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Biomedical subjects

F C Chu

Publications and source records attributed to F C Chu.

At least 19 recordsLinked to original sources
PubMed2001

Competency-based education in a clinical course in conservative dentistry.

The conceptual difference between a competency-based education and an education based upon a conventional dental curriculum is, perhaps, the starting point for the development of new curricula. The two systems are not, in themselves, exclusive. There is common ground to be found, and the concept of combining instruction with competency-based learning experiences is emerging in recent publications. This paper describes a competency-based approach applied to a clinical course in conservative dentistry. The learning outcomes of the fourth-year dental students in the new course were assessed using methods that included continuous clinical assessments, student presentations and peer-group reflective evaluations, patient management reviews, a clinical progress examination, the range and amount of work completed, and a written examination and viva voce. Different weightings were given to various elements of the assessment. A formal student assessment of the course rated it as being satisfactory.

Clinical Competence↗
PubMed2001

Computer-assisted learning (CAL) in undergraduate clinical dentistry: a review.

OBJECTIVE: To review the effectiveness of computer-assisted learning (CAL) in undergraduate clinical dentistry. METHODS: A review of dental and related medical literature was conducted using a selective MEDLINE search and by manual search. RESULTS: An attempt was made to evaluate the results of computer-based teaching methods in clinical dentistry, and the future. Analysis of several controlled studies showed equivocal learning improvements for CAL when compared with other teaching methods in clinical dentistry. However, CAL technology and appreciation of the standards required for effective learning programmes have changed considerably since these early studies were published. CONCLUSIONS: There is considerable potential for effective computer-based education in undergraduate clinical dental programmes, and the Internet can provide better access to such material. However, using newer technologies, further controlled studies of the learning effectiveness and cost-effectiveness of CAL in clinical dentistry are required.

Computer-Assisted Instruction↗
PubMed2000

Gangrenous cholecystitis in the laparoscopic era.

BACKGROUND: We reviewed our data of laparoscopic cholecystectomies between 1990 and 1997 with reference to gangrenous cholecystitis. METHODS: In a consecutive series of 1304 patients having laparoscopic cholecystectomies, prospective data collection has permitted analysis of the relationship between gangrenous cholecystitis (GC), acute (non-gangrenous) cholecystitis (AC) and non-acute cholecystectomies (NAC). RESULTS: Twenty-five patients had gangrenous cholecystitis and 238 had acute cholecystitis. We found that patients with GC were significantly older (65.4 years vs 56.1 years (AC) and 52.7 years (NAC), P < 0.05) and had a higher M: F ratio (1.5:1 vs 1:2.6 (AC) and 1:2.8 (NAC), P < 0.05). Cardiac disease was found to be a significant factor but not diabetes. Preoperative ultrasonography correctly identified only 17 patients with acute inflammatory changes. Seven patients had an absent sonographic Murphy's sign. The gall bladder wall was generally thicker (4.11 mm vs 3.8 mm (AC) and 2.7 mm (NAC), P < 0.05) but there was marked overlap between the three groups. The common bile duct (CBD) was more dilated (6.1 mm vs 4.8 mm (AC) and 4.6 mm (NAC), P < 0.006) and there was increased incidence of CBD stones in the GC group. Our conversion rate was 8.7% with minimal complications and no operative mortality. CONCLUSION: Patients with GC were generally older, more likely to be male and had increased incidence of cardiovascular disease. Preoperative ultrasound cannot accurately identify those patients with gangrenous cholecystitis, but with conversion rates of 8.7% and no operative mortality, they can generally be managed safely with laparoscopic surgical techniques.

Acute Disease↗
PubMed2000

Effects of surface treatments on shear bond strengths between a resin cement and an alumina core.

STATEMENT OF PROBLEM: Although bonding to all-ceramic restorations is desirable, there is little information on the use of resin cements containing a phosphate monomer, and the importance of different surface treatments on their adhesion to high-strength core materials. PURPOSE: This study attempted to determine the shear bond strength values between Panavia 21 resin cement (Kuraray) and an alumina core material (In-Ceram) after 3 surface treatments and the application of a silane coupling agent. MATERIAL AND METHODS: Forty-five In-Ceram cylindrical rods were fabricated and assigned to 3 groups. Group I specimens were treated with a 9.5% hydrofluoric (HF) acid, group II with a 5% HF acid, and group III were sandblasted. All specimens were coated with a silane coupling agent (Cavex Clearfil Photobond and Activator) before cementation with Panavia 21 to sandblasted nickel-chromium rods. As a control, group IV consisted of 8 porcelain (Vitadur Alpha) rods treated with a 5% HF acid and silane. All specimens were subjected to a load of 1.2 kg during cementation, then stored under water for 36 hours. A jig mounted on a Hounsfield Universal Testing machine was used at a crosshead speed of 0.5 mm/min to test the shear bond strengths. RESULTS: The results were 14.65 +/- 4.64 MPa for group I, 18.03 +/- 6.13 MPa for group II, and 22.35 +/- 5.98 MPa for group III In-Ceram specimens; and 18.05 +/- 8.46 MPa for control (group IV). CONCLUSION: The use of Panavia 21 resin cement and a silane coupling agent can achieve a successful bond between either sandblasted or 5% HF acid-etched In-Ceram core material.

