Biomedical subjects

P R Liu

Publications and source records attributed to P R Liu.

4 recordsLinked to original sources

PubMed1999

Use of pulsed field gel electrophoresis as an epidemiological tool for analysis of sporadic associated strains of Salmonella typhi isolated in Taiwan.

In order to characterize the subtypes of Salmonella typhi which cause sporadic disease in Taiwan, 55 isolates of Salm. typhi obtained from unrelated patients of sporadic cases during 1992-96 were subjected to chromosomal DNA digestion and pulsed field gel electrophoresis (PFGE). When DNAs of these 55 Salm. typhi strains were digested with XbaI, 41 PFGE patterns were observed. Strains sharing the same XbaI digestion pattern could not be further discriminated by PFGE analysis using SpeI and NotI as digestion enzymes. Thus, considerable genetic diversity exists among the Salm. typhi isolates. Although strains of the same patterns were mainly isolated during the same time, recirculation of certain infectious strains could be possible. When 12 antibiotics, i.e. ampicillin, trimethoprim/sulfamethoxazole, erythromycin, norfloxacin, tetracycline, sulphonamide, streptomycin, neomycin, chloramphenicol, kanamycin, cefoperazone and gentamycin were used to test the antibiotic susceptibility for these Salmonella isolates, only three antibiogram patterns were obtained and 49 of the 55 Salm. typhi isolates were found to belong to one pattern. Phage typing and plasmid profiles were also poor in discriminating these strains. Thus, PFGE alone may be used as a powerful tool for analysis of sporadic associated Salm. typhi strains.

Bacterial Typing Techniques↗

PubMed1994

Congenital coronary artery-cardiac chamber fistulae: a study of fourteen cases.

BACKGROUND: Congenital coronary artery fistula is a rare heart defect. Symptoms of the patient and characteristics of the fistula were investigated and the role of surgical treatment was evaluated. METHODS: Fourteen patients with congenital coronary artery fistulae were diagnosed here between January, 1983, and December, 1991. Only one patient was asymptomatic, but diagnosis was suspected from clinical presentation of a continuous murmur. In the 13 symptomatic patients, angina and exertional dyspnea were the most common symptoms. Congestive heart failure and subacute bacterial endocarditis were rare complications. Cardiac catheterization with selective coronary angiography was performed in all of these patients. The left anterior descending coronary artery was most commonly involved in this series. Findings, different from those in other literature, were the right coronary artery has more usually been reported. Fistulous communication was most often found in the pulmonary artery, right ventricle and right atrium. The mean ratio of pulmonary-to-systemic flow was 1.67 in 10 patients, and the shunt flow of another 4 accidentally diagnosed patients was trivial. Six patients, including all 4 patients, age < 20 years at diagnosis, underwent surgical correction; only 1 patient was not given an aid of cardiopulmonary bypass. RESULTS: The six patients who received surgical treatment, one died of pneumonia and respiratory failure and the other five patients had no evidence of residual fistula. All five were asymptomatic during a mean follow-up period of five years. The symptoms were slowly progressive, and functional status worsened in two who refused operation and in two high risk patients. In four patients with accidentally diagnosed small fistulae, the symptoms remained unchanged during six years of follow-up. CONCLUSIONS: The objective of surgical treatment was closure of the fistula tract without compromise of normal flow through the coronary artery. Surgical intervention was recommended for all symptomatic patients and asymptomatic young patients as well, to prevent the development of fistula-related complications.

Adolescent↗

PubMed1993

Evaluating CAD-CAM generated ceramic veneers.

As the CAD-CAM technique has been expanded to include porcelain facings, of particular interest is adapting the veneer to the prepared surface. In a comparison of the gap dimension of CAD-CAM generated veneers to those produced in the laboratory, no statistically significant differences were detected.

Analysis of Variance↗

PubMedDate not supplied

An alternative restorative method for regional odontodysplasia: case report.

A 5-year-old Caucasian male presented with early loss of multiple deciduous teeth. All the characteristics were consistent with the diagnosis of regional odontodysplasia (ROD). Significant initial findings included premature loss of multiple primary mandibular teeth and some malformed permanent teeth. The affected teeth showed hypoplastic enamel and dentin, short roots, and wide pulp chambers, and were localized in the mandibular dentition. Treatment objectives for this patient were to provide improved esthetics, restored chewing function, and space maintenance by the construction of a temporary prosthetic restoration. However, with limited tooth support and an unusual occlusal pattern, it is difficult to obtain satisfactory retention and esthetics with traditional prosthetic techniques. In this article we introduce an alternative method for fabricating a custom removable denture and discuss the prognosis of the malformed permanent dentition and further treatment plan.

Child, Preschool↗