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Biomedical subjects

Y L Chang

Publications and source records attributed to Y L Chang.

At least 55 records · Page 3Linked to original sources
PubMed2000

US-guided transthoracic cutting biopsy for peripheral thoracic lesions less than 3 cm in diameter.

PURPOSE: To evaluate the safety and accuracy of ultrasonography (US)-guided transthoracic cutting biopsy for diagnosing peripheral thoracic lesions (<3 cm). MATERIALS AND METHODS: Fifty consecutive patients with peripheral thoracic lesions less than 3 cm in diameter underwent US-guided percutaneous transthoracic cutting biopsy with a modified technique. Fifty lesions (43 parenchymal lung, two pleural, two chest wall, and three anterior mediastinal lesions) were sampled for biopsy. The final diagnosis was based on histopathologic analysis of surgical specimens (n = 18) or clinical follow-up (n = 32). RESULTS: The histology recovery rate was 98% (49 lesions), and the correct diagnosis was obtained in 48 lesions (96%). Twenty-four (48%) lesions were malignant, and 26 (52%) were benign. The diagnostic accuracy for malignant lesions was 92% (22 of 24 lesions). A specific benign diagnosis was made in 17 (65%) of the 26 benign lesions, and the negative predictive value for malignancy was 93% (26 of 28 lesions). Only two patients (4%) developed postbiopsy pneumothorax, and three (6%) developed postbiopsy hemoptysis. Biopsy helped prevent surgery or thoracoscopy in 32 patients (64%): 18 patients with benign disease and 14 with multiple metastases or inoperable cancer. CONCLUSION: US-guided transthoracic cutting biopsy appears to be a safe and effective method for diagnosing peripheral thoracic lesions less than 3 cm in diameter. The high diagnostic accuracy for benign lesions and metastatic lung cancer can help prevent surgery in many cases.

Adolescent↗
PubMed2000

Actinomycosis imitating nasopharyngeal carcinoma.

The incidence of nasopharyngeal actinomycosis is exceedingly rare. To our knowledge, only 1 case has been reported previously. This article presents 4 cases of actinomycosis involving the nasopharynx that imitated nasopharyngeal carcinoma. Acidic gas exposure and farming of aquatic products are possibly involved in the pathogenesis of nasopharyngeal actinomycosis. Patients in the case studies completely recovered after 4 weeks of oral antibiotic treatment. We recommend including actinomycosis in the differential diagnosis of nasopharyngeal neoplasms.

Abscess↗
PubMed2000

Simultaneous determination of unbound cefoperazone in rat blood and brain using microdialysis.

A sensitive microbore HPLC method was developed for the simultaneous determination of unbound cefoperazone in rat blood and brain using microdialysis. Two microdialysis probes were inserted into the jugular vein/right atrium and brain striatum of Sprague-Dawley rats. Cefoperazone (50 mgkg(-1), i.v.) was then administered via the femoral vein. Blood and brain dialysates were collected and eluted with a mobile phase containing methanol-100 mM monosodium phosphoric acid (30:70, v/v, pH 5.5). The wavelength of the UV detector was set at 254 nm. The detection limit of cefoperazone was 20 ng mL(-1). Isocratic separation of cefoperazone was achieved within 10 min. The intra- and inter-assay accuracy and precision of the analyses were < or =10% in the range of 0.05-10 microg mL(-1). The ratio of the area under the concentration curve of cefoperazone in rat brain and blood was estimated to be about 7-8%. It is concluded that cefoperazone is capable of penetrating the blood-brain barrier.

Animals↗
PubMed2000

Extraskeletal Ewing's sarcoma of the scalp.

Extraskeletal Ewing's sarcoma/primitive neuroectodermal tumour (EES/PNET) is a rare disease entity. Scalp EES/PNET has been reported rarely. We report a case of an 11-year-old boy who had painful and rapidly growing subcutaneous nodes over the scalp and neck. The final diagnosis was EES/PNET after biopsy and immunohistochemical assay. The patient underwent surgical excision, chemotherapy and radiotherapy with a dose of 2000 cGy. Now he has been free of disease for two years. Early awareness and treatment of this rare disease, and wide resection followed by chemotherapy and radiotherapy might improve patients' long-term survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Pulmonary infection in human immunodeficiency virus-infected patients in Taiwan.

