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Biomedical subjects

Y L Chang

Publications and source records attributed to Y L Chang.

At least 91 records · Page 5Linked to original sources
PubMed1998

Primary pulmonary plasmacytoma with lobar consolidation: an unusual presentation.

Extramedullary plasmacytoma is a rare form of plasma cell tumor that frequently involves the upper respiratory tract. Primary pulmonary plasmacytoma is even more rare. The usual presentation of primary pulmonary plasmacytoma is a solitary pulmonary nodule. We describe the case of a 58-year-old woman who presented with the chief complaints of progressive dyspnea on exertion, cough, and subsequently, hemoptysis. The main finding on chest imaging studies, including plain radiography, sonography, computed tomography, and magnetic resonance imaging, was consolidation of the right middle lobe. Percutaneous transthoracic lung biopsy of the right middle lobe demonstrated sheets of atypical plasma cells. Immunohistochemical study showed IgA lambda monoclonality. A bone marrow study and whole body bone scan showed normal findings. To the best of our knowledge, this is the first reported case of primary pulmonary plasmacytoma presenting with lobar consolidation of the lung but without a well-defined tumor mass.

Biopsy, Needle↗
PubMed1998

False-positive 2-[F-18]-fluoro-2-deoxy-D-glucose positron emission tomography studies for evaluation of focal pulmonary abnormalities.

Positron emission tomography (PET) with 2-[F-18]-fluoro-2-deoxy-D-glucose (FDG) can demonstrate the glucose metabolism characteristics of a lesion, which may be helpful in differentiating between benign and malignant focal pulmonary lesions. Malignant cells demonstrate higher glucose metabolic activity than benign lesions. However, some inflammatory processes also show significant FDG uptake. We present two cases where high FDG uptake was found in inflammatory lesions in the lungs. The first case was that of a 38-year-old woman with chronic cough for more than 20 years. FDG PET revealed a hypermetabolic lesion with a lesion-to-background ratio of 8.0 at the posterior aspect of the right middle lung. She underwent thoracotomy and tumor resection, and was diagnosed with cryptococcosis. The second case was that of a 72-year-old woman who had pulmonary tuberculosis previously with cavitation in the left lower lobe. She suffered from fever, chills and severe hemoptysis for several days before this admission. FDG PET revealed a hypermetabolic ring at the periphery of the cavity. The lesion-to-background ratio was 7.8. Echo-guided biopsy showed no evidence of malignancy. She was treated with antibiotics and the symptoms subsided gradually. Lung abscess complicating a pre-existing cavity was diagnosed. These two cases substantiate that positive FDG PET results should be interpreted with caution in differentiating benign from malignant pulmonary abnormalities, especially in regions with a high prevalence of granulomatous lesions.

Adult↗
PubMed1997

Undifferentiated carcinoma of the major salivary glands.

BACKGROUND: Undifferentiated carcinoma of the salivary glands is a rare disease, the incidence of which is highest among the Inuit of Greenland and North America. It was demonstrated to be closely related to Epstein- Barr virus (EBV) infection. However, the relation of EBV to this tumor has not been studied to any great extent here in Taiwan because of the small number of cases. METHODS: Twelve cases of undifferentiated carcinoma of the salivary glands from the period 1977-1996 were retrieved from the cancer registry at National Taiwan University Hospital. The clinical data were analyzed retrospectively based on the medical records. Eleven formalin fixed, paraffin embedded tissue sections were used for in situ hybridization with an antisense probe complementary to EBV-encoded RNA 1 (EBER1). RESULTS: Ten of 12 tumors originated from the parotid gland and 2 from the submandibular gland. The patients' ages ranged from 22 to 63 years, with an average of 38.1 years. One patient was lost to follow-up, 2 patients died of metastatic disease, and the remaining 9 patients were all alive and disease free at last follow-up. The actuarial 5-year survival rate was 79.8%. In situ hybridization demonstrated EBER1 in 9 of the undifferentiated carcinomas with lymphoid stroma, but EBER1 was not demonstrated in the other 2 tumors without lymphoid stroma. CONCLUSIONS: Undifferentiated carcinoma with lymphoid stroma of the major salivary glands is closely associated with EBV. The mainstay of treatment is surgery and postoperative radiotherapy. The outcomes in this series were good except for two elderly patients who died of rapid and progressive distant metastases.

