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Biomedical subjects

C H Lai

Publications and source records attributed to C H Lai.

At least 55 records · Page 3Linked to original sources
PubMed2001

Lens subluxation: 10-years' experience at Chang Gung Memorial Hospital, Kaohsiung.

BACKGROUND: This study aimed to describe the clinical manifestations and surgical outcomes of subluxated lens. METHODS: Reviewing charts from January 1991 to June 2000, we studied 110 patients (123 eyes) who had lens subluxation at Chang Gung Memorial Hospital, Kaohsiung. For 21 eyes, patients accepted conservative treatment, and 102 eyes underwent surgery (8 eyes had Marfan syndrome; 18 eyes had idiopathic dislocation; and 76 eyes had experienced trauma). Indications of surgery included reduction in visual acuity, uncorrectable refractive error, and secondary glaucoma. RESULTS: There were 81 male and 29 female patients. Their mean age was 47.6 years (range, 2-76 years). The mean post-operative follow-up period was 22.24 months (range, 2-118 months). In spite of the different lens statuses, similar visual results were found between the surgical treatment group and the nonsurgery group. In the surgery group, 47 eyes (46.1%) achieved best corrected visual acuity (BCVA) of 20/40 or better. A total of 80 eyes (78.4%) achieved an improvement (log MAR change >0.3) in BCVA. The major postoperative complications included glaucoma (11 eyes), retinal detachment (9 eyes) and intraocular lens dislocation into the vitreous cavity (3 eyes). CONCLUSIONS: Results indicate that the presence of a subluxated lens alone is not an absolute indication for surgical removal. The lens status had no significant influence on surgical outcome. Most cases can achieve an improvement in BCVA after appropriate management.

Adolescent↗
PubMed2000

Competence of Aedes albopictus and Culex quinquefasciatus as vector of Dirofilaria immitis after blood meal with different microfilarial density.

Aedes albopictus and Culex quinquefasciatus were fed canine blood with different microfilarial density of Dirofilaria immitis ranging from 2500 to 25,000 mff/ml. Larval development in these two mosquito species did not differ significantly. Although C. quinquefasciatus ingested more microfilariae, the number of larvae which developed in A. albopictus was invariably greater than in C. quinquefasciatus. Mortality of the engorged A. albopictus was significantly greater than that of C. quinquefasciatus, and higher microfilarial density raised the mortality in both species. The vector efficiency index of A. albopictus was greater than C. quinquefasciatus at all microfilarial densities, but its survival time was much reduced. Thus, dogs with low microfilarial density are implicated as the main source for the transmission of D. immitis from dogs to mosquitoes.

Aedes↗
PubMed2000

Heterobimetallics of nickel-iron dinitrosyl: electronic control by chelate and diatomic ligands.

Reaction of [PPN][Fe(NO)2(SePh)2] (1) with dimeric [Ni(mu-SCH2CH2SCH2CH2S)]2 in the presence of additional NO2- produced the neutral heterobimetallic [(ON)Ni[(mu-SCH2CH2)2S]Fe(NO)2] complex (2). The X-ray crystal structures of 1 and 2 show distorted tetrahedral iron dinitrosyl groups, assigned according to the Feltham-Enemark notation as [Fe(NO)2]9 The Fe-NO bonds are off linearity by an average of approximately equals 10 degrees for compounds 1 and 2, while a more linear Ni-NO coordination with a Ni-NO distance of 1.644(2) A was found in 2. The v(NO) value of complex 2 is consistent with an assignment for [Ni(NO)]9 of Ni0(NO)+ as is known for analogous phosphine derivatives, P3Ni0(NO)+. EPR signals of g values = 2.02-2.03 confirmed the existence of the odd electron in the chalcogenated [Fe(NO)2]9 compounds. Two [Fe(NO)2]10 complexes coordinated by the nickel(II) dithiolate, (bismercaptoethanediazacyclooctane)nickel(II), (Ni-1), (Ni-1)Fe(CO)(NO)2 and (Ni-1)Fe(NO)2, were prepared for comparison to the Ni0(NO)+ derivative and other monomeric and homodimetallic derivatives of the Fe(NO)2 fragment. While the oxidation level of Fe(NO)2 is the primary determinant of v(NO) values, they are also highly sensitive to ancillary ligands and, thereby, the distal metal influence through the bridging thiolate donor.