BACKGROUND: Pulmonary infection is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients. METHODS: We conducted a retrospective analysis of the pathogens causing pulmonary infection in 272 HIV-infected patients admitted to a university hospital from January 1993 through December 1998. RESULTS: A total of 158 (58%) patients had pulmonary complications, all but two of whom had acquired immunodeficiency syndrome (AIDS). There were 156 episodes of pulmonary infection, involving 124 patients. The most common pulmonary infection was Pneumocystis carinii pneumonia (PCP): 66 patients had 77 episodes of PCP, all of which occurred in patients with CD4+ lymphocyte counts below 0.2 x 10(9)/L (200/microL). Pulmonary tuberculosis (TB), diagnosed in 47 patients, was the second most common pulmonary infection. Twenty TB patients had open TB. HIV-infected patients who were immigrants from Southeast Asia (9/23, 39%) had a higher risk of developing pulmonary TB than nonimmigrants (38/249, 15%) (p = 0.004). Only one of 17 episodes of community-acquired bacterial pneumonia was caused by Streptococcus pneumoniae. Less common opportunistic pulmonary pathogens included cytomegalovirus (5 cases), Aspergillus species (3), Cryptococcus neoformans (3), Mycobacterium avium complex (2), Penicillium marneffei (1), Nocardia species (1), and Rhodococcus equi (1). CONCLUSIONS: PCP and pulmonary TB are the two leading pulmonary infections in Taiwanese HIV/AIDS patients. These findings should be taken into consideration when developing management strategies and public health policies.

Adolescent↗
PubMed2000

Swyer-James syndrome complicated by lung abscess.

Swyer-James syndrome, a rare disease with unilateral hyperlucent lung due to bronchiolitis obliterans and pulmonary artery hypoplasia, generally develops after lower respiratory tract infection during early childhood. Invasive procedures, including bronchoscopy and angiography, are often necessary for a definitive diagnosis. We report a 17-year-old man admitted because of cystic bronchiectasis complicated by lung abscess. Chest roentgenography showed the typical findings of Swyer-James syndrome. Noninvasive magnetic resonance angiography was used to confirm hypoplasia of the right pulmonary artery. The patient received antibiotic therapy, underwent a right lower lobectomy for the lung abscess, and recovered.

Adolescent↗
PubMed1999

Antiplatelet actions of aporphinoids from Formosan plants.

Seventeen aporphines were tested for antiplatelet activity. L-(+)-hemovine HCl and 7-hydroxydehydrothalicsimidine strongly inhibited platelet aggregation induced by adenosine 5'-diphosphate (ADP), arachidonic acid (AA), collagen, and platelet-activating factor (PAF). The latter showed the strongest antiplatelet activity with an IC50 of 70.4 microM against AA-induced platelet aggregation.

Animals↗
PubMed1999

Prognostic factors and treatment for placental site trophoblastic tumor-report of 3 cases and analysis of 88 cases.

OBJECTIVE: In order to understand the prognostic factors of placental site trophoblastic tumors (PSTT), we performed a MEDLINE search for cases from 1976 through 1998 and report three cases. MATERIALS AND METHODS: The patients' age at presentation, antecedent pregnancies, and responses to treatment were analyzed according to the extent of disease, disease status after treatment, and survival in 88 cases. RESULTS: Patients with disease extending outside the uterus at presentation had a median latency of 24 months between the antecedent pregnancy and presentation of PSTT, which was significantly longer than that of 12 months in those with disease confined to the uterus. Patients with metastatic diseases were 3 years older than patients with diseases confined to the uterus and had a higher incidence of term delivery as their antecedent pregnancy. The outcomes of patients with FIGO stage I-II disease after hysterectomy were excellent, while those with FIGO stage III-IV diseases had a 30% survival. Although initial partial responses to chemotherapy were observed in some patients, only 5 patients achieved a complete remission and 3 of these 5 received a combination of etoposide, methotrexate, and actinomycin-D, alternating with cyclophosphamide and vincristine. CONCLUSION: FIGO stage is the most important prognostic factor, and complete removal of all lesions provided good outcomes in PSTT patients. For those with unresectable tumors, combination chemotherapy showed a high response rate, but only a few achieved a complete response.