Adult↗
PubMed1997

Salvage surgery for recurrent nasopharyngeal carcinoma.

OBJECTIVE: To assess the efficacy of salvage surgery for patients with recurrent nasopharyngeal carcinoma (NPC) at the primary site after radiotherapy. DESIGN: Retrospective analysis of 24 patients treated by transpalatal, transmaxillary, or transmandibular approach to resect the recurrent tumor, with maximum follow-up of 50 months. SETTING: Academic tertiary referral center. RESULTS: Radiotherapy before salvage surgery included 1 to 3 courses of radiation to the nasopharynx, with doses ranging from 60 to 190 Gy. Eighteen (75%) of the patients relapsed within 2 years, and 6 (25%) relapsed more than 6 years after the last irradiation. In 4 of 6 late-relapsing cases, the histopathological type changed to keratinizing squamous cell carcinoma, which is rare in cases of NPC in Taiwan. Fourteen patients (58%) survived for 8 to 50 months after surgery (median, 18 months). The surgical complications were tolerable. CONCLUSIONS: Salvage surgery is feasible in selected patients with recurrent disease at the primary site. Thus, we can offer alternative retreatment in addition to external irradiation for patients with recurrent NPC.

Carcinoma↗
PubMed1997

Salvage neck dissection for cervical recurrence of nasopharyngeal carcinoma.

OBJECTIVE: To evaluate the effectiveness of salvage neck dissection as part of a multidisciplinary treatment approach in persistent or recurrent metastatic nasopharyngeal carcinoma, after failure of initial radiotherapy at the regional site. DESIGN: A retrospective study of 31 patients treated during a 14-year period from March 1981 through May 1995, with a maximum follow-up of 152 months. Factors evaluated include patients' sex, age, and initial stage of tumor, mobility and number of nodal recurrences, surgical and pathological findings, and postoperative irradiation. SETTING: Academic tertiary referral center. PATIENTS: Twenty-six men and 5 women were studied; one patient had neck dissection to both sides of the neck on separate occasions, for a total of 32 operations. All patients had pathologically proved nasopharyngeal carcinoma and had been previously treated at the primary site and both sides of the neck with definitive radiotherapy. INTERVENTION: Patients underwent a radical, modified radical, or level I-sparing radical neck dissection. MAIN OUTCOME MEASURE: Surgical morbidity, time to recurrence at the regional site, and survival time. RESULTS: Clinically, there was a disease predilection of 81% at levels II and V. Surgical morbidity was minimal. Regional control was achieved in 20 (65%) of the patients, and the overall 5-year survival was 67%. Tumor involvement of the posterior triangle musculature and spinal accessory nerve was associated with failure to control neck disease. Extracapsular nodal extension correlated with a poor survival outcome. CONCLUSION: Control of regional disease by salvage neck dissection when radiotherapy has failed is both safe and effective in properly selected patients.

Adult↗
PubMed1997

Performance characteristics of combined haemodialysis/haemoperfusion system for removal of blood toxins.

The application of high clearance haemodialysis (HD) for removal of small molecules of waste metabolites, has been practised for many years. Haemoperfusion (HP) is capable of effective removal of middle and protein-bound molecules. The combined HD/HP system is thought to give a more effective treatment for patients of renal failure or drug intoxication. This paper discusses the performance characteristics of removal of toxic substances (e.g. paraquat and creatinine), using the combined HD/HP recycled system in two different arrangements (HD-HP and HP-HD). The results demonstrate that for most favourable adsorbing solutes, the HD-HP arrangement gives higher performance whereas, HP-HD arrangement is more suitable and gives more effective detoxication characteristics for unfavourable adsorbing solutes.

Adsorption↗
PubMed1997

Low dietary protein impairs blood coagulation in BHE/cdb rats.