Aluminum Oxide↗
PubMed2000

Clinical considerations for reattachment of tooth fragments.

Trauma to anterior teeth is relatively common among children and teenagers; it has been estimated that approximately one quarter of the population under the age of 18 years sustain traumatic injury in the form of anterior crown fracture. Reattachment of a fractured fragment to the remaining tooth can provide esthetically pleasing results provided that the fragment is available. In this report, a systematic clinical approach through evaluation of periodontal, endodontic, coronal, and occlusal aspects is presented to help dentists analyze the factors affecting selection of techniques and materials. In addition, use of adhesive materials for tooth fragment reattachment is illustrated. Modifications of the reattachment process, including placement of veneer and radicular post, are also discussed.

Acid Etching, Dental↗
PubMed2000

Oral health status, oral microflora, and non-surgical periodontal treatment of renal transplant patients receiving cyclosporin A and FK506.

OBJECTIVES: To determine the oral health status, oral microflora and the effect of non-surgical periodontal treatment on gingival overgrowth of renal allograft recipients receiving either cyclosporin A (CsA) or FK506 (Tacrolimus) as an immunosuppressant. MATERIALS AND METHODS: A total of 47 patients receiving CsA (mean age 43.1 years) and 10 receiving FK506 (mean age 40.1 years) were included in the study. Stone casts were taken for measurement of gingival overgrowth. An oral rinse technique was used to investigate the prevalence of yeasts, and aerobic and facultatively anaerobic Gram-negative rods (AGNR). RESULTS: The CsA and FK506 patients exhibited a Gingival Overgrowth Index (GOI) of 45.2%, and 25.1%, respectively (p < 0.05). The CsA patients had a GOI of 15.2% after one year of non-surgical periodontal treatment. The difference between pre- and postoperative gingival overgrowth indices was significant (p < 0.0001). Candida albicans and Klebsiella pneumoniae were the most notable yeast and AGRN found. CONCLUSIONS: Renal transplant patients, being immunocompromised, constitute a high-risk group for gingival overgrowth. However, the FK506 regime appeared to ameliorate this effect, compared with CsA. Non-surgical periodontal treatment was effective in reducing established gingival overgrowth in both CsA and FK506 patients (p < 0.05). Adequate pre- and post-transplant oral health care is recommended, for these patients, irrespective of the drug regime.

Adult↗
PubMed1995

Ocular pathologic findings of chronic granulomatous disease of childhood.

PURPOSE/METHODS: To demonstrate ocular histopathologic findings of chronic granulomatous disease of childhood. The histopathologic results of two enucleated eyes from two patients with chronic granulomatous disease were studied using light microscopy. RESULTS/CONCLUSION: Histopathologic changes in the eye specimens in patients with chronic granulomatous disease included multiple foci of granulomatous inflammation of choroid and sclera.

Choroid↗
PubMed1995

Organ and functional preservation in the management of breast cancer.

Breast conservation surgery combined with radiation therapy has established itself as a good alternative to mastectomy for patients with stage I and II breast cancer. This method can also be used to treat patients with DCIS. Careful clinical, mammographic, and pathological evaluations are essential for appropriate selection of patients for breast conservation treatment. Particular attention must be paid to the application of skillful surgical and radiotherapeutic techniques in order to achieve satisfactory long-term control, survival, and cosmetic results. Adjuvant chemotherapy may be used when indicated. The integration of chemotherapy with radiation therapy may be sequential or concurrent, but the optimal method of integration has not yet been determined.

Breast Neoplasms↗
PubMed1992

The value of mammography after limited breast surgery and before definitive radiation therapy.