Binding Sites↗
PubMed2000

Adsorption/desorption properties of copper ions on the surface of iron-coated sand using BET and EDAX analyses.

This study was conducted to develop a heating process for coating hydrated iron oxide on the sand surface to utilise the adsorbent properties of the coating and the filtration properties of the sand. BET and scanning electron microscope (SEM) analyses were used to investigate the surface properties of the coated layer. An energy dispersive X-ray (EDAX) technique of analysis was used for characterising metal adsorption sites on the iron-coated sand surface. The results indicated that the iron-coated sand had more micropores and higher specific surface area because of the attachment of iron oxide. Copper ions could penetrate into the micropores and mesopores of iron oxide on sand surface, and the regeneration of the iron-coated sand could be achieved by soaking with pH = 3.0 acid solution. Besides, the results of EDAX analysis showed that copper ions were chemisorbed on the surface of iron-coated sand. Results of the study developed an innovative technology for coating iron oxide on sand surface for the treatment of heavy metal in water.

Adsorption↗
PubMed2000

Successful treatment of recurrent pelvic desmoid tumour with tamoxifen: case report.

The case report of a young woman with recurrent pelvic desmoid tumour successfully treated with tamoxifen is described. The desmoid tumour recurred within 6 months after the initial exploratory laparotomy. Tamoxifen therapy led to complete relief of ascites within 2 months and complete tumour regression by the end of the fourth month, and the patient has remained stable for 6 years. Without sacrificing pelvic organs or major vessels and preserving reproductive ability, tamoxifen should be considered as the first drug of choice in such a recurrent condition.

Adult↗
PubMed2000

Identification of novel human genes evolutionarily conserved in Caenorhabditis elegans by comparative proteomics.

Modern biomedical research greatly benefits from large-scale genome-sequencing projects ranging from studies of viruses, bacteria, and yeast to multicellular organisms, like Caenorhabditis elegans. Comparative genomic studies offer a vast array of prospects for identification and functional annotation of human ortholog genes. We presented a novel comparative proteomic approach for assembling human gene contigs and assisting gene discovery. The C. elegans proteome was used as an alignment template to assist in novel human gene identification from human EST nucleotide databases. Among the available 18,452 C. elegans protein sequences, our results indicate that at least 83% (15,344 sequences) of C. elegans proteome has human homologous genes, with 7,954 records of C. elegans proteins matching known human gene transcripts. Only 11% or less of C. elegans proteome contains nematode-specific genes. We found that the remaining 7,390 sequences might lead to discoveries of novel human genes, and over 150 putative full-length human gene transcripts were assembled upon further database analyses. [The sequence data described in this paper have been submitted to the

Amino Acid Sequence↗
PubMed2000

Ginseng flowers stimulate progesterone production from bovine luteal cells.

Our previous report first showed evidence that polysaccharides isolated from ginseng leaves obtained from Jilin, China possess luteotropic activities. In this study, we made further investigations on the root and flowers of Korean ginseng by means of the same bioassay system described briefly as follows. Frozen-thawed bovine luteal cells (1 x 10(5) cells/ml/well) in M199 were incubated in 24-well culture plates at 37 degrees C in a 5 % CO2 incubator. Ten microl of tested drugs with 1, 10 and 100 microg/ml were added into each well. After 4- and 24-hr incubation, the media were harvested and assayed for progesterone by an enzyme immunoassay. The production of progesterone from cells is the indicator for evaluating the action of tested drugs. Results showed that hot water extracts ofginseng flowers (GF-1) with 10 to 100 microg/ml significantly increased progesterone production, whereas those from ginseng root (GR-1) could not. Crude polysaccharides (GF-2) isolated from GF-1 is the active component and the small molecules (mw < 10,000 dalton) are excluded, indicating that the ginseng root has no luteotropic activities, but the polysaccharides of ginseng flowers have.

