Biomedical subjects

R S Lai

Publications and source records attributed to R S Lai.

25 records · Page 2Linked to original sources

PubMed1996

CYFRA 21-1 enzyme-linked immunosorbent assay. Evaluation as a tumor marker in non-small cell lung cancer.

BACKGROUND: The CYFRA 21-1, a newly developed sandwich enzyme-linked immunosorbent assay (ELISA), was used to measure soluble cytokeratin 19 fragment in serum that is expressed in simple epithelium and its malignant counterpart. The present study was designed to investigate whether CYFRA 21-1 is a sensitive and specific tumor marker for non-small cell lung cancer. METHODS: CYFRA 21-1 assay, using two specific monoclonal antibodies (KS 19.1 and BM 19.21) for cytokeratin 19, was measured in 312 serum samples, including 164 lung cancer, 118 benign pulmonary disease, and 30 healthy individuals. The sensitivity of CYFRA 21-1 was also compared with two other markers, carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC), in 164 patients with lung cancer. RESULTS: The median value of healthy individuals was 1.3 ng/mL (95th percentile 1.8). In patients with benign pulmonary diseases, the median was 1.5 ng/mL (95th percentile 2.9). There is no significant difference between sexes, smoking habit, and the subgroups of benign pulmonary disease, such as tuberculosis, pneumonia, or COPD. Using the cutoff value of 3.3 ng/mL, defined at 95% specificity for benign lung disease, the sensitivities of CYFRA 21-1 for squamous cell carcinoma (n=74), adenocarcinoma (n=54), undifferentiated large cell carcinoma (n=11), and small cell lung cancer (n=25) were 62%, 39%, 36%, and 20%, respectively. Despite the cell types, the sensitivities of CYFRA 21-1 in non-small cell lung cancer (NSCLC, n=169) were 51% (CEA 42%, SCC 20%). The sensitivity of CEA was significantly higher in patients with adenocarcinoma (58%) than other markers; while in patients with squamous cell carcinoma, CYFRA 21-1 assay has the highest sensitivity. The median level of CYFRA 21-1 in squamous cell carcinoma is significantly higher than that of other cell types (Mann-Whitney test, p<0.001). The serum level and sensitivity of CYFRA 21-1 were well correlated with staging and tumor size in squamous cell carcinoma. The CYFRA 21-1 values were measured for monitoring progression of disease in 20 patients with squamous cell carcinoma. There is significant difference in paired observation of CYFRA 21-1 level in patients with progressive disease (Wilcoxon signed-rank test, p<0.05), but no difference was observed in patients with stabilized disease (p>0.1). CONCLUSION: For patients with NSCLC, especially in squamous cell carcinoma, CYFRA 21-1 is not only a sensitive and specific tumor marker, but also may be a useful adjunctive marker for disease monitoring.

Adenocarcinoma↗

PubMed1994

Evaluation of urinary pseudouridine as a tumor marker in lung cancer.

The urinary concentration of pseudouridine, primarily a breakdown product of tRNA, was determined by high-performance liquid chromatography in 33 patients with small cell lung cancer (SCLC), 18 patients with non-small cell lung cancer (NSCLC), 18 patients with benign pulmonary diseases (eg, TB, COPD), and 16 healthy controls. The mean urinary pseudouridine concentration levels of the patients with SCLC, NSCLC, benign pulmonary disease and the healthy controls were 22.7 +/- 11.8, 15.6 +/- 6.0, 13.4 +/- 3.6, 12.1 +/- 3.2 nmol/mumol creatinine (mean +/- SD), respectively. The mean urinary pseudouridine concentration was significantly higher in patients with SCLC than that in patients with NSCLC, benign pulmonary disease and in the healthy controls. There was no significant difference in the urinary pseudouridine levels of patients with NSCLC and healthy controls or patients with benign pulmonary disease. Urinary pseudouridine levels above 18.5 nmol/mumol creatinine (mean value +/- 2SD for healthy controls) were noted in 54.5% of patients with SCLC, including 11 of 17 (64.7%) in extensive stage and seven of 16 (43.8%) in limited stage, and 27.8% of the patients with NSCLC. Of the 12 patients with SCLC who had follow-up urinary samples taken in series during chemotherapy courses, there was considerable urinary pseudouridine level change which paralleled the change in clinical response. Although urinary pseudouridine is not a specific marker for SCLC, it represents the tumor burden and reflects the clinical status. These findings indicate that urinary pseudouridine may be a useful tumor marker in patients with SCLC.

Aged↗

PubMed1993

[Evaluation of the mechanism of decreased tensile strength of fetal membrane in premature rupture of membrane].

