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Biomedical subjects

C J Yu

Publications and source records attributed to C J Yu.

At least 55 records · Page 3Linked to original sources
PubMed1997

Sialomucin expression is associated with erbB-2 oncoprotein overexpression, early recurrence, and cancer death in non-small-cell lung cancer.

Mucin production, when heavily sialylated, can promote cancer cell invasion and metastasis, and modulate the immune recognition system of the host. To explore the prognostic implication of sialomucin expression in lung cancer, we studied 116 patients with non-small-cell lung cancer (NSCLC). Tumor specimens were stained immunohistochemically with monoclonal antibodies (mAbs) against mucin glycoprotein (17Q2, HMFG2, SM3), and histochemically with periodic acid-Schiff/alcian blue to differentiate neutral mucin from acid mucin, and with high-iron diamine/alcian blue to differentiate sialomucin from sulfomucin. The expression status of two established molecular prognostic factors, the p53 and erbB-2 oncoproteins, were evaluated immunohistochemically. The staining was performed on two separately archived, paraffin-embedded tumor blocks for each patient, with normal lung as a control. Correlations were subsequently made among stains and various clinicopathologic factors. All analyses were blinded, and included Kaplan-Meier survival estimates with Cox proportional hazards regression modeling. Associations were established among adenocarcinoma histotype and erbB-2 overexpression, sialomucin expression, and 17Q2 and HMFG2 immunohistochemical positivity (p < 0.05). Sialomucin expression was closely linked to erbB-2 overexpression (p = 0.01). Significant univariate predictors (p < 0.05) of recurrence and cancer death were surgical stage, p53 expression, erbB-2 overexpression, and sialomucin expression. These four factors remained as independent predictors of early recurrence (p < 0.05) after multivariate analysis. For cancer death prediction, p53 and sialomucin expression had a marginal effect. We concluded that sialomucin expression is also a poor indicator of prognosis, which is associated with erbB-2 oncoprotein overexpression, early postoperative recurrence, and cancer death in NSCLC.

Actuarial Analysis↗
PubMed1997

Serodiagnosis of tuberculosis. A study comparing three specific mycobacterial antigens.

To compare the efficacy of different mycobacterial specific antigens and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, three ELISA tests derived by Antigen 60, 38kda, and Kp90 were evaluated in 594 Chinese patients (312 patients with active pulmonary tuberculosis and 282 control subjects). Quantified levels of sensitivity and specificity were compared with those in the nontuberculous control groups. Antigen 60 IgG (sensitivity and specificity, 80.77 and 88.4%) was more antigenic and more effective in its determination than was 38kda IgG (sensitivity and specificity, 64.21 and 80.74%) and Kp90 IgA (sensitivity and specificity, 62.58 and 66.3%). The clinical significance of the difference, however, was not striking: negative predictive value of Antigen 60, 38kda, and Kp90 was 93, 86 and 83%, respectively; positive predictive value of Antigen 60, 38kda, and Kp90 was 71, 54, and 39%, respectively. Combination of different antigens could improve the sensitivity and specificity by no more than 10%, with the sacrifice of the opposite parameter by no less than 20%. The same improvement in sensitivity could be easily achieved by adjusting the cutoff values in the ELISA test by a single antigen. We conclude that the sensitivity and specificity of presently available antigens for serodiagnosis of tuberculosis still remains limited at around 80%, which makes it a poor diagnostic tool for disease confirmation. In low incidence areas, its clinical value may be useful in disease exclusion. A combination of several different antigens provides no more improved diagnostic yield than what can be provided by cutoff value adjustment in a single antigen serologic test.

Adult↗
PubMed1997

Elevated serum levels of mucin-associated antigen in patients with acute respiratory distress syndrome.