The influence of dietary protein on blood coagulation tests was evaluated in BHE/cdb rats. Three experiments were conducted in order to compare effects of diets with low (8 g/100 g diet) or high (38 g/100 g diet) protein, to establish values for coagulation tests at intermediate (12-30 g/100 g diet) concentrations of dietary protein, and to compare feeding identical quantities of diets with 8 g protein/100 g diet vs. 18 g protein/100 g diet. After 4 wk of feeding the semipurified diets, bleeding time exceeded 15 min in the groups fed low protein diets, compared to a range of 3-6 min for the groups fed high protein diets. Several in vitro tests of coagulation were abnormal in the rats fed low protein diets. For example, prothrombin time averaged 27 +/- 8 s in rats fed 8 g protein/100 g diet plus beef tallow, but 17 +/- 1 s in rats fed 38 g protein/100 g diet plus tallow. The coagulation deficit in rats fed low protein was not affected by fat source (tallow vs. menhaden oil), but fibrinogen was elevated in rats fed diets with menhaden oil. Conversely, no differences in coagulation tests were observed among rats fed 12-30 g protein/100 g diet. Bleeding times ranged from 7 to 9 min, and prothrombin time was 17-18 s. Significant differences in plasma fibrinogen concentration and prothrombin time were observed in rats fed 8 vs. 18 g protein/100 g diet at a fixed rate of 6 g/100 g body weight. Platelet and blood cell numbers were unaffected by dietary protein. The evidence for multiple deficits in the coagulation system suggests that hepatic function in BHE/cdb rats may become impaired when the rats are fed low protein diets of the composition used here.

Animals↗
PubMed1997

Antiplatelet effects of some aporphine and phenanthrene alkaloids in rabbits and man.

Two aporphines (boldine and laurolitsine) and five phenanthrene alkaloids (litebamine, secoboldine, N-cyanosecoboldine, N-methylsecoglaucine and N-methylsecopredicentrine) were evaluated in-vitro for their ability to inhibit platelet aggregation. All seven alkaloids inhibited aggregation of rabbit platelets and inhibited the release of ATP induced by arachidonic acid and collagen in rabbit platelets. Those aggregations induced by platelet-activating factor (PAF), thrombin, U46619 and ADP were inhibited by the three N-substituted secoboldine derivatives only. Thromboxane B2 formation caused by arachidonic acid was also suppressed by these compounds. They did not affect the generation of [3H]inositol monophosphate caused by collagen, PAF and thrombin in the presence of indomethacin. Platelet cyclic AMP level was unaffected by litebamine, but was increased by N-methylsecoglaucine. Litebamine suppressed the secondary aggregation, but not the primary aggregation, induced by ADP and adrenaline in platelet-rich plasma from man, whereas N-methylsecoglaucine inhibited both primary and secondary aggregation. It is concluded that the antiplatelet effect of these seven aporphine and phenanthrene alkaloids is mainly a result of inhibition of thromboxane A2 formation; N-methylsecoglaucine has additional antiplatelet activity as a result of increasing the levels of platelet cyclic AMP.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1997

Surgical treatment for pulmonary aspergilloma: a 28 year experience.

BACKGROUND: Pulmonary aspergilloma has been treated surgically for many years but the mortality rates of larger surgical series, varying from 7% to 23%, is not considered acceptable by today's standards. The authors report their experience in the surgical treatment of pulmonary aspergilloma and present a review of the literature. METHODS: Sixty seven patients who underwent thoracotomy for pulmonary aspergilloma from 1968 to 1995 were studied retrospectively by reviewing their medical records. RESULTS: The most common clinical presentation of pulmonary aspergilloma was haemoptysis which occurred in 61 patients (91.0%). Tuberculosis was the most common pre-existing disease, occurring in 54 patients (80.6%). The plain chest radiograph showed the typical "air-crescent" sign in 36 patients (53.7%). Systemic antifungal therapy neither palliated the clinical symptoms nor eradicated the aspergilloma, and transarterial embolisation was also unsuccessful. Surgery offered the only chance of cure for both unilateral and bilateral disease. Procedures varied from segmentectomy to pneumonectomy with most (61.4%) undergoing lobectomy. There was one death following surgery from pneumonia and 15 postoperative complications occurred in 12 patients-empyema (7), massive bleeding (3), bronchopleural fistula (2), wound infection (2), and Horner's syndrome (1). Postoperatively, most of the patients were symptom-free. CONCLUSIONS: With appropriate preoperative evaluation and judicious surgical technique, surgery is the preferred treatment for pulmonary aspergilloma, both for eradicating the tumour and for curing the underlying disease.

