-EBA. On the contrary significantly increased PGE2 levels were measured with Ketac Endo, AH Plus, regular and calcium hydroxide-based gutta-percha points (p < or = 0.001).

Biocompatible Materials↗
PubMed2003

Mechanical properties of subchondral cancellous bone of the radial head.

OBJECTIVE: To quantify the mechanical properties of subchondral bone of the radial head, with special interest in the regional variations in bone stiffness and strength. DESIGN: Transverse subchondral cancellous bone slices obtained from the proximal radial head were subjected to indentation tests. SETTING: Biomechanics laboratory with a servohydraulic materials testing machine. SPECIMENS: Thirteen previously frozen, cadaver proximal radii of mean age 69 +/- 9 years. MAIN OUTCOME MEASUREMENTS: The mean indentation modulus and local yield strength were calculated for the anteromedial (AM), anterolateral (AL), posteromedial (PM), and posterolateral (PL) quadrants of the radial head. RESULTS AND CONCLUSIONS: There were no differences in mean indentation modulus across all 4 quadrants (AL, 55.56 +/- 16.20 MPa; AM, 53.48 +/- 20.67 MPa; PM, 49.20 +/- 18.31 MPa; PL, 49.96 +/- 14.97 MPa) (P > 0.05). The AM quadrant had higher local yield strength than the PL and PM quadrants, as did the AL compared with the PL quadrant (AL, 24.89 +/- 8.52 Mpa; AM, 28.39 +/- 10.52 Mpa; PM, 23.01 +/- 6.99; PL, 20.62 +/- 4.83 MPa) (P < 0.05). This suggests that the high frequency of radial head fractures in the AL quadrant is likely not due to the local strength of cancellous bone. Rather, the location of fracture may be influenced by the composite strength or the mechanisms of loading at the radiocapitellar and proximal radioulnar joints. The modulus results suggest that similar screw purchase can be achieved in all areas of the radial head during internal fixation of fractures. These results may also influence implant design and fixation. This study was limited to an older population and may not be representative of a younger population.

Age Factors↗
PubMed1997

Characterization of cocaine binding sites in the rat testes.

PURPOSE: An estimated 29 million individuals use cocaine in the United States. Studies have shown a high affinity for dose dependent binding of cocaine in the testes. Recent work done in our laboratory has shown that chronic administration of cocaine to male rats has an adverse effect on fertility and spermatogenesis by producing extensive morphological changes in the testes, leading to reduction in sperm production. As a first step toward understanding this process, we characterized and identified the pharmacological properties of [3H]cocaine binding sites in the testes. MATERIALS AND METHODS: Crude membranes from the testes were prepared from 35 days old male Sprague-Dawley rats. [3H]cocaine binding was measured by using the method of Madras et al. (1989) with modifications. The data from saturation binding assays were analyzed by Inplot (GraphPad Software, San Diego, CA) to determine the Kd and Bmax. RESULTS: Specific binding of [3H]cocaine was linearly dependent on membrane protein concentrations ranging from 0.2 to 8 mg./ml. The pooled data from three independent experiments revealed a mean affinity of 36 +/- 2.0 nM and Bmax of 1.84 +/- 0.13 pmol/mg. The present study demonstrates that testicular tissue has receptor protein that binds [3H]cocaine saturably and specifically. Competition displacement experiments revealed a shallow displacement curve for (-)cocaine and Win 35,428 with r2 = 0.96, indicative of multiple binding components. Computer analysis confirmed that a two component binding model was preferred statistically over a one component model in all three experiments (p < 0.001). CONCLUSION: The results from these studies suggest that the testicular tissue contains a protein that binds [3H]cocaine in a saturable and specific manner. It has a different sensitivity from the [3H]cocaine binding protein in the brain and placenta. Further clarification of the relationship between cocaine and its recognition site is necessary to understand the mechanism of testicular damage after cocaine exposure.

Animals↗
PubMed2005

Bending and torsional stiffness in cadaver humeri fixed with a self-locking expandable or interlocking nail system: a mechanical study.