Increased serum levels of mucin-associated antigen have been previously demonstrated in patients with cystic fibrosis (CF) and interstitial pneumonia, and in lung-transplant recipients. The present study assessed the serum airway mucin levels in patients with acute respiratory distress syndrome (ARDS). An enzyme-linked immunosorbent assay (ELISA) method with a human-airway-mucin-specific monoclonal antibody (17Q2) was used to measure serum mucin levels in normal subjects, chronic smokers, patients with chronic bronchitis and other pulmonary diseases, patients with acute cardiogenic lung edema, and patients with ARDS. The serum mucin levels measured 9.9 +/- 0.8 ng/ml (mean +/- SEM, n = 59) in normal subjects, 12.7 +/- 1.6 ng/ml (n = 29) in chronic smokers, 21.8 +/- 1.9 ng/ml (n = 28) in patients with chronic bronchitis and other pulmonary diseases, 9.0 +/- 3.1 ng/ml (n = 5) in patients with acute cardiogenic lung edema. The serum mucin level was 53.8 +/- 6.6 ng/ml (n = 13) in patients with ARDS (p < 0.05, as compared with the four other groups). Serial measurements of serum mucin levels were obtained in patients with ARDS. Statistical analysis showed an inverse correlation of serial measurements of serum mucin with static respiratory-system compliance (p = 0.021), an inverse correlation of sequential serum mucin levels and log(Pa(O2)/Fl(O2)) (p = 0.016), and a positive correlation of sequential serum mucin levels and lung injury score (LIS) (p = 0.019). Gel-filtration analysis showed that mucin-associated antigens in ARDS sera were polydispersed and smaller than the antigens in normal sera. This study indicates that an increasing amount of degraded mucin occurs in patients with ARDS.

Acute Disease↗
PubMed1997

Estrogens may reduce mortality and ischemic damage caused by middle cerebral artery occlusion in the female rat.

The present study was undertaken to determine if estrogens protect female rats from the neurodegenerative effects of middle cerebral artery (MCA) occlusion. The rats were ovariectomized and 7 or 8 days later various estrogen preparations were administered before or after MCA occlusion. Pretreatment with 17beta-estradiol (17beta-E2) or a brain-targeted 17beta-E2 chemical delivery system (CDS) decreased mortality from 65% in ovariectomized rats to 22% in 17beta-E2-treated and 16% in 17beta-E2 CDS-treated rats. This marked reduction in mortality was accompanied by a reduction in the ischemic area of the brain from 25.6+/-5.7% in the ovariectomized rats to 9.8+/-4% and 9.1+/-4.2% in the 17beta-E2-implanted and the 17beta-E2 CDS-treated rats, respectively. Similarly, pretreatment with the presumed inactive estrogen, 17alpha-estradiol, reduced mortality from 36 to 0% and reduced the ischemic area by 55 to 81%. When administered 40 or 90 minutes after MCA occlusion, 17beta-E2 CDS reduced the area of ischemia by 45 to 90% or 31%, respectively. In summary, the present study provides the first evidence that estrogens exert neuroprotective effects in an animal model of ischemia and suggests that estrogens may be a useful therapy to protect neurons against the neurodegenerative effects of stroke.

Animals↗
PubMed1997

Sonographic imaging of the trachea.

We evaluated the feasibility of ultrasonography for imaging of the trachea and its effectiveness in the diagnosis and follow-up of patients with tracheal stenosis due to various diseases. Twenty normal volunteers and six adult patients with tracheal stenosis were included in the study group. Subjects were examined with ultrasonography in a supine position with the neck hyperextended or in a sitting position. At the level of the thyroid isthmus, the anterior tracheal wall thicknesses imaged by ultrasonography were 1.54 +/- 0.22 mm (mean +/- SD) and 1.22 +/- 0.18 mm for normal male and female volunteers, respectively. Ultrasonography could reveal the intrinsic tracheal wall lesions and extrinsic lesions compressing the trachea in patients with tracheal stenosis. These ultrasonographic images correlated with CT images. In conclusion, ultrasonography may be useful in imaging of the trachea.

Adolescent↗
PubMed1997

Life-threatening scrub typhus with meningoencephalitis and acute respiratory distress syndrome.

A 21-year-old man presented with fever, rash, seizure, stiff neck and rapidly progressive bilateral pulmonary infiltrates. Cerebrospinal fluid (CSF) study revealed pleocytosis with predominant polymorphonuclear cells, and hypo-glycorrhachia. Status epilepticus occurred, followed by acute respiratory distress syndrome with respiratory failure. Blood and CSF cultures for bacteria were negative, but an indirect immunofluorescence assay revealed a fourfold rise in antibody to Rickettsia tsutsugamushi in paired serum and a 1:2560 (+) IgM antibody titer. Severe scrub typhus with meningoencephalitis and extensive pneumonitis was diagnosed. The patient survived after intravenous minocycline therapy and intensive care, including aggressive seizure control, supportive mechanical ventilation and avoidance of fluid overloading. He had a nearly complete recovery. Practicing physicians in Taiwan should be aware of this reportable disease and its potentially serious complications if not promptly diagnosed and treated.