Animals↗
PubMed2000

Randomized trial of neoadjuvant cisplatin, vincristine, bleomycin, and radical hysterectomy versus radiation therapy for bulky stage IB and IIA cervical cancer.

PURPOSE: To compare the efficacy of neoadjuvant chemotherapy (NAC) followed by radical hysterectomy with that of radiotherapy (R/T) for bulky early-stage cervical cancer. PATIENTS AND METHODS: Women with previously untreated bulky (primary tumor >/= 4 cm) stage IB or IIA non-small-cell carcinoma of the uterine cervix were randomly assigned to receive either cisplatin 50 mg/m(2) and vincristine 1 mg/m(2) for 1 day and bleomycin 25 mg/m(2) for 3 days for three cycles followed by radical hysterectomy (NAC arm) or receive primary pelvic radiotherapy only (R/T arm). The ratio of patient allocation was 6:4 for the NAC and R/T arms. Women with enlarged para-aortic lymph nodes on image study were ineligible unless results of cytologic or histologic studies were negative. RESULTS: Of the 124 eligible patients, 68 in the NAC arm and 52 in the R/T arm could be evaluated. The median duration of follow-up was 39 months. Thirty-one percent of patients in the NAC arm and 27% in the R/T arm had relapse or persistent diseases after treatment, and 21% in each group died of disease. Estimated cumulative survival rates at 2 years were 81% for the NAC arm and 84% for the R/T arm; the 5-year rates were 70% and 61%, respectively. There were no significant differences in disease-free survival and overall survival. CONCLUSION: NAC followed by radical hysterectomy and primary R/T showed similar efficacy for bulky stage IB or IIA cervical cancer. Further study to identify patient subgroups better suited for either treatment modality and to evaluate the concurrent use of cisplatin and radiation without routine hysterectomy is necessary.

Adult↗
PubMed2000

High-risk HPV DNA detection by Hybrid Capture II. An adjunctive test for mildly abnormal cytologic smears in women > or = 50 years of age.

OBJECTIVE: To determine whether high-risk human papillomavirus (HPV) DNA testing could improve the detection of cervical intraepithelial neoplasia (CIN) and cancer in older women (> or = 50 years old) with mildly abnormal results on conventional cytology. STUDY DESIGN: The study was based on 119 patients aged over 50 (median, 62; range, 50-78) referred for colposcopy with Pap smears reported as atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesion (LSIL) from February 1997 to September 1998. The presence of high-risk HPV DNA (including HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68) was determined with the Hybrid Capture II (Digene, Inc., Silver Spring, Maryland) microplate method. Cytologic examination by Pap smear was based on the Bethesda System and, cervical biopsy was done via colposcopy. RESULTS: High-risk HPV DNA was demonstrated in 75.6% (34/45) of patients with LSIL and 52.7% (39/74) with ASCUS. Those who were HPV positive were significantly more likely to have CIN or cancer (odds ratio, 33.40; 95% confidence interval, 11.89-93.97; P < .0001). The sensitivity of HPV assay for detection of lesions more severe than CIN 2 was 100%, specificity 64.8%, positive predictive value 66.7% and negative predictive value 100%. CONCLUSION: The addition of a high-risk HPV DNA assay to cytologic examination appears to provide excellent sensitivity and negative predictive value for early detection of high grade CIN or cancer in older women with minimally abnormal Pap smears.

Age Factors↗
PubMed2000

Comparison of clinical behaviors and responses to radiation between squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas of the cervix.