Pathological morphology, thickness, tensile strength, coefficient variation of elasticity and immunohistochemical characteristics of fetal membrane in 246 cases of premature rupture of membrane (PROM) and 30 cases of control were investigated. The results showed that fetal membrane of PROM group appeared to be thinner, mainly composing of chorionic membrane lacking of mature development of fibroid component. The thickness of fetal membrane at the rupture site (54 +/- 11 microns) in PROM group was significantly thinner than that (208 +/- 94 microns) in control. The difference of tensile and elasticity strength of fetal membrane between 2 groups was highly significant. According to the findings of some immunohistochemical indices such as collagen type IV, FN, vimentin, MNF116, hCG and desmin, different component including collagenic fibers, basal membrane, fibroblastic cells, myofibroblastic cells and trophoblastic cells in fetal membrane and villus of PROM group revealed either dysplasia or aging. The mechanism of changes in biophysical characteristics of fetal membrane in PROM caused by noninfectious factors has been evaluated mainly.

Adult↗

PubMed1992

Intrathoracic schwannoma of vagus nerve.

Intrathoracic neurogenic tumors are relatively common mediastinal tumors generally located in the posterior mediastinum. The most common origin is the intercostal nerve or the sympathetic chain. These tumors rarely arise from vagus nerve in the anterior mediastinum. The English literature demonstrates a total of 29 cases, which are more often on the left than the right. Here, we present another case: a 41-year-old man with a history of chronic cough for 10 years, whose chest radiograph showed a homogenous mass in the right anterosuperior mediastinum. The chest CT scan revealed a well-defined mass, 4-cm in diameter, located at the right side of trachea. Marked compression and lateral displacement of the R't innominate vein were noted. The mass was heterogenous with partial area of relative lower density and only mild enhancement was noted after contrast medium infusion. Sternotomy with tumor resection from the right vagus nerve was done. The histological diagnosis was schwannoma.

Adult↗

PubMed1992

Primary lung cancer complicated with pneumothorax.

Eighteen lung cancer patients with a pneumothorax complication were studied. Pneumothorax appears rarely in lung cancer patients, having been found in 18 out of 5567 (0.32%) at our hospital over a period of ten years. Of the 18 patients, eight had adenocarcinoma, seven epidermoid carcinoma and three alveolar cell carcinoma. Unlike those of previous reports, our results showed pneumothorax not to be found exclusively on the same side as the lung cancer. It was contralateral in five cases. Pneumothorax was the initial manifestation of lung cancer in three cases and occurred as a complication in another 15. Of these 15 patients, 11 were described as developing pneumothorax between one and twelve months after completion of radiation therapy for lung cancer. Another two patients developed pneumothorax following cytotoxic chemotherapy. Pneumothorax occurred prior to any treatment for lung cancer in the remaining two patients. The factors contributing to pneumothorax in the lung cancer patients were the rupture of the necrotic neoplastic tissue into the pleural cavity, the rupture of a subpleural bleb or the formation of interstitial air due to partial bronchial obstruction by the tumor, complications arising from radiation therapy and cytotoxic chemotherapy, or any combination of such factors. Pneumothorax was an ominous sign for the lung cancer patients. Most (12/14) died within six months of the onset of pneumothorax.

Aged↗

PubMed1991

[Bronchopulmonary sequestration and pseudosequestration].

Bronchopulmonary sequestration is a rare congenital anomaly in which part of the pulmonary tissue is detached from the normal lung without normal connection with tracheobronchial trees and pulmonary artery. It is supplied by anomalous systemic artery. Pseudosequestration is referred as the combination of systemic arterial supply to lung with normal bronchial connection and coexistent infection. It is presumed that chronically inflamed lung may activate neovascularization from systemic circulation in this strage, we reported 15 cases of all pulmonary sequestration and 1 case of pseudosequestration. Most of the cases were young adults with the mean age of 24.6 years old. The intralobar type comprised 86.6% of all cases. In 84.6% of the cases, the aberrant artery originated from the thoracic aorta. Preoperative diagnosis was gained in 47% of cases. In 80% of all cases, the chest mainly characterized with homogeneous mass lesion or cyst(s) with air-fluid level. The distinction between sequestration and pseudosequestration is a diagnostic challenge because the radiologic findings are similar between both conditions. There are clinically significant complications, such as recurrent infections or massive bleeding during operation.

Adolescent↗

PubMed1991

[Morphology of placental lobes and clinical pathophysiology in fetal distress].

In order to make a basic study of the etiology, clinical pathophysiology and prevention and management of the fetal distress, an investigation of the placental coefficient, pathomorphology, immunochemistry, and 6 other items were carried out. The placenta lobes of 357 cases with fetal distress were need and a corresponding control was established in each case. The results indicate that the rate of infection of the placenta in fetal distress was 39.5%. The placental coefficient in comparison with the control showed a significant increase (P less than 0.05). Edema of the villi and disease of the villous vascular membrane was prominent. The cytotrophoblast, Hofbauer cell showed cellular compensation proliferation. Estradiol reception (E2R) and progesterone receptor (PgR) were positive mainly in the cyto-trophoblast. The rate of positive finding of Carcinoembryonic Antigen (CEA), AFP and Lysozyme was greater in the fetal distress group in comparison with the control (P less than 0.05). The results indicate that in pregnant women with fetal distress or with risk factors for fetal hypooxygenimia, the administration of anti-infection agents, and improvement of the villus blood circulation as well as giving of anti-amine agents may be beneficial in prevention and management of fetal distress.

Adult↗