Adult↗
PubMed1997

Comparison of inflammatory cytokine concentration and physiologic parameters in septic shock.

Cytokine-related systemic intravascular inflammation may represent a common pathogenic link between initial insult and multiple organ failure in septic shock patients. We conducted a prospective study with controls in the National Taiwan University Hospital intensive care unit to compare plasma levels of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and circulating intercellular adhesion molecule 1 (cICAM-1) with clinical physiologic parameters in the outcome of patients with septic shock. Healthy volunteers (n = 37) and patients with septic shock admitted to the unit from January to December 1994 (n = 31) were enrolled. Clinical data, APACHE (Acute Physiology and Chronic Health Evaluation) III scores, multiple organ failure scores, the presence of acute respiratory distress syndrome, and outcome were evaluated. The plasma levels of TNF-alpha, IL-6, and cICAM-1 were measured using enzyme-linked immunosorbent assay. Subgroups of survivors and nonsurvivors were compared for plasma levels of these factors or days 1, 2, 3, 7, and 14 after diagnosis of septic shock. Of the patients with septic shock, 20 survived and 11 died. The initial plasma levels of IL-6 were significantly higher in nonsurvivors (p < 0.05). There was a significant inverse correlation between plasma IL-6 level and survival in the first week (r = 0.4297-0.7242, p < 0.05). APACHE III score (r = 0.4335, p = 0.015), acute respiratory distress syndrome (r = 0.5913, p < 0.001), and multiple organ failure score (r = 0.736, p < 0.001) were more strongly (negatively) correlated with survival than the concentrations of TNF-alpha and cICAM-1 by Spearman's rank sum test. Our results showed that in patients with septic shock, of the inflammatory cytokines, only IL-6 showed significantly higher plasma levels in the nonsurvivor group. Inflammatory cytokine levels were not more strongly correlated with the outcome of patients with septic shock than physiologic parameters.

Adult↗
PubMed1996

Overexpression of MUC5 genes is associated with early post-operative metastasis in non-small-cell lung cancer.

Mucin glycoprotein can promote tumor-cell invasion metastasis and modulate the immune recognition of cancer. This study aimed to elucidate the clinical significance of mucin gene overexpression in lung cancer. We collected 60 lung cancer samples and paired non-tumorous lung portions of varying types and stages. Slot-blot analysis with specific anti-sense oligonucleotide probes derived from tandem repeat sequence of MUC1, -2, -3, -4, 5B and 5AC were utilized to compare the amount of mucin gene mRNA in tumor samples with that of the non-tumorous counterparts. A ratio higher than 1.5 for each specific mucin mRNA amount was considered to indicate mucin gene overexpression in tumors. Immunohistochemical staining of monoclonal antibodies against mature airway mucin (17Q2) and MUC1 mucin protein (HMFG2) were also used to analyze mucin protein. The study showed that overexpression of mucin genes frequently occurred in lung cancer (25 out of 60, 41.7%), but that there was no preferential expression of a particular mucin gene or a combination of mucin genes in these tumors. The overexpression of mucin genes and mucin protein had no correlation with tumor stage, nodal stage, histology or pathological differentiation grade. Tumors of smokers had higher MUC5B and MUC5AC mRNA expression ratios than those of non-smokers. Tumors with increased expression of mucin genes tended to be associated with post-operative relapse, especially when MUC5B and MUC5AC genes were overexpressed (p = 0.015 and 0.025, respectively). The study suggests that overexpression of novel tracheobronchial mucin genes may result in an increased likelihood of post-operative lung-cancer recurrence or metastases.

Adult↗
PubMed1996

Tuberculosis antigen A60 serodiagnosis in tuberculous infection: application in extrapulmonary and smear-negative pulmonary tuberculosis.