One hundred twenty consecutive patients who had breast-conserving surgery for cancer and were referred for definitive radiation therapy (RT) had a mammogram performed before starting RT. This was done to determine the presence of residual neoplasm or other abnormalities that may alter or delay the planned RT and are undetected by other means. It also was performed to provide a baseline for the diagnosis of postoperative changes and recurrence of disease on follow-up studies. In six (5%) patients, calcifications or masses were found that proved to be residual tumors. This led to reexcision in two, mastectomies in two, and a higher radiation booster dose to the tumor bed in two. Eight (6.6%) patients had postoperative hematomas larger than 4 cm in diameter, which delayed the start of RT by 2 to 3 weeks. In 39 (32%) patients, the pre-RT mammogram provided information considered to be helpful for the interpretation of post-RT mammograms. Such information may lead to a decrease in the number of diagnostic biopsies based on indeterminate mammographic findings. Therefore, a routine mammogram is recommended before RT is started.

Adult↗
PubMed1992

Radiation therapy of cancer in prosthetically augmented or reconstructed breasts.

The authors review the literature and report their experience with radiation treatment of 39 prosthetically augmented or reconstructed breasts in 37 patients with primary or recurrent breast cancer. Group 1 consisted of 10 patients (12 primary breast cancers), of whom six had undergone previous breast augmentation and were later treated with lumpectomy and radiation therapy. Four patients were treated with mastectomy, reconstruction, and postoperative irradiation. Local tumor control was achieved in all patients. Excellent or good cosmetic results were achieved in all but two patients. Group 2 consisted of 27 patients with recurrent breast cancer after mastectomy and reconstruction. Local tumor control was achieved in 78% (21 of 27), with a mean duration of 34 months. Excellent or good cosmetic results were achieved in 93% (25 of 27). Patients who develop primary or recurrent breast cancer in prosthetically augmented or reconstructed breasts can be offered radical radiation therapy, with satisfactory tumor control and aesthetic results.

Adult↗
PubMed1990

Effects of halothane on intraocular pressure in anesthetized children.

Intraocular pressure (IOP) measurements in children are usually performed under nitrous oxide and halothane anesthesia. We studied the effects of both time and end-tidal halothane concentration on IOP in 80 children (mean age +/- SD = 4.5 +/- 2.9 yr), to determine the most optimal time to make such measurements in anesthetized children. In 30 children the end-tidal halothane and nitrous oxide concentrations were kept constant while IOP was measured at 1-min intervals after the induction of anesthesia. Intraocular pressure did not change with time. In another 50 children IOP was measured immediately after induction, after 10 min of steady-state end-tidal halothane concentrations of both 0.5% and 1.0% in 66% nitrous oxide, and immediately after tracheal intubation. Intraocular pressure did not differ significantly at either halothane concentration but increased after tracheal intubation. We conclude that in patients anesthetized with halothane and nitrous oxide, IOP after induction remains constant over time and is not affected by end-tidal halothane concentrations up to 1.0% but is affected by tracheal intubation. Thus, the optimal time to measure IOP in children receiving up to 1% halothane in 66% nitrous oxide is during the first 10 min after induction, but before tracheal intubation.

Anesthesia, Inhalation↗
PubMed1986

Benzydamine HCl, a new agent for the treatment of radiation mucositis of the oropharynx.

Benzydamine HCl is a new nonsteroidal analgesic and anti-inflammatory compound which is not chemically related to local anesthetics such as procaine and xylocaine. A double-blind, randomized clinical investigation was carried out to determine the analgesic and anti-inflammatory effectiveness of benzydamine HCl in patients with radiation-induced mucositis of the oropharynx. Of the 67 patients in the study, 37 were on benzydamine and 30 on placebo. Patients developed radiation mucositis, hyperemia, and throat pain when the total radiation dose reached above 2,000 rad over 2 weeks (200 rad per fraction, five treatments per week). Analysis of the data showed that benzydamine HCl used as a rinse/gargle provided a statistically significant and clinically meaningful alleviation of the symptoms of oropharyngeal mucositis. There was also significant improvement in terms of reduction in hyperemia and mucositis in benzydamine group. No systemic side effects associated with benzydamine medication were noted. In view of the relative ineffectiveness of systemic analgesics and topical anesthetics for these conditions, benzydamine HCl promises to be a useful addition to the therapeutic armamentarium.

Analgesics↗
PubMed1985

Adaptive response to ocular muscle weakness in human pursuit and saccadic eye movements.