OBJECTIVES: This study was designed to gain data about a new expandable, noninterlocked intramedullary nail's capacity to stabilize unstable transverse humeral shaft fractures without the need for interlocking, thus making nail implantation simpler and to prove our goal hypothesis: that in a midshaft osteotomy of the humeral shaft the expandable humeral nail will show the same bending and torsional stiffness as an interlocked humeral nail, when implanted correctly according to the manufacturer's instructions. DESIGN: Pair randomization. SETTING: Mechanical laboratory testing. PARTICIPANTS: Eight pairs of freshly harvested cadaveric humeri. INTERVENTIONS: Fracture model was a midshaft transverse osteotomy, gapped to 3 mm. Each humerus pair received an expandable humeral nail (Fixion) or an interlocked humerus nail (Synthes) through a retrograde approach. The humeri were fixed in polymethylmethacrylate cylinders and tested in a servo-pneumatic material-testing machine. MAIN OUTCOME MEASUREMENTS: Torsional stiffness and bending stiffness of the nail-bone-construction. RESULTS: Expandable nails (interlocked nails) showed a lateral bending stiffness of 0.73 +/- 0.14 (0.63 +/- 0.1) KN/mm (P = 0.026) and a frontal bending stiffness of 0.67 +/- 0.18 (0.58 +/- 0.09) KN/mm (P = 0.084). Torsional stiffness values were 0.13 +/- 0.19 (0.43 +/- 0.09 Nm/degrees) (P = 0.012). Lower torsional stiffness in the expandable nail group was observed in humeri with a funnel shaped proximal intramedullary canal. CONCLUSIONS: The nail systems showed similar characteristics for frontal bending (P = 0.084), but not for lateral bending (P = 0.026). For lateral bending, the Fixion nail showed significantly more stiffness than the UHN nail (P = 0.026). There was significantly lower torsional stiffness with expandable nails compared with interlocked nails. Clinical correlation would suggest that in rotationally unstable fractures (A2 and A3 diaphyseal fractures), interlocked nails would provide increased stability over expandable nails.

Biomechanical Phenomena↗
PubMedDate not supplied

Human papillomavirus (HPV) genotyping by HPV DNA chip in cervical cancer and precancerous lesions.

OBJECTIVES: The human papillomavirus (HPV) is a well-known cause of cervical cancer. HPV tests are used as an adjunct test to decrease the false-negative rate of cytological screening. However, attempts are being made to replace the cytological screening with HPV tests. Therefore, this study was performed to examine the possibility of using HPV tests as screening test. MATERIALS AND METHODS: The results of the tests that were performed at the same time including the ThinPrep cytology, the high-risk group hybrid capture II (HC-II) test, the HPV DNA chip (HD-C) test, and a punch biopsy were compared in 400 women who were referred to us due to abnormal cytology or cervicogram. The accuracy of each test was then evaluated, and the type of virus was investigated using a HD-C test. RESULTS: The positive predictive values detected by the high-risk group HC-II test and HD-C test according to the histological diagnosis outcomes were 56.8 and 53.8%, respectively, for cervicitis; 91.5 and 91.5%, respectively, for cervical intraepithelial neoplasia I (CIN I); 88.1% and 81.0%, respectively, for CIN II; 88.6 and 84.2%, respectively, for CIN III, and 92.5 and 88.7%, respectively, for cancer (in 53 patients). The most prevalent types of HPV according to the HPV tests were types 16, 58, 18, and 52 in which type 16 was detected in the more advanced lesions. The sensitivity was 88.4% for the ThinPrep cytology, 89.9% for the HC-II for the high-risk group, and 86.2% for the HD-C test. CONCLUSION: These results suggest the possibility of using the HC-II and HD-C tests as screening tests, which have a similar sensitivity as the ThinPrep cytology. Nonetheless, randomized controlled trials will be needed before the actual application of the HPV tests as screening tests. Despite the fact that the importance of HPV type 16 in cancer development was confirmed, the prevalence of types 58 and 52 were relatively high compared with those found in other studies, showing a need for further studies on this subject. These HPV types need to be considered in vaccine development.

Cytodiagnosis↗
PubMed1996

Contact allergy to gold in dental patients.

Gold sodium thiosulphate (GSTS) in patch test series commonly yields positive reactions. In this study of dental patients, the clinical relevance of these positive reactions, the suitability of gold compounds as patch test materials, and value of the lymphocyte proliferation test in gold contact allergy, were evaluated. The frequency of positive patch test reactions to GSTS was 12.4% in the dental series. Fifty-two patients, only two of whom were male, were studied. Thirteen (25%) had had symptoms from jewellery or dental restorations. However, in most cases gold allergy was subclinical. A 10% aqueous solution of gold sodium thiomalate (GSTM) was almost as good as 0.5% GSTS in petrolatum as a marker of gold contact allergy, but 0.001% potassium dicyanoaurate (PDCA) yielded a high percentage of false-negative results. Seventy-three per cent of the subjects with positive patch tests to GSTS responded to gold compounds in vitro in the lymphocyte proliferation test, whereas 13 controls without gold contact sensitivity were negative. Consistent results in skin and lymphocyte proliferation tests provide support for the concept that gold salt-induced 'allergic-like' reactions are truly allergic in nature.

Adolescent↗