Adult↗
PubMed1997

Haemoperfusion treatment in pigs experimentally intoxicated by paraquat.

1. Because of their similarity in renal morphology and physiology to humans, domestic pigs (gilts, 70 kg) were bolus treated by intramuscular injection of 74, 17, and 6 mg kg-1 and by oral loading (70 mg kg-1 n = 4) of paraquat. The concentration peak of plasma paraquat was reached at 1.5 - 2.5 h. Renal clearance of paraquat rose to its maximum at 5-6 h after intoxication and then sharply decreased indicating renal failure. All the intoxicated pigs died. 2. An additional 10 gilts were also orally treated with 70 mg kg-1 paraquat but received haemoperfusion from 2 h post intoxication for either 2 h (n = 6) or 6 h (n = 4). The 2 h haemoperfusion resulted in a 5.1% toxin removal but failed to save any of six poisoned pigs. Prolonged 6 h haemoperfusion successfully rescued three out of four intoxicated pigs. 3. The plasma paraquat concentrations of the three surviving pigs were above 2 mg l-1 at 10 h post intoxication. This level is not only similar to those of untreated animals that died later, but also well beyond the suggested limit for survival of poisoned patients. 4. Pigs proved to be a good animal model for studies in paraquat poisoning and/or haemoperfusion. It is also suggested that early haemoperfusion is effective in treating paraquat poisoning even in very severe cases due to its possible detoxicating effect in addition to toxin removal.

Animals↗
PubMed1997

Synthesis and antiplatelet evaluation of alpha-methylene-gamma-butyrolactone bearing 2-methylquinoline and 8-hydroxyquinoline moieties.

In a search for inhibitors of platelet aggregation, some alpha-methylene-gamma-butyrolactones bearing 2-methylquinoline and 8-hydroxyquinoline moieties were synthesized and evaluated for antiplatelet activities against thrombin (Thr)-, arachidonic acid (AA)-, collagen (Col)-, and platelet-activating factor (PAF)-induced aggregation in washed rabbit platelets. With the exception of 2-[[2,3,4,5-tetrahydro-4-methylene-5-oxo-2-(4-phenylphenyl)-2 -furanyl]methoxy]-8-hydroxyquinoline (8f), these alpha-methylene-gamma-butyrolactones completely inhibited the platelet aggregation induced by AA and Col. The 2-methylquinoline derivatives were also active against Thr- and PAF-induced aggregation, while their 8-hydroxyquinoline counterparts were relatively inactive.

4-Butyrolactone↗
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

ADP-mimicking platelet aggregation caused by rugosin E, an ellagitannin isolated from Rosa rugosa Thunb.

Among the nine ellagitannins, rugosin E was the most potent platelet aggregating agent with an EC50 of 1.5 +/- 0.1 microM in rabbit platelets and 3.2 +/- 0.1 microM in human platelets. The aggregations caused by rugosin E and ADP were inhibited by EGTA, PGE1, mepacrine, sodium nitroprusside and neomycin, but not by indomethacin, verapamil, TMB-8, BN52021 and GR32191B. Rugosin E-induced thromboxane formation was suppressed by indomethacin, EGTA, PGE1, verapamil, mepacrine, TMB-8 and neomycin. ADP-scavenging agents, such as CP/CPK and apyrase inhibited concentration-dependently ADP (20 microM)-, but not rugosin E (5 microM)-induced platelet aggregation. In thrombin (0.1 U/ml)-treated and degranulated platelets, rugosin E and ADP still caused 63.5 +/- 3.0% and 61.2 +/- 3.5% of platelet aggregation, respectively. Selective ADP receptor antagonists, ATP and FSBA inhibited rugosin E- and ADP-induced platelet aggregations in a concentration-dependent manner. Both rugosin E and ADP did not induce platelet aggregation in ADP (1 mM)-desensitized platelets. In contrast to ADP, rugosin E did not decrease cAMP formation in washed rabbit platelets. Both rugosin E and ADP did not cause phosphoinositide breakdown in [3H]myo-inositol-labeled rabbit platelets. In fura-2/AM-load platelets, both rugosin E and ADP induced increase in intracellular calcium concentration and these responses were inhibited by ATP and PGE1. All these data suggest that rugosin E may be an ADP receptor agonist in rabbit platelets.