Eye movement deficits caused by ocular muscle weakness vary according to the position of the eye in the orbit and the direction of eye movement. We studied the ability of both the saccadic and pursuit eye-movement systems to compensate for these anisotropic deficits in four patients with ocular muscle weakness. The eye-position dependence of each patient's motor deficit was characterized by plotting the position of the weak eye against that of the normal eye (in various orbital positions) when fusion was prevented, thus giving a static eye-position curve from which relative muscle strength could be inferred. Movements of the weak eye were smaller and slower than those made by the normal eye, so that the weak eye required more time to acquire a visual target. When patients were forced to view monocularly with their weak eye for several days, both the saccadic and pursuit systems showed changes in the movements of the normal eye consistent with an increased central innervation designed to decrease the time it takes to bring the target's image onto the fovea of the weak eye and to keep it there. These adaptive changes varied with eye position and movement direction and compensated for the weak muscle in both its agonistic and antagonistic actions. Saccadic adaptation consisted of a change in the relationship between saccadic amplitude and retinal error (distance between the target's image and the fovea) to compensate for hypometria (undershoot) and a readjustment of the ratio of the phasic (pulse) and tonic (step) components of the saccadic innervation to suppress postsaccadic ocular drift. Pursuit adaptation consisted of an increase in the relationship between eye acceleration and the rate of motion of the image of the target on the retina during the initial phase of tracking as well as an increase in the velocity during tracking of a target moving at a constant velocity. These changes reflect an increase in pursuit innervation that would cause the weak eye's velocity to approach target velocity sooner. The average acceleration of the normal eye during the initial period of tracking (130 ms) increased by as much as threefold. The corresponding maximum smooth eye velocity increased so that, for example, the pursuit response to a 15 degree/s target movement could be over 50 degree/s in the normal eye.

Adaptation, Physiological↗
PubMed1985

Head shaking and vestibulo-ocular reflex in congenital nystagmus.

The authors investigated the mechanisms underlying the head shaking shown by some patients with congenital nystagmus (CN). In order to improve visual function by head shaking, a patient with CN must have some visual acuity loss due to retinal image motion created by the nystagmus; an abnormal vestibulo-ocular reflex (VOR); and the head shaking must be correlated with the nystagmus. The authors measured the VOR gain (eye velocity/head velocity) and examined eye-head coordination in five patients with CN with various combinations of these three factors. One patient met all three criteria and was able to increase his acuity by shaking his head. Other patients who shook their heads either had no loss of visual acuity due to the nystagmus or had a normal VOR. In either case, head shaking was of no apparent visual benefit and may represent, instead, an associated pathologic tremor in the cephalomotor control system.

Adult↗
PubMed1984

Graphic analysis of paralytic strabismus with the Lancaster red-green test.

We used the Lancaster red-green test to monitor changes in ocular alignment in patients with paralytic strabismus. By inferring the position of the right eye and that of the left eye at many different positions of gaze and then plotting the data on a graph, one can derive a static eye position curve. The location of the curve relative to the line depicting normal ocular alignment ( orthophoria ) indicates whether there is an esodeviation or an exodeviation . The slope of a line drawn tangent to the curve indicates, for that particular point, whether the deviation is concomitant or not and which eye is relatively weak or restricted and by how much. This graphic technique provides a simple, sensitive, and quantitative measure of ocular alignment that may be especially useful for detecting subtle changes in the relative positions of the two eyes. This method may be a useful adjunct in the planning and evaluation of therapy for patients with paralytic strabismus.

Humans↗
PubMed1984

Ocular abnormalities in abetalipoproteinemia. A clinicopathologic correlation.

The present paper documents the clinical characteristics and ocular pathology in a patient with abetalipoproteinemia. Noteworthy were: the predominant involvement of the posterior fundus characterized by a loss of photoreceptors; loss or attenuation of the pigment epithelium (producing a sharply demarcated white appearance on ophthalmoscopy); preservation of the submacular pigment epithelium with an excessive accumulation of lipofuscin (including bizarre laminar profiles by electron microscopy); invasion of the retina by macrophage-like pigmented cells. The retina and pigment epithelium in the periphery were morphologically normal. The patient died of a presumably unrelated brain tumor which was believed to have accounted for the terminal blindness and loss of ganglion cells in the retina.

Abetalipoproteinemia↗
PubMed1984

Ocular findings in Turner syndrome. A prospective study.

We performed complete ophthalmological examinations of 30 consecutive patients with Turner syndrome. Twenty-three had 45XO and 7 had 45XO/46XX karyotypes (mosaicism). Non-familial strabismus was the most prominent ocular abnormality and was present in 33% of the patients. Other eye findings included ptosis (16%), hypertelorism (10%), epicanthus (10%), and antimongoloid slants (10%). Red-green color deficiency was found in 10% of the patients. One patient had congenital periodic alternating nystagmus.

Adolescent↗