Adult↗
PubMed1999

Significance of P53 and Rb protein expression in surgically treated non-small cell lung cancers.

BACKGROUND: Alterations of the P53 or Rb gene are among the most frequently observed genetic changes in primary lung cancer. Nevertheless, there has been no final conclusion on the relationship between P53 or Rb protein expression and clinico-pathological parameters in primary lung cancer. A large-scale study was performed to examine the clinicopathological and prognostic significance of P53 and Rb expressions in 207 surgically resected non-small cell lung cancer (NSCLC) patients. METHODS: Tumor specimens were obtained from 207 primary NSCLC surgically resected from January 1990 through December 1994. The avidin-biotin-peroxidase method was used to determine the expression of P53 or Rb of tumor cells using anti-P53 or anti-Rb monoclonal antibodies. The relationships between P53 or Rb protein expression and the clinicopathological parameters were analyzed. RESULTS: Expression of P53 or Rb protein was detected in 115 (55.6%) and 136 (65.7%) of the 207 lung tumors, respectively. P53 had significantly higher positive results in patients with regional lymph node metastasis and advanced tumor stage. Rb expression was significantly lower in lung cancers with a macro- or microscopic picture of tumor necrosis. Additionally, an inverse correlation between the expression of Rb and P53 was found. By multiple variate analysis, P53 expression and pathological stage were independent, significant prognostic factors. Further analysis demonstrated P53 expression was an independent prognostic factor in stage 1, but not in other stages. CONCLUSIONS: P53 expression is especially useful as a prognostic factor in stage 1 lung cancer.

Adult↗
PubMed1999

Effects of palmatine on isometric force and intracellular calcium levels of arterial smooth muscle.

The effects of palmatine on isometric force and intracellular free calcium levels ([Ca2+]i) were determined in isolated rat arterial strips. Palmatine dose-dependently relaxed the contractile responses stimulated by phenylephrine (PE) in aortic strips. In contrast, it only partially relaxed aortic strips contracted by 51 mM KCl. Pretreatment with palmatine shifted the dose-response curves of PE both rightwards and downwards in a dose-dependent manner. When Ca2+-free solution and re-addition of Ca2+ were applied to assess PE-induced phasic and tonic contractions, palmatine was found to be effective in inhibiting both contractions. The effects of palmatine on intracellular calcium levels were measured with the bioluminescent calcium indicator aequorin in rat tail artery strips. Palmatine caused a concomitant, dose-dependent decrease in PE-activated isometric force and [Ca2+]i, resulting in small changes in the [Ca2+]i-force relationship. These results suggest that vasodilatory effect of palmatine was mediated by reducing [Ca2+]i as well as affecting [Ca2+]i sensitivity of the contractile apparatus. Palmatine-induced [Ca2+]i decreases appeared to involve decreases in both Ca2+ release from intracellular stores and Ca2+ influx through calcium channels.

Aequorin↗
PubMed1999

In vitro and in vivo effects of naringin on cytochrome P450-dependent monooxygenase in mouse liver.

In vitro and in vivo effects of naringin on microsomal monooxygenase were studied to evaluate the drug interaction of this flavonoid. In vitro addition of naringin up to 500 microM had no effects on benzo(a)pyrene hydroxylase (AHH) activity of mouse liver microsomes. In contrast, the aglycone naringenin at 300 to 500 microM decreased AHH activity by 50% to 60%. Analysis of Lineweaver-Burk and Dixon plots indicated that naringenin competitively inhibited AHH activity with an estimated Ki of 39 microM. Naringenin at 100 microM also reduced metabolic activation of benzo(a)pyrene to genotoxic products as monitored by umuC gene expression response in Salmonella typhimurium TA1535/pSK1002. In the presence of equimolar naringenin and benzo(a)pyrene, umuC gene expression presented as beta-galactosidase activity was reduced to a level similar to the control value. Administration of a liquid diet containing 10 mg/ml naringin for 7 days caused 38% and 49% decreases of AHH and 7-methoxyresorufin O-demethylase activities, respectively. In contrast, the administration had no effects on cytochrome P450 (P450)-catalyzed oxidations of 7-ethoxyresorufin, 7-ethoxycoumarin, N-nitrosodimethylamine, nifedipine, erythromycin and testosterone. Microsomal P450 and cytochrome b5 contents and NADPH-P450 reductase activity were not affected. Immunoblot analysis using MAb 1-7-1, which immunoreacted with both P450 1A1 and 1A2, revealed that the level of P450 1A2 protein was decreased by 38%. These results demonstrate that naringenin is a potent inhibitor of AHH activity in vitro and naringin reduces the P450 1A2 protein level in vivo. These effects may indicate a chemopreventive role of naringin against protoxicants activated by P450 1A2.