An ELISA diagnostic test for tuberculosis antigen A60 (TBA60) IgG/IgM was used in a tertiary referral hospital in Taiwan. From June 1992 to December 1993, serum samples obtained from 907 patients were analyzed for TBA60 IgG and IgM titres. The final diagnosis of these patients was confirmed by microbiological study and clinical follow up for 18-24 months. Among 147 patients with active pulmonary tuberculosis, IgG was positive in 112 (76.2%), IgM was positive in 14 (9.52%). Among 90 patients with active extrapulmonary tuberculosis, IgG was positive in 53 (58.9%), IgM was positive in 9 (10%). Among 153 patients with inactive tuberculosis, IgG was positive in 28 (18.3%), IgM was positive in 1 (1.6%). Among 517 patients with nontuberculous disease, IgG was positive in 50 (9.7%), IgM was positive in 3 (0.6%). In this study population with 26% (237/907) active tuberculous infection rate, the TBA60 ELISA IgG had a diagnostic sensitivity of 69.6% and a specificity of 92.1%. These results indicate a positive predictive value of 67.9% and a negative predictive value of 89.2%. The sensitivity of IgM was 10.5% and specificity, 99.4%. The serum IgG tire had good correlation with the extent of pulmonary TB had a higher percentage of IgG seropositivity (83.9%) than those with smear-negative pulmonary TB (70.6%) and extrapulmonary TB (58.9%). In 50 cases with active tuberculosis, follow-up examinations were carried out one month after treatment. In 18 cases with initially negative IgG and IgM titres, 13 showed elevation of serum IgG titres into positive level, one had positive seroconversion of IgM which was the only serological marker indicating active infection. Therefore, 77.8% (14/18) gained diagnostic benefit from follow-up serological examination. It was concluded that TBA60 IgG and IgM ELISA is a useful test when diagnosing tuberculosis. This test also assists in the clinical judgement of tuberculosis when used as an adjunct to symptoms and sputum smear, and for monitoring therapeutic response at the commencement of treatment.

Adolescent↗
PubMed1996

Efficacy of tracheal gas insufflation in acute respiratory distress syndrome with permissive hypercapnia.

This study was conducted to assess the CO2-elimination efficiency of tracheal gas insufflation (TGI) in 20 patients with acute respiratory distress syndrome and to compare its efficacy during volume-controlled (VCV) and pressure-controlled ventilation (PCV). TGI was initially applied as an adjunct to VCV, with continuous flows (Vcath) of 4 and 6 L/min delivered through a catheter positioned 2 cm above the carina. Total effective tidal volume (VTeff) was held constant. The percent reductions in PaCO2 (% delta PaCO2) were 13.3 +/- 2.1 and 16.7 +/- 2.7% at Vcath 4 and 6 L/min, respectively, which correlated well with the percent reduction in the end-tidal PCO2 from baseline (% delta PETCO2) (r = 0.75, p < 0.001). An inverse relationship (r = -0.65, p < 0.001 and r = -0.59, p < 0.01 at Vcath 4 and 6 L/min, respectively) was found between the % delta PaCO2 and the baseline ratio of artery to PETCO2 difference to PaCO2, which was determined as the fraction of alveolar dead space (VDalv) relative to total alveolar ventilation. Twelve patients were subsequently switched to PCV combined with Vcath 6 L/min, which provided a % delta PaCO2 of 16.1 +/- 3.0% (p = NS versus 17.1 +/- 2.6% during VCV). These data suggest that in patients with ARDS the change in PETCO2 may be helpful in predicting the decrement in PaCO2 during TGI, and the existence of a high VDalv tends to limit its effectiveness. Further, the efficacy of TGI with VCV is equivalent to that with PCV.

Adult↗
PubMed1995

Clinical spectrum of tuberculosis in older patients.