BACKGROUND: Adenocarcinomas/adenosquamous carcinomas (AC/ASC) are relatively uncommon histological subtypes in cervical cancer. In this study, we retrospectively compared the clinical behaviors and responses to radiation of squamous cell carcinomas (SCC) and AC/ASC in patients with stage I-IVA cervical cancer primarily treated by radiotherapy (RT). METHODS: Nine hundred twenty-eight patients with cervical cancer primarily treated with RT were included in this study. Ninety-four percent of the patients had SCC and 6% had AC/ASC. The association of histological subtype to various clinical parameters was assessed. Tumor response and failure patterns were analyzed, and the prognostic significance of histological subtype and other clinical parameters were evaluated by univariate and multivariate analyses. RESULTS: (1) Patients with AC/ASC had a significantly higher percentage of bulky I-IIA disease, a younger age (< 45 years), and an elevated carcinoembryonic antigen (CEA) level, but a lower percentage of elevated squamous cell carcinoma antigen (SCC-Ag) level, than patients with SCC. Hemoglobin (Hb) levels and lymph node status were not significantly different between SCC and AC/ASC patients. (2) A higher percentage of AS/ASC patients had residual induration 2 to 3 months after RT than those with SCC (40% vs. 21.6%, p = 0.008). Higher local failure rates were found for AC/ASC patients compared to SCC patients (38% vs. 15%, p = 0.001). (3) The 5-year disease-specific survival rate was 66% and 50% for SCC and AC/ASC patients, respectively (p = 0.016). Advanced stages, Hb levels lower than 10 g/dl, positive lymph nodes, AC/ASC histological subtype, and SCC-Ag levels higher than 10 ng/ml were independent prognostic factors for worse survival for all patients. For patients with AC/ASC in particular, only stage and positive lymph nodes were significant prognostic factors. CONCLUSION: Cervical cancer patients with AC/ASC are relatively younger and have a higher incidence of elevated CEA and a lower incidence of elevated SCC-Ag levels than those with SCC. For AC/ASC patients, the tumor responses to RT were relatively slow and poor. This group of patients had a worse survival rate than patients with SCC, mainly because of the higher incidence of uncontrolled local disease for AC/ASC patients.

Adenocarcinoma↗
PubMed2000

Comparison of microbial composition in the subgingival plaque of adult crowded versus non-crowded dental regions.

It has been reported in the literature that certain species of bacteria (periodontopathogens) present in the subgingival plaque are associated with destructive periodontal disease. The purpose of this study was to investigate and compare the presence and proportional distribution of periodontopathogens in the subgingival plaque of adult crowded versus non-crowded dental regions. Thirty adult patients with anterior dental crowding were selected from the Orthodontic Clinic of the University of Pennsylvania. After orthodontic records were taken and the periodontal examination was performed, subgingival plaque samples were collected from crowded (experimental) and contralateral non-crowded regions (control) of each patient. The presence of 9 periodontopathic species, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Eikenella corrodens, Campylobacter rectus, Capnocytophaga species, Fusobacterium species, Peptostreptococcus micros, Porphyromonas gingivalis, and Bacteroides forsythus, was determined using culture and immunofluorescence techniques. The bacterial morphotype was also determined by the use of dark-field microscopy. It was found that supragingival plaque accumulation in crowded regions was significantly greater than in non-crowded regions. Analysis of the bacteria showed that the samples from crowded regions consistently contained more species of periodontopathogens than the samples from non-crowded regions. Morphologically, more spirochetes and motile rods were present in the crowded-region samples. In terms of the presence of individual periodontopathogens, Fusobacterium species, Capnocytophaga species, C rectus, and P micros were significantly more common in the crowded samples than in the non-crowded samples. It was concluded that: (1) more plaque accumulated in crowded areas; (2) more species of periodontopathogens were present in the subgingival plaque of crowded regions; (3) morphologically, more spirochetes and motile rods were present in crowded areas; and (4) Fusobacterium species, Capnocytophaga species, C rectus, and P micros were present more often in crowded areas than in non-crowded areas (P < 0.05).

Adolescent↗
PubMed1999

Identification and gene structure of a novel human PLZF-related transcription factor gene, TZFP.