Animals↗
PubMed1999

Thoracic solitary fibrous tumor: clinical and pathological diversity.

Fourteen cases (13 pleural and one intrapulmonary) of solitary fibrous tumors (SFTs) (the so-called fibrous mesothelioma) were studied. The lesions occurred more in females (nine cases) than males (five cases). The age of patients ranged from 44 to 73 years old (median 60 years). The tumors presented as cough with or without blood-tinged sputum, exertional dyspnea, chest pain, nausea, body weight loss, fever, or as asymptomatic masses detected by routine chest radiograph. Two patients with huge (tumor larger than 20 cm) malignant tumors had accompanying pleural effusion and one associated with hypoglycemia. Ten benign tumors measured 2-11 cm (median size 7 cm) while the remaining four histologically malignant ones measured 20-30 cm in size. All of them were well circumscribed and thinly encapsulated. Hemorrhage and necrosis were more frequently seen in the malignant tumors. Histologically, these lesions were characterized by 'patternless pattern' with occasional hemangiopericytic features (three cases). The tumor cells were all immunoreactive for vimentin, CD 34, and focally actin-positive in one case, but not for keratin, desmin, S-100 protein, carcinoembryonic antigen, alpha 1-ACT and F VIII-related antigen, supported a primitive mesenchymal origin. p53 protein was expressed in two of the malignant cases. Proliferating cell nuclear antigen stain was positive with 50 and 80% of the labeling index in the benign and malignant tumors, respectively, but retinoblastoma gene protein was negative in all tumors. This analysis confirmed the relationship between histological malignant SFTs and tumor size, cellularity, mitotic activity, necrosis and tumor suppressor gene expression. However, the clinical behavior was unpredictable. Complete respectability seemed to be the most important indicator of clinical outcome in the less aggressive tumors.

Actins↗
PubMed1999

Biomechanical and morphometric analysis of hydroxyapatite-coated implants with varying crystallinity.

PURPOSE: The level of crystallinity in hydroxyapatite (HA) is thought to be responsible for its degradation in the physiologic milieu. The purpose of this study was to compare the in vivo bony response to HA coatings of varying levels of crystallinity and determine the optimum composition for promoting osseointegration. MATERIALS AND METHODS: Cylindrical implants of sand-blasted CP titanium and HA-coated titanium of 50% (low), 70% (medium), and 90% (high) crystallinity were inserted into the canine femur for 1, 4, 12, and 26 weeks. Morphometric analysis of undecalcified sections determined the percentage of bone contact with the implant surface. A pullout test was used to measure the interfacial attachment strength of the bone-implant interface. Scanning electron microscope (SEM) examination of the implant surface aided in identifying the failure mode. Coating thickness was measured under light microscopy to determine whether degradation occurred. RESULTS: No significant differences could be found in the percentage of bone contact and interfacial attachment strength between the three types of HA-coated implants throughout the four implantation periods. A significantly higher percentage of bone contact on HA-coated implants than on uncoated titanium implants was noted at 4 weeks. (ANOVA, P<.05). HA-coated implants were also found to have significantly higher interfacial attachment strength than titanium implants at 4, 12, and 26 weeks. Coating thickness decreased gradually with time. The most noticeable reduction was found on the low-crystallinity coatings during the first 4 weeks. Failure of the bone-coating-implant complex occurred mostly within the coating or near the coating-implant interface. CONCLUSIONS: HA coatings on metal implants enhance osseointegration in the early stage of bone healing and provide strong bone-bonding capability, although titanium implants had about the same level of bone contact in the later stage of healing. Crystallinity of HA coatings has no significant influence over the bone formation capacity and the bone bonding strength. However, an HA coating of higher crystallinity is more desirable in providing durability and maintaining osteoconductive properties.

Analysis of Variance↗
PubMed1999

Chemical constituents and biological activities of the fruit of Zanthoxylum integrifoliolum.