OBJECTIVE: To investigate the clinical differences between old and young patients infected with Mycobacterium tuberculosis in a developing country. DESIGN: Retrospective chart and chest radiograph review. SETTING: A university-affiliated teaching hospital. PATIENTS: The medical records of patients with documented tuberculosis (TB) from January 1990 through December 1991 were analyzed. Clinical assessment included sex, age, diagnosis at first visit, past history, symptoms and signs, laboratory data, X-ray findings, bacteriological examinations, outcome, time elapsed from first visit to initiation of anti-TB therapy and the major determinants for starting anti-TB therapy. Statistical significances were analyzed by Student's t test and chi 2 tests. RESULTS: Among 205 patients with culture-proven TB, 57 were 65 years of age and older (range, 65 to 91; mean, 73) and 148 under 65 years of age (range, 16 to 64; mean, 41). There was a higher incidence of previous TB (26.3% vs. 16.2%) and diabetes mellitus (24.5% vs. 14.3%) in the elderly patients. Initial diagnosis of TB at first visit was less frequent in the elderly than in the young group (38.6% vs. 47.3%), although symptoms and signs at first visit were similar in each of the age groups. Radiographic presentation with mass lesions was more frequently encountered in elderly patients (10.5% vs. 2.1%, P < .05). Elapsed time from the first visit to suspicion of TB and the initiation of anti-TB therapy was frequently delayed in elderly patients (22 +/- 23 vs. 13 +/- 20 days, P < .05). The incidence of drug-resistance (39% vs. 16%, P < .05) and unfavorable response to anti-TB therapy (17.5% vs. 3.4%, P < .05) were significantly higher in the older patients. CONCLUSIONS: Although clinical presentation of TB in the elderly did not differ significantly from that in younger patients, this study showed that diagnosis and treatment were more often delayed in the elderly, and there was a higher incidence of treatment failure.

Adolescent↗
PubMed1995

Direct determination of cryptococcal antigen in transthoracic needle aspirate for diagnosis of pulmonary cryptococcosis.

Pulmonary cryptococcosis causes significant morbidity and mortality in immunocompromised patients. Definitive diagnosis of pulmonary cryptococcosis is usually difficult. The use of direct determination of cryptococcal antigen in transthoracic needle aspirate to diagnose pulmonary cryptococcosis was investigated. Over a 2-year period, we studied a total of 41 patients with respiratory symptoms and pulmonary infiltrates of unknown etiology who were suspected of having pulmonary cryptococcosis. Twenty-two patients were immunocompetent patients and 19 patients were immunocompromised. A diagnosis of pulmonary cryptococcosis was based on cytological examination, culture for Cryptococcus neoformans, histopathologic examination, and clinical response to antifungal therapy. All patients underwent chest ultrasound and ultrasound-guided percutaneous transthoracic needle aspiration to obtain specimens for cryptococcal antigen determination. The presence of cryptococcal antigen was determined by the latex agglutination system (CALAS; Meridian Diagnostics, Cincinnati, Ohio). An antigen titer equal to or greater than 1:8 was considered positive. The specimens were also sent for cytological examination, fungal culture, and/or histopathologic examination. A final diagnosis of pulmonary cryptococcosis was made in eight patients. Direct determinations of cryptococcal antigen in lung aspirate were positive in all eight patients with pulmonary cryptococcosis (100% sensitivity, 97% specificity, a positive predictive value of 89%, and negative value of 100%), and there was only one false-positive in noncryptococcosis patients. The diagnostic accuracy was 97.5%. Serum cryptococcal antigen was positive in only three patients with pulmonary cryptococcosis (sensitivity, 37.5%). This study showed that direct measurement of cryptococcal antigen in lung aspirate can be a rapid and useful test for diagnosis of pulmonary cryptococcosis.

Adolescent↗
PubMed1995

Transthoracic needle biopsy of thoracic tumours by a colour Doppler ultrasound puncture guiding device.

BACKGROUND: Ultrasound guided transthoracic needle aspiration biopsy has recently been used to obtain specimens for histological diagnosis of pulmonary and mediastinal tumours. Conventional real time, grey scale puncture guiding devices cannot differentiate vascular structures, and clear visualisation of the needle shaft or tip within a desired target is not always possible. This study describes a new built-in colour Doppler ultrasound puncture guiding device and assesses the relative safety of transthoracic needle aspiration biopsy of thoracic tumours by grey scale or colour Doppler ultrasound guidance. METHODS: Thirty patients with radiographic evidence of pulmonary (22 patients) or mediastinal tumours (eight patients) underwent ultrasonographic evaluation and transthoracic needle aspiration biopsy by using the colour Doppler ultrasound puncture guiding device (Aloka UST 5045P-3.5). These tumours were initially examined by grey scale ultrasound, and colour Doppler imaging was then used to evaluate the number of blood vessels surrounding and within the target tumour and the possibility of visualisation of the needle shaft or needle tip during the aspiration biopsy procedure. RESULTS: The colour Doppler ultrasound guiding device was far superior to the grey scale device for identification of the number of vessels surrounding or within the target tumour (83% v 20%) and for visualisation of the needle shaft or needle tip (80% v 17%). CONCLUSIONS: By using the colour Doppler ultrasound puncture device, vascular structures surrounding or within the target tumour can be verified. Visualisation of the needle shaft or tip is also better. Biopsy routes can be selected to avoid puncturing vessels. This approach should be particularly helpful for guiding biopsies of mediastinal tumours, where puncturing the heart or great vessels is a potential complication.