Adenosine↗
PubMed1997

Fusarium solani fungemia in a bone marrow transplant recipient.

Disseminated Fusarium solani infection, with its distinctive skin lesions, is an emerging cause of mortality in bone marrow transplant recipients worldwide. However, it has never been reported before in Taiwan. We report a 21-year-old man with disseminated fusariosis who developed fever, myalgia and generalized erythematous papules on day 8 after undergoing allogeneic bone marrow transplantation for severe aplastic anemia. Histopathology of the skin lesion revealed mycotic emboli. Cultures of both blood and tissue from skin biopsy grew Fusarium solani. Despite amphotericin B therapy, fever persisted and graft failure developed. A second transplantation, using mobilized peripheral blood stem cells from the same donor, was tried but the patient died of progressive multiple organ failure before any evidence of engraftment.

Adult↗
PubMed1997

Evaluation of multiple antibodies to Epstein-Barr virus as markers for detecting patients with nasopharyngeal carcinoma.

Five serological tests were assessed for their sensitivity for screening and early detection of nasopharyngeal carcinoma (NPC). The tests included the detection of antibodies to various gene products of EBV: viral capsid antigen (VCA) using an indirect immunofluorescence assay (FA), DNase using an activity neutralisation test (NT), Dnase using an enzyme-linked immunosorbent assay (ELISA), DNA polymerase (DP) using NT, and major DNA binding protein (MDBP) by ELISA. Sera from 100 NPC outpatients and 20 NPC patients, who were detected in a prospective study, were examined. The results showed that levels of antibody to DNase detected by ELISA and to DP detected by NT and the positivity rate for VCA by FA increased with NPC stage. More species of EBV antibody became detectable as NPC progressed. The detection of anti-MDBP antibody by ELISA was suitable for screening for NPC. Anti-DP antibody detected by NT was a valuable marker both for early detection and prognosis of NPC. Detection of anti-DNase antibody by ELISA was the most sensitive method for detection of NPC. No single test was sufficient to detect all the NPC patients and a combination of anti-DNase by ELISA with other tests are recommended to identify NPC patients.

Antibodies, Viral↗
PubMed1997

Osteomyelitis and tenosynovitis due to Mycobacterium marinum in a fish dealer.

Osteomyelitis caused by nontuberculous mycobacteria is rarely reported. We describe a case of tenosynovitis and osteomyelitis of the right middle finger and metacarpal bone caused by Mycobacterium marinum in a fish dealer. This 52-year-old woman suffered progressive pain, numbness, tenderness, and erythematous swelling of the right middle finger over a 2-month period. A radiograph of the right hand disclosed osteolytic lesions at the third metacarpal bone and the third proximal phalanx. She was treated successfully with repeated surgical debridement and antimicrobial agents, including clarithromycin, ethambutol, rifampin, and doxycycline for 1 month, followed by ethambutol and clarithromycin. Pathologic examination of the debrided tissue disclosed epithelioid granuloma, caseous necrosis, and numerous acid-fast bacilli, which were later identified as M. marinum using conventional biochemical tests and by the characteristic gas-liquid chromatogram of esterified cellular fatty acid. The wound healed completely after 7 months of treatment. The patient is still under treatment, and clarithromycin and ethambutol will be given for a total of 18 months.

Animals↗
PubMed1996

Pineal ganglioglioma with premature thelarche. Report of a case and review of the literature.

We report a case of a 6-year-old girl with a ganglioglioma in the pineal region presenting with a rare clinical picture of premature thelarche. Intracranial gangliogliomas are rare, especially in the pineal region. Their character, origin, treatment, and prognosis remain controversial. The pathophysiology of precocious puberty associated with pineal ganglioglioma is discussed.

Brain Neoplasms↗