Through continuing studies on the chemical constituents and antiplatelet aggregation principles of the fruit of the Formosan Zanthoxylum integrifoliolum, four new compounds-including two new lignans, (+)-pinoresinol-di-3,3-dimethylallyl ether (1), and (+)-pinoresinol-3,3-dimethylallyl ether (2); zanthonitrile (3), and one new flavonoid, 3,5-diacetyltambulin (4)-and 18 known compounds were isolated from the CHCl3-soluble fraction. Their structures were elucidated on the basis of spectral data and chemical evidence. Among the isolates, including the previously reported isobutylamides, 13 compounds showed strong in vitro antiplatelet aggregation activity, with only (-)-tetrahydroberberine showing weak vasorelaxing effect in high potassium- or norepinephrine-induced contraction of rat aorta.

Animals↗
PubMed1999

Lung transplantation for patients with end-stage Sauropus androgynus-induced bronchiolitis obliterans (SABO) syndrome.

Sauropus androgymus (SA), a vegetable of the Euphorbiaceae family, is a common food source in Malaysia. In Taiwan, over 30 patients have developed progressive respiratory failure after consuming the extract from raw SA leaves as a means of losing weight. Symptoms consistent with a severe obstructive ventilatory defect progressed, despite cessation of SA intake and treatment with bronchodilators, corticosteroids, cytotoxic agents and plasmaphresis. Five patients with end-stage Sauropus androgynus-induced bronchiolitis obliterans (SABO) syndrome underwent lung transplantation. There was no early mortality. One patient died of post-transplant lymphoproliferative disorder and another patient died of bronchial stenosis with infection, 5 and 3.5 months, respectively, post-transplantation. The remaining 3 patients have been followed from 29 to 34 months, with improved general condition and pulmonary function. Perfusion/ventilation scans revealed that these improvements were exclusively attributed to the functional grafts. We believe that lung transplantation is the only effective modality of treatment for patients with end-stage SABO syndrome.

Adult↗
PubMed1999

A huge cystic hygroma of the neck associated with intraventricular haemorrhage in a term neonate.

We report on a female term neonate who presented with a huge cystic hygroma of the right neck associated with intraventricular haemorrhage as demonstrated by computerized tomography and magnetic resonance imaging studies. She underwent extraventricular drainage and excision of the neck mass with stable postoperative condition. Psychomotor retardation was found thereafter. To our knowledge, the association of a large cystic hygroma of the neck with intracranial haemorrhage has not been reported previously. The possible mechanism of the occurrence of the haemorrhage is discussed.

Central Venous Pressure↗
PubMed1999

Diverse manifestations of oral methylene chloride poisoning: report of 6 cases.

OBJECTIVE: Methylene chloride is a solvent used in domestic and industrial preparations, such as paint removers and degreasing agents. Although it is considered of low toxicity, acute toxic manifestations have been reported following inhalation of methylene chloride, mainly from working in an enclosed environment. Oral ingestion of methylene chloride, however, remains rare and its consequences are less clearly understood. CASE REPORTS: The various clinical manifestations of 6 patients with oral ingestion of methylene chloride are reported. Central nervous system depression, tachypnea, and corrosive gastrointestinal injury were the most common presentations following ingestion. An elevated carboxyhemoglobin level was documented in only 2 patients (35% and 8.4% carboxyhemoglobin, respectively). Due to a frequent misleading history of "chloroform" ingestion and unawareness of probable carboxyhemoglobin production in these patients, carboxyhemoglobin was not routinely measured. Renal failure, hepatic failure, and acute pancreatitis occurred in the 2 most severe cases of methylene chloride ingestion. CONCLUSIONS: Ingestion of methylene chloride can result in diverse manifestations, including a high carboxyhemoglobin level. Corrosive gastrointestinal injury is common in oral poisoning and needs further therapeutic consideration. A high index of suspicion and appropriate laboratory studies are needed in those patients who allegedly ingest "chloroform" but do not present the incriminating solvent to their treating physicians. The presence of an elevated carboxyhemoglobin level suggests the diagnosis of methylene chloride poisoning. Symptomatic and supportive measures remain the mainstay in the treatment of patients with oral methylene chloride poisoning.

Administration, Oral↗