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Biomedical subjects

C P Lin

Publications and source records attributed to C P Lin.

132 records · Page 8Linked to original sources
PubMedDate not supplied

A nontoxic Pseudomonas exotoxin A induces active immunity and passive protective antibody against Pseudomonas exotoxin A intoxication.

Pseudomonas exotoxin A (PE) is one of the most potent cytotoxic agents produced by Pseudomonas aeruginosa. In this study, we examined the possibility of using PE with a deletion of 38 carboxyl-terminal amino acid residues, designated PE(Delta576-613), for active immunization against PE-mediated disease. We first examined the toxic effects of PE and PE(Delta576-613) on 5- and 9-week-old ICR mice. The results show that the subcutaneous administration of PE(Delta576-613) at a dose of 250 microg was still nontoxic to 5- and 9-week-old ICR mice, while native PE was lethal at a dose of 0.5 and 1 microg, respectively. PE(Delta576-613) was then used to immunize ICR mice. The minimum dose of PE(Delta576-613) that could effectively induce anti-PE antibodies in 5- and 9-week-old ICR mice was found to be 250 ng. However, immunization with 250 ng PE(Delta576-613) failed to protect the immunized mice from a lethal dose of PE. The effective immunization dose of PE(Delta576-613) that could protect mice against a 2 microg PE challenge was found to be 15 microg. In addition, sera obtained from PE(Delta576-613)-immunized ICR mice were able to neutralize PE intoxication and effectively protect mice from PE. Thus, PE(Delta576-613) may be used as an alternative route to new PE vaccine development.

3T3 Cells↗
PubMedDate not supplied

An in vitro study on restoring bond strength of a GIC to saliva contaminated enamel under unrinse condition.

OBJECTIVES: This study attempted to find a method of restoring the tensile bond strength of glass ionomer cement (GIC) to saliva contaminated enamel under unrinse condition. METHODS: One hundred and thirty human non-carious permanent teeth were divided into two major groups. Either treatment with air drying, acetone, polyacrylic acid, maleic acid, tartaric acid, Scotchbond primer or no treatment at all was applied to both clean and saliva contaminated enamel surfaces prior to GIC placement. Samples were debonded in tension after 7 days of storage in water using a universal testing machine. Statistical analysis was performed using one-way ANOVA, Tukey's studentized range test and Wilcoxon's rank sums test to determine the significance of the difference of tensile bond strengths within and between the two major groups. RESULTS: Bond strength of GIC to clean enamel was 2.46+/-0.79 MPa while the bond strength of GIC to wet contaminated enamel was significantly reduced to 1.28+/-0.32 MPa (p<0.01). However, the bond strengths were restored when the contaminated enamel surfaces were air-dried (2.19+/-0.38 MPa) or applied with either maleic acid (2.80+/-0.63 MPa) or Scotchbond primer (2.13+/-0.65 MPa) before placing GIC over the enamels. CONCLUSIONS: Air drying, or application of maleic acid or Scotchbond primer to the contaminated enamel without rinsing prior to GIC placement can restore the tensile bond strength to a level similar to that of non-contaminated control.

Acetone↗
PubMedDate not supplied

Combined use of an amniotic membrane and tissue adhesive in treating corneal perforation: a case report.

We report a new method combining the use of an amniotic membrane and cyanocrylate tissue adhesive to seal a corneal perforation. A 47-year-old male suffered from an alkali injury complicated with corneal melting and perforation in the left eye. We placed an amniotic membrane of optimal size in the anterior chamber directly under the corneal perforation lesion. The cyanocrylate tissue adhesive was then applied over the perforation site and sealed successfully. Three weeks later, the tissue adhesive had dislodged. The amniotic membrane had sealed the perforated lesion and was well adhered to the surrounding corneal tissue with complete epithelial covering. Vision was 20/25 six months after the operation. The combined use of an amniotic membrane and tissue adhesive is a promising method in the treatment of corneal perforation.

Amnion↗
PubMedDate not supplied

Non-functioning islet cell tumors of the pancreas--a multicentric clinical study in Taiwan.

BACKGROUND/AIMS: Islet cell tumors of the pancreas are rare. Functioning tumors are characterized by the symptoms induced by the hormones they secrete. The clinical behaviors of non-functioning tumors are quite different. In this retrospective study, we scrutinized 16 patients with non-functioning islet cell tumor in three tertiary university hospitals in Taiwan during a 20-year period. METHODOLOGY: There were 12 women and 4 men with a mean age of 47 years. Body-weight loss, abdominal pain and palpable mass were the most frequent symptoms. RESULTS: The mean size of these tumors was 8.9 cm in diameter. Ten tumors were located at the tail of pancreas, the other 6 located at the head. Except for hyperbilirubinemia in 2 patients, none of the patients with non-functioning islet cell tumor showed abnormalities of laboratory data including serum tumor markers. Preoperative detection of these tumors by imaging modalities was not difficult due to the large size of the tumors. However, differentiation with functioning tumor or ductal cell carcinoma required clinical and imaging correlation. Fourteen tumors were malignant including 8 with regional lymph nodes involvement, 3 with locally microscopic invasion, 2 with hepatic metastasis and 2 with nearby organ invasion. CONCLUSIONS: Even with its malignant behavior, non-functioning islet cell tumor still possessed a good prognosis after adequate surgical removal in comparison with a higher mortality rate of ductal carcinoma of the pancreas.

Adenoma, Islet Cell↗
PubMedDate not supplied

Bonded amalgam restorations: using a glass-ionomer as an adhesive liner.

Due to the lack of adhesiveness of amalgam to tooth structure, several adhesive cements have been utilized in bonded amalgam restorations. This study evaluated whether Fuji-II glass-ionomer cement is an appropriate adhesive liner in bonded amalgam restorations. Two adhesive composite luting cements (Amalgambond Plus and Panavia-21) and Copalite cavity liner were compared. The study was conducted in two phases. In the first part, we quantitatively assessed the tensile bond strengths as well as the failure modes of amalgam bonded to human dentin, using different adhesive liners. In each group, the flat dentin surface was treated with the assigned adhesive cement with a Teflon mold, followed by condensation of amalgam (Valiant PhD) onto it. Each group's mean tensile bond strengths were recorded and the statistical analysis by one way ANOVA showed no significant differences among groups (p > 0.05). Similar to the fracture patterns of the Amalgambond Plus and Panavia-21 groups, the failure mode of Fuji-II group was predominantly adhesive fracture. In the second part, the fracture strengths of amalgam restored teeth were measured using different adhesive liners. Standard MOD cavities were prepared in each tooth except for the intact tooth group. After treatment with the assigned adhesives or varnish, the cavities were restored with amalgam. Fracture strengths were then measured and the fractured interfaces examined using a scanning electron microscope. The fracture strengths of the intact tooth, Amalgambond Plus, Panavia-21 and Fuji-II groups were significantly higher than those of the Copalite and prepared cavity without restoration groups (p < 0.01). Accordingly, Fuji-II glass-ionomer cement, when used as an adhesive liner of amalgam restoration, may effectively reinforce the remaining tooth structure and, therefore, enhance the fracture resistance of the amalgam-restored teeth.

Analysis of Variance↗