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Biomedical subjects

C S Liu

Publications and source records attributed to C S Liu.

At least 91 records · Page 5Linked to original sources
PubMed1995

Differentiation of Aspergillus parasiticus from Aspergillus sojae by random amplification of polymorphic DNA.

Aspergillus parasiticus and Aspergillus sojae are two morphologically similar species belonging to the Aspergillus section flavi. A new method to distinguish the two species, the aflatoxin producer A. parasiticus and the koji mold A. sojae, was developed. Single primers with arbitrary sequences were used to generate random amplified polymorphic DNA (RAPD) markers from strains of these two species. Three decamers, OPA-04, OPB-10, and OPR-01, allowed adequate discrimination between strains of A. parasiticus and A. sojae in RAPD analyses. A. sojae was further separated into group I and group II with the three primers. On the other hand, A. parasiticus was divided into group A and group B when amplified with OPA-04 and OPR-10 primers. The previously misidentified stain CCRC 32423 and the misclassified strain CCRC 30227 were identified as Aspergillus flavus and A. sojae, respectively, on the basis of RAPD patterns and morphological characteristics. We suggest that the RAPD technique is a rapid and reliable tool to distinguish A. parasiticus from A. sojae.

Aspergillus↗
PubMed1995

Utility of Argyrophilic nucleolar organizer regions (AgNOR) in differentiating malignant from benign of colorectal tumors.

BACKGROUND: Argyrophilic nucleolar organizer regions (AgNOR) can reflect the activity of cellular proliferation. The purpose of this study is to evaluate the potential value of AgNOR in differentiating benign from malignant colon epithelial neoplasms, and to determine the correlation between the nucleus AgNOR and the grade of colonic adenocarcinomas. METHODS: In this study, AgNOR technique was applied to 61 paraffin embedded sections of colorectal tissue including normal mucosa (n = 10), adenomatous polyp (n = 16), and adenocarcinoma (n = 35). RESULTS: The mean +/- standard error (SE) numbers of AgNOR dots per nucleus of normal mucosa, adenomatous polyp, and adenocarcinoma were 2.17 +/- 0.07 (n = 10) 3.89 +/- 0.10 (n = 16) and 5.52 +/- 0.10 (n = 35), respectively (p < 0.00001). In addition, the mean numbers of AgNOR dots per nucleus of well differentiated (WD) adenocarcinoma (n = 14), moderately differentiated (MD) adenocarcinoma (n = 11) and poorly differentiated (PD) adenocarcinoma (n = 10) were 5.20 +/- 0.12, 5.81 +/- 0.20, 5.67 +/- 0.15, respectively. MD and PD tumor had significantly higher AgNOR count than that of WD tumor (p < 0.05). However, there was no significant difference between MD and PD colorectal adenocarcinoma. CONCLUSION: AgNOR method is a simple, rapid method in diagnosis of colorectal tumors, and it provides a useful adjunct to histopathology in the diagnosis of colorectal tumors.

Adenocarcinoma↗
PubMed1995

Does Helicobacter pylori infection play a role in the pathogenesis of non-ulcer dyspepsia--a study of gastric emptying time.

UNLABELLED: To investigate the relationship between gastric motility and Helicobacter pylori infection in patients with non-ulcer dyspepsia, 28 patients and 10 asymptomatic healthy persons underwent gastroduodenal endoscope examinations and scintigraphic test of solid phase gastric emptying time using Chinese fried rice as a test meal. Clinical symptoms were also recorded using questionnaires for scoring. Half emptying times for ingested food (t1/2) between H. pylori infected (190.86 +/- 112.53 minutes) and uninfected patients (227.69 +/- 179.29 minutes) were not different statistically. Seven of the 15 patients with H. pylori infection (46.6%) had delayed gastric emptying time (t1/2 > 197.7 minutes), compared to 4 out of 13 without infection (30.07%) (p > 0.05). There was also no association between the status of H. pylori infection and severity of clinical symptoms (total symptoms scores: H. pylori positive: 10.07 +/- 3.84; H. pylori negative: 7.62 +/- 2.25) (p > 0.05). Seven patients from whom H. pylori was found to have been eradicated using triple therapy (colloid bismuth subcitrate 120 mg q i d, tetracycline 500 mg q i d and metronidazole 250 mg q i d for 14 days) did not show significant changes in gastric emptying time (before: 171.14 +/- 128.13; after: 158.57 +/- 182.49 minutes) but showed improvement in total symptoms scores (before: 9.28 +/- 3.85; after: 3.85 +/- 4.22) (p = 0.0277). CONCLUSIONS: infection by H. pylori in patients with non-ulcer dyspepsia did not influence solid phase of gastric emptying time and was not associated with clinical symptoms. Eradication of H. pylori infection relieved the clinical symptoms of the patients with non-ulcer dyspepsia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Evaluation of the severity of Helicobacter pylori infection with urease test: its correlation with histopathology and bacterial density.