A novel cDNA clone was identified through yeast two-hybrid experiments. Following cross-examination between the cDNA clones, EST clones, and the cosmid clone, we could digitally assemble a new zinc finger transcription factor gene. This predicted gene has a cDNA size of about 1960 bp and is translated into a 487-amino-acid protein. According to database analysis, this gene contains three C2H2 zinc finger motifs and is highly related to human PLZF (promyelocytic leukemia zinc finger protein). The full-length coding region of the gene was isolated, and its sequences were confirmed by DNA sequencing. Interestingly, one splicing variant lacking exon III was also identified. Northern blot analysis revealed that this gene is mainly expressed in human testis. In conclusion, we have identified a new member of the PLZF zinc finger protein family, the testis zinc finger protein (TZFP), which is mainly expressed in testis tissue.

Amino Acid Sequence↗
PubMed1999

Preoperative prognostic variables and the impact of postoperative adjuvant therapy on the outcomes of Stage IB or II cervical carcinoma patients with or without pelvic lymph node metastases: an analysis of 891 cases.

BACKGROUND: The purpose of this study was to investigate pretreatment variables that could predict prognosis and to evaluate the impact of postoperative adjuvant therapy on the outcomes of patients with Stage IB or II cervical carcinoma with or without pelvic lymph node metastases. METHODS: Eight hundred ninety-one patients with Stage IB or II cervical carcinoma who underwent radical hysterectomy and bilateral pelvic lymphadenectomy as primary treatment at a single institution were analyzed. Potential prognostic variables were studied. RESULTS: Among the variables that could be assessed before treatment, depth of cervical stromal invasion (determined by magnetic resonance imaging), clinical stage, tumor size, grade of differentiation, and DNA index (determined by flow cytometry) were independent predictors of outcome in multivariate analysis using a Cox regression model. Three distinct prognostic groups (low, intermediate, and high risk) were defined using these variables. Five-year recurrence free survival (RFS) rates for the low, intermediate, and high risk groups were 94.6%, 82.7%, and 62.3%, respectively (P = 0.0001), and overall survival (OS) rates were 98.4%, 84.5%, and 68.7%, respectively (P = 0.0001). Among patients with pelvic lymph node metastases who were free of parametrial extension, those who received postoperative chemotherapy or chemoradiotherapy had significantly better RFS (P = 0.017) and OS (P = 0.043) than those who received no adjuvant therapy. Among patients without pelvic lymph node metastases but at high risk of recurrence, those who received adjuvant radiotherapy had significantly better RFS (P = 0.015) and marginally improved OS (P = 0.087) compared with those who received no adjuvant therapy. CONCLUSIONS: A model containing assessable pretreatment variables for predicting the prognoses of patients with early stage cervical carcinoma was formulated. Subsets of patients for whom postoperative chemotherapy or radiotherapy might be beneficial were identified. The data from this retrospective review may be useful when future prospective trials of the treatment of early stage cervical carcinoma are designed.

Adult↗
PubMed1999

A study of diagnostic failure of loop conization in microinvasive carcinoma of the cervix.

OBJECTIVE: The aim of this study was to evaluate the specimen adequacy and the histological interpretation of loop conization for microinvasive cervical carcinoma. METHODS: We retrospectively reviewed the histopathological findings of the original cone specimens together with the final hysterectomy specimens in patients with microinvasive carcinoma of the cervix. From 1990 to 1995, 63 consecutive patients with microinvasive carcinoma of the cervix were included in the study, of which 35 patients underwent loop conization and 28 underwent cold-knife conization. All patients had a hysterectomy. RESULTS: The mean width, depth, and cone volume of the conization specimens were 2.44 cm, 2.15 cm, and 3.96 cm3, respectively, in the loop group versus 2.3 cm, 2.35 cm, and 4.38 cm3 in the cold-knife group. No significant differences were seen between the two groups. The application of loop conization was completed in a single slice in 27 patients (77.1%) and multiple slices by the loop in 8 (22.9%), in spite of the attempt to perform conization in a one-pass application when possible. In assessing these cone specimens microscopically, the rate of transection of tissue was significantly higher in the loop cone than in the cold-knife cone (17.1% versus 0%, P = 0.02). Because of transection of tissue and misorientation, pathologic determination of the depth and width of stromal invasion was undetermined in two loop cone specimens compared with none in the cold-knife cones. CONCLUSION: Our study suggests that cold-knife conization is a preferred method in assessing microinvasive carcinoma of the cervix if multiple applications of loop conization are inevitable.

Adult↗
PubMed1999

The prognostic factors for patients with early cervical cancer treated by radical hysterectomy and postoperative radiotherapy.

PURPOSE: This study was undertaken to evaluate the efficacy of postoperative radiotherapy (post-OP RT) and to investigate the prognostic factors for early-stage cervical cancer patients who were treated by radical surgery, and the pathological findings suggested a relatively high risk of relapse with surgery alone. MATERIALS AND METHODS: From January 1990 to December 1995, 222 patients with stage IB-IIA cervical cancer, treated by radical surgery and a full course of post-OP RT, were included in this study. The indications for post-OP RT were based on pathological findings, including lymph node metastasis, positive surgical margins, parametrial extension, lymphovascular permeation, and invasion of more than two-thirds of the cervical wall thickness. The radiation dose of external beam was 44-45 Gy to the whole pelvis and 50-54 Gy to the true pelvis. One hundred seventy-two patients also received intravaginal brachytherapy as a local boost. The minimal follow-up period was 2 years. RESULTS: The actuarial 5-year overall and disease-specific survival rates for all patients were 76 and 82%, respectively. The tumor control rate within the pelvis reached 94%, and distant metastasis was the major cause of treatment failure. Univariate analysis of clinical and pathological parameters revealed that clinical stage, bulky tumor size, positive lymph nodes, parametrial extension, and histologic type were significant prognostic factors. After multivariate analysis, only positive lymph nodes (P = 0.01), bulky tumor size (P = 0.02), and parametrial extension (P = 0.05) independently influenced the disease-specific survival (DSS). For patients with lymph node metastasis, the number and location of the nodal involvement significantly affected the prognosis. The 5-year DSS for patients with no, one, and more than one lymph node metastasis were 87, 84, and 61% (P = 0.0001), respectively. Patients with upper pelvic lymph node metastasis had a higher incidence of distant metastasis (50% vs 16% in lower pelvic node group, P = 0.03). In the subgroup of single lower pelvic nodal metastasis, the prognosis was similar to that of patients without lymph node involvement (5-year DSS 85% vs 87%, P = 0.71). CONCLUSION: Our results indicate that post-OP RT can achieve very good local control in stage IB-IIA cervical cancer patients whose pathological findings show risk features for relapse after radical surgery. The prognostic factors for treatment failure identified in this study can be used as selection criteria for clinical trials to test the effects of other adjuvant treatments, such as chemotherapy. Patients with a single lower pelvic lymph node metastasis have a relatively good prognosis and may not need adjuvant treatment beyond radiation therapy.

Adult↗
PubMed1999

Recurrent cervical carcinoma after primary radical surgery.

OBJECTIVE: This study was undertaken to investigate prognostic factors in patients with recurrent cervical carcinoma who had undergone a primary radical hysterectomy and pelvic lymphadenectomy. STUDY DESIGN: A retrospective analysis of 177 patients with recurrent cervical carcinoma after radical hysterectomy and pelvic lymphadenectomy for stage IB to II disease at a single institution was performed to evaluate clinicopathologic parameters, time to recurrence, pattern of failure, use of salvage therapy, and survival after recurrence. RESULTS: The 5-year survival rate from diagnosis of recurrence in this series was 10.1%. Survival after recurrence was significantly decreased in patients with pelvic lymph node metastasis at primary surgery and adenocarcinoma-adenosquamous carcinoma histologic type. Patients with extravaginal recurrences receiving chemoradiation for recurrent cervical carcinoma had significantly better outcomes than those receiving radiation alone. Six patients who had a distant relapse at a sole site had prolonged survival after salvage therapy, which was accomplished by chemoradiation, surgery plus radiotherapy, or surgery alone. CONCLUSIONS: Our results demonstrate the benefit of adding chemotherapy to radiotherapy in the treatment of recurrent cervical carcinoma. Salvage multimodality treatment should be offered to selected patients who have isolated relapse at a single distant site.

Adenocarcinoma↗