Adult↗
PubMed1995

Tumor angiogenesis correlates with histologic type and metastasis in non-small-cell lung cancer.

This study investigated the clinico-pathologic correlation of tumor angiogenesis in non-small-cell lung cancers. Formalin-fixed, paraffin-embedded surgical specimens of 55 consecutive patients with primary non-small-cell lung cancers were examined. Included were 26 squamous cell carcinomas and 29 adenocarcinomas. Twenty-five patients had stage I disease, eight patients had stage II disease, and 22 patients had stage IIIA or IIIB disease. Among them, 28 had nodal metastasis and 27 did not. The microvessel was demonstrated by immunocytochemical staining for factor VIII and platelet endothelial cell adhesion molecules (PECAM-1). The microvessels in the areas of highest neovascularization were counted under light microscopy in 200x field by two independent observers without knowledge of clinical information. At least three separate fields were counted for each specimen. The Mann-Whitney U test was used for statistical analysis. The microvessel counts in adenocarcinoma were significantly higher than in the squamous cell carcinoma (54.4 +/- 35.65 versus 26.16 +/- 20.46 in factor VIII staining and 80.52 +/- 48.42 versus 40.04 +/- 32.33 in PECAM-1 staining; p < 0.001). The microvessel counts in patients with Stages I-II disease were significantly lower than that of stages IIIA-IIIB disease (23.63 +/- 16.21 versus 65.36 +/- 31.92 in factor VIII staining and 41.85 +/- 36.76 versus 93.00 +/- 43.08 in PECAM-1; p < 0.001). Patients with nodal metastasis had higher microvessel density than those without nodal metastasis (56.67 +/- 35.55 versus 23.44 +/- 15.77 in factor VIII staining and 86.89 +/- 46.46 versus 36.30 +/- 25.83 in PECAM-1 staining; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1995

Legionnaires' disease with acute renal failure: report of two cases.

Acute renal failure in Legionnaires' disease is rare, but the mortality rate is high [1-3]. Although the actual pathogenesis is not clear, the renal pathology discloses either acute tubulointerstitial nephritis or acute tubular necrosis in most cases [3]. We report two cases of Legionnaires' disease complicated by acute renal failure. One patient was completely healthy before, and the other had underlying gouty arthritis and diabetes mellitus. Their renal function was normal before these episodes. The diagnosis of Legionella infection was proved by the indirect fluorescent antibody test on paired sera. After erythromycin treatment, both patients survived. One patient required long-term maintenance hemodialysis, and the other recovered to only mild azotemia after a follow-up period of 5 months. Including our cases, only 55 patients have been reported to have Legionella-induced acute renal failure. This is a rare and serious complication of Legionnaires' disease. Early recognition and treatment is mandatory.

Acute Kidney Injury↗
PubMed1994

Ultrasound guided pericardial drainage and intrapericardial instillation of mitomycin C for malignant pericardial effusion.

BACKGROUND: Conservative treatment of malignant pericardial effusion by intrapericardial instillation of a sclerosing agent may be an alternative to surgery. METHODS: Twenty patients with malignant pericardial effusion were treated by ultrasound guided pericardiocentesis and the intrapericardial instillation of mitomycin C. RESULTS: Mitomycin C was effective in controlling the pericardial effusion in 70% of patients without causing side effects, except for pericardial constriction seven months later in one subject. CONCLUSIONS: Ultrasound guided intrapericardial instillation of mitomycin C is a suitable alternative in the management of malignant pericardial effusion.

Adult↗