In 69 patients, the severity of Helicobactor pylori (H. pylori) infection was evaluated by bacterial density of tissue implants and inflammatory responses by histology. The specimens were taken from gastric angle and antrum (greater and lesser curvature sides) by gastroduodenal endoscopy. In urease test, the severity was measured in 3 grades according to color change of the agar: those change are within 30 minutes (grade 3), 30 minutes to 3 hours (grade 2), and 3 to 6 hours (grade 1), respectively; while the grade 0 indicated no color change occurring 6 hours after tissue inoculation. The severity of infection was assessed according to the bacterial density under high power microscopic fields (Gram's stain). Grade 0 indicated no bacterium seen; grade 1, only 1 to 10 bacteria at all fields; grade 2, 1 to 3 bacteria in each high power field; and grade 3 was 4 bacteria or more on average in each high power field. The degree of inflammatory response was evaluated by inflammatory cell infiltration (H & E stain) and classified into grade 0, 1 and 2, which indicated the inflammatory cell infiltration below 50%, between 50% and 75%, and above 75%, respectively. There are no positive relationships among urease test reaction time, bacterial density grading and degrees of inflammatory cell infiltration. Clinically, the reaction time of urease test cannot reflect the severity of H. pylori infection semi-quantitatively, either in terms of bacterial density or cellular inflammatory response.

Adult↗
PubMed1994

Long-term follow-up and serological study after triple therapy of Helicobacter pylori-associated duodenal ulcer.

OBJECTIVE: The purpose of this study was to monitor the change of IgG antibodies to Helicobacter pylori during the course of a long-term follow-up after the eradication of H. pylori, as well as to evaluate the efficacy of triple therapy in preventing the recurrence of duodenal ulcer (DU). METHODS: Twenty-three DU patients with positive H. pylori were studied; among those patients, 20 ulcers healed after initial treatment of triple therapy. Each patient received a follow-up endoscopy and biopsy examination every 3 months for 1 yr, or whenever the ulcer symptoms recurred. Serological tests for IgG antibodies were performed with a commercial ELISA. RESULTS: Of the 20 patients with healed ulcers, one dropped out of this study; the recurrence rate of DU at 1 yr was 5% (1/19). There was no recurrence of ulcer in 17 H. pylori-negative patients and only one recurrence out of two H. pylori-positive patients. After the eradication of H. pylori, the seroconversion rates of IgG were 5%, 21%, 42%, 76%, and 94% at 0, 3, 6, 9, and 12 months, respectively. After 6 months, 95% (18/19) of the patients in which H. pylori was eradicated had at least a one-grade fall in IgG titers (p < 0.001). One patient had a relapse of H. pylori which was accompanied with re-elevating IgG titers. CONCLUSIONS: We conclude that seroconversion, which usually occurs after 1 yr, indicates complete eradication of H. pylori. Furthermore, we suggest that the success of the eradication of H. pylori can be judged without endoscopic examination, 8 months after treatment by triple therapy, according to the fall of IgG titers or seroconversion. Re-elevating IgG titers may be a warning of the possibility of relapse or reinfection of H. pylori.

Anti-Ulcer Agents↗
PubMed1994

Hyperbaric oxygen therapy in hemorrhagic radiation cystitis: a report of 20 cases.

Radiation cystitis with macroscopic hematuria has been a frustrating clinical problem for urologists. Since 1985 hyperbaric oxygen (HBO) has been used to treat this disease, showing favorable results. Between November 1989 and October 1992, 20 female patients with hemorrhagic radiation cystitis were treated with HBO at a pressure of 2.5 atm abs, breathing 100% O2 for 100 min in our multiplace hyperbaric chamber. After an average of 44 HBO sessions, macroscopic hematuria was completely halted in 16 patients (80%) and markedly decreased in 2 patients (10%). Comparison of the cystoscopic findings before and after HBO showed a significant decrease in hemorrhagic sites and telangiectasis of the bladder mucosa. One patient had urinary frequency and urgency without hematuria during her hospital stay. After 30 sessions of HBO therapy, her symptoms subsided, and the cystoscopic findings were much improved. Only one patient failed to respond to HBO and underwent ileal conduit diversion. The mean follow-up period was 14 mo. (5-41 mo.). From our clinical results and cystoscopic findings, we suggest that HBO is an effective and safe treatment for hemorrhagic radiation cystitis.

Adult↗
PubMed1994

Histiocytosis X involving thyroid gland: a case report.

Diffuse histiocytosis X involving thyroid gland is rare. A 10-year-old boy with progressively enlarged neck mass, skin rash over scalp and face, splinter hemorrhage, otitis externa, episodes of pneumothorax and abnormal liver function was hospitalized. Thyroid scan showed a nonfunctioning mass in the right lobe of the thyroid and needle aspiration biopsy suspected histiocytosis X. Right thyroid lobectomy was performed and revealed histiocytosis X in light and electron microscopic examinations.

Biopsy, Needle↗
PubMed1994

The excursion length of posterior cruciate ligament during range of motion in prosthetic knee.

Restriction of knee motion after total knee replacement was noted to be associated with lengthening of the posterior cruciate ligament during flexion of the knee which was replaced with a cruciate retaining knee prosthesis. The purpose of this study was to measure the excursion length of the PCL in the normal knee in four different cruciate-retaining knee prostheses, and in five cadaveric knees which were replaced with the Tricon prosthesis. For every knee, the tibial part was fixed on a stand and the femoral part was allowed to do flexion-extension motion upon the tibial plateau. The angle of the motion was monitored by the self-readout goniometer. A thin wire cord was attached to the proposed origin site of the PCL on the femur. The wire cord was passed through a tiny hook which was attached to the proposed insertion site of the PCL on the tibia and connected to a dial gauge. The excursion length of the PCL during 90 degrees flexion was measured. The same measurement was repeated five times in each cadaver knee and prosthetic knee studied, and in five knee specimens which were replaced with the Tricon prosthesis. The excursion length of the PCL during 0 degrees to 90 degrees of flexion in five cadaver knees averaged 0.08cm of lengthening. Three different origin sites of the ligament were designated to represent the anterior, middle and posterior part of the ligament.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMed1994

Isolation and characterization of a toxic phospholipase A2 from the venom of the Taiwan habu (Trimeresurus mucrosquamatus).

A toxic phospholipase A2 (PLA2) was isolated from Taiwan-habu-snake (Trimeresurus mucrosquamatus) venom by sequential chromatographies on CM-52, Sephadex G-75 and S-Sepharose columns. This basic PLA2 has a single polypeptide with an estimated M(r) of 15,000. The PLA2 activity was Ca(2+)-dependent and inactivated by p-bromophenacyl bromide and its specific antibody. The toxic PLA2-induced myotoxic and direct haemolytic effects as well as respiratory distress in mice with an intraperitoneal LD50 of 1.17 micrograms/g body weight. The histological examination showed it caused haemorrhage and congestion in the viscera of mice. It was also cytotoxic to myeloma cells (NS-1), baby-hamster-kidney (BHK) cells and human umbilical endothelial cells. By neutralization experiments with a specific antibody against toxic PLA2, it was found that the enzymic activity of toxic PLA2 is essential for its myotoxicity, but it is not the only factor responsible for the lethal toxicity.

Acetophenones↗
PubMed1993

Eradication of Helicobacter pylori infection and the recurrence of duodenal ulcers.

The purpose of this study was to compare the performance of different regimens on Helicobacter pylori (H. pylori) eradication and duodenal ulcer recurrence. During a four-week period, 59 patients with duodenal ulcers who were positive for H. pylori infection were randomly treated with one of three regimens. Seventeen patients were treated with ranitidine, 19 with colloidal bismuth subcitrate (CBS), and 23 with triple therapy (CBS, tetracycline and metronidazole). Forty-six patients with healed ulcers after treatment received follow-up for six months without maintenance therapy. The recurrence rates of duodenal ulcers confirmed by endoscopy in these three groups were 64%, 33% and 0% at the third month, and 73%, 67% and 5% at the sixth month, respectively. In the ranitidine therapy group, H. pylori infection was still present at the final follow-up. In the CBS therapy group, H. pylori was suppressed initially, but recurred in all cases. In the triple therapy group, there was only one case in which H. pylori infection persisted and where ulcer recurrence occurred after 3.5 months. The remaining cases were all H. pylori negative and had no recurrence of duodenal ulcers during the six months of follow-up. Overall, 19/27 (70%) patients positive for H. pylori had a recurrence of duodenal ulcers, while none of the 19 patients who were negative for H. pylori had a recurrence of ulcers at the sixth month. This study shows that triple therapy is more effective than the other two regimens in the eradication of H. pylori and in reducing the recurrence of ulcers. H. pylori may play a role in the recurrence of the duodenal ulcer.

Adolescent↗
PubMed1993

Factors affecting knee motion after total knee arthroplasty: a cadaveric study of the collateral ligament.

Many of the factors affecting postoperative knee motion are related to collateral ligament imbalance. In a cadaveric knee model, the center of origin of either the medial or lateral collateral ligament was found to be located at the center of the quarter circle of the posterior femoral condyle. Two distances were identified: OD (from the center of origin of the collateral ligament to the distal tibiofemoral articulation) and OP (from the center of origin of the collateral ligament to the posterior tibiofemoral articulation). The effect of the collateral ligaments on knee motion was demonstrated by stimulating joint line elevation and ligamentous stretching in a cadaveric knee model. In the knee with an elevated joint line without concomitant anterior displacement (OD reduced, OP unchanged), the flexion limit was reduced. When the collateral ligaments were stretched in a knee with constant OD and OP, both the flexion and extension limits were reduced. A correct joint level can be achieved by measuring the OD, OP and the tension of the collateral ligaments during total knee arthroplasty.

Arthroplasty↗
PubMed1993

[Value of fine needle aspiration cytology in the diagnosis and management of fibroadenoma of the breast].

Cytological and histopathological biopsies were obtained from 121 breast lumps clinically diagnosed as fibroadenomas. Of these 98.3 percent of the lesions were benign. The cytological diagnosis was benign in 95.1 percent of 101 (83.4% of total) cases confirmed as fibroadenomas, histopathologically, but inadequate for diagnosis in 4.9 percent. The remaining 20 lesions included one breast cancer and one primary malignant lymphoma. In this group aspiration cytology was inadequate for diagnosis in 20 percent of the cases (P < 0.05). The cytological reports cast suspicion in the two malignant cases. No lesion with benign cytology was subsequently shown to be malignant. Ninety-five (78.5%) cases of the lesions, representing 72 women under 35 years of age, which has been clinically diagnosed as fibroadenomas, showed fibroadenoma, histopathologically, in 89.5% of these cases. The other 26 (21.5%) lesions in 21 patients, who were over 35 years in age, had 61.5 percent fibroadenomas, cytological results cast suspicion of fibroadenoma in 87.1 percent of these cases. The other 16 histopathologically diagnosed fibroadenomas in patients over 35 years of age showed 62.5% were cytologically suspected of being fibroadenomas (P < 0.025). As a result of this study it is reasonable to suggest that a typical clinical fibroadenoma can be treated conservatively in women under 35 years, but only if an adequate cytological smear obtained by fine needle aspiration does not show malignant of suspicious cells.

Adenofibroma↗
PubMed1992

The primary structures of growth hormones of three cyprinid species: bighead carp, silver carp, and grass carp.

The primary structures of growth hormone (GH) of three cyprinid species, bighead carp, silver carp, and grass carp, were determined by a chemical method and/or by molecular cloning. The bighead carp GH was extracted from pituitary tissue by use of an alkaline medium, then successively purified by gel filtration, hydrophobic interaction column chromatography, and reverse-phase high-pressure liquid chromatography. The primary structure of bighead carp GH determined chemically is identical to that deduced from the cDNA nucleotide sequence. By molecular cloning, the primary structures of silver carp and grass carp GHs were also determined. The GHs of these three cyprinid species all contain 188 amino acid residues and their sequences are identical. When four of the five cysteines of cyprinid GHs were arranged to match the same positions of cysteines of other vertebrate GHs, a maximally matched alignment was achieved. Among fishes, GHs are relatively conserved within the same order (82 to 100% identity) but they are more diversified between orders (49 to 68% identity). In further comparison, fish GHs are even more different from tetrapod GHs (37 to 58% identity). Although the primary structures of vertebrate GHs are relatively variable, four homologous sequences, notably one located at the C-terminal, are found.

Amino Acid Sequence↗
PubMed1992

Primary structure of an inactive mutant of phospholipase A2 in the venom of Bungarus fasciatus (banded krait).

From the acidic components of Bungarus fasciatus venom, a very small amount (0.16%) of a novel phospholipase A2 was obtained. Both neurotoxicity and enzyme activity were found to be lacking. Amino acid sequence study showed that it has a normal backbone of group I snake venom phospholipase A2 with 118 amino acid residues. The lack of enzyme activity was attributed to its mutation of the indispensable Asp residue to an Ala residue, i.e., the usual His-Asp47 turned out to be His-Ala47. This is the eighth isoform of phospholipase A2 found from the venom of Bungarus fasciatus. Examination of structural homology with three other isoforms revealed 66% similarity at most.

Amino Acid Sequence↗
PubMed1992

Life expectancy in keratoconus.

It is observed that few patients over the age of 60 regularly attend the keratoconus clinic at Moorfields Eye Hospital. The hypothesis that patients with keratoconus have a shorter life expectancy owing to underlying connective tissue related disease was tested. From patient records a sample of 337 keratoconus patients aged at least 40 years by 1991 were identified, of which 279 were living, 13 were deceased, and 45 were untraceable. The mortality rate for keratoconus patients was compared with that of the general population using actuarial English life tables. Results show no significant difference between the general population mortality rate and that of the keratoconus sample even with adjustment for social class. Possible explanations for the non-attendance of older patients are discussed.

Adult↗
PubMed1992

[Flow cytometric analysis of DNA in esophageal cancer].

Malignancy is the first of the ten leading causes of death in Taiwan area, however, since 1978, esophageal cancer is on the first ten causes of malignancy. Esophageal cancer is an aggressive neoplasm with a generally poor prognosis. This is usually related to the advanced stages of the neoplasm at presentation and at diagnosis. In this study, the DNA content in tumor was analyzed by flow cytometry, and compared it with clinical- pathological data, especially the survival time. All thirty seven cases (36 male, 1 female, mean age: 56.5 +/- 10.3 y/o) received operation at Kaohsiung Medical College Hospital in the past 11 years and 29 cases (27 male, 2 female, mean age: 62.2 +/- 9.6 y/o) proved to be esophageal cancer by endoscopic biopsy were assayed in this study. The formalin fixed-paraffin embedded block is used to analyze DNA content by flow cytometry. After comparing these results with clinical-pathological data, there were no significant difference in sex, age, duration, tumor location and length. However, there is a significant correlation between ploidy and tumor cell differentiation, that is, most of the diploid cells were well differentiated while most of the aneuploid cells were poorly differentiated. The median survival time of diploid cases was 325 days which was longer than the 277 days in aneuploid group, but there was no significant difference between these two groups. The same result was noticed in DNA index. Multiple variables analysis of prognostic factors disclosed that there were significant difference in correation with age tumor location tumor length, and whether there was combined radiotherapy and operation. But there were no significant relationship between survival and DNA ploidy DNA index distant metastasis surrounding tissue invasion sex duration and tumor cell differentiation. These data suggest that DNA folw cytometry analysis alone, may not provide a sueful biologic basis for the variable prognosis seen with esophageal tumors.